Digestive System Disorders Flashcards
define dysphagia
dysphagia is difficulty eating - it usually results from oral pain, masses, foreign objects, trauma, neuromuscular dysfunction or a combination of these
‘halitosis typically signifies..’
an abnormal bacterial proliferation secondary to tissue necrosis, tartar, periodontitis, or oral/esophageal retention of food.
causes of oral pain resulting in dysphagia
- fractured bones/teeth
- trauma
- periodontitis or caries (esp. in cats)
- mandibular or maxillary osteomyelitis
- other causes; retrobulbar abscess/inflammation, various other abscess or granulomas of the oral cavity, temporal-masseter myositis
- stomatitis, glossitis, pharyngitis, gingivitis, tonsillitis, or sialoadenitis
- immune-mediated disease
- feline viral rhinotraceitis, calicivirus, leukemia virus, immunodeficiency virus
- lingual FB, granulomas
- tooth root abscess
- uremia
- electrical cord burn
- misc. causes; thallium, caustics
- pain associated with swallowing; esophageal stricture or esophagitis
ddx. for oral masses causing dysphagia
- tumour
- oesinophilic granuloma
- foreign object (oral, pharyngeal, laryngeal)
- retropharyngeal lymphadenomegaly
- inflammatory poly of the middle ear (cats)
- sialocele
neuromuscular diseases that can cause dysphagia
- localized myasthenia
- temporal-masseter myositis
- temporomandibular joint disease
- oral, pharyngeal, or cricopharyngeal dysfunction; cricopharyngeal achalasia
- tick paralysis
- rabies
- tetanus
- botulism
- various cranial nerve dysfunctions/central nervous system disease
ddx. for halitosis
- food retained in mouth; anatomic defect (exposed tooth roots, tumour, large ulcer), or neuromuscular defect (pharyngeal dysphagia)
- food retained in the esophagus
- tartar or periodontitis
- damaged oral tissue; neoplasia/granuloma, severe stomatitis/glossitis
- eating noxious substances; feces, necrotic or odoriferous food
major causes of drooling
Ptyalism
- nausea
- hepatic encephalopathy (esp. feline)
- seizure activity
- chemical or toxic stimulation of salivation (organophosphates, caustics, bitter drugs (atropine, metronidazole))
- behaviour
- hyperthermia
- salivary gland hypersecretion
Pseudoptyalism
- oral pain, esp. stomatitis, glossitis, gingivitis, pharyngitis, tonsillitis, sialoadenitis
- oral or pharyngeal dysphagia
- facial nerve paralysis
which cranial nerves are involved in swallowing?
CN V, VII, IX, XII
define
I) regurgitation
II) vomiting
III) expectoration
I) expulsion of material from the mouth, pharynx or esophagus
II) expulsion of material from the stomach and/or intestines
III) expulsion of material from the respiratory tract
what is the expected pH of regurgitation vs. vomit
regurg >7
vomit <5
what does the presence of bilirubin in vomit signify?
it is duodenal in origin
what are the two major reasons for esophageal regurgitation?
- muscular weakness
- obstruction
what are congenital causes of esophageal obstruction?
- vascular ring anomaly; persistent 4th right aortic arch (most common)
- esophageal web (rare)
what are acquired causes of esophageal obstruction?
- FB
- cicatrix/stricture
- neoplasia; esophageal tumours (carcinoma, sarcoma caused by Spirocerca lupi, leiomyoma of lower easophageal sphincter) vs. extraesophageal tumours (thyroid carcinoma, pulmonary carcinoma, mediastinal lymphosarcoma)
- achalasia of the lower esophageal sphincter (sometimes found in dogs)
- gastroesophageal intussusception (very rare)
causes of esophageal weakness
Congenital
- idiopathic
- achalasia-like syndrome
Acquired
- myasthenia (generalised or localized)
- hypoadrenocorticism
- severe esophagitis;
Gastroesophageal reflux (hiatal hernia, anaesthesia-associated reflux, spontaneous reflux),
Foreign body
Caustic ingestion (doxycycline, Clindamycin, ciprofloxacin, nonsteroidal anti-inflammatory drugs NSAID), disinfectants, chemicals
Persistent vomiting
Excessive gastric acidity (gastrinoma, MCT)
Fungal organisms (pythiosis)
- myopathies
- misc. (Achalasia-like syndrome, Dysautonomia, Spirocerca lupi, Dermatomyositis (esp. in Collies), Botulism, Tetanus, Lead poisoning, Canine distemper)
Idiopathic
5 broad causes of vomiting
1) Motion sickness
2) Ingestion of emetogenic substances
3) GI tract obstruction
4) Abdominal inflammation/irritation
5) Extragastrointestinal tract diseases that may stimulate the medullary vomiting center region of the chemoreceptor trigger zone
list drugs that are likely to cause vomiting
- digoxin
- chemotherapeutics (cyclophosphamide, cisplatin, dacarbazine, doxorubicin)
- selected ABs: erythromycin, tetracycline/doxycycline, amoxicillin + clavulanic acid
- penicillamine
- NSAIDs
- apomorphine
- xylazine
ddx. gastric outflow obstruction
- benign pyloric stenosis
- FB
- gastric antral mucosal hypertrophy
- neoplasia
- non-neoplastic infiltrative disease (eg. pythiosis)
- gastric malpositioning
- GD/GDV (partial)
ddx. for intestinal obstruction
- foreign object; nonlinear vs. linear
- neoplasia
- intussusception
- cicatrix (rare)
- torsion/volvulus (very rare)
causes of gastritis
+/- ulcers/erosions
- non-obstructing FB
- parasitic (Physaloptera, Ollulanus)
causes of enteritis
- parvovirus
- acute hemorrhagic diarrhoea syndrome
- parasites
- IBD (more common in cats)
broad areas of GI/abdominal inflammation
- gastritis
- enteritis
- pancreatitis
- peritonitis
- colitis
- splenitis
extra-alimentary tract dieseases that cause vomiting
- uremia
- adrenal insufficiency
- hypercalcaemia
- hepatic insufficiency or disease
- cholecystitis
- diabetic ketoacidosis
- pyometra
- endotoxaemia/septicaemia
miscellaneous Causes of vomiting
- dysautonomia
- feline hyperthyroidism
- post-operative nausea/ileus
- overeating
- idiopathic hypomotility
- CNS disease; tumours, meningitis, increased intracranial pressure
- sialoadenitis/sialoadenosis
- behaviour
- physiologic (epimeletic in female dogs)
broad categories of causes of hematemesis
- coagulopathy
- alimentary tract lesion
- extra-alimentary tract lesion; blood is swallowed and then vomited
causes of GI tract ulceration/erosion
- neoplasia; leiomyoma, carcinomas, lymphomas
- pythiosis (esp. younger dogs in the southeastern US)
- IBD
- shock; hypovolaemic, septic shock (SIRS), post-GD/GDV, neurogenic shock, extreme or sustained exertion (common in select working animals)
- hyperacidity; MCT, gastrinoma (rare)
- Iatrogenic: NSAIDs, glucocorticoids
- hepatic disease
- hypoadrenocorticism
- pancreatitis (uncommonly causes ulceration)
- renal disease (uncommonly causes ulceration)
- inflammatory diseases
- gastritis (acute, AHDS, helico-bacter associated)
- gastric-mucosal trauma from vigorous vomiting
- gastric polyps
- esophageal disease (tumours, severe esophagitis, trauma)
- GB disease (tumours) - rare
- bleeding oral lesions
what are the three principal indications for endoscopy in animals with upper GI blood loss
1) distinguishing potentially resectable ulcers from widespread unresectable erosions in patients with life-threatening GI bleeding
2) localizing ulcers when considering surgical resection
3) determining the cause of GUE in patients with upper GI blood loss of unknown cause
dietary causes of acute diarrhoea
- intolerance/allergy
- poor-quality food
- rapid dietary change (esp. pups/kittens)
- bacterial food poisoning
- dietary indiscretion
parasitic causes of acute diarrhoea
- helminths
- protozoa; giardia, tritrichomonas (feline), coccidia
infectious causes of acute diarrhoea
- Viral
- parvovirus
- coronavirus
- feline leukaemia virus
- FIV
- various others; rotavirus, canine distemper virus - Bacterial causes
- Salmonella spp.
- Clostridium perfringens (common and important in large bowel diarrhoea)
- Verotoxin-producing E.coli
- Campylobacter jejuni (uncommon)
- Yersinia enterocolitica (questionable) - Rickettsial infection; salmon poisoning (regionally important)
non-infectious causes of acute diarrhoea
- dietary related
- AHDS
- intussusception
- ingestion of toxins; chemicals, heavy metals, various drugs (ABs, antineoplastics, anthelmintics, antiinflammatories, digitalis, lactulose), ‘garbage can’
- acute pancreatitis
- hypoadrenocorticism
clinical features of large intestinal diarrhoea
- weight loss is uncommon
- polyphagia is rare to absent
- frequency of bowel movements is sometimes very increased but often normal
- volume of feces; sometimes decreased (because of increased frequency) but can be normal
- hematochezia sometimes
- mucus sometimes
- tenesmus sometimes
clinical features to ID small intestinal diarrhoea
- weight loss is expected
- polyphagia sometimes
- frequency of bowel movements is often near normal
- volume of feces is often increased but can be normal volume
- blood in feces causes melena and is rare
- mucus is uncommon
- tenesmus is uncommon but may occur later in chronic cases
what major categories can chronic small intestinal diarrhoea be put into?
