9.5.3: Acute diarrhoea Flashcards
Causes of acute diarrhoea
- Diet: acute gastroenteritis e.g. allergy, intolerance, scavenging, toxins
- Drugs: antimicrobials, chemo
- Infectious: viral, bacterial, parasitic
- Inflammatory disease: CE/IBD, pancreatitis
- Metabolic disease: hypoadrenocorticism
- Anatomic disease: intussusception / FB
- Neoplasia: peracute lymphoma, paraneoplasia
- Anomalous: stress/ anxiety - usually mixed/large bowel
Which animals would you particularly expect infectious diarrhoea in?
- Young animals / immunocompromised
- Animals in colonies / kennels
- Mixed infections e.g. parasites + viruses will be worse. Often worms are the complicating factor and treating worms makes the other disease more manageable.
- Seen less in vaccinated, healthy animals
Viruses that cause acute infectious diarrhoea
- Parvovirus
- Coronavirus
- Adenovirus
- FeLV, FIV - chronic enteritis, weight loss, lymphoma in FeLV
- Rotavirus
- (Norovirus)
Bacteria that cause acute infectious diarrhoea
- Salmonella
- Campylobacter
- E. coli - ETEC, EHEC, EPEC
- Clostridium perfringens, Clostridium difficile
- Shigella
- Yersinia enterocolitica - rarely reported
Parasites that cause acute infectious diarrhoea
- Helminths
- Protozoa e.g. Giardia, Tritrichomonas
Clinical signs of parvovirus infection
- Vomiting
- Haemorrhagic diarrhoea: profuse and foetid, with mucosal sloughing
- Rapid dehydration
- Panleucopaenia
- Depression
- Anorexia
- Pyrexic
- Loss of mucosal barrier -> septicaemia / endotoxaemia and shock / DIC
- Ileus
Signalment for parvovirus
- Young puppies with low maternal immunity (pre-vaccination)
- Older unvaccinated dogs (breed predisposition - black and tan?)
Causative agent of parvovirus and characteristics
Canine parvovirus 2 (CPV-2)
* Virus stable in environment for years
* Faeco-oral - 3-6 days incubation
Differential diagnoses for parvovirus
- HGE including neoplasia and idiopathic HGE (AHDS)
- Salmonella, enteric infection
- Intussusception
- FB
- Hypoadrenocorticism
- Acute intoxication: e.g. spoilt food
AHDS
Acute haemorrhagic diarrhoea syndrome
Diagnosis of parvovirus
- Signalment and clinical signs highly suggestive
- Faecal analysis: antigen SNAP - severe necrosis of GIT may lead to false -ves
- Haematology and biochemistry - consequences of disease - panleucopaenia; azotaemia, acid-base disturbance, electrolyte disturbances, liver enzymes abnormal, possibly low TP
Management of parvovirus
- Aggressive fluid therapy; assess acid-base status in case severe imbalance - may need to consider colloid/ plasma/ whole blood
- Antibiotics: broad spectrum (amox/clav ± quinolone), take care re age of patient; gram -ve coverage difficult in young animals
- Anti-emetics (aggressively!!) e.g. maropitant, metoclopramide due to marked nausea
- Pro-motility medications e.g. metoclopramide as enteritis decreases motility
- Antacids and ulcer coating medication - severe gastritis can develop along with reflux oesophagitis and strictures
- Begin oral fluid/ nutients ASAP; may require assistance e.g. NO tube
Prevention of parvovirus
- Vaccination + do not take puppies out too early!
- Cleaning and disinfection: bleach/ Virkon
Pathogenesis, signalment and clinical signs of haemorrhagic gastroenteritis
Syndrome of acute haemorrhagic diarrhoea (AHDS)
* Idiopathic in most cases; may be Type I hypersensitivity reaction or C. perfringens enterotoxin production
* Usually small breed dogs
Clinical signs
* Vomiting ± blood
* Foetid diarrhoea including protein loss - brown water
* Depression, anorexia - very ill
* Haemoconcentration (fluid shift into GIT means hypovolaemia before clinical dehydration apparent)
Differential diagnoses for haemorrhagic gastroenteritis and how you could differentiate between them
Ddx for HGE:
* Parvoviral enteritis - HGE will not show leucopaenia but parvo will
* Intussusception
* Pancreatitis
Treatment and prognosis of HGE
Treatment
* Aggressive fluid therapy - same as parvo; colloid/ plasma/ whole blood depends on degree of haemorrhage and complications
* Antimicrobial - only if signs of sepsis: amox/clav + metronidazole + fluoroquinolone
Prognosis
* Good in most cases
* If TP low and systemic inflammatory response = guarded
Pathogenesis of feline panleucopaenia
- Feline panleucopaenia virus (basically feline parvo; cats can also be infected by canine parvovirus)
- Kittens/ colonies often affected, virus widespread in feral cats
- Transmission and signs the same as canine parvovirus
- Also: repro failure / cerebellar hypoplasia (infections in utero)
Signalment, clinical signs and treatment of coronavirus infection in dogs
Signalment
* Young dogs (pos age-related immunity)
* Highly contagious
Clinical signs
Mild villus destruction - enterocytes at tips
* Usually subclinical but strain-related and co-infection can worsen disease
* Predominantly small bowel diarrhoea
* If severe, may see vomiting and watery/ mucoid diarrhoea
Treatment
* Supportive IVFT
* Nutritional support for GIT
Importance of feline enteric coronavirus in cats
- FECV can mutate into FIP-causing coronavirus
- More a problem in multi-cat households
Diagnosis and treatment of bacterial enteritis
Diagnosis - difficult! Must correlate the bacteria found with clinical signs; don’t treat bacteria just because you find them, they might be commensals.
Treatment
* Manage the presenting situation e.g. if immunocompromised owner
* Consider campylobacter and risk factors e.g. home, kennel environment etc.
* Need multiple samples as microbiome fluid in some patients, static in other
* Boxers with large intestinal signs - treat for E. coli
Clinical signs of Campylobacter jejuni, Campylobacter upsaliensis
Commensal in dogs - potential long-term zoonosis. Clinical signs ususally in immunocompromised animals and those with additional infectious agents (giardia, parvo)
Clinical signs
* Acute enterocolitis NOT chronic low grade diarrhoea
* Diarrhoea ± blood and mucus
* Vomiting
* Straining - large intestinal type diarrhoea
* Pyrexia
* Abdominal pain
* Can become enteroinvasive due to host stress
Diagnosis and treatment of Campylobacter
Diagnosis
* Faecal stain / culture - need fresh faeces
* PCR
Treatment
* Treat underlying disease if present e.g. CIBD
* Treatment most frequently with fluoroquinolones, can use erythromycin but this can lead to vomiting
Signalment for Salmonella
- Mainly young and immunocompromised animals
- Commensal in many dogs
- More common if fed raw
- Significant risk to owners
Clinical signs of Salmonella
4 scenarios after infection: transient asymptomatic disease, acute gastroenteritis, carrier state, bacteraemia.
Clinical signs
* Mild or severe
* Haemorrhagic diarrhoea
* Pyrexia
* Sepsis due to translocation across gut wall
Treatment and prognosis of Salmonella
Treatment
* Only treat if severe sepsis and shock + culture results
* Do not treat if mild disease - like Campylobacter ; if disease is mild, likely not significant findings
Negative prognostic indicators:
* Hypoglycaemia
* Pyrexia >40C
* SIRS and DIC
Presentation in cats
* Cats - usually mild but if songbird fever (ingest migrating birds) can lead to acute febrile illness with diarrhoea
Presentation and treatment of Clostridial enteritis
Presentation
* C. perfringens, C. difficile part of normal anaerobic flora
* Diarrhoea due to enterotoxin production
* History of trigger: diet change, hospitalisation, kennels
* Large intestinal type diarrhoea / HGE / AHDS
Treatment
* Metronidazole (alternatives: ampicillin, tylosin)
* Manage complications
* Environmental spores very resistant - use hypochlorite to disinfect, care re fomites
* Unclear zoonotic risk
Presentation, diagnosis, and treatment of E. coli enteritis
Presentation
* Common gut commensal and faecal isolate
* Various strains present - try to identify if possible
* EHEC = shigatoxin, secretory diarrhoea
* EPEC
* EHEC = possible reverse zoonosis
DIagnosis
* In Boxers, need biopsy to identify histiocytic ulcerative colitis
Treatment
* Metronidazole / fluoroquinolones
1-5
6-8
9-17
18-20
Signalment and clinical signs of ascarid infections
Signalment
* Puppies/ kittens
Clinical signs
* Failure to gain weight
* Pot-bellied appearance
* Vomiting and small bowel diarrhoea
* Obstruction of GIT if large burdens along with respiratory disease when migration
Signalment and clinical signs of hookworms
Signalment
* Kennelled dogs
Clinical signs
* Diarrhoea
* Weight loss
* Anaemia with Ancyclostoma
* Interdigital dermatitis / perineal irritation
Signalment and clinical signs of cestodes
Signalment
* Kennelled and farm dogs most at risk
Clinical signs
* Signs rare in adults
* Zoonotic risk necessitates control
Diagnosis and treatment of helminth parasites
Diagnosis
* Clinical signs and history
* Faecal exam
Treatment
* Heavy importance due to public health considerations (VLM, OLM)
* Treatment does not remove encysted larvae
* Occult parasite infestation should be considered in animals being treated for IBD
Signalment and clinical signs of coccidiosis
Signalment
* Isospora canis - dog
* Isospora felis, isospora revolta - cat
* When seen in puppies/kittens, animals in poor condition -> leads to most severe signs
Clinical signs
* Small intestinal location but mixed bowel signs often seen
* May see chronic intermittent shedding by carriers during stress / concomittant disease
* Can be severe and mortality can occur
Diagnosis and treatment of coccidiosis
Diagnosis - faecal exam - direct or flotation for oocysts
Treatment
* Mild disease is self-limiting
* TMPS, toltrazuril, diclazuril if needed
* Shedding can reoccur after treatment
Presentation and diagnosis of Cryptosporidium
Presentation
* Dogs and cats infected by host-specific crypto
* Seen in puppies, kittens, poor conditions -> need to steam clean environment to control
* Many animals infected but a few develop diarrhoea
* = malabsorptive and secretory diarrhoea
* Co-infection with giardia or tritrichomonas increases severity of signs
Diagnosis
* Faecal smear
* IFA
* PCR
Treatment of Crytosporidium
Treatment
* Often self limiting unless there is an underlying cause
* Determine underlying cause if present
* Consider dietary manipulation and neutraceuticals
* Antibiotics of limited benefit - could consider tylosin, azithromycin and paromomycin
* Zoonotic potential!
Clinical signs and diagnosis of Giardia infection
Clinical signs
* Acute to chronic, usually mild diarrhoea - soft wateru with mucus (mixed bowel)
* Can result in severe chronic disease with weight loss (due to toxin liberation, induction of IBD, dysmotility, inhibition of enterocyte function)
Diagnosis
* Faecal smear evaluation (Direct smear of flotation techniques)
* SNAP test (ELISA)
Treatment of Giardia
- Fenbendazole 3-5 days (licensed)
- Metronidazole may help
- Fibre may help
- Unclear benefit of neutraceuticals
Presentation, diagnosis and treatment of Tritrichomonas foetus
Presentation
* Strictly large intestinal parasite
* Affects cats and rarely dogs
* Affects colonies/ breeders
* Causes large bowel diarrhoea
* Often presents as secondary pathogen
Diagnosis
* Microscopy
* Culture
* PCR
Treatment
* Difficult to treat - ronidazole
Key history questions to ask in the case of acute diarrhoea?
- Vaccination and worming status?
- Scavenging, diet?
- On any drugs?
- Contact wtih other animals?
- Environment/ travel?
- Health of owners - consider zoonoses
- Any previous illnesses/ surgeries?
- Are any other body systems involved?
Examples of adsorbants and why you might use them
Examples: koalin, pectin, chalk, bismuth subsalicylate, magnesium aluminium silicate, activated charcoal
Why to use:
* Alter intestinal flora / bind flora
* Coat or protect mucosa
* Absorb toxins
* Bind water; possibly antisecretory
True/false: probiotics are useful in managing acute diarrhoea.
True
We should be using these often.
What are some examples of prokinetics? How often would we use these in acute diarrhoea?
Examples:
* Metoclopramide (upper GIT)
* Erythromycin (encourages gastric emptying)
* Ranitidine - not very widely available
* Lidocaine (small intestinal motility)
These are rarely indicated in acute diarrhoea. They might be used when a disease process has led to ileus.
