Diarrhea. Acute diseases of small intestine Flashcards
Clinical signs of GI disorders
- diarhhea - primary
- bloody feces: melena vs hematochesia
- defecation: dyschesia (painful defecation), tenesmus (difficulty in defecation), constipation
- vomiting
- weight loss, sarcopenia (decreased muscle mass)
- abdominal pain/discomfort
- borborygmus (increased intestinal sounds), flatulence (increased gas production)
- change in appetite: anorexia/hyporexia/polyphagia/pica (eating indigestible things)
- apathy, depression, weakness
Diarrhea. Definition
Increase of water content of feces (fecal fluidity).
Can be accompanied by increased defecation frequency and increased volume of feces
Pathophysiology of diarrhoea (possible mechanisms)
- Osmotic diarrhea: undigested osmotically active content: overeating, EPI
- Secretory diarrhoea: secretion of fluid > normal absorption: e.g. due to toxins
- Exudative diarrhea: increased permeability: e.g. due to inflammation (parvo, neoplasms of GIT, IBD
- Dysmotlity: abnormal peristalsis (often secondary condition)
Usually there is a combination of these
Diarrhea. Classification
- DURATION: acute vs chronic (<3 weeks<)
- ETIOLOGY: intestinal vs extraintestinal
- LOCALISATION: small bowel (SB) vs large bowel (LB) vs diffuse
- SEVERITY: mild vs severe
Aim: to narrow DD list
Extraintestinal disorders causing diarrhea as minor sign
- Digestion disorders
- disorders of pancreas (pancreatitis, EPI)
- liver/bile ducts disorders - Toxic effect/metabolic dysfunction (e.g. uremia, PSS)
- Inflammation (e.g. SIRS)
- Disorders affecting motility
- obesity
- endocrine disorders: hyperthyroidism in cats, atypical addisons in dogs (rare)
- pain, stress - Disorders affecting blood supply (heart failure, portal hypertension, hypovolemic shock)
How to localise diarrhea
- FECES
- large amount of watery feces vs small amount of “dense” feces
- mucus in LB
- melena vs hematochesia - DEFECATION
- tenesmus present?: yes -> LB
- frequency significantly increases?: yes -> LB - OTHER SIGNS
- vomiting: common in SB
- dehydration: common in SB
- weight loss: common in SB
Diarrhea. Diagnostic steps
- Signalment, history
- Physical examination
- Routine fecal analysis
- Routine lab tests
- Diagnostic imaging
- Endoscopic examination
- Exploratory laparotomy
- Gut biopsy
- Special fecal and lab tests
Usually more severe and especially chronic the diarrhea is, more examination is needed to diagnose it
Important aspects of signalment of patient with diarrhea
- age: young are predisposed to infectious disorders; older: predisposed to chronic enteropathies and neoplasms
- breed predilection
Important breed predilections to GI diseases
- German shepherd: chronic inflammatory enteropathy, EPI
- Retrievers: food responsive enteropathy (FRE)
- Yorkshire terrier: lymphangiectasia
- Border collie: chronic inflammatory enteropathy
- Boxers, french bulldogs: granulomatous colitis (or histiocytic ulcerative colitis)
History collection of patient with diarrhea
- detailed characterstics of feces, defecation
- environmental and dietary assessment
- exposure to parasites, toxins
- contact with infected animals
- previous therapies and illnesses
- vaccination and deworming status
- drugs
Physical examination of patient with diarrhea
General physical examination
Special attention to:
- BCS and MCS (muscle condition score): malabsorption?
- dehydration: fluid requirement?
