Small Intestinal Disease Flashcards
What comprises the small intestine?
Everything from the pyloric sphincter to the ileocolic junction
Duodenum- Jejunum- Ileum
What is the function of the small intestine?
- Digestion of ingesta/food
- Secretion of water and mucous
- Absorption of nutrients- peptidases, nucleases, disaccharides, bile acids, pancreatic enzymes
- Barrier to infection
What are villi?
Protrusions of the intestinal mucosa to increase surface area
What are the villi comprised of?
- Mucosal immune system
- Lamina propria
- Enterocytes
- Digestive enzymes, carrier proteins, goblet cells
- Crypt cells
How long does it take for enterocytes to completely turn over?
3 days from the base of crypts
What do crypt cells do?
- Some secretory capacity
- Make undifferentiated epithelial cells
What is the main energy requirement of enterocytes?
Glutamine
What will happen to enterocytes if they do not have enough glutamine?
- Decline in villi structure
- Loss of epithelial integrity
- Decreased immune function
- Decreased absorptive function
What are some clinical signs of small intestinal disease?
- SI diarrhea
- Melena or steatorrhea
- Inappetence
- Systemic illness
- Abdominal distension or pain
- Borborygmi
- Flatulence (usually mild)
- Vomiting and weight loss
- Ravenous appetitie
- Coat changes
What are acute enteropathies typically caused by?
- Dietary indiscretion or change
- Infection
- Medications
- Stress
- Pancreatitis
What are chronic enteropathies typically caused by?
- Food allergy or hypersensitivity
- Inflammatory bowel disease
- Lymphangiectasia
- Infections (SIBO or parasites)
- Neoplasia
- EPI
What is HGE and AHDS?
HGE= Hemorrhagic gastroenteritis AHDS= Acute hemorrhagic diarrhea syndrome
What are the animals predisposed to AHDS and how does it typically present?
Small breed dogs
Marked hemoconcentration with fluid shifts
Typically require hospitalization
T/F: Dogs with AHDS will typically enter hypovolemic shock prior to having clinical evidence of dehydration.
True
What are the clinical signs of AHDS?
Hematemesis and hematochezia
Typically profuse and very hemorrhagic
What is the etiology of AHDS?
Usually viral, hypersensitivity, or clostridium perfringens
What are the expected PCV and TS levels in AHDS patients?
PCV >60% and TS not horribly elevated due to GI loss
How do you treat AHDS?
IV fluids, antibiotics, gastroprotectants, antiemetics, nutritional support
What is the prognosis of AHDS?
Good with aggressive supportive care
Decreases with severe hypoproteinemia or signs of sepsis
What helminths are found in the small intestine?
Toxocara canis Trichuris vulpis Ancyclostoma caninum Dipylidium caninum Strongyloides stercoralis
What is the best test when you suspect worms?
Fecal (if negative do 3 consecutive days testing)
Can just deworm empirically
All the things about Diplydium caninum.
- Ingestion of fleas with immature worms
- Shed proglottids with in 2-3 weeks
- Peri-rectal irritation and rarely small intestinal impactions
- Teat with praziquantal or fenbendazole
Other tapeworm species: Taenia or Echinococcus
All the things about Toxocara canis/cati.
- Ingestion of eggs or maternal transmission
- Adults in small intestine
- Babies most affected and can be fatal
- Small intestinal obstruction are possible but rare
Clinical signs: vomiting or defecating live worms, unthrifty, rounded belly, diarrhea
Treatment: fenbendazole, pyrantel
What protozoa live in the small intestine?
Giardia Tritrichomonas foetus Coccidia Cryptosporidium Toxoplasma gondii
What are the primary clinical signs and pathophysiology of protozoa infections?
Clinical signs: Diarrhea +/- weight loss
Pathology: Destruction of enterocytes and villi
How do you diagnose Giardia?
Direct smear to visualize cysts or trophozoites, IFA, Antigen/ELISA
How do you diagnose Tritrichomonas foetus?
Direct fecal smear, culture, PCR preferred
CATS ONLY
T/F: Giardia is non-species specific so it can be passed between dogs and cats and to humans.
False- species specific so any cross infections would be self-limiting
T/F: Subclinical infection of Giardia are very common.
True
What is the goal of treatment of Giardia?
Stop diarrhea
Fenbendazole or metronidazole effective
Elimination of infection is very difficult
What are the clinical signs of coccidia infections?