- maldigestion
- nonprotein-losing malabsorptive disease
- protein-losing enteropathy
major causes of malabsorptive diseases in dogs
- parasitism (giardiasis, nematodes)
- dietary responsive (food intolerance/allergy)
- antibiotic-responsive enteropathy (‘dysbiosis)
- IBD
- neoplastic bowel disease (esp. lymphoma)
- fungal infections (regionally important); pythiosis, histoplasmosis
major causes of malabsorptive diseases in the cat
- dietary responsive (food allergy/intolerance)
- parasitism; giardiasis
- IBD; lymphocytic-plasmacytic enteritis
- neoplastic disease (esp. lymphoma)
major causes of PLE in dogs
- intestinal lymphagiectasia
- alimentary tract lymphoma
- severe IBD
- alimentary tract fungal infections (histoplasmosis, pythiosis)
- chronic intussusception (esp. young dogs)
- alimentary tract hemorrhage (ulceration, erosion, neoplasia, parasites)
- unusual enteropathies (chronic purulent enteropathy, severe ectasia of mucosal crypts)
- massive hookworm or whipworm infestation
major causes of PLE in cats
- alimentary tract lymphoma (important)
- severe IBD
- alimentary hemorrhage; neoplasia, duodenal polyps, idiopathic ulceration
major causes of chronic large intestinal diarrhoea in dogs
- dietary responsive (intolerance/allergy)
- fibre-responsive
- parasitism; whipworms, Heterobilharzia
- bacterial diseases; clostridial colitis, histiocytic ulcerative colitis (Boxers and Frenchies)
- fungal infections; histoplasmosis, pythiosis
- IBD (uncommon in dogs)
- neoplasia; lymphoma, adenocarcinoma
majors causes of chronic large intestinal diarrhoea in cats
- dietary responsive (intolerance or allergy)
- fibre-responsive
- IBD
- Tritrichomonas (esp. in exotic cats and catteries)
- Feline leukaemia virus infection (+ infections secondary to it)
- FIV infection (+ infections secondary to it)
major causes of hematochezia in dogs
Anal-rectal Disease
- anal sacculitis
- neoplasia; rectal adenocarcinoma, rectal polyp, colorectal leiomyoma or leiomyosarcoma
- perianal fistulas
- anal foreign body
- rectal prolapse
- anal-rectal trauma (FB, thermometer, enema tube, fecal loop, pelvic fractures)
Colonic/intestinal disease
- parasitism whipworms, hookworms (severe infections can involve the colon)
- dietary responsive
- clostridial collitis
- AHDS
- parvovirus enteritis
- histoplasmosis
- pythiosis
- intussusception; ileocolic, cecocolic
- IBD
- colonic trauma
- coagulopathy
- colonic vascular ectasia
major causes of hematochezia in cats
- dietary responsive (allergy or intolerance)
- IBD
- coccidia
- rectal tumours
major causes of melena in the dog
- hookworms
- gastroduodenal tract ulceration/erosion; gastric or small intestinal tumour; lymphoma, adenocarcinoma, leiomyoma or leiomyosarcoma, polyp
- ingested blood; oral lesions, nasopharyngeal lesions, pulmonary lesions, diet
- hypoadrenocorticism
- coagulopathies
major causes of melena in cats
- GI tumours; lymphoma, duodenal polyps, other tumours (MCT, adenocarcinoma)
- coagulopathies; vit. K deficiency (intoxication or resulting from malabsorption)
major causes of tenesmus +/- dyschezia in dogs
- perineal inflammation or pain; anal sacculitis
- rectal inflammation/pain; perianal fistulae, tumours, proctitis (primary or secondary to diarrhoea/prolapse), histoplasmosis/pythiosis
- colonic/rectal obstruction; rectal neoplasia, granuloma, perineal hernia, constipation, prostatomegaly, pelvic fracture, other pelvic canal masses, rectal foreign object
major causes of tenesmus +/- dyschezia in the cat
- urethral obstruction
- rectal obstruction; pelvic fracture, perineal hernia
- constipation; abscess near rectum
causes of constipation
Iatrogenic;
- drugs; opiates, anticholinergics, carafate, barium sulfate
Behavioural/Environmental causes
- change in household/routine (esp. cats)
- soiled litter box/no litter box
- house training
- inactivity
Refusal to defecate
- behavioural
- pain in rectal/perineal area
- inability to assume position to defecate; orthopedic problem, neurologic problem
Dietary Causes
- excessive fibre in dehydrated animals
- abnormal diet; hair, bones, indigestible material (plants, plastic)
Colonic obstruction
- pseudocoprostasis
- deviation of rectal canal: perineal hernia
- intraluminal/intramural disorders; tumours, granuloma, cicatrix, rectal foreign body, congenital stricture
- extraluminal disorders; tumours, granuloma, abscess, healed pelvic fracture, prostatomegaly, prostatic or paraprostatic cyst, sublumbar lymphadenopathy
Colonic weakness
- systemic disease; hypoK, hypoT, hypercalcaemia
- localized neuromuscular disease; spinal cord trauma, pelvic nerve damage, dysautonomia, chronic/massive dilation of the colon causing irreversible stretching of the colonic musculature
Misc
- severe dehydration
- idiopathic megacolon (esp. cats)
ddx. for fecal incontinence
- lower motor neuron disease (eg. lumbosacral stenosis, caudal equina syndrome)
- partial rectal obstruction
- severe irritative proctitis
major causes of weight loss
- food; not enough, poor quality, inedible
- anorexia
- dysphagia
- regurgitation/vomiting
- maldigestive disease (EPI)
- malabsorptive disease (SI disease)
- malassimilation; organ failure (cardiac, hepatic, renal, adrenal)
- excessive utilization of calories; lactation, pregnancy, increased work, hyper T, fever/inflam, extremely cold environment
- increased loss of nutrients; DM, PLE, PLN
- Neuromusc disease; LMN
- cancer cachexia
major causes of anorexia/hyporexia
- inflammatory diseases anywhere in the body
- dysphagia; nausea, metabolic disease, CNS, cancer cachexia, anosmia, psychological
major causes of acute abdomen
- septic inflam; perforated gastric ulcer, intestines, devitalized intestines, ruptured GB, abscess/infection, pyometra
- non-septic inflam; pancreatitis, pansteatitis, uroabdomen
- organ distension/obstruction
- ischemia; thromboemboli, torsions
- abdo hemorrhage/neoplasia
DDx. of MSK conditions that mimic abdominal pain
- fractures
- IVDD
- diskospondylitis
- abscesses
urogenital system causes of abdominal pain
- pyelonephritis
- UTIs
- prostatitis
- non-septic cystitis
- cystic/ureteral obstruction/rupture
- urethritis or obstruction
- metritis
- uterine or testicular torsion
- neoplasm
- mastitis (mimics abdo pain)
misc. causes of abdo pain
- post-op
- iatrogenic; drugs (misoprostol, bethanechol)
- adrenalitis (assoc. w/ hypoA)
- heavy metal intox
- vasculopathy; infarct, Rocky Mountain Spotted Fever Vasculitis
causes of abdominal enlargement
- Tissue; pregnancy, infiltrative diseases, neoplasias, lipidosis, granulomas
- Fluid; contained in organs, torsions, cysts, FF
- Gas; free vs. contained in organs (dilation/obstructions/gas-producing bacteria)
- Fat; lipoma, obesity
- Weak Abdo muscles: hyperadrenocorticism
- Faeces
what faecal digestion tests exist and when are they indicated?
- examining faeces for undigested food particles by staining thin fecal smears with the Sudan stain (for fat) or iodine (for starch and muscle fibers) is discouraged.
- finding excessive amounts of undigested fecal fat is supposedly suggestive of EPI but this result have many false-positive and false-negative results
- fecal analysis for proteolytic activity (faecal trypsin content) is rarely necessary to diagnose EPI caused by pancreatic duct obstruction (which is very rare)
- faecal occult blood analyses are seldom useful (false positives from meat by-products, cimetidine, oral iron preparations, some veggies) *if desired need to feed meat-free for 3-4 days
what potential pathogens are most commonly cultured from feces in small animals?
- Clostridium perfringens
- Salmonella spp.
- E.coli
- Campylobacter jejuni
explain parvovirus shedding and diagnosis
- ELISA parvo test is very specific; however parvovirus may not be excreted in the feces for the first 24-48 hours after onset of CS + faecal shedding decreases substantially during the ensuring 7-14 days.
what do typical canine faecal PCR panels detect?
- Giardia, Cryptosporodium, Salmonella, C.perfringens enterotoxin A
- enteric coronavirus, parvovirus +/- distemper virus
what do typical feline diarrhoea PCR panels detect?
- giardia, cryptosporidium, Toxoplasma gondii, Tritrichomonas blagburni, C.perfringens enterotoxin A
- coronavirus, +/or panleukopenia virus
+/- C.jejuni, C.coli
explain the limitations of cytologic evaluation of faeces
- Spores; finding excessive numbers of spore-forming bacteria was thought to strongly suggest clostridial colitis –> however neither specific nor sensitive
- Uniform bacterial population; uncertain value, it shows that normal bacterial flora is disrupted but no cause/effect
- Large spirochetes; often plentiful in diarrhoea but are not C.jejuni and are of uncertain pathogenicity
- Fungal organisms; are rarely found by fecal examination
- Leukocytes; indicate a transmural colonic inflammation instead of just superficial - however ddx. or cause not possible through just this
abdominal ultrasonography is particularly useful for detecting…
- intussusceptions
- pancreatitis
- abdominal infiltrative disease
- small amounts of effusion not seen on rads
- evaluating hepatic parenchyma
- identifying abdominal neoplasia in animals with abdominal effusion
outline how you would perform a contrast-enhanced gastrogram
- Fasted for 24 hours prior, faeces removed via enema
- Pre-procedure rads to confirm stomach is empty
- Liquid barium sulfate administered orally (8-10ml/kg in small dogs and cats, 5-8ml/kg in large dogs)
- Animal should receive no motility-altering drugs that delay outflow
- Immediately after 3 view Abdo rads –> then again at 15 and 30 minutes, then again hourly from 1 to 3 hours.
what is a double contrast gastrogram?
performed by administering barium via stomach tube then immediately removing it, then insufflating the stomach with gas until it is mildly distended
what is gastric emptying considered delayed?
- if liquid barium does not enter the duodenum within 15 to 30 minutes after administration
OR - if the stomach fails to almost completely empty within 3 hours
how do you perform a diagnostic peritoneal lavage?
- a sterile catheter is inserted into the abdomen and warm, sterile physiologic saline solution (20ml/kg) is administered rapidly
- the abdomen is massaged vigorously for 1-2 minutes and then some fluid is aspirated
what is serum TLI?
- most sensitive and specific test for EPI
- TLI assay detects circulating proteins produced by a normally functioning exocrine pancreas and is even valid in animals receiving pancreatic enzyme supplements orally
- animals must be fasted overnight
what may cause in increase in serum TLI concentrations?
- pancreatitis
- renal failure
- severe malnutrition
what are normal serum TLI concentrations in dogs vs. cats?
Dogs: 5.2-35ug/L
Cats: 28-115ug/L
what values of serum TLI conc. confirm a diagnosis of EPI in the dog?
<2.5ug/L
when is serum gastric concentration measured?
animals with signs suggestive of gastrinoma (chronic V+, weight loss, D+ in older animals, esp. if there is concurrent esophagitis or duodenal ulceration)
when may serum gastrin concentrations be increased?
- gastrinoma
- gastric outflow tract obstruction
- renal failure
- short-bowel syndrome
- atrophic gastritis
- receiving PPIs
what is fecal a1-protease inhibitor?
can be measured in faeces as a marker for GI protein loss
- it is rarely indicated but can be useful when trying to distinguish whether hypoalbuminaemia is at least partly due to a protein-losing enteropathy in a patient with known renal protein loss or hepatic insufficiency
what mass is commonly found at the lower oesophageal sphincter?
leiomyomas
what might cytologic preparations of gastric mucosa show?