- abdomen: pain, bowels, foreign body, bowel sounds
- rectal digital palpation
Diarrhea. Fecal analysis. Routine tests
- fecal smear, flotation: protozoa, worms
- bacterial culture: Campylobacter, Salmomella - if there are relevant clinical signs (inflam leukogram, fever, severe diarrhea)
- fecal ag ELISA: parvo, Giardia
Diarrhea. Labarotary tests
Aims:
-
to exclude extraintestinal causes
- liver, kidney, pancreas, FeLV, FIV
- endocrine (thyroid, adrenal glands) -
to evaluate the severity
- PCV, TP, lactate, electrolytes, glucose: to evaluate hemostasis, plan fluid therapy
- CRP in dogs: to evaluate the severity of inflammation -
to evaluate function of GIT in chronic SB disorder
- decreased cholesterol: malabsorption
- decreased albumin: protein-losing enteropathy -
to localise proble in chronic SB enteropathy
- folate: is absorbed in proximal duodenum
- vit B12 (cobalamin): is absorbed in distal SB (ileum)
Diarrhea. Diagnostic imaging
- Plain radiography: radiodense foreign body
- Contrast radiography: radiolucent foreign body
- Abdominal USG: motility, content, GI wall (esp relevant in chronic cases)
- Endoscopic examination: gross examination of mucosa (NOT in the jejunim)(friability, granularity, erosion, lymphatic dilatation, mass); biopsy
Diagnostic laparotomy. Indications
- intestinal obstruction
- resection of mass lesion
- full-thickness biopsy (neoplasm/lymphoma
- jejunum is affected
Intestinal biopsy
Histology can be diagnostic IF: standardised sampling and interpretention
Molecular technics:
- enteroinvasive pathogens: FISH (fluorescence in situ hybridisation)
- malignancy: immunohistochemistry, flow cytometry
Acute small intestinal disorders
- diet-related
- drugs, toxins
- AHDS - acute hemorrhagic diarrhea syndrome
- infectious
- ileus
- unknown cause - most common, especially in mild cases
Chronic small intestinal disorders
- CIE: chronic inflammatory enteropathy
- lympangiectasia
- neoplasms of SI
- subileus (rare)
- infectious (rare)
AHDS: acute hemorrhagic diarrhea syndrome (previously hemorrhagic gastroenteritis)
- Severe, acute/peracute
- vomiting and then severe bloody diarrhea develops -> hypovolemia
- aetiology: toxigenic Clostridium perfrigens (NetF toxin), BUT IT’S NOT AN INFECTIOUS DISORDER
- PCV increased, neutrophilic left-shift
- treatment: aggressive fluid therapy —> if asap: good prognosis
- AB are usually not indicated (only if signs of septicaemia or if no response to fluid therapy))
- overall: symptomatic treatment: antiemetics, analgesia, GI-diet
Infectious SI disorders
VIRAL
- canine parvoviral enteritis (CPV)
- feline parvoviral enteritis (FPV)
- canine coronaviral enteritis (CCoV)
- other viral enteropathies of cats (FCoV, FIP)
BACTERIAL
- Campylobacteriosis
- Salmonellosis
- Miscellaneous bacterial enteritis
(FUNGAL)
- Histoplasmosis (not in Hungary)
Canine parvovirus enteritis. General info
- CPV-2, CPV-2a,b,c
- frequent worldwide
- extremely stable virus, highly contagious
- immunisation failures are common
- severe outbreaks in kennels
- severe disease
Parvo. Pathophysiology
- high affinity to rapidly dividing cells: SI crypt epithelium, lymphopoietic tissue and bone marrow (damage of immune system!)
- destruction of intestinal crypt—> necrosis and villus atrophy, impaired absorptive capacity —> bloody diarrhea —> fluid, acid-base and electrolyte disturbances —> patients are very very weak!!
- if intestinal mucosa is severely damaged —> failure of gut protective barrier —> bacterial translocation (of own intestinal bacterial microbiota) —> sepsis (due to immunocompromised state)
Parvo. Clinical signs
- incubation period 5-10 days
- usually acute, severe; severity depends on age, breed, immune system, environment (stress), virulence, other intestinal disorders
- usually affected dogs are 8 weeks - 6 months (maternal immunity is already lost and no vaccine)
- vomiting, fever, letargy, abdominal pain
- fluid and electrolyte imbalance
- sepsis, endotoxaemia, DIC —> death
Parvo. Diagnosis
- history + clin signs
- leukopenia (correlates with severity and prognosis)
- anemia, hypoglycemia, hypokalemia
- definitive diagnosis: fecal antigen ELISA (pet-side SNAP test**
- fecal analysis: check for concurrent infections
- abdominal USG: to check complications (paralytic ileus, intussusception)
Is it possible that fecal antigen ELISA test for parvo will be falsely negative? Why?
Test can be negative after 5-7 days after onset of symptoms as viral shedding decreases
Parvo. Treatment
- FLUID THERAPY !!: homeostasis is damaged + risk of sepsis
- ANTIMICROBIAL THERAPY: because of bacterial translocation + immunosuppressive state -> risk of sepsis
- FEEDING: to support enterocytes
Fluid therapy in parvo
A LOT
Crystallised, electrolyte, K+, glucose
Antimicrobial therapy in parvo
- risk of septicemia
- no time to check for susceptibility —> usage of broad spectrum ABs (amoxiclav + enrofloxacin IV)
Feeding of parvo patient
- GI (highly digestible diet) though animal often has nausea, abdominal pain —> decreased food intake
- nasoesophageal feeding tube (liquid diet)
- VERY VERY IMPORTANT
What is the difference between melena and hematochesia?