Weight loss, dehydration, may be hemorrhagic
Typically self limiting in a healthy adult animal
Worse in young or immune compromised patients
How do you diagnose coccidia?
Direct smear or fecal floatation
How do you treat coccidia?
Sulfadimethozine, ponazuril, supportive care
What is the prognosis of coccidia?
Good in adults with mild symptoms
Guarded in systemically ill patients
How is cryptosporidium transmitted and what are the clinical signs?
Transmission: fecal oral or contaminated food/water; zoonotic potential
Clinical signs: self limiting small bowel diarrhea, can be severe/life threatening in immunocompromised patients
How do you diagnose cryptosporidium?
Direct smear or fecal float, ELISA, PCR, biopsy
How do you treat cryptosporidium?
Paromomycin or tylosin
What is a major concern with toxoplasma?
Zoonosis
What are the parasitology facts about toxoplasma?
- Oocysts require 1-5 days to become infectious
- Disease only seen in immunecompromised patients
- Disease mostly seen in cats
- Transmission: predation or fecal contamination
What are the clinical signs of toxoplasma?
- Pneumonitis
- Vomiting or diarrhea
- Encephalitis
- Lymph node, liver issues
- Chorioretinitis
- Fever, weight loss, lethargy
T/F: Animals are unlikely to be shedding oocysts while they are significantly ill.
True- they have to have intestinal disease in order to shed oocysts and will typically show severe clinical sings only when extra-intestinal
How is toxoplasma diagnosed?
Fecal flotation and antibody titers (more useful)
Antibody titers do not predict oocyst shedding or clinical disease
How do you treat toxoplasma?
Clindimycin or trimethoprim-sulfonamide
Supportive care
What fungal infections do you see in the small intestine?
Pythiosis, histoplasmosis, candidiasis
What is pythium insidiosum?
An aquatic oomycete that will infect mammal hosts, typically in gulf coast states
Lives in standing water and infects via skin or mucosal penetration by motile zoospores
Most common in dogs and zoonosis has not been documented
What are the clinical signs of GI pythiosis?
Vomiting, weight loss, diarrhea, hematochezia, abdominal pain
Palpable abdominal mass, dehydration, poor body condition
What are the clinical signs of cutaneous pythiosis?
Non-healing skin lesion, Very ulcerated and granular looking with draining tracts
May have LN involvement
Dogs: base of tail, extremities, ventral neck, and perineum
Cats: cervical, inguinal, and truncal
T/F: Skin and GI pythiosis often occur together.
FALSE- very rarely occur together
What will your diagnostics show in pythiosis?
CBC: eosinophilia, anemia
Chem: hypoalbuminemia, hyperglobulinemia
Pythium ELISA (culture difficult)
Biopsy- severe transmural segmental thickening with pyogranulomatous and eosinophilic inflammation ; GMS stain to observe organisms
Rads: poor serosal detail with weight loss, mass lesion in abdomen or esophagus
Ultrasound: segmental thickening of GI, thickened gastric outflow tract, enlarged LN
How do you treat pythiosis?
Surgical removal or effected tracts
Iraconazole, terbinafine +/- immunotherapy for at least 2-3 months
What is the prognosis of pythiosis?
Poor with disseminated disease and no resection
less that 20-25% respond to medical management
Overall pretty grave
What is histoplasmosis?
Dimorphic fungus that occurs worldwide
Occurs in dogs and cats
Transmission: aerosols into lungs and thoracic LNs, GI tract, may enter bloodstream from primary site and cause wide spread disease
What are the clinical signs of histoplasmosis?
Diarrhea (usually large) Weight loss to emaviation Chronic cough Fever Anemia, hepatomegaly, splenomegaly, lymphadenopathy Nasopharyngeal and GI ulceration Lameness Respiratory difficulty Skin lesions
Cats do not get GI signs
How do you diagnose histoplasmosis?
Chest rads: nodules, enlarged LNs
US: spleen liver and LN enlargement with thickened LI/SI wall
FNA or biopsy of abnormal tissues
ELISA antigeen tests
CBC, CHEM, and UA all have non-specific findings
How do you treat histoplasmosis?
Prolonged therapy with anti-fungals
Intraconazole, fluconazole or ketoconazole
Amphotericin B in severe cases
What is the prognosis of histoplasmosis?
Acute: may be fatal after 2-5 weeks
Poor condition/multisystem involvement: guarded to poor
One organ involved: still not great but better
What are all the things with candidiasis?