- adenocarcinoma
- lymphoma
- various inflammatory cells
- spirochetes
what might cytologic studies of intestinal mucosa show?
- oesinophilic enteritis
- lymphoma
- histoplasmosis
- protothecosis
- giardiasis, bacteria or Heterobilharzia ova
when performing full-thickness biopsies what tissue should you collect?
- stomach
- duodenum
- jejunum
- ileum
- mesenteric LNs
- liver
- pancreas (in cats)
+ any obvious lesions/tumours
define proctitis
inflammation of the rectum’s lining
define cicatrix
refers to a scar, or the fibrous tissue that forms after a wound has healed
what is ‘epimeletic behaviour’
refers to care-giving behaviours, most notably vomiting or regurgitation by a female dog to feed her puppies
what is short bowel syndrome?
occurs when a significant portion of the small intestine is missing or damaged, leading to the inability to absorb enough nutrients from food
- can be due to surgery, birth defects or disease affecting the SI
electrolyte abnormalities consistent with vomiting
hypokalaemia
hypochloraemia
metabolic alkalosis
electrolyte abnormalities consistent with diarrhoea
hypokalaemia +/- acidosis (typically)
pex findings consistent with (early) SIRS
- red OMM
- warm extremities
- strong, bounding femoral pulse
what is ‘one blood volume’ in ml/kg for cats and dogs
cats: 50ml/kg
dogs: 90ml/kg
what rate should hypertonic saline be given when treating shock?
4-5ml/kg of hypertonic saline solution (ie. 7%) given over 10-20minutes
Do not exceed 1ml/kg/min
why are hetastarch and pentastarch useful in maintaining plasma oncotic pressure in animals with severe PLE?
because they are larger than albumin and persist in the IV space longer than albumin
define a ‘bland’ diet
‘bland’ (easily digested) diets are low in fat and fiber (both delay gastric emptying) and high in complex carbohydrates
list examples of commercial ‘bland’ (highly digestible) diets
- Hills Prescription Diet i/d
- Imams Intestinal Plus Low-Residue
- Purina CNM EN-Formula
- Royal Canin GI High Energy
- Royal Canin Canine Low Fat
examples of homemade hypoallergenic diets
- 1 part boiled white chicken/turkey meat without skin + 2 parts boiled/baked potato without skin
- swap meats (boiled white fish, mutton, venison, rabbit, low-fat cottage cheese)
- rice can be used instead of potato
- not balanced diets but usually okay for 3-4 months in an adult dog otherwise require nutritionist to balance calcium and phosphorus
list partially hydrolzed diets available
- Purina HA
- Hill’s z/d
- Hypoallergenic Hydrolyzed Protein HP diets
- Ultamino RC
what types of diets are indicated in intestinal lymphangiectasia?
- ultra low fat diets; because long-chain fatty acids enter and accumulate in lacteals, removing them from the diet helps prevent dilation and rupture of lacteals and subsequent intestinal lymphatic loss
what time frame should elimination diet trials be effective?
improvement is typically evident within 3 weeks, although rare patients require 6+ weeks - critical that no treats/other foods (eg. flavoured toys, pills, medications) can be given during this time.
- if signs resolve during this time, the diet should be continued for at least 4-6 weeks more to ensure cause and effect
how may fibre be increased in the diet?
- a commercial high-fibre diet may be used
- add Psyllium hydrocolloid (metamucil) 1-2tsp/can of food
- or add coarse, unprocessed wheat bran (1-4 tablespoons/can of food)
- canned pumpkin pie filling in cats (1-3 tbsp/day) to lessen constipation
if fibre responsive will usually see clinical improvement in 4-5 days
what is the approx. kcal/kg/day MER for mature dogs and cats
60kcal/kg/day
what are the major risks associated with gastrostomy tubes?
- tube leakage and peritonitis
- tubes must be left in place for at least 7 - 10 days to allow an adhesion to form between the stomach and the abdominal wall
list centrally acting anti-emetics
- Maropitant - neurokinin-1 receptor antagonist
- Serotonin receptor antagonists; ondansetron, metoclopramide
- Phenothiazine derivatives; Chlorpromazine, Prochloperazine
list the 3 major types if antacid drugs
- acid titrating drugs; aluminium/magnesium hydroxide
- gastric acid secretion inhibitors (H2 receptor antagonists; ranitidine, famotidine)
- PPIs; omeprazole, pantoprazole, esomeprazole
MOA of ranitidine
Histamine-2 receptor antagonist; a competitive inhibitor of histamine - they prevent histamine from stimulating the gastric parietal cell
possible adverse effects of H2 receptor antagonists
- bone marrow suppression
- central nervous system problems
- diarrhoea
IV injections (esp. ranitidine) may cause nausea, vomiting or bradycardia
indications to use misoprostol
- limited
- not shown to be as effective in preventing NSAID- induced ulcers in dogs as it is in people
- PPIs appear to be as effective with less major adverse effects (abdominal cramping, diarrhoea, abortifacient)
when may motility modifiers be required?
to symptomatically treat diarrhoea; it excessive fluid or electrolyte losses or owners demand control of the diarrhoea at home
what can an overdose of Loperamide (Imodium) cause?
an overdose can cause narcotic intoxication (collapse, vomiting, ataxia, hypersalivation) which requires treatment with narcotic antagonists
*dogs deficient in P-glycoprotein (MDR gene mutation) are at greater risk for CNS AEs
what is bethanechol?
an acetylcholine analog that stimulates intestinal motility and secretion
- produces strong contractions that can cause pain thus infrequently used
what is pepto-bismol and why might it be used?
Bismuth subsalicylate is effective in many dogs with acute enteritis, probably because of the antiprostaglandin activity of the salicylate moiety.
Disadvantages; turns stools black, tastes terrible, AKI risk
what is octreotide?
- a synthetic analog of somatostatin that inhibits alimentary tract motility and secretion of GI hormones and fluids
- it has had limited use but might be helpful in selected animals with intractable diarrhoea or lymphangiectasia
what is salicylazosulfapyridine?
a combination of sulfapyridine + 5-aminosalicylic acid used to treated colonic inflammation
- colonic bacteria split the molecule and 5-aminosalicylic acid is ‘deposited’ on diseased colonic mucosa
- respond in 3-5 days, but can take up to 2 weeks
- gradually wean if signs resolve
list 3 immunosuppressive drugs that can be used to treat IBD?
- cyclosporine (atopica)
- chlorambucil
- azathioprine
outline the use of chlorambucil in cats with severe IBD
starting dose 1mg twice weekly (if <3.2kg) or 2mg twice weekly for >3.2kg cat.
- beneficial effects may not be seen for 4-5weeks
- dose should be tapered over 2-3months
- monitor for myelosuppression
approach to ARE
- tylosin is commonly used
- prepare to treat patient for 3 weeks before deciding that therapy for ARE has been unsuccessful
- commonly ABs not required
what combination of drugs is effective in treating Helicobacter gastritis?
- Amoxicillin, Metronidazole + Bismuth
define ‘pre-biotic therapy’
administering a specific dietary substance to specifically increase or decrease the numbers of specific bacteria
what pro-biotic bacteria are typically administered to dogs?
- Lactobacillus
- Bifidobacterium
- Enterococcus
what does fenbendazole cover?
Hook
Round
Whip
Giardia
what does metronidazole cover?
giardia
what does ronidazole voer?
- giardia
- tritrichomonas in cats
what does pyrantel cover?
Hook
Round
Physaloptera (in dogs)
rpt in 2 weeks for dogs
once only in cats
what does pyrantel/febantel/praziquantel cover? + what product is it?
Drontal Plus
Tapeworm
Hook
Round
Whip
Giardia (q24h 3 days)
what is advantage multi and waht does it cover?
Imidocloprid/moxidectin
- topical
Hook
Round
Whip
what is in heartguard plus for dogs?
ivermectin + pyrantel
hook
round
what product names are milbemycin? + what does it cover?
Sentinel, Trifexis
Hook
Round
Whip
what does praziquantel cover?
TAPEWORMS
10mg/kg (double dose) for juvenile Echinococcus spp. or Spirometra
what does epsiprantel cover?
tapeworms
what does TMS cover?
coccidia
30mg/kg for 10 days
what does sulfadimethoxine cover?
coccidia, 50mg/kg day 1 then 27.5mg/kg q12h for 9 days
list possible laxatives/cathartics./bulking agents to treat constipation
- Bisacodyl
- Coarse wheat bran, psyllium, canned pumpkin pie filling
- lactulose
- dioctyl sodium sulfosuccinate
list 3 types of laxatives
- irritative (bisacodyl)
- bulk
- osmotic
define sialocele
accumulations of saliva in subcutaneous tissues caused by salivary duct obstruction and/or rupture and subsequent leakage of secretions into subcutaneous tissues - most are traumatic, some are idiopathic
clinical features of sialoceles
- large swelling found under the jaw or tongue, or in the pharynx
- acute swelling may be painful but most are nonpainful
- classically found in 2-4yr old dogs
- GSheps, Mini.Poodles
what is the etiology of sialoadenitis/sialoadenosis/salivary gland necrosis?
- unknown, but apparently has occurred as an idiopathic event as well as secondary to chronic V+/regurg
clinical features of sialodenitis
- painless enlargement of one or more salivary glands (usually submandibular)
treatment of sialodenitis
- surgical removal
- treat underlying cause of vomiting if present
- phenobarbital at anticonvulsant doses
ddx. for neoplasms of the canine oral cavity
- most malignant; melanoma, squamous cell carcinoma, fibrosarcoma
- other; acanthomatous ameloblastomas (epulides), fibromatous epulides (in Boxers), oral papillomatosis, eosinophilic granulomas (Siberian Huskies and CKCS)
what is the typical appearance/location of oral squamous cell carcinoma?
- gingiva; fleshy/ulcerated on rostral gingiva
- tonsils; fleshy/ulcerated on one or (rarely) both tonsils
- tongue margin (dogs); ulcerated
- base of tongue (cats); ulcerated
which location of oral squamous cell carcinoma is most likely to metastasise and well as be locally invasive?
tonsils commonly spread to local lymph nodes
what is the treatment of oral squamous cell carcinomas?
Dogs;
- if on gingiva or tongue margin; wide surgical resection +/- radiation + piroxicam for palliation
- if on tonsils; piroxicam for palliation +/- chemotherapy - terrible prognosis
Cats;
- radiation palliatively - terrible prognosis
typical appearance/location and met site for oral malignant melanoma?
- gray, black or pink - can be smooth, usually fleshy on gum, tongue or palate
- very early metastases to lungs; high met rate of 60-80%
treatment of oral malignant melanoma?
