Horses 2 Flashcards
what are the 7 main differential diagnosis for acute colitis and types common
1) salmonella - type B and C
2) clostridium - type A and C most common
3) antimicrobia-assoacited colitis
4) potomac horse fever
5) viral - coronavirus
6) cyasthostomiasis (parasite)
7) non-pathogenic - grain overload and right dorsal colitis (NSAID toxicosis)
acute colitis how important is the diagnosis
REGARDLESS OF THE CAUSE, CLINICAL APPEARANCE IS THE SAME - smell, haemorrhagic, non-haemorrhagic
YOU CANNOT MAKE A DIAGNOSIS BASED ON CLINICAL SIGNS ALONE
Problem list for acute enteritis cases
- Diarrhoea ○ Infectious (vs. noninfectious) - Hypovolaemia/ haemoconcentration ○ Fluid loss in diarrhoea - Hypoproteinaemia ○ Protein-losing enteropathy - SIRS (“endotoxaemia”) Secondary to GI compromis - Thrombocytopenia ○ Hypercoagulable state - Leukopenia/neutropenia ○ SIRS - Mild azotaemia ○ Pre-renal/renal/post-renal ○ Probably pre-renal - Hyperglycaemia ○ Stress ○ Severe disease
Acute enteritis diagnostic plan what need to submit
- WILL need to start treatment before results back
○ OFTEN don’t get an answer, need to tell the owners - Samples to submit
○ Faeces
§ Clostridial toxins
§ Salmonella PCR/culture (series of 5) -> one negative doesn’t indicate horse is negative
□ Shed in varied quantities, intermittently
§ Parasitology
○ If PHF season/area
§ EDTA blood – PHF PCR
§ Serum – PHF IFAT
+/- Ultrasound - can help assess oedema
What are the 4 main complications of acute colitis and when at risk
- Laminitis - most common - ANY CASE ○ All colitis cases at risk ○ PHF, grain overload big risks - Coagulopathy ○ Thrombophlebitis – consequence of SIRS - Hypertriglyceridaemia - Rectal prolapse - really oedematous rectums straining to pass large amounts of diarrhoea
Acute enteritis describe the supportive/preventative measures needed
○ Reduce risk laminitis
§ Ice boots (how long?) -> a few days after white cell count normalises
○ Anti-diarrhoeals
§ Di-tri-octahedral smectite (Biosponge®)
○ Probiotic?
§ Saccharomyces boulardii
○ Analgesia
§ Control colic pain
□ Usually due to ileus, dysmotility, (colon infarction)
§ NSAIDs (not in right dorsal colitis (RDC)- caused by NSAIDS)
□ Look a lignocaine and opioids
○ Anti-endotoxin treatment??
§ (Hyperimmune plasma) -> 50:50 in literature, risks that have with transfusions
§ Flunixin meglumine (not RDC) -> works on the clinical effects -> WORKS
foal diarrhoea difference to adults, result, treatment and how to balance referral and management on farm
- Easier to diagnose - generally higher identification of the pathogen
- Neonates do become bacteraemia (useful to take blood culture)– consequences
○ Sepsis
○ Septic joints/other synovial structures
○ Omphalitis - umbilical structures - Treatment largely supportive, still expensive
- Referral vs. management on farm
○ Severity of disease (i.e. intensity of required treatment)
○ Ability and knowledge of owners/farm managers
What are the 9 main differentials for neonatal foal diarrhoea
- Salmonellosis
- Clostridiosis – usually perfringens – often haemorrhagic - can be so severe than become anaemic
- Coronavirus
- Rotavirus - 5d - 4w - lactase replacement
- Cryptosporidium - zoonosis - self-limiting
- Enterococcus durans***
○ New discovery in terms of being pathogenic - Nutritional – orphans especially - incorrect milk replacer
- FOAL HEAT - 7-9d, ‘mare foal heat’ - coprophagic - self-limiting
- Parasitic – Strongyloides
What are the 4 main differentials for older foals/weanlings
- Strongyles
- Ascarids
- Rhodococcus equi
- Equine proliferative enteropathy/Lawsonia (weanling age, usually chronic)
Rhodoccus equi what cause in foals and 2 other causes of diarrhoea
- Usually pneumonia (pulmonary abscesses), but many extrapulmonary manifestations ○ Ulcerative colitis 1) Sepsis, neonatal encephalopathy ○ Period of poor perfusion to GI tract ○ Treat primary problem, supportive care 2) Intestinal nematode parasites ○ Older foals/weanlings
In general what are more likely colic causes in young horses (neonates) and immature horses
Young horses
- First manure getting stuck (meconium impaction)
- congenital abnormalities of the gut (atresia coli)
Immature
- Prone to infectious problems
- Enteritis (small intestinal)
- Parasitic
○ Ascarid impactions of the small intestine (foal lecture)
○ Intussusception (association with worms)
Broodmare colic what need to consider and main differentials and when high risk
- Broodmare: pre or post-partum?
- Pre-partum -> Pregnant causes
a. Foal movement can result in low gr colic
b. foaling/ate term abortion
c. uterus can twist: uterine torsion (last 2 months)
Post-partum
a. rupture of uterine artery - most common
b. foal can damage uterus during foaling
c. can also damage GI tract - peritonitis/endotoxaemia - euthanse
Foaled within 3 months - HIGH RISK - most common large colon volvulus (this until proven otherwise) - surgical emergency - CV compromise
Rupture of uterine artery leading to colic in recently foaled broodmare what is the treatment options
□ NSAIDs, careful sedation to calm -> don’t want to drop blood pressure too dramatically
® Detomidine and top up if needed
□ Tranexamic acid: antifibrinolytic (10mg/kg in 1L IV) - stabilises the clot
□ +/- blood transfusion (indications below)
® Decided by: lactate>4, HR 80, Hb<8g/dL, PCV<15% (unreliable in acute stage)
® Can lose approx 11L without need to transfuse
® (1/3 of blood volume: b.vol = 8% body weight)
What are the 4 main causes of colic based on geographical location
1) sandy soil - sand impactions - SA,WA, VIC
2) enteroliths - WA,NSW,QLD (NOT VIC)
3) infectious agents - QLD, northern NSW
4) swim colic - racehorse swum for excercise within 30mins - most respond to pain relief (95%)
Febrile colic what is generally the cause types of pathogen within large intestine, small intestine and abdominal cavity
- Febrile suggests infectious (most commonly)
○ Bacterial
§ Large intestine= Colitis (Salmonella/Clostridia)
§ Small intestine= Anterior Enteritis (Clostridia)
§ Abdominal cavity=
□ Peritonitis (Actinobacillus equuli)
□ Peritonitis due to GI catastrophe
○ Viral
§ Hendra
Analyse situation and give diagnosis - General history ○ 8yo TB, Quiet /lying down approx 12 hrs ○ Little manure passed today No drugs given so far - Physical exam ○ Occasional flank watching/dull ○ HR 48 ○ Mmbs salmon pink ○ Hasn’t passed much manure ○ Temp 39.0 ○ NGTube: no reflux ○ Abdominocentesis: Turbid, yellow WCC 210x109 cells/L TP 30 g/dL Lactate <2 mmol/L
No drugs - know that pain is the actual level
PE
- Low grade abdominal pain consistent with MMbs salmon pink
- hasn’t passed much manure -> § Reduced LI motility? - Large colon impaction - know if rectal
FEVER NARROWS DOWN
§ Narrows ddx down: SI / LI / peritoneal cavity - no longer routine LC impaction
□ Ddx Colitis, Anterior Enteritis, Peritonitis
- no reflex - NOT ANTERIOR ENTERITIS
- abdominocentesis - peritonitis
What are the 6 main differentials diagnosis for chronic diarrhoea in horses
a. Right dorsal colitis (NSAID toxicity)
b. Sand enteropathy
c. Cyathostomiasis
d. Inflammatory bowel diseases
e. Alimentary lymphosarcoma
f. Equine proliferative enteropathy (Lawsonia intracellularis)
Right dorsal colitis treatment and prevention
- Treatment
○ NO NSAIDs – use alternative analgesics to control colic pain
○ Supportive, esp. colloids
○ +/- misoprostol (Prostaglandin replacement)
§ No good evidence surrounding use
§ Need to wear gloves -> nothing that is pregnant
○ Omeprazole, sucralfate for concurrent gastric ulceration
○ Low roughage diet - finely chopped chaff, off hay
○ Surgical resection in severe cases - Prevention
○ Monitor TP in cases receiving prolonged NSAID treatment
Cyathostomiasis which causes issues, what are those issues and diagnosis
- Encysted larval stages – L3
- Commonly causes chronic diarrhoea, assoc. with ill thrift
- Acute severe diarrhoea associated with mass emergence of encysted larvae
- Diagnosis
○ FEC – but won’t tell you about encysted larvae
§ Useful for herd management but not individual management
○ Hypoalbuminaemia
○ Response to treatment
○ Rectal mucosal biopsy - generally not done -> lucky to get piece of tissue with encysted larvae
Cyathostomiasis treatment and prevention
- Treatment ○ Anthelmintics - larvicidal § Fenbendazole – 10 mg/kg PO SID for 5 days □ Resistance problems § Moxidectin – 0.4 mg/kg PO once (usual dose) ○ Supportive - Prevention ○ Good de-worming protocol
Inflammatory bowel disease what are the 4 recognized types how common in what age group, main presentation and prognosis
1) Granulomatous enteritis (GE)
○ Young horses, idiopathic, low % have diarrhoea
2) Lymphocytic-plasmacytic enterocolitis (LPE)
○ Rare, no specific identifying features
3) Eosinophilic enterocolitis (EE)
○ Colic primary sign, not weight loss; better prognosis
4) Multisystemic eosinophilic epitheliotropic disorder (MEED)
○ Young horses, skin lesions, other organs affected (liver, spleen)
Inflammatory bowel disease diagnosis
○ Glucose absorption test
§ Prior fasting, feed withheld during test (water OK)
§ 1 g/kg glucose (as 20% solution) administered via NGT
§ Blood glucose measurements taken at baseline, then q 30 min for 3-4 hours, then q 60 min for another 2-3 hours (total 6 hours)
§ Glucose should peak (>85% of baseline value) by 120 minutes.
§ D-xylose absorption test alternative
○ Abdominal ultrasound
○ Rectal biopsy
○ Intestinal biopsy (if colic surgery)
○ Abdominocentesis
○ Can be elusive
Inflammatory bowel disease treatment and prognosis
○ Often palliative
§ EE may gain long-term success
○ Often ongoing
○ Corticosteroids – tapering until find lowest dose that controls clinical signs
§ Some horses may have periods of not needing corticosteroids at all
- Prognosis generally poor
Alimentary lymphosarcoma diagnosis, treatment and prevention
- Diagnosis as for IBD ○ Partial to complete malabsorption - glucose absorption test ○ Abdominal ultrasound ○ Rectal exam ○ Abdominocentesis ○ +/- Rectal biopsy ○ Can be elusive - Treatment as for IBD - Prognosis generally poor