Normal flora but opportunistic infections associated with the disruption of mucosal integrity can be seen
Cats- oral and URI, pyothorax, ocular, intestinal, cystitis
Dogs- Peritonitis and fungemia, perforating lesions after sx, mucosal and cutaneous candidiasis has been noted in immunosupressed animals
What bacterial diseases are associated with the small intestine?
Campylobacter Salmonella Clostridium E. coli Yersinia Mycobacterium
What are the top 3 bacteria associated with intestinal disease?
Campylobacter
Salmonella
E. coli
All associated with acute diarrhea
What animals are prone to bacterial infections?
Young, kenneled, immunocompromised
Can happen in apparently healthy pets
Are fecal cultures useful when diagnosing bacterial infections of the GIT?
Not really since most pathogenic bacteria can be found in small numbers in a healthy GIT
Must be interpreted with clinical signs and other lab data
Performed only in chronic diarrhea or severely debilitated animals
What is salmonella?
Gram - facultative anaerobic bacteria that is part of the normal flora of the intestinal tract
Seen in young, parasitized, immunocompromised, or stressed animals
Ingestion of raw/contaminated food
Zoonoticc
T/F: Salmonella destroys intestinal villi.
True- just like protozoa
What are the clinical signs of Salmonella?
Acute transient diarrhea - can be supportively treated
Septic, shock, hospitalized from illness
How do you diagnose salmonella?
Culture: blood or feces depending on disease type
PCR: lacks validation
How do you treat salmonella?
None if primary and transient
IV abx and supportive care with severe illness
What is the pronosis for salmonella?
Good unless septic
What is E. coli?
Normal flora gram - anaerobic rod shaped bacterium that is mostly non-pathogenic
Rarely causes disease unless immunocompromised or particularly virulent strain
What are the clinical signs of E. coli infections?
Diarrhea, vomiting, dehydration, lethargy
How do you diagnose E. coli?
Culture of blood or feces
How do you treat E. coli and what is the prognosis?
IV supportive care and antibiotics
Good prognosis unless septic
What is the causative agent of salmon poisoning disease?
Neorikettsia helminthoeca or elokominica transmitted by Nanophyetus salmincola
What are the clinical signs of salmon poisoning disease?
High fever, hematemesis, diarrhea +/- hematochezia, vomiting, lethargy, anorexia, nasal and ocular discharge, enlarged lymph nodes
How do you diagnose salmon poisoning disease?
- Fluke eggs in feces
- History of ingested fish
- Inclusion bodies on macrophages in lymph nodes
- PCR or serology
- Thrombocytopenia
Chem and UA non specific
How do you treat salmon poisoning disease and what is the prognosis?
Hospitalized support and antibiotics (oxytetracycline, doxycycline) and praziquantel for the fluke
Prognosis is fair to good with aggressive supportive care but death in 90% of untreated cases
What viruses effect the small intestine?
Parvo, distemper, feline panleukopenia, coronavirus, FIV, FELV
All things canine parvo.
- Type 2 pathogenic
- Fecal oral transmission highly contagious
- Infects enterocytes and bonemarrow
- Typically seen in puppies
- Severe hemorrhagic diarrhea
- Dx: ELISA test useful but can cross react with vaccine
- Tx: Aggressive supportive care
- Prog: full recovery if they survive the first few days
All things feline parvo.
- Clinical signs similar to canine parvo but less severe enteritis usually
- 50-90% fatal without aggressive support
- Causes cerebellar hypoplasia in peri-natal infection
- Can use canine snap test to diagnose
All things coronavirus.
Canine- limited enteric pathology
Feline- self-limiting to moderate diarrhea and rarely causes CS; may mutate and manifest as FIP
What are the most common intestinal neoplasms in cats?
Lymphoma, adenocarcinoma, mast cell
What are the most common intestinal neoplasms in dogs?
Lymphoma, adenocarcinoma, smooth muscle tumors
All things small cell lymphoma.
Infiltrative /diffuse type disease diagnosed via biopsy
Tx: chlorambucil and prednisone
Prognosis: survival up to 3 years with treatment
What are the criteria that you can classify intestinal obstruction by?
Extraluminal vs Luminal
Mechanical vs. Functional
What are some conditions that can cause intestinal obstruction?
- Mass lesions
- Foreign bodies
- Ganulomatous disease
- Inflammatory disease
- Hypertrophy
- Inussusceptions
- Hypomotility or ileus
- Volvulus or torsion
- Hernia
What is an intussusception?