- surgery +/- radiation for local control; surgical cure is extremely rare dt met rate
- systemic control; carboplatin has been used with limited success
typical appearance/location and behaviour of oral fibrosarcoma?
- pink and fleshy on palate or gums
- malignant; very invasive locally
- biologically high-grade, histologically low-grade tumours in young Labs, Goldens, GSheps have higher metastatic potential
treatment of oral fibrosarcoma
- wide surgical resection +/- radiation in some cases
typical appearance/location and behaviour of acanthomatous ameloblastoma (epulis)?
- pink and fleshy on gums or rostral mandible
- benign, locally invasive into bone
treatment for acanthomatous ameloblastoma
surgical resection +/- radiation for gross microscopic disease
*must remove associated tooth and dental ligament
typical appearance/location and behaviour of fibromatous epulis?
- pink, fleshy, solitary or multiple on gums
- benign
treatment of fibromatous epulis
surgical resection, must remove associated tooth and dental ligament
typical appearance/location and behaviour of ossifying epulis?
- pink, fleshy, solitary or multiple on gums
- benign
typical appearance/location and behaviour of oral papillomatosis?
- pink, or white, cauliflower-like, multiple/seen anywhere
- benign; BUT malignant transformation to squamous cell carcinoma may occur rarely
typical appearance/location and behaviour of oral plasmacytoma?
- fleshy or ulcerated growth on gingiva
- malignant, locally invasive, rarely metastasizes
treatment of ossifying epulis
- surgical resection, must remove associated tooth and dental ligament
treatment of oral papillomatosis
- nothing, surgical resection or cryotherapy
treatment of oral plasmacytoma
surgical resection and/or radiation or melphalan chemotherapy
outline the preferred diagnostic approach in a dog with a oral cavity mass
- image the area; CT
- perform a deep incisional biopsy to avoid misdiagnosis that often occurs if only the superficial, ulcerated, necrotic surface is obtained
- if malignancy is possible, thoracic radiographs or CT should be performed for a met check – very poor prognostic sign if present
- FNA of regional LNs (if enlarged should be removed and submitted for histopath regardless of cytology)
why is histopathology required for definitive diagnosis with oral melanoma? (+ others)
melanomas may be amelanotic and can cytologically resemble fibrosarcomas, carcinomas or undifferentiated round cell tumours
most common oral neoplasm of cats
Squamous cell carcinoma
how do feline oral neoplasms differ from canine?
cats can have sublingual squamous cell carcinomas and oesinophilic granulomas which mimic carcinoma but have a must better prognosis
treatment considerations for feline oral neoplasms
- surgical excision is desirable but cats often do not tolerate aggressive oral surgery as well as dogs do
- long term or permanent feeding tubes may be required
etiology of feline eosinophilic granuloma?
- uncertain cause
- hypersensitivity reactions are thought to be responsible, and a genetic predisposition has been suggested
clinical features of feline eosinophilic granuloma complex
- the complex includes; indolent ulcer, eosinophilic plaque and linear granuloma
- indolent ulcers are classically found on the lip or oral mucosa (esp. maxillary teeth) of middle-aged cats
- eosinophilic plaque usually occurs on the skin of the medial thighs and abdomen
- linear granuloma is typically found on the posterior aspect of the rear legs or young cats but may also occur on the tongue, palate and oral mucosa
- severe oral involvement of an eosinophilic ulcer or plaque may produce dysphagia, halitosis and/or anorexia
- eosinophilic granuloma may affect the chin and paw pads in addition to the mouth
diagnosis of eosinophilic granuloma complex in cats
- a deep biopsy specimen of the mass is required
treatment of indolent ulcers and eosinophilic plaques in cats?
- systemic antibiotics against Staphylococcus spp. (eg. amoxyclav, TMS)
- if ABs ineffective, high dose glucocorticoids (2.2-4.4mg/kg/day) or cyclosporine
- last resort; methylprednisolone acetate injections (20mg every 2-3 weeks as needed) but can cause diabetes mellitus, mammary tumours, uterine problems
treatment of gingivitis/periodontitis
- dental
- ABs effective against anaerobic bacteria (eg. amoxicillin, Clindamycin, metronidazole)
- brushing teeth + oral rinsing with veterinary chlorhex solution
common causes of stomatitis
- renal failure (primarily with severe, acute renal injury)
- trauma; FB, causing agents, chewing on electrical cords
- Immune-mediated; pemphigus
- chronic ulcerative paradental stomatitis (esp. Maltese Terriers)
- upper respiratory viruses (feline viral rhinotracheitis, feline Calicivirus)
- infection secondary to immunosuppression (feline leukaemia virus, feline immunodeficiency virus(
- tooth root abscesses
- severe periodontitis
- osteomyelitis
- thallium intoxication (very rare)
treatment of stomatitis
- thorough teeth cleaning and aggressive AB therapy
- systemic ABs effective against anaerobes and aerobes + oral rinses with antibacterial solutions
what is the etiology of feline lymphocytic-plasmacytic gingivitis and pharyngitis/caudal stomatitis?
An idiopathic disorder, feline lymphcytic-plasmacytic gingivitis might be caused by feline calicivirus, Bartonella henselae, immunodeficiency from FeLV or FIV infection, or any stimulus-producing sustained gingival inflammation. Cats might have marked gingival proliferation dt excessive oral inflammatory response.
clinical features of feline lymphocytic-plasmacytic gingivitis and pharyngitis/caudal stomatitis?
- hyporexia and/or halitosis are the most common signs
- reddened gingiva around teeth +/- posterior pillars of the pharynx
- proliferative gingiva that bleeds easily
- dental neck lesions
- teeth chattering
treatment of feline lymphocytic-plasmacytic gingivitis and pharyngitis/caudal stomatitis?
- proper cleaning and polishing of teeth + AB therapy against anaerobic bacteria
- high dose glucocorticoids ( Pred 2.2mg/kg/day, methylprednisolone 10-20mg SQ, triamcinolone 0.2mg/kg PO SID)
- in some cases multiple tooth extractions (esp. premolars and molars) may alleviate the source of the inflammation in which case it is important that the root and periodontal ligament also be removed *extraction of canines should be removed if possible
- if required; chlorambucil or cyclosporine (2-4mg/kg PO BID)
what is the etiology and clinical features of masticatory muscle myositis?
- masticatory muscle myositis/atrophic myositis if an idiopathic immune-mediated disorder that affects muscles of mastication in dogs
- in acute stages the temporalise and masseter muscles may be swollen and painful, however may dogs are not presented until the muscles are severely atrophied and the mouth cannot be opened
diagnosis of masticatory muscle myositis?
- histopathology w/ immunohistochemistry of the temporalise and masseter muscles confirms the diagnosis
- finding antibodies to type 2M fibers strongly supports this diagnosis
- also commonly have increased serum CK activity
treatment of masticatory muscle myositis?
- high dose Pred 2.2mg/kg/day +/- azathioprine 50mg/mg2 q48h typically controls acute disease but seldom helps patients with chronic disease that cannot open their mouths
- once control achieved taper pred slowly to prevent recurrence
- if mouth cannot be opened; gastrotomy tube - some clinicians may try to break adhesions but can cause mandibular fracture and is not recommended
what is cricopharyngeal achalasia/dysfunction
- there is an inco-ordination between the cricopharyngeus muscles and the rest of the swallowing reflex which produces obstruction at the cricopharyngeal sphincter during swallowing (ie sphincter doesn’t open at the right time)
- cause is unknown but usually congenital, has a genetic basis in golden retrievers
treatment of cricopharyngeal achalasia?
- injection of the cricopharyngeal muscle with Botulism toxin
- surgery; cricopharyngeal myotomy (good prognosis if cicatrix does not occur post-operatively)
what is the etiology of pharyngeal dysphagia?
- primarily an acquired disorder with neuropathies, myopathies and junctionopathies (eg. localized MG) seeming to be the main causes
- inability to form a normal bolus of food at the base of the tongue and/or propel the bolus into the oesophagus is often associated with lesions of CNs IX or X
- simultaneous dysfunction of the cranial oesophagus may cause food retention just caudal to the cricopharyngeal sphincter
treatment of pharyngeal dysphagia?
- treat underlying cause
- bypass the pharynx (gastrotomy tube)
breeds that appear to be at increased risk of congenital megaoesophagus?
- Mini Schnauzers
- Great Danes
- Dalmations
- Chinese Shar-Peis
- Irish Setters
- Lab. Retrievers
outline medical management of congenital megaO
- cisapride 0.1-0.5mg/kg (increased LES pressure to reduce concomitant gastroesophageal reflux)
- feeding in vertical position and maintained for 5-10 minutes after
- dietary modification (trial and error)
- managing aspiration pneumonia when occurs
treatment of local MG megaO
- typically respond to pyridostigmine, which is preferred to physostigmine and neostigmine
what are negative prognostic indicators of megaO?
- if older than 13months at time of onset of CS because they are less likely to experience spontaneous remission
- aspiration pneumonia
which common medications can cause severe esophagitis?
- tetracyclines
- clindamycin
- ciprofloxacin
- NSAIDS
treatment of esophagitis
- PPIs (Omeprazole)
- Cisapride 0.1-0.5mg/kg
- Viscous lidocaine PO
- sometimes gastrotomy feeding tube to protect the oesophagus while mucosa is healing and ensures a positive nitrogen balance
what is dysautonomia?
- dysautonomia in dogs and cats is an idiopathic condition that causes loss of autonomic nervous system function
- in Key-Gaskell syndrome of cats it might be due to a clostridial toxin
clinical features of dysautonomia?
- CS vary substantially
- megaO and subsequent regurgitation
- dysuria and distended urinary bladder
- mydriasis and lack of pupillary light response
- dry OMM, weight loss, constipation, vomiting, poor anal tone +/- anorexia
how can a presumptive antemortem diagnosis of dysautonomia be made?
- pilocarpine 0.05% 1-2 drops in one eye; finding that the treated eye rapidly constricts whereas the untreated eye does not is consistent with dysautonomia
- Bethanechol 0.04mg/kg SQ in dysuric dog with large urinary bladder causing urination is suggestive as well
- definitive diagnosis req. histopathology of autonomic ganglia obtained at necropsy
treatment and prognosis of dysautonomia?
- palliative; bethanechol 2.5-15mg daily to aid in urinary evacuation, ABs for aspiration pneumonia, prokinetics to lessen vomiting
- prognosis is grim
what is the most common vascular ring anomaly that causes esophageal obstruction and how do you diagnose it?
Persistent right fourth aortic arch (PRAA) diagnosed via contrast esophagram
treatment of PRAA
- surgical resection
- conservative (dietary) management is inappropriate because dilation will probably progress
prognosis of oesophageal obstruction due to PRAA?