Melena - digested blood
Hematochesia - fresh blood
Diarrhea. Fecal analysis. Special tests
- molecular tests: PCR for Tritrichomonas in cats
- biomarkers of inflammation: fecal calprotectn in chronic enteropathy
- dysbiosis index: PCR for intestinal microbiota strains
Parvovirus. Additional treatment
- antiemetics: maropitatnt, metoclopramide, ondansetron
- analgesics
- GI-protectants: omeprazole, sucralfate
- concurrent infections
- supportive treatments: adsorbents, vitamins
- dysbiosis: probiotics, fecal microbiota transplantation
- complications
Feline panleukopenia
- parvovirus, disease overall is very similar to canine parvoviral infection
- highly contagious, high mortality
- clinical findings: fever, vomiting, hemorrhagic diarrhea, neutropenia, thickened, painful intestinal loops
- viral shedding is very short (1-2 days)
- diagnosis, treatment ~ canine parvovirus
Canine coronaviral enteritis. Types
- Canine coronavirus - enteral:
- watery-mucoid diarrhea
- NO fever, NO leukopenia
- may be asymptomatic - Pantropic coronavirus:
- mutant form -> severe form ~ parvovirus + neurological signs
Coronavirus destroys tips of villi (crypts stay intact) —> normal enterocyres still can be produced —> clinical signs are much milder comparing to parvovirus
Feline viral enteropathies
FELINE CORONAVIRUS
- feline enteral coronavirus: subclinical, mild; acute, watery diarrhea in kittens
- severe mutation: feline infectious peritonitis
FELINE IMMUNODEFICIENCY VIRUS (FIV)
- usually: FIV + secondary infections —> enteritis
- chronic diarrhea, anorexia
FELINE LEUKEMIA VIRUS (FeLV)
- fatal peracute enterocolitis
- chronic diarrhea
Bacterial enteritis. Aetiology and occurrence.
- Campylobacter
- Salmonella
- Clostridium
- pathogenic E.coli
- pets are normally carriers of these bacteria both pathogenic and non-pathogenic
- majority of them are asymptomatic carriers but in special conditions these bacteria will cause enteritis (mild or severe but usually acute)
- severity depends on pathogenicity of bacteria, general immune state of the patient, state of GIT mucosa, microbiota
- predisposing factors: stressful environment, unhygienic environment, concurrent disorders, raw meat diet
- severity correlates with diarrhea (no/mild/bloody)
Bacterial enteritis. Diagnosis
- culturing is usually difficult (e.g. clostridium is anaerobic)
- PCR, toxin detection (ELISA)
- just detection is not enough, relevant clinical signs should be present!
- zoonotic: Campylobacter, Salmonella but usually infection is through food
Bacterial enteritis. Treatment
- Mild cases: DO NOT TREAT WITH ANTIBIOTICS
- resistance
- recover with symptomatic treatment
- resistant strains can be transmitted to humans (zoonotic) - Severe cases: ISOLATE AND TREAT
- risk of sepsis/symptomatic treatment doesn’t help —> ab use: azithromycin (campylobacter), enrofloxacin (Salmonella)
- isolation: pets and people: esp YOPI: young, old, pregnant, immunodeficient
- Cystoisospora
- Giardiasis
Cytoisospora infection
- common in <1 month y.o.
- often part of concurrent infection
- acute diarrhea
- trimethoprim SAs, toltrazuril (Procox)
Giardiosis
- very common
- no/mild signs, can be severe in young
- chronic cases are rare
- diarrhoea has special appearance: “cowpat”-like, very fetid
- pet-side test: fecal ag. ELISA
- fecal flotation (keep in mind intermittent shedding!)
- fenbendazole, metronidazole (if no respond)
- prevent reinfection ! (clean feces asap, bath patient)
Roundworms in small intestine
- Ascarids: Toxocara
- young: ”potbelly”, diarrhea, failure to thrive
- larval migration -> tissue damage of lungs, liver - Hookworms: Ancylostoma, Uncinaria
- young: diarrhea (bloody), anemia - Tapeworm: Dipylidium, Echinococcus
- intermediate hosts: flees
- clin signs are rare