Telescoping of one bowel loop into the adjacent segment
Often associated with parvovirus, masses, or diffuse ileus
T/F: Intussuscpetion is the most common cause of extraluminal obstruction.
True- most commonly at the ileocolic junction
What animals are predisposed to intussusceptions?
- Young animals with severe gastroenteritis
- Causes of gasteroenteritis
- Neoplasia
- Postparturient bitches
What are the clinical signs and physical exam findings of animals with intussusceptions?
CS: vomiting, diarrhea, anorexia
PE: Abdominal pain, tube like structure, associated illness
How do you diagnose and treat intussusceptions?
Dx: palpation of tube like mass, radiographs, ultrasound (double walled structure)
Tx: spontaneous reduction possible, surgery, treat underlying disease
All things intestinal volvulus.
Rare often fatal twisting of the intestines
Acute onset of CS, patients typically present in shock
Surgery is obligatory as bowel is mot often diffusely necrotic
What is an intestinal hernia?
Intestinal loops slip outside abdominal cavity into the SQ tissues
Can lead to strangulation and necrosis of intestines with intermittent GI signs
What is the difference between direct and indirect intestinal hernias?
Direct- rent in the body wall from trauma or surgery
Indirect- existing ring of tissue such as umbilical ring, inguinal ring, or scrotum
Aka congenital and acquired
How do you diagnose and treat intestinal hernias?
Dx: Palpate, radiographs, ultrasound
Tx: Sugery
What is EPI?
Exocrine pancreatic insufficiency
Insufficient secretion and production of pancreatic enzymes leading to maldigestion
What are some etiologies of EPI?
- Acinar atrophy
- Chronic pancreatitis
- Aplasia or hypoplasia
Congenital in GSD, rough coated collies, eurasians
What are the clinical signs of EPI?
1 is weight loss
Loose stools and steatorrhea Ravenous appetitie Poor hair coat Borborygmi Flatulence Can be subclinical
How do you diagnose EPI?
CBC, CHEM, UA: rules out other causes
TLI levels: species specific
B12: often low in EPI and requires supplementation
How do you treat EPI?
Dried pancreatic extract powder or fresh pancrease in the diet (pancrealipase powder)
B12 supplementation
Why does EPI treatment fail?
Concurrent intestinal disease
Too much acid in the stomach (start on antacid)
Prognosis usually excellent but requires lifelong therapy
When should you biopsy a patient with a suspected primary enteropathy?
To prioritize and optimize therapy or when empiric therapy fails or patient status dictates definitive answer
What are examples of empiric therapy?
Deworming
Diet change
Antibiotic trial
Probiotics
What conditions are extremely responsive to diet change?
Food allergies or hypersensitivity
How do you diagnose and what are treatment options for food allergy or hypersensitivity?
Dx: resolution of CS with diet change
Tx: Hydrolyzed diets, novel antigen diets
How long will it take to see a clinical response to a food responsive disease?
Around 2 weeks
May take a couple different diets before medication trial
What are hydrolyzed diets?
Proteins are split up into a very small sized so that the immune system cannot recognize them as foreign
Most are around 7-10 KD
What is idiopathic antibiotic responsive diarrhea?
Due to small intestnial bacterial overgrowth
No reliable test or specific etiology
What are some mechanisms that cause IARD?
Host-bacterial interactions or bacterial overgrowth secondary to defects in mucosa, aberrant mucosal immune response, qualitative changes in enteric flora (dysbiosis)
What are the clinical signs of ARD?
- Small bowel diarrhea
- +/- colitis and weight loss
- Stunted growth
- Borborygmi and flatulence
- Appetite change
- Vomiting
How do you treat ARD?
Metronizadole, tylosin, oxytetracycline
Diet trials can be done but has a variable response- high quality protein with low fat seems to have the best outcome
What are the most common diseases diagnosed on biopsy?
Inflammatory bowel disease
Lymphangectasia
Lymphoma
What parts of the GIT can be accessed with gastroduodenoscopy?
Esophagus, stomach, proximal duodenum
What parts of the GIT can be accessed with colonoscopy?
Anus, rectum, colon, +/- ileum
What are some reasons to perform endoscopic biopsies?
- Concurrent concerns for colitis
- Concerns for lower SI disease
- Concerns for neoplasia
Why would a surgical biopsy be better than an endoscopic biopsy?