- guarded
- some will have minimal to no improvement after surgery dt concomitant esophageal weakness
- complication; post-surgical stricture may require ballooning or secondary surgery
ddx. esophageal neoplasms
- primary oesophageal sarcomas in dogs often dt Spirocerca lupi
- carcinomas (unknown etiology)
- leiomyomas and leiomyosarcomas often found at LES in older dogs
- invasive thyroid carcinomas and pulmonary alveolar carcinomas
- squamous cell carcinomas is the most common in cats
treatment of eosophageal neoplasms?
- surgical resection is rarely curative (except for leiomyomas near the LES) because of the advanced nature of most esophageal neoplasms when they are diagnosed
- resection may be palliative
- photodynamic therapy may be beneficial in dogs and cats with small superficial esophageal neoplasms
etiology of AHDS
suspected to be Clostridium sp.
etiology of chronic gastritis
- several types (lymphocytic/plasmacytic, osinophilic, granulomatous, atrophic)
- lymphocytic-plasmacytic gastritis might be an immune and/or inflammatory reaction to a variety of antigens; Helicobacter spp. and Physaloptera rara may produce a reaction in some patients
- eosinophilic gastritis may present an allergic reaction, possible to food antigens
- atrophic gastritis may be the result of chronic gastric inflammatory disease and/or immune mechanisms
- Ollulanus tricuspis may cause granulomatous gastritis in cats
treatment of lymphocytic-plasmacytic gastritis
- sometimes responds to diet (low-fat, low-fibre, elimination diets)
- glucocorticoids 2.2mg/kg/day
- PPIs
- rarely, azathioprine
treatment of canine eosinophilic gastritis?
- usually responds well to strict elimination diet
- glucocorticoids if diet fails; pred 1.1-2.2mg/kg/day
treatment of atrophic and granulomatous gastritis?
- diets low in fat and fibre may help control signs
- antacids, antiinflammatories, prokinetic therapy may treat atrophic gastritis
- idiopathic granulomatous gastritis is idiopathic and doesn’t respond well to diet or glucocorticoids
what is the etiology of Helicobacter-associated disease in dogs?
Non-H.pylori Helicobacter (NHPH) - H.felis, H.heilmanii, H.bizzozeronii, H.salomonis are the principal spirochetes in dogs and cats
*unlike humans with H.pylori
diagnosis of Helicobacter infection
gastric biopsy identified Helicobacter organisms on H&E stain, Giemsa stain, Warthin-Starry stain, as well as fluorescent in situ hybridization (FISH)
treatment of helico-bacter associated disease
- combination of metronidazole, amoxicillin, bismuth (subsalicylate or subcitrate) for at least 14 days
- in cats azithromycin and clarithryomycin have been substituted for bismuth
- no benefit of PPIs
prognosis of Helicobacter-associated illness
- responds well to treatment and has a good prognosis but recurrence by 6 months is common
how does Physaloptera rara cause disease in dogs?
Physaloptera rara is a nematode that has an indirect life cycle.
A single P.rara attached to the gastric mucosa can cause intractable vomiting - affect animals usually otherwise healthy
diagnosis of P.rara?
- ova seldom found in faeces; require sodium dichromate or magnesium sulfate solutions to find the eggs
- usually diagnosed on gastroduodenoscopy visualising parasites
tx. of P.rara
pyrantel pamoate or ivermectin
clinical features of Ollulanus tricuspis infection
- vomiting; cats more commonly affected then dogs
- spread via vomited material
ddx. for gastric outflow obstruction/stasis
- benign muscular pyloric hypertrophy (pyloric stenosis)
- gastric antral mucosal hypertrophy
- gastric foreign objects
- iatrogenic gastric outflow obstruction
- GD/GDV
- Partial or intermittent chronic gastric volvulus
- Idiopathic gastric hypomotility
- Bilious vomiting syndrome
etiology of benign muscular pyloric hypertrophy?
uncertain, some research suggests that gastrin promotes development of pyloric stenosis
treatment of benign pyloric muscular hypertrophy
- surgical correction; pyloroplasty (Y-U-plasty)
etiology of gastric antral mucosal hypertrophy?
- antral mucosal hypertrophy is idiopathic
- caused by proliferation of non-neoplastic mucosa that occludes the distal gastric antrum
- different from benign muscular pyloric stenosis where normal mucosa is thrown up into folds secondary to submucosal thickening
difference in typical signalment between antral hypertrophy and benign pyloric muscular hypertrophy?
Antral: older, small-breed dogs
Pyloric: young, brachycephalics, Siamese cats
treatment of antral mucosal hypertrophy
mucosal resection usually combined with pyloroplasty
GDV risk factors
- large, giant breed dogs with deep, narrow chests
- purebred status
- middle to older aged animals
- first-degree relative with history of GDV
- reported risk factors; eating a large meal, rapidly, once daily from an elevated platform, ‘nervous dog’, eating dry foods that have fats/oils listed at one of the first four ingredients
pathophysiology of GDV
- the stomach is partially twisted because of the stretched hepatogastric ligaments (typically the pylorus rotates ventrally from the right side of the abdomen below the body of the stomach to become positioned dorsal to the gastric cardia on the left side). At this point, affected dogs are clinically normal and can pass fluids and solids into the intestines —> subsequent aerophagia causes sufficient dilation gas and other gastric contents cannot pass into the intestines
- splenic congestion and torsion may occur with the spleen on the right side of the abdomen
- massive gastric distension obstructs the hepatic portal vein and posterior vena cava causing mesenteric congestion, decreased cardiac output, severe shock, DIC, endotoxaemia as well as putting pressure on the diaphragm inhibiting respiration
- gastric blood supply (esp. short gastric vessels) may be impaired causing gastric wall necrosis
factors associated with poorer prognosis in GDV cases
- tx being delayed more than 5-6hours after onset
- hypothermia, hypotension, depression/comatose
- preoperative cardiac arrhythmias
- gastric wall necrosis
- peritonitis
- sepsis
- DIC
- combination of partial gastrectomy, splenectomy and post-op acute renal failure
what is the rate of recurrence of GDV with vs without gastropexy?
with; 10%
without; 50%
etiology and clinical features of Bilious vomiting syndrome?
- appears to be caused by gastroduodenal reflux that occurs when the dog’s stomach is empty for long periods of time (eg. overnight fast)
- usually affects an otherwise normal dog that is fed once daily in the morning; usually vomits once a day late at night or in the morning just before eating
causes of gastric ulceration
- Drugs; NSAIDs, glucocorticoids
- Stress; hypovolemia, sepsis, neurogenic shock (surgery, trauma, endotoxaemia), extreme exertion
- Gastric neoplasms and other infiltrative diseases (pythiosis)
- MCT and gastrinoma (typically in pancreas) paraneoplastic gastric acid secretion
- Renal Failure
- Foreign objects; rarely cause ulceration but can prevent healing
common gastric neoplasms
Dogs; adenocarcinoma, lymphoma, leiomyomas, leiomyosarcomas, stromal tumours
Cats: lymphoma
endoscopic appearance of a gastric leiomyoma
submucosal mass pushing into the lumen, covered with relatively normal-appearing mucosa often with one or more obvious ulcers
typical endoscopic appearance of a gastric scirrhous adenocarcinoma
thickened, ulcerative lesion with hard, black center
which gastric neoplasms are easily endoscopically biopsied with flexible forceps
- mucosal lymphoma
- nonscirrhous adenocarcinomas
which gastric tumours are often resectable
- leiomyomas, leiomyosarcomas, stromal tumours
is chemotherapy helpful in treating gastric neoplasms?
only in cats with lymphoma
- rarely in dogs
prognosis of gastric neoplasms
- adenocarcinomas is very poor unless detected early
- with early diagnosis, leiomyomas/sarcomas can be cured surgically
- low-grade gastric lymphoma in cats might be comparable to Helicobacter-induced, MALT-associated lymphoma in people which benefits from ABs +/- surgery, but usually quite diffuse and req. chemo
etiology of pythiosis
Pythiosis is a fungal infection caused by Pythium insidiosum.
Any area of the GI tract or skin can be affected. Typically causes intense submucosal infiltration of fibrous connective tissue and a purulent, eosinophilic, granulomatous inflammation causing GUE - prevents peristalsis causing stasis.
Found in Gulf Coast area of SE USA.
diagnosis of pythiosis
- serology or seeing the organism cytologically or histologically
- ELISA (antibodies) or PCR (antigen)
- Biopsies should include submucosa because the organism is more likely to be there than in the mucosa.
- Fungal hyphae that do not stain and appear as ‘ghosts’ with typical Romanowsky-type stains are suggestive of pythiosis
treatment of pythiosis
- complete surgical excision provides best chance for cure (usually not possible)
- antifungals and immunotherapy has been associated with remission of signs but not expected to cure
prognosis of pythiosis
- grim; usually spreads to root of mesentery, pancreas surrounding bile duct preventing surgical excision
what destroys parvovirus in the environment?
bleach diluted in water (1:32), takes 10 minutes contact time
etiology of canine parvovirus enteritis
two types of parvoviruses infect dogs;
- canine parvovirus-1 (CPV-1) is a relatively nonpathogenic virus that is sometimes associated with gastroenteritis, pneumonitis +/- myocarditis in puppies 1-3 weeks old
- canine parvovirus-1 (CPV-2) is responsible for classic parvovirus enteritis (3 strains; CPV-2 a, b, and c).
CPV-2 usually causes signs 5-12 days after the dog is infected via the fecal-oral route by destroying rapidly diving cells (eg. bone marrow progenitors and intestinal crypt epithelium)
diagnosis of parvoviral enteritis
- faecal PCR testing is sensitive and specific
- POC testing; ELISA, immunochromatography, immunomigration *vaccination with a mod.live parvoviral vaccine may cause a weak positive result for 5-15 days after vaccination
- shedding decreased rapidly and may be undetectable by 10-14 days post infection
general guidelines for treatment of parvoviral enteritis
- Fluids; +/- KCl, Dextrose, Plasma/hetastarch
- Antibiotics; for febrile/neutropenic dogs
- Anti-emetics
- Anthelmintics
- Pro-biotics
- PPIs for esophagitis
- Nutritional therapy; small amounts, micro-enteral nutrition via NG tube
- Monitoring
etiology of feline parvoviral enteritis
feline parvoviral enteritis (feline distemper, feline panleukopenia) is caused by feline panleukopenia virus (FPV) which is distinct from CVP-2b.
POC feline CPV testing
ELISA tests for fecal CPV are comparable to that in dogs but it is important to note that the test may be positive for only 1 to 2 days after infection; by the time the cat is clinically ill, this test may not be able to detect viral shedding in the feces.
how do canine coronavirus and parvovirus differ when attacking the intestines?
