3.1.3: Bacterial endocarditis and traumatic reticulopericarditis Flashcards
(31 cards)
Effects of TRP on cardiac function
- Cardiac tamponade
- Reduced cardiac output -> forward failure
- Progresses to congestive heart failure (backward failure) - this is when animal presents as clinical signs now apparent
Early stage traumatic reticulopericarditis: clinical signs
- Pain: abducted elbows, withers positive, arched back
- Rubbing/friction/tinkling/splashing on auscultation as there is liquid pus
- Tachycardia
- Pyrexia ± associated BRD signs
Heart sounds may change daily in the acute stages! Hard to diagnose.
Later stage traumatic reticulopericarditis: clinical signs
- Muffled heart sounds bilaterally: regular rhythm with splashing/squeaking/rubbing sounds
- Difficulty palpating apex beat; cardiac sounds obscured due to fibrin in pericardium
- ± Pyrexia
- Signs related to congestive heart failure: jugular distension, ventral oedema, tachycardia, dyspnoea, injected scleral vessels
What clinical pathological findings might be expected with traumatic reticulopericarditis?
- Leukocytosis, hyperfibrinogenaemia, hyperglobulinaemia (elevated TP) -> inflammation
- Neutrophilia -> infection/inflammation
- Elevated liver enzymes -> hepatic congestion esp if congestive heart failure
What is the diagnostic method of choice for traumatic reticulopericarditis? How would you carry this out?
Ultrasonography
* ICS 3-5 on both sides
* Rectal scanner can be used
What would you expect to see on ultrasonography of a cow with TRP?
- Purulent fluid in the pericardial sac ± fibrin
- Fibrin provies the “snowstorm” appearance within the pericardium
Describe these findings
“Snowstorm” appearance within the pericardium caused by purulent material and fibrin
This is consistent with traumatic reticulopericarditis
True/false: congenital cardiac defects are more common in cattle than acquired cardiac disease.
False
Congenital cardiac defects are rare in cattle
Acquired disease e.g. TRP is more common
True/false: pericardiocentesis can help differentiate the cause of pericarditis in the cow.
True but this is not really done in practice. Could be done in some hospitals.
* Useful for differentiating septic pericarditis from lymphoma and idiopathic haemorrhagic pericarditis (latter = not seen in UK, seen in US)
True/false: pericardiocentesis can help differentiate the cause of pericarditis in the cow.
True but this is not really done in practice. Could be done in some hospitals.
* Useful for differentiating septic pericarditis from lymphoma and idiopathic haemorrhagic pericarditis (latter = not seen in UK, seen in US)
Describe the PM findings shown here
- The pericardium is extremely thickened (normally it is transparent)
- Lots of grey-coloured fibrin has accumulated on the epicardium
- This is a chronic septic pericarditis/TRP
Treatment and prognosis for early TRP
- Fair to reasonable prognosis if caught before there has been perforation/septic pericarditis
- Treatment: bolus with magnet, give broad spectrum antibiotics (i.e. amoxicillin, oxytetracycline)
Treatment and prognosis for late TRP
- Poor to hopeless prognosis
- Euthanise on welfare grounds -> this animal goes for fallen stock
Prevention of traumatic reticulopericarditis
- Due diligence regarding silage and other feed management
- Magnets costs £2/3-4 per head and are effective
- Can put more than one magnet in if need be
Describe the pathophysiology of bacterial endocarditis in cattle
- There is a bacteraemia secondary to chronic bacterial infection elsewhere e.g. mastitis, metritis, pneumonia, lameness
- The bacteria circulate, reach the heart and adhere to the endothelium
- Particular predilection sites for bacteria to adhere: right and left AV valves
Clinical signs of bacterial endocarditis
Ante-mortem diagnosis is challenging!
* Murmur ± palpable thrill
* Persistent tachycardia
* Ill thrift
* Milk drop (may be episodic)
Clinical pathological findings for bacterial endocarditis
Findings usually non-specific so clin path rarely used.
* Leukocytosis/ hyperfibrinogenaemia/ hyperglobulinaemia (elevated TP) -> inflammation
* Neutrophilia -> infection/inflammation
* Non-regenerative anaemia -> chronic disease
* Elevated liver enzymes -> hepatic congestion if CHF
Describe the post-mortem appearance of a normal healthy heart valve
Crisp/shiny, regular shape
Describe the post-mortem appearance of a heart valve in a cow with endocarditis
Rough, irregular shape. This allows turbulence and therefore murmurs can be heard.
What diagnostic techniques could be used to investigate endocarditis?
- Ultrasonography - can be challenging to get a good image. Would see fluffy appearance of the affected valve.
- Blood culture - not commonly performed as expensive, hard to access and need repeat samples.
Describe these findings
- Valve has much large diameter than expected and “fluffy” appearance
- Consistent with bacterial endocarditