acute diarrhoea Flashcards
what is the pathophysiology of accute diarrhoea?
- osmotic
◦ maldigestion (eg EPI, damage to the brush border)
◦ malabsorption (eg mucosal damage, villus atrophy, infiltrative disease such as lymphoma) - secretory
◦ toxin
◦ infection related - inflammatory (altered permeability)
◦ inflammatory bowel disease (eg adverse food reaction, idiopathic chronic enteropathy)
◦ motility disorder
How is canine parvovirus spread?
in what dogs is it seen? what occurs?
- Virus stable in environment for years
- Faecal-oral – 3-6 days incubation
- Generally see in young puppies with low maternal immunity (pre-vaccination), older unvaccinated dogs (breed predisposition – black and tan?)
- Infects rapidly dividing cells
◦ Gut crypts, bone marrow, lymphoid tissue, (myocytes and CNS in some neonates)‣ Vomiting ‣ Haemorrhagic diarrhoea – profuse and foetid, mucosal sloughing ‣ Rapid dehydration ‣ Panleucopaenia (as infects the bone marrow, get sepsis) ‣ Depressed, anorexic, pyrexic ‣ Loss of mucosal barrier – septicaemia/endotoxaemia and shock/DIC ‣ Ileus
what are the differentials for canine parvovirus?
- HGE - including neoplasia and idiopathic HGE (AHDS)
- Salmonella, enteric infections
- Intussusception
- FB
- Hypoadrenocorticism
- Acute intoxication
how is canine parvovirus diagnosed?
- Signalment and clinical signs strongly supportive
- Faecal analysis – EM for virus, Ag tests (SNAP) or PCR
- Care with positive results after MLV vaccination (SNAP ok….)
- Severe necrosis of GIT can lead to false negative Ag tests
- Haematology and biochemistry – consequences of disease
- Panleucopenia – consequence of viral replication
- Azotaemia, acid-base disturbance, electrolyte disturbances, liver enzymes abnormal, possibly low total protein
- Clotting times may be prolonged if severe systemic consequences present
what is the managemet of canine parvovirus?
- Fluid therapy
◦ LRS – be aggressive, maintain electrolytes via supplementation – requires monitoring of blood pressure, and regular assessment of weight
◦ Acid-base status assessment – can be severe imbalance
◦ Colloid/plasma/whole blood - Antibiotics
◦ Broad spectrum due to GI translocation of bacteria - Clav-amox, +/- quinolone –care with age of patient, gram negative coverage is difficult in young animals - Anti-emetics
◦ important as marked nausea – metoclopramide, maropitant and ondansetron/dolasetron - Pro-motility medication
◦ Metoclopramide – enteritis reduces GI motility, major consequences - Antacid drugs and ulcer coating medication
◦ severe gastritis can develop along with reflux oesophagitis and stricturesBegin oral fluid/nutrients ASAP - Enteric support is crucial
- Aggressive anti-emetic use
- May require assisted feeding, care with reflux and aspiration
◦ E.g.Naso-oesophageal tubes
what is the prevention of canine parvovirus?
- Vaccination – various protocols
◦ Early vaccination and late vaccination in susceptible breeds and environments - Cleaning and disinfection – bleach/Virkon
◦ Resistant to some disinfectants
what is the aetiology of acute haemorrhagic diarrhoea syndrome (AHDS)?
what are the ddx?
AKA haemorrhagic gastroenteritis
* Idiopathic in most cases
◦ DDx parvovirus enteritis/intussusception/pancreatitis
◦ Aetiology may be type I intestinal hypersensitivity reaction or the result of Clostridium perfringens enterotoxin production
what are the clinical signs and laboratory findings of dogs affected with acute haemorrhagic diarrhoea syndrome?
- Small breed dogs usually
- Vomiting +/- blood
- Foetid diarrhoea – inc protein loss – brown water
- Depression, anorexia – very poorly
- Haemoconcentration –
◦ fluid shift into GIT means severe hypovolaemia before clinical dehydration is apparent
◦ PCV high
◦ TP not so high as GI loss
◦ No leucopenia (c.f. parvo)
what is the treatment and prognosis for acute haemorrhagic diarrhorea syndrome?
- Fluid therapy – must be aggressive as with CPV
- Colloid/plasma/whole blood
◦ Depends on degree of haemorrhage and complications - Antimicrobial –
◦ Potential for clostridial infection and sepsis
◦ Four quadrant cover only if signs consistent with sepsis – G+, G-, aerobes and anaerobes
‣ Clav-amox, metronidazole, fluoroquinolone - Prognosis is good in most cases however severe cases where proteins are low and systemic inflammatory response develops is guarded
◦ These cases are most critical in the acute presentation stage
◦ take a while to get better so don’t PTS too early
what is the feline ‘parvovirus’?
how is it spread?
what does it cause?
Feline panleucopaenia
* Transmission and signs as CPV
◦ Kittens/colonies
◦ Widespread in feral cats
◦ Cats can be infected by CPV-2
◦ Diagnosis same as for CPV
* Feline vaccine used in early CPV outbreaks as there seems to be cross protection
- Reproductive failure/cerebellar hypoplasia (infections in-utero)
what dogs does coronavirus affect?
what is the pathogenesis and what does it cause?
what is the treatment?
what does coronavirus cause in cats?
Dog
* Young dogs (age related immunity?), highly contagious
* Mild villus destruction – enterocytes at tips
* Usually subclinical but strain related and co-infection can worsen disease
* Predominantly small bowel but can be mixed
◦ If severe – v+ and watery/mucoid d+
◦ Treatment – supportive IVFT and nutritional support for GI tract
Cat – FECV
* Signs as dog
* NB link to FIP – mutates to FIP-causing coronavirus
what campylobacter species are commensals in dogs, what is the issue with this?
what disease canthey cause in dogs?
Campylobacter jejuni and upsaliensis - zoonotic
* Clinical disease in young, immunocompromised animals or those with additional infectious agents (giardia, parvo etc)
- Acute enterocolitis (NOT CHRONIC LOW-GRADE DIARRHOEA)
◦ d+ +/- blood/mucus
◦ Vomiting
◦ Straining – large intestinal “type” d+
◦ Fever, abdominal pain
◦ Can become enteroinvasive due to host stress (IFN and noradrenaline mediated)
how is campylobacter diagnosed and treated in dogs?
- Diagnosis
◦ Faecal stain/culture
‣ Fragile therefore best isolated from fresh faeces
‣ slender motile seagull-shaped bacteria
‣ Standard culture may be misleading as speciation is not performed,
◦ PCR - Treat underlying disease if present – e.g. CE/IBD
- Treatment most frequently with 4-fluoroquinolones (can use erythromycin, can lead to vomiting)
Salmonella has a similar aetiopathogenesis to campylobacter
* Mainly seen in young and immunocompromised animals or those with concomitant infections
* Is a commensal in many dogs
it poses a potential zoonotic risk to owners
what are the 4 scenarios after infection?
◦ Transient asymptomatic diarrhoea
◦ Acute Gastroenteritis
◦ Carrier state
◦ Bacteraemia
salmonella infections can be mild or severe what are the clinicla signs of sever infection?
what are the negative prognostic indicators?
when should you treat salmonella infection?
haemorrhagic diarrhoea, pyrexia and sepsis (due to translocation across gut wall)
◦ Negative prognostic indicators – hypoglycaemia, temp > 40C, degenerate left shift
◦ SIRS and DIC – RIP
- Only treat if severe sepsis and shock and only on basis of culture results
◦ NOT if patient is well/mild d+ as unlikely to be significant if found on diagnostic testing
what type of disease does salmonella cause in cats? what altenative disease can it cause?
usually mild D+, but songbird fever when ingest birds (migration season) can lead to acute febrile illness with diarrhoea
what speces cause clostridial enteritis?
why do they cause diarrhoea?
what type of diarrhoea do they cause?
how is clostridial enteritis treated and managed?
- C. perfringens, C. difficile – normal anaerobic flora!
◦ Diarrhoea generally due to enterotoxin production
◦ Relationship with kennels and both acute and chronic diarrhoea but causation still unclear - ?need trigger – diet change, hospitalisation etc
causes Large intestinal type d+/HGE (AHDS)??
- Manage complications
- Treat with metronidazole as first choice with ampicillin and tylosin alternatives (less effective)
- Environmental spores are very resistant - Hypochlorite with no fomites
- Unclear zoonotic risk at present
what type of colitis can boxers get due to E. coli? how is it treated?
- Histiocytic ulcerative colitis in boxers newly discovered attaching and invasive isolate
◦ Can develop rapid resistance however 4-fuoroquinolone treatment or metronidazole is effective in many cases
there are various strains oe E. Coli that can cause enteritis, why is it important to know what strain a dog is infected with?
clear that plasmid genes code for pathogenicity
Important aspect are extended-spectrum beta-lactamases ESBL (impart resistance to 3rd generation cephalosporins and quinolones) and wider dissemination to G-ve bacteria
what age of animal are affected by ascarids?
what are the clinical signs?
- Puppies/kittens mostly – adults have low burdens and worm migration patterns are different (adults have mainly somatic migration which generally leads to cyst formation in tissues)
- Fail to gain weight
- Pot bellied appearance
- Vomiting and small bowel diarrhoea
- Obstruction of GIT if large burdens along with respiratory disease when migrating
what animals are affected by hookworms?
what are the clinical signs?
- Kennelled dogs most commonly identified
- Diarrhoea
- Weight loss
- Anaemia with Ancylostoma?
- Interdigital dermatitis/perineal irritation
what coccidian species affect dogs and cats?
what are the clinical signs of coccidiosis in dogs and cats?
how is coccidiosis diagnosed?
what is the treatment ?
- Isospora canis – dog
- I. felis, I. rivolta – cat
Pups/kittens, poor conditions etc lead to most severe clinical signs - diarrhoea - Small intestinal location but mixed bowel signs often seen
◦ Can seen chronic intermittent shedding by carriers during stress or concomitant disease - Can be severe and mortality can occur
Dx with faecal exam – direct or flotation for oocysts
Tx - mild disease is self-limiting
◦ if underlying cause present will resolve when this is resolved
◦ Sulphonamides or potentiated sulphonamides
◦ Toltrazuril and diclazuril can also be effective
◦ Studies however indicate shedding can recur after treatment
if happening in an older dog then need to think about immunosuppressive disease happening in the background
what type of diarrhoea does cyrptosoridium cause in dogs and cats?
what can cause increased severity of signs?
how is crypto diagnosed?
howis it treated?
Many animals infected but few develop diarrhoea
◦ Malabsorptive and secretory diarrhoea
* Co-infection with giardia or tritrichomonas increased severity of signs
Diagnosis by feacal smear, IFA or PCR
Self limiting unless underlying cause
Treatment determine underlying cause
◦ Dietary manipulation and neutraceuticals
◦ Antibiotics of limited benefit – tylosin, azithromycin and paromomycin
need to steam clean environment
* Zoonotic potential
where does Giardia (felis and canis) infect in the animal?
what type of disease does it cause?
how is it diagnosed?
how is it treated?
Surface of small bowel: dog (duodenum) and cat (ileum) – faecal-oral transmission, can be subclinical infection in many animals
* Acute – chronic, usually mild (soft watery with mucus – ie mixed bowel characteristics)
◦ (can be present in CE cases and exacerbate background disease - always test for it)
* Can result in severe, chronic disease with weight loss
◦ Via liberation of toxins, development of dysbiosis, induction of IBD, dysmotility, inhibition of enterocyte function
* Dx – faecal smear evaluation (direct smear evaluation or flotation techniques) also SNAP test (ELISA) available – for faecal antigen along with IFA (this is poorly specific)
* Tx-
◦ Fenbendazole 3-5 days – LICENSED
◦ metronidazole, ronidazole and tinidazole
◦ fibre may help, unclear benefit of neutraceuticals
what protozoal large intestinal parasite affects cats (rarely dogs)?
how is it diagnosed and treated?
Tritrichomonas foetus
* Large bowel diarrhoea
* Common (30% of cats with d+?)
* Often present as secondary pathogen (there due to enteropathy)
* Microscopy, culture, PCR
* Difficult to treat - ronidazole
- Clinical approach of diarrhoea will be dictated by your initial database– i.e. signalment, history and clinical examination findings
- This enables problems and DDx to be generated
what are the 3 main outcomes from this in first opinion practice?
◦ Not worried - Manage consequences of diarrhoea
◦ Not sure – screen and support
◦ Worried – investigate and (likely) more intensive support (pyrexia and abdominal pain)
why is hypertonic water loss seen with acute diarrhoea?
what happends to the patients blood if they are also vomiting, why?
◦ Increased motility
◦ Increased secretion
◦ Decreased absorption
◦ Loss of sodium (and often bicarbonate)
Care if vomiting in conjunction will also lose chloride and H+ which makes acid base status often complex (pateint will become acidotic)
what fluid should be used with acute diarrhoea patients?
- Balanced isotonic solution (Hartmann’s – also has buffering capacity) or 0.9% saline
- Choice should be based on evaluation of electrolytes or acid base status.
- However SOME fluid is better than no fluid!
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what adsorbents can be used with acute diarrhoea?
what is the thought process behind them (efficacy not proven)?
◦ Kaolin (Kaogel)
◦ Pectin
◦ Chalk
◦ Bismuth subsalicylate
◦ Magnesium aluminium silicate
◦ Activated charcoa
- Alter intestinal flora/bind flora
- Coat or protect mucosa
- Absorb toxins
- Bind water and possibly antiscretory
Peridale 98 % w/w Granules
* Orange-coloured granules containing sterculia 98 %
* Bulk promoting agent.
what are the indications in dogs?
- Management of infected anal sacs.
- Control of stool consistency following surgery.
- Control of specific and non-specific diarrhoea.
- Constipation.
what are the two classes of antimotility drugs, which is used in small animals?
- Opiates (avoid in cat)
- spasmolytics - rarely indicated
what opiates are used as antipotility drugs in dogs?
when does care need to be taken when using these drugs?
◦ Loperamide/diphenoxylate
◦ Morphine – increases contractions (segmental) but decreases propulsion – increased large intestinal tone; overall leads to constipation
◦ Codeine similar effect to morphine
◦ They decrease intestinal secretion and promote absorption
◦ Care in breeds with** MDR-1 mutation** due to CNS side effects
◦ Contraindicated in animals with suspected FB or infectious conditions
◦ Care when suspect ileus as this can be exacerbated
Spasmolytics are rarely indicated in small animals
* No licensed product
* Safe and effective doses yet to be determined
what are the two types and what are the drugs within these types?
musculotropic antispasmodics (direct action on gut muscles causing relaxation)
◦ Mebeverine and pinaverine
muscarinic antagonists (care with SI Diarrhoea)
◦ Butylscopolamine (hyoscine) and metamizole (dipyrone - caution)
◦ Aminopentamide – less risks
when are antibiotics indicated in acute diarrhoea?
- Helicobacter – of questionable significance – triple therapy
- Definitively diagnosed infectious diarrhoea
- Loss of GI mucosal integrity and evidence for sepsis
- Neutropenia/immunosuppression - e.g. parvo/post chemotherapy