- canine coronavirus invades and destroys mature cells on the intestinal villi, but the intestinal crypts remain intact thus villi regenerate more quickly than in parvovirus
common canine enteric viruses
- parvovirus
- coronavirus
- circovirus
- rotavirus
characteristics of feline coronaviral enteritis
- infections in adults are often asymptomatic, whereas kittens may have mild transient diarrhoea and fever
- death is rare
- disease is important because affected animals seroconvert and may become positive on FIP serologic analysis –>mutation may cause FIP
etiology of feline leukaemia virus - panleukopenia-like syndrome
FeLV-associated panleukopenia is uncommon. The intestinal lesion histologically resembles that produced by feline parvovirus. The bone marrow and lymph nodes are not consistently affected as they are in cats with parvoviral enteritis. Rarely, there can be co-infection with FeLV and FPV.
clinical features of FeLV- panleukopenia like syndrome
- chronic weight loss, vomiting and diarrhoea are common
- large-bowel disease type diarrhoea
- anaemia
diagnosis of FeLV-panleukopaenia-like syndrome
- histologic lesions resembling FPV in a cat with FeLV should be definitives
- cats are typically neutropenia with chronic diarrhoea
treatment and prognosis of FeLV-panleukopaenia-like syndrome
symptomatic therapy + elimination of other problems that compromise intestines
prognosis is poor dt FeLV-related complications
FIV-associated diarrhoea etiology
FIV may be associated with diarrhoea; acute FIV infection is associated with transient diarrhoea and terminal FIV may be associated with AIDS-like enteropathy which can produce chronic diarrhoea, severe weight loss and/or purulent colitis. Unclear pathogenesis.
diagnosis of FIV-associated diarrhoea
- detection of FIV antibodies + diarrhoea allow presumptive diagnosis
FIV-associated diarrhoea treatment and prognosis
– supportive treatment
- guarded to poor prognosis; survival time months
etiology of salmon poisoning/Elokomin fluke fever
- caused by Neorickettsia helminthoeca
- dogs are infected when eating fish (esp. salmon) infected with fluke (Nanophyetus salmincola) that carries the rickettsia
- the rickettsia spreads to the intestines and most LNs causing inflammation
- found in the US Pacific NW (because intermediate host snail Oxytrema silicula) lives there
clinical features of salmon poisoning
- initial fever
- hyporexia – weight loss +/- V+/D+
- D+ is typically small bowel but may become bloody
- lymphadenomegaly
diagnosis of salmon poisoning
- history + finding Nanophyetus spp. ova in feces is suggestive
- finding rickettsia in FNAs/biopsies of enlarged LNs is confirmatory
treatment of salmon poisoning
- symptomatic
- Rickettsia; tetracycline, oxytetracycline, doxycycline, enro
- Fluke: praziquantel
prognosis of salmon poisoning
- most dogs respond favourably within 24 hours
- untreated has a poor prognosis
clinical features of symptomatic campylobacteriosis
- diagnosed in animals younger than 6 months living in crowded conditions or as a nosocomial infection
- mucoid D+, anorexia +/- fever
- usually self limiting
which species of Campylobacter are associated with GI disease
C.jejuni most commonly
Sometimes C.upsaliensis
treatment of campylobacteriosis
erythromycin 11-15mg/kg PO q8h,
Enrofloxacin 5mg/kg PO q24h or neomycin 15mg/kg PO q12h
should be treated for at least 1 to 3 days beyond resolution of clinical signs, assuming they respond within 5 days
diagnosis of salmonellosis
- culture of salmonella spp. from normally sterile areas (eg. blood) confirms it is causing disease but simply identifying it in faeces does not allow confident diagnosis
- Salmonella can be identified in faeces by culture or PCR (faster and more sensitive than faecal culture)
treatment of salmonellosis
- if not too bad; supportive only
- if febrile/septic –> quinolones, potentiated sulfa drugs, amoxicillin, chloramphenicol
etiology of clostridial disease (AHDS)
Clostridium perfringens and Clostridium difficile can be found in clinically normal dogs. For C.perfringens to produce disease, environmental conditions must be appropriate for the bacteria to produce toxin
diagnosis of Clostridial diarrhoeal diseases
- finding spore-forming bacteria on fecal smears, culturing the bacteria from faeces and detecting C.perfringens enterotoxin are neither sensitive nor specific for disease due to C.perfringens.
- must use ELISA to first check for bacterial antigen, then if positive, use ELISA to check for toxin A and B
treatment of C.perfringens diarrhoeal diseases
- amoxicillin 22mg/kg PO BID or tylosin 20mg/kg PO SID
+ dietary modification; high-fiber - consider fecal transplant or probiotic therapy
treatment of C.diffile diarrhoeal disease
metronidazole
E.coli associated diarrhoeal diseases
Several strains that produce different syndromes;
- Enterotoxigenic E.coli - acute feline and canine diarrhoea
- Adherent-invasive E.coli (AIEC) - histiocytic ulcerative colitis (Boxers, Frenchies)
3 less common causes of bacterial diarrhoea
- Yersinia enterocolitica
- Aeromonas hydrophila
- Plesiomonas shigelloides
etiology of histoplasmosis
Histoplasma capsulatum; mycotic infection that may affect the GI, resp and/or reticuloendothelial systems, as well as bones and eyes
clinical features of GI histoplasmosis
- colon most severely affected segment; diffuse, severe, granulomatous, ulcerative mucosal disease –> bloody stools, PLE, intermittent fever +/- weight loss
- sometimes forms focal colonic granulomas or involves SI
definitive diagnosis of GI histoplasmosis
- ELISA for antigen shed in urine
- cytologic preparations of colonic mucosal scraping to ID yeast (sometimes revealed in rectal scrapings)
- fecal culture for the yeast is unreliable
treatment and prognosis of GI histoplasmosis
- itraconazole itself or preceded by lipid emulsion amphotericin B; for 4-6 months
- if multiple organ system or CNS involvement - poor prognosis
clinical features of pythiosis (Pythium insidiosum)
- may occur anywhere in the alimentary tract
- rectal lesions often cause partial obstruction
- fistulae may develop, resembling perianal fistulae and the dog may be presented for constipation and/or hematochezia
- in rare cases infarction of mucosa/vessels with subsequent ischaemia
treatment of pythiosis
complete surgical excision is preferred
- no medication have been consistently effective; but temporary benefit seen with itraconazole, amphotericin B, terbinafine
etiology of protothecosis
Prototheca zopfii is an alga that invades tissue. Appears to be acquired from the environment, and some type of deficiency in the host’s immune system might be necessary for the organism to produce disease.
Principally involves skin, colon and eyes but may disseminate through the whole body.
diagnosis of protothecosis
- demonstrating the organism from biopsy or mucosal cytology
- grows well if cultured
- may be shed in urine in disseminated disease
treatment and prognosis of Protothecosis
no drug works consistently; can try high dose amphotericin B + tetracycline
prognosis is poor, relapse is common
etiology of whipworm
Trichuris vulpis; acquired through ingestion of ova, adults burrow into the colonic and cecal mucosa causing inflammation +/- PLE
what endocrine disorder can whipworm mimick?
hypoadrenocorticism by causing severe hyponatremia and hyperkalemia
treatment of whipworm
fenbendazole for 3 months
etiology of roundworms
Dogs: Toxocara canis and Toxascaris leonina
Cats: Toxocara cati and Toxascaris leonina
Ingest ova or paratenic host, T.canis transplacentally, T.cati transmammary, T.leonina can use intermediate host.
Tissue migration of immature forms can cause hepatic fibrosis and pulmonary lesions. Adults live in SI lumen and migrate against flow of ingesta. Can cause eosinophilic infiltrates in the intestinal wall.
clinical features of roundworm infections
- D+, stunted growth, poor haircoat, poor weight gain in young
- runts with potbellied appearance
treatment of roundworm infections
- pyrantel; treated at 2 to 3 week intervals
- puppies can be treated from 2 weeks old
- bitches; high dose fenbendazole 50mg/kg/day PO from day 40 gestation until 2 weeks post-partum can reduce somatic roundworm burden and lessen transplacental transmission to puppies
- new born puppies; treated with fenbendazole 100mg/kg for 3 days; which kills more than 90% of prenatal larvae
- preweaning kittens treated at 6,8,10 weeks
- preweaning puppies treated at 2,4,6,8 weeks
etiology of hookworms
Ancylostoma and Uncinaria spp. in dogs > cats.