- When disease is deeper than the mucosal layer
- When other organs are affected
- When you have a diffuse lesion requiring surgical removal
What are the pros and cons of endoscopy?
Pro: minimaly invasive, same day GI and recover well, can biopsy many regions
Con: deeper layers missed, cannot access jejunum, cannot sample/assess other organs
What tests can be done to evaluate a biopsy?
H&E staining
IHC for cellular contents and differentiation of inflammation
Special stains for organisms
FISH analysis- for AIEC on colonic biopsy
What is AIEC?
Adherent invasive E. coli
What is inflammatory bowel disease?
- Chronic GI disease of dogs and cats
- Fails to respond to deworming, antibiotics and diet
- Histopath reveals mucosal changes and inflammatory infiltrate
- Can involve any or all of the GIT
What causes IBD?
- Disruption of physiologic interaction of innate and adaptive immune response
- Defective mucosal barrier
- Inappropriate reaction to normal GIT components
What are pattern recognition receptors?
Health: maintain hyporesponsiveness to luminal contents, diet, and protects the mucosa
What is the most common infiltrate in IBD?
Lymphoplasmacytic infiltrate
What is the pathogenicity of IBD?
- Loss of normal villous structure
- Goblet cell changes
- Crypt abscesses and cysts in advanced disease and lymphangectasia
- Moderate to severe infiltrates are often associated wit protein losing disease
What are the types of IBD?
- Minimal change
- Granulomatous or neutrophilic
- Lymphoplasmacytic
- Eosinophilic
- Lymphangectasia
What are the characteristics of minimal change enteropathy?
- Low clinical disease score
- Albumin >2.0
- Normal B12
- Normal to minimal inflammation on histopathology
What is the treatment for minimal change enteropathy?
- Deworm
- Diet trial
- Antibiotic trial with probiotics (chronic therapy may be necessary)
What are the characteristics of granulomatous or neutrophilic enteropathy?
- Infrequent diagnosis
- Macrophages/histiocyticc and/or neutrophilic infiltrate
- Prompts to look for infectious disease (must rule out)
How do you treat granulomatous or neutrophilic enteropathy?
- Treat underlying infectious disease
- Antibiotic trial
- Immunosupressive medications if infectious disease is excluded
Guarded to poor prognosis if underlying etiologic agent isn’t identified
What are the characteristics of lymphoplasmacytic enteropathy?
- Lymphocyte and plasma cell infiltrate
- Variable clinical presentation
- May be PLE
- Typically systemically ill
- Typically diet responsive (60-88%)
What is the treatment for lymphoplasmacytic enteropathy?
- Hydrolyzed or novel antigen diet
- Antibiotics trial
- Immunosuppressants when no response to above
- Anti-clotting medications with hypoalbuminemia
Better response when younger dogs with normal albumin
What are the characteristics, prognosis, and treatment of eosinophilic enteropathy?
- Eosinophil infiltrates
- Typically reaction to parasites or food allergy
- Good prognosis in dogs
- Guarded to poor prognosis in cats
- Tx: deworm, diet, immunosuppressant therapy
What are characteristics of lymphangectasia and crypt cell cysts?
Local or generalized lymphatic disease
Common cause of PLE
Basenhi, SCWT, Torkie, and Lundehunds over represented
What does lymphangectasia look like on endoscopy?
- White granules/blebs on mucosal surface
- Abnormal distension of lymphatic vessels within mucosa
What is the treatment for lymphangectasia and crypt cell cysts?
Diet: hydrolyzed and low fat Antibiotics: metronidazole or tylosin Immunosuppresants: prednisolone or cyclosporine may need parenteral administration Anti-clot medications Diuretics- in cases of ascites
What is the prognosis of lymphangectasia and crypt cell cysts?
Fair to guarded pending response to treatment and severity of clinical signs
What are potential causes of protein losing enteropathy?
- Inflammatory disease
- Lymphangectasia
- Infiltrative neoplasia
- Infectious disease
- Endoparasites
- Intussusception
- Portal hypertension
What is the treatment for protein losing enteropathy?
- Treat the underlying disease
- Diuretics as needed
- Abdominocenteisis (do not remove all the way)
What is the prognosis of PLE?
-Guarded to good
Depends on severity of pets condition and response to therapy
What are some negative indicators for prognosis?
Low albumin, low B12, Neoplasia
What are the best way to provide enteral nutrition in a GI disease patient?
Nasogastric or nasoesophageal tubes
Esophagostomy tubes
PEG tubes- used more for chronic cases