ingestion of ova or transcolostral or freshly hatched larvae may also penetrate the skin
- adults live in SI lumen; plugs of intestinal mucosa +/- blood are ingested, can be found in the colon in severe infections
clinical features of hookworm infestations
- blood loss/iron deficiency anaemia, melena, Frank faecal blood, D+, failure to thrive
- peracute transmammary transmission in puppies can cause death before ova are found in the faeces (5-10 days old)
hookworm treatment
various anthelmintics; should be repeated in 3 weeks to kill parasites entering the intestinal lumen from the tissues
most common tapeworm of dogs and cats
Dipylidium caninum; infected by eating an intermediate host (lice/fleas)
clinical features of tapeworm infections
- anal irritation associated with shed segments
- rarely can cause intestinal obstruction
treatment of tapeworms
Praziquantel and episprantel,
control of intermediate hosts (fleas and lice)
etiology of strongyloidiasis
Strongyloides stercoralis - young puppies in crowded conditions
- parasites produce motile larvae that penetrate unbroken skin/mucosa; infested from own/contaminated faeces
clinical features of strongyloidiasis
- asymptomatic or mucoid haemorrhagic D+ and lethargy
- resp. signs if parasites penetrate lungs
diagnosis of S.stercoralis
finding larvae in fresh faeces; direct fecal exam or Baermann sedimentation
treatment of strongyloidiasis
fenbendazole for 5 days
etiology of coccidiosis
Cystoisospora spp. are the coccidia infecting cats and dogs
- infested by ingesting infective oocysts from the environment
- coccidia invade and destroy villous epithelial cells
clinical features of coccidiosis
- very common in pups/kittens
- asymptomatic or large volume watery D+
diagnosis of coccidiosis
- fecal flotation - oocysts
treatment of coccidiosis
TMS 10 - 20 days
Toltrazuril, amprolium, ponazuril
etiology of cryptosporidia
Cryptosporidium spp. may infect animals that ingest sporulated oocysts
- thin-walled oocysts are produced which can rupture in the intestine and produce autoinfection –> infests the brush border of the SI epithelial cells and causes D+
diagnosis of cryptosporidiosis
- oocysts on fecal float
- immunofluorescence assay (IFA), ELISA or PCR
C.parvum is the smallest and easy to miss on faecal exam
treatment of cryptosporidiosis
- anytime cryptosporidiosis is diagnosed one should look for causes of immunosuppression in the host
- treat with tylosin, azithromycin
- uncertain prognosis, many young dogs with cryptosporidiosis related D+ die or are euthanized
- cats can be asymptomatic
etiology of giardiasis
- infected with protozoan Giardia when they ingest cysts shed from infected animals often via water
- found in SI - interfere with digestion (unknown mechanism)
clinical features of giardiasis
- asymptomatic to severe D+; persistent, intermittent or self-limiting
- D+ can begin 5 days after exposure before cysts appear in the faeces
- D+ is cow-patty like without Blood or mucus typically
diagnosis of giardiasis
- finding motile trophozoites in fresh faeces or duodenal washes
- finding cysts with faecal float (w/ zinc sulfate solution) or IFA
- or finding giardial antigens in feces using ELISA or PCR
at least 3 faecal exams should be done over 7 - 10 days before ruling out giardia
treatment of giardia
1) environmental decontamination; quaternary ammonium compounds, pine tars
2) bathing patient to remove cysts from hair
3) drugs; metronidazole 7 days, fenbendazole 5 days or febantel 5 days + praziquantel
etiology of trichomoniasis
- trichomoniasis in cats is caused by Tritrichomonas blagburnii; animals infected by faecel-oral route
- dogs are rarely affected; T.blagburnii or T.foetus
clinical features of trichomoniasis
- large bowel diarrhoea
- exotic breed cats (somalis, Bengals, ocicats)
- can resolve spontaneously
diagnosis of trichomoniasis
- ID motile trophozoite by examining fresh feces diluted with warm saline solution
- PCR most sensitive test available
- colonic mucosal biopsies
treatment and prognosis of trichomoniasis
- ronidazole 30mg/kg PO SID for 10 - 14 days
- routine environmental hygiene
etiology of heterobilharzia
Heterohilharzia Americana infects dogs and lives in the liver - ova laid in the veins end up in the intestinal wall and liver where they elicit a granulomatous inflammation
- primarily found in Gulf Coast states and southern atlantic coast states
clinical features of Heterobilharzia
- large bowel + hepatic disease
- D+, hematochezia, weight loss, PLE may occur, granulomatous reactions can be associated with hypercalcaemia
diagnosis of heterobilharzia
finding ova in faeces or mucosal biopsy specimens
- faecal PCR
treatment of heterobilharzia
- fenbendazole + praziquantel will kill the parasite and ova
- prognosis varied depending on granulomatous reaction
etiology of EPI
canine EPI is caused by pancreatic acinar cell atrophy or destruction due to pancreatitis
clinical features of EPI
chronic SI diarrhoea, ravenous, weight loss
+/- steatorrhea (grey stools)
etiology of dietary responsive diarrhoea
an all-inclusive term that includes dietary allergy (a hyperimmune response to a dietary antigen) and a dietary intolerance (a non-immune-mediated response to a dietary substance)
how long is the usual response to a novel protein diet in dietary responsive diarrhoea?
within 3 weeks, but can be longer
etiology of antibiotic-responsive enteropathy (ARE)
a syndrome in which there are many E.coli or similar enterics coupled with an intestinal host defense that is not capable of maintaining tolerance and subsequently has an abnormal response to these bacteria.
presumably enterocytes are damaged by deconjugation of bile acids, fatty acid hydroxylation, generation of alcohols, increased permeability, generation of inflammatory cytokines +/- other MOA
treatment of ARE
- tylosin 20mg/kg PO SID (often effective)
- metronidazole 15mg/kg PO SID sometimes effective
- combination of metro + enro (7mg/kg q24h) if prior therapy has failed
*should treat for 3 weeks before judging effect
*faecal transplantation
approach to small intestinal ARE + dietary-responsive D+
- eliminate parasites
- dietary trials (hydrolyzed 3 weeks –> novel if no response for 3 weeks)
- +/- Cobalamin supplementation, even if levels not measured.
- Antibiotics added (tylosin - 3 weeks)
- Further; probiotics, fecal transplant
- GI biopsies
- Immunosuppressives/steroids
etiology of IBD
IBD is defined as an idiopathic inflammation affecting any portion of the canine or feline small or large intestine. The cause is believed to involve an inappropriate response by the intestinal immune system to bacterial and/or dietary antigens that evolves into a self-perpetuating state of inflammation.
lymphocytic-plamacytic enteritis (LPE) is the most commonly diagnosed form of canine and feline IBD
what to small intestinal diseases are difficult to distinguish even on histopath?
- well-differentiated small cell lymphocytic lymphoma
- severe Lymphocytic-plasmacytic enteritis (LPE)
treatment of canine LPE
- usually dietary + ARE that also requires antiinflammatories
- Pred 2.2mg/kg/day PO
- if not responsive to pred; consider cyclosporine, chlorambucil, azathioprine, budesonide
how does treatment of canine and feline LPE differ
- cats can have complete resolution of CS with cobalamin supplementation
- antimicrobials/diet elimination trials are difficult because cats are fussy and difficult to medicate
- cats are less likely to have alimentary histoplasmosis and are more resistent to iatrogenic hyperadrenocorticism than dogs - thus glucocorticoid therapy is commonly used
how long should it take for fibre-responsive large bowel diarrhoea to resolve with fibre-supplemented diet?
3-5 days
how does the prognosis for colonic IBD compared to small intestinal IBD?
it is better in colonic than SI
diagnosis of large intestinal inflammatory bowel disease?
requires excluding other causes (parasites, diet/fibre responsive, clostridial/fungal/algal colitis) + demonstrate colonic mucosal inflammation
etiology of granulomatous/histiocytic ulcerative colitis
- caused by adherent-invasive E.coli and may reflect immune system idiosyncrasies in the commonly affected breeds
- principally affects Boxers and French Bulldogs
what is required to diagnose granulomatous/histiocytic ulcerative colitis?
- histopathology; finding PAS-positive macrophages in the mucosa (usually deeper mucosa)
treatment for granulomatous/histiocytic ulcerative colitis?
- antibiotic responsive disease; but usually resistant to multiple ABs
- colonic mucosal biopsy for culture is strongly recommended
- critical to treat for 8 weeks; stopping prior to this is associated with recurrence of infection and development of resistance to the ABs used
common causes of PLE
- lymphangiectasia
- alimentary tract lymphoma
- severe chronic IBD
- in puppies; hookworm and chronic intussusception
etiology of intestinal lymphangiectasia
IL primarily affects dogs. Lymphatic obstruction causes dilation and rupture of intestinal lacteals with subsequent leakage of protein, lymphocytes and chylomicrons into the intestinal submucosa, lamina propria and lumen. Because these proteins may be digested and resorbed, there must be sufficient loss so that the intestine’s ability to resorb the protein is exceeded.
Rupture of lymphatics in the intestinal wall or at the mesenteric border can produce lipogranulomas, which exacerbate lymphatic obstruction.
Many severely symptomatic patients only have segmental disease.
Most cases are idiopathic.
which breeds are at a higher risk of intestinal lymphangiectasia?
yorkshire terriers, soft-coated wheaten terriers, lundehunds
diagnosis of intestinal lymphangiectasia
- severe hypoalbuminemia, hypocholesterolaemia +/- panhypoproteinaemia
- +/- lymphopaenia
- US: hyperechoic intestinal mucosal striations
- definitive diagonsnis requires histopath (surgical biopsies sometimes required), but gross endoscopic appearance can also be diagnostic *feed fat the night before can make ID easier
treatment of intestinal lymphangiectasia
- underlying cause rarely identified
- diet; ultra-low-fat diet essentially devoid of long-chain fatty acids helps prevent further intestinal lacteal engorgement and subsequent protein loss; in early diagnosed cases this diet alone will cause in increase in serum albumin in 7-12 days
- +/- prednisolone 1.1-2.2mg/kg/day PO or cyclosporine 3-5mg/kg PO BID
etiology of PLE in soft-coated wheaten terriers
- predisposition to PLE and PLN
- cause is uncertain; but possible food hypersensitivity
etiology of immunoproliferative enteropathy in basenjis
- probably has a genetic basis or predisposition, and intestinal bacteria may play an important role
- it is an intense lymphocytic-plasmacytic SI infiltrate often associated with villous clubbing, mild lacteal dilation, gastric rugal hypertrophy, lymphocytic gastritis +/- gastric mucosal atrophy
clinical features of immunoproliferative enteropathy of basenjis
- a severe form of LPE that waxes and wanes, particularly when the animal is stressed
- weight loss, SI D+, v+ and hyporexia are commonly seen
- basenjis at 3-4 yrs
treatment of immunoproliferative enteropathy of basenjis
- diet modification (highly digestible elimination diet)
- antimicrobials
- immunosuppressive therapy (cyclosporine/glucocorticoids)
prognosis of immunoproliferative enteropathy in basenjis
- most animals die 2-3 years after diagnosis
- poor prognosis for recovery, but some can be maintained
- in a few dogs; GI lymphoma develops
etiology of chinese shar-pei enteropathy
- prone to severe enteropathy as well as other immune system abnormalities –> exaggerated inflammatory reactions in the GIT
- also recognized as often having extremely low serum cobalamin levels
diagnosis of Chinese sharpei enteropathy
small intestinal biopsy; eosinophilic and lymphocytic-plasmacytic intestinal infiltrates are typically found
treatment of Chinese sharpei enteropathy
- elimination diets
- antimicrobial drugs
- anti-inflammatory/immunosuppressive drugs typically used
- cobalamin supplementation is also reasonable
prognosis of IBD in Shiba dogs
most affected dogs die within 3 months of diagnosis
what electrolyte/acid-base derangements are consistent with a SI obstruction?
classically produces a hypokalaemic-hypochloremic metabolic alkalosis
+/- some degree of lactic acidosis from poor perfusion
which cat breed has a higher incidence of intussusception
Main Coon
etiology of short bowel syndrome
- occurs when massive resection (75-90%) of SI results in the need for special nutritional therapy until the intestines are able to adapt
clinical features of short bowel syndrome
- severe weight loss and intractable diarrhoea (typically without mucus or blood) which occurs shortly after eating
treatment of short bowel syndrome
- prevention
1. Highly digestible diet; low-fat cottage cheese, potato, 3-4 meals/day
2. Opiate antidiarrhoeals; loperamide
3. PPs
4. Antibiotics if required to control the large bacterial populations that occur in the SI
common neoplasms of the SI
- lymphoma
- adenocarcinoma
- leiomyoma/ leiomyosarcoma/stromal tumour
etiology of alimentary lymphoma
- cause is uncertain; FeLV might be involved in cats
- LPE has been suggested to be prelymphomatous (esp in cats)
- more common in cats than dogs
- different forms of alimentary lymphoma; lymphoblastic lymphoma is found in dogs and cats, well-differentiated SCL primarily in cats, large granular lymphocyte lymphoma is rare, very severe form in cats
diagnosis of alimentary lymphoblastic lymphoma
demonstrate neoplastic lymphocytes
- FNAs, squash/imprint cytology
- histopath is the most reliable
diagnosis of alimentary SCL in cats
- is difficult; poor quality endoscopic biopsies are notorious for resulting in erroneous diagnosis of LPE instead of SCL
- finding lymphocytes in the submucosa is not specific for lymphoma
- in some cases, finding lymphocytes in organs where they should not be found (liver) allows diagnosis of SCL
distinguishing SCL from LPE
- immunohistochemistry (staining for CD3 and CD79a) has been used
- clonality testing with PCR to diagnose SCL in some cases
- finding lymphocytes where they should not be found (ie. liver)
treatment of feline SCL
- prednisolone and chlorambucil; usually respond well
treatment of intestinal adenocarcinoma
- good prognosis if surgical excision is possible, but mets to regional LNs are common
-post-op chemo does not appear to substantially affect survival time
typical intestinal adenocarcinoma lesions
- more common in dogs than cats
- diffuse intestinal thickening or focal circumferential mass lesions
- scirrhous carcinomas have very dense fibrous connective tissue that often requires surgery to get diagnostic sample
primary clinical signs associated with intestinal leiomyoma/leiomyosarcoma/stromal tumour
- intestinal hemorrhage
- iron deficiency anaemia
- obstruction
+/- hypoglycaemia (paraneoplastic)
which GI tumours often require surgical biopsies to diagnose?
- scirrhous carcinomas
- leiomyomas/leiomyosarcomas
- stromal tumours
prognosis of intestinal leiomyoma/ leiomyosarcomas/ stromal tumours
- surgical excision may be curative if no mets
- if mets, chemo is palliative but prognosis is poor
clinical features of rectal polyps
- hematochezia, tenesmus, rarely obstruction
- detected during rectal exam - resemble adenocarcinomas but very large
diagnosis of adenocarcinoma
- histopath > cytology because epithelial dysplasia may be present in benign lesions causing a false-positive cytologic diagnosis of carcinoma
- most colonic neoplasms arise near the recumt thus digital exam is the best screening test
treatment of colonic adenocarcinoma
complete surgical excision is curative; transanal pull-through rectal amputation is beneficial in selected cases.
- many cases do not respond well due to late diagnosis and extensive local invasion plus distance mets to regional LNs
prognosis of incarcerated SI?
guarded
why does mesenteric torsion have such a poor prognosis?
much of the intestine is typically devitalised by the time surgery if performed
etiology of cecocolic intussusception?
cause unknown, some suggest that whipworm-induced typhlitis may be responsible
treatment and prognosis of cecocolic intussusception?
typhlectomy is curative and prognosis is good
etiology of short bowel syndrome?
- occurs when massive resection of SI results in the need for special nutritional therapy until the intestines are able (if able) to adapt
- usually caused if 75-90% of SI is resected
- large numbers of bacteria may also reach the upper SI, esp. if ileocolic valve is removed
treatment of short bowel syndrome
Prevention!
- diet: highly digestible frequent small meals (3-4x/day) (low fat cottage cheese, potato)
- opiate antidiarrheals (loperamide) + PPIs may help to lessen diarrhoea
- antibiotics may be required to control the large bacterial populations that can occur
etiology of alimentary lymphoma
- neoplastic proliferation of lymphocytes with uncertain cause; FeLV might be involved in cats
- LPE has been suggested to be prelymphomatous (esp. in cats)
different common forms of alimentary lymphoma
- lymphoblastic lymphoma (LL)
- well-differentiated small cell lymphoma (primarily in cats)
- large granular lymphocyte lymphoma (rare, severe, found in cats)
gross intestinal changes consistent with alimentary lymphoma
- can be grossly normal looking
- nodules, masses, diffuse intestinal thickening, dilated sections of intestine that are not obstructed and/or focal constrictions are possible
diagnosis of alimentary lymphoblastic lymphoma
- require demonstration of neoplastic cells; FNAs, imprints, squash cytology preparations
- diagnosis tends to be relatively easy in the dog/cat
why is diagnosis of feline SCL difficult?
- poor quality endoscopic biopsy samples (eg. too superficial, having excessive artefact) are notorious for resulting in erroneous diagnosis of LPE instead of SCL
- finding lymphocytes in organs where they should not be found (ie. liver) can allow diagnosis of SCL
what tests can be used to differentiate LPE and SCL?
- finding lymphocytes in other organs (liver)
- immunohistochemistry (eg. staining for CD3 and CD79a) has been used to help distinguish SCL from LPE.
- clonality testing with PCR appears necessary to accurately diagnose SCL in some cases
treatment of SCL
prednisolone and chlorambucil; generally good response
compare prognosis of LL with SCL in cats?
prognosis is poor with LL, but many cats with SCL will have a high quality of life for years.
intestinal lesions typical of adenocarcinoma
- more common in dogs
- intestinal thickening or focal circumferential mass lesions
treatment and prognosis of intestinal adenocarcinoma
- surgical excision; prognosis good is complete excision is possible but often Mets to regional LNs
- post-op chemo does not appear to substantially affect survival time
typical lesions of intestinal leiomyo-mars/sarcomas
usually from a distinct mass in the SI or stomach
which SI tumours do not typically exfoliate well for cytology/FNAs
- leiomyomas
- leiomyosarcomas
- stromal tumours
- scirrhous adenocarcinomas
prognosis of leiomyo-mas/sarcomas, stromal tumours of the SI
if surgical excision is curative - good, but Mets make prognosis poor
- chemo can be palliative
more common neoplasms of the colon
- adenocarcinoma
- rectal polyps
why is histopath preferred to cytologic diagnosis of intestinal neoplasia?
- epithelial dysplasia may be present in benign lesions causing a false-positive cytologic diagnosis of carcinoma
treatment and prognosis of colonic adenocarcinoma
- complete surgical excision is curative; transanal pull-through rectal amputation is beneficial in selected cases
- often late diagnosis with Mets to regional LNs and extensive local invasion
- can palliative with radiotherapy
treatment of rectal polyps
- complete excision via surgery (everting the rectal mucosa)
treatment of rectal prolapse
- reposition mucosa, place a purse-string suture for 1-3 days (large enough to allow defecation)
- sometimes epidural anaethetic is required
etiology of perineal hernia
- occurs when the pelvic diaphragm (ie. coccygeus and levator Ani muscles) weakens and the rectal canal deviates laterally
clinical features of perineal hernias
- older, small breed intact male dogs esp. Boston terriers, corgis, boxers, pekingeses
- dyschezia, constipation, perineal swelling, urinary bladder herniation into this defect may cause a potentially fatal post renal uremia
etiology of perianal fistulae
impacted anal crypts and/or anal sacs have been hypothesized to become infected and rupture unto deep tissues
- an immune-mediated mechanism is likely
ddx. for perianal fistulae
rectal pythiosis
treatment of perianal fistulae
- immunsuppressive therapy; cyclosporine or topical tacrolimus +-/ ABs
clinical features of anal sac (apocrine glands) adenocarcinoma
- paraneoplastic hypercalcaemia causing hyporexia, weight loss, vomiting and polyuria-polydipsia is common
- Mets to sublumbar LNs common and occurs early, further Mets are rare
prognosis of anal gland adenocarcinoma
guarded
etiology of perianal gland tumours
- arise from modified sebaceous glands
- perianal gland adenomas have testosterone receptors - male hormones appear to stimulate their growth; rare tumours but are usually large, infiltrative, ulcerated masses with high met potential
causes of constipation
- pelvic canal obstruction caused by malaligned healing of old pelvic freactures
- benign rectal strictures
- dietary indiscretions (bones, hair, paper)
- itiopathic megacolon
- any perineal or perianal disease that causes pain/obstruction
diagnosis of benign rectal stricture
biopsy specimen including the submucosa is required to confirm he lesion is benign and fibrous and not fungal/neoplastic
treatment of rectal strictures
- balloon dilation
- pred 1.1mg/kg/day PO after dilation to impede stricture reformation
etiology of idiopathic megacolon
- a feline disease
- cause unknown; may involve behaviour or altered colonic neurotransmitters
treatment of feline idiopathic megacolon
- multiple warm water retention/cleansing enemas over 2-4 days
- add fibre to a moist diet (metamucil/pumpkin pie filling)
- osmotic laxatives
+/- prokinetic drugs (Cisapride)
If this therapy fails; can consider subtotal colectomy
prognosis of idiopathic megacolon
- fair to guarded; many cats respond well to medical therapy if treated early
common causes of septic peritonitis in the dog
- GIT perforation/devitalisation caused by neoplasia, ulceration (NSAIDs, steroid induced), intussusception, foreign objects, dehiscence of suture lines
- biliary tract leakage; GB rupture
- pyometra
causes of septic peritonitis in cats
- perforation due to lymphosarcoma is an important cause
- GIT perforation/devitalisation
what glucose differences is strongly suggestive of septic peritonitis (plasma vs. Abdo fluid)
finding a plasma glucose concentration that is >38mg/dL more than the peritoneal fluid conc. strongly suggest septic peritonitis
what is PBP?
primary bacterial peritonitis (spontaneous); in which there is no identifiable source of infection
- gram positive organisms tend to be more common
ddx. for hemabdomen
- iatrogenic (caused by abdominocentesis)
- traumatic (eg. MVA trauma, splenic torsion, splenic hematoma)
- coagulopathy (eg. ingestion of vit.K antagonist)
- malignancy (eg. hemangiosarcoma, hepatocellular carcinoma)
clinical features of abdominal hemangiosarcoma
- found in older dogs; esp. GSheps, Labs, Goldens
- anemia, abdominal eff., periodic weakness or collapse from poor peripheral perfusion
prognosis of abdominal hemangiosarcoma
poor; because tumours Mets early
- chemo may be used as an adjuvant post-op
etiology of abdominal carcinomatosis
abdominal carcinomatosis involves widespread military peritoneal carcinomas that can originate from various sites
- intestinal and pancreatic adenocarcinomas are common causes of carcinomatosis
treatment and prognosis for abdominal carcinomatosis
- intracavitary chemo can be palliative but generally there is no effective treatment for the disorder and the prognosis is grim
clinical features of mesothelioma
- often causes bicavitary effusion
- tumours may appear as fragile clots adhering to the peritoneal surface of various organs
diagnosis of mesothelioma
- fluid cytology is rarely diagnostic because reactive mesothelial cells are notorious for mimicking malignancy
- laparoscopy/laparotomy is typically required for a definitive diagnosis
characteristics of FIP Abdo effusions
pyogranulomatous (Macs and nondegenerate neutrophils) with a relatively low NCC (<10000/uL)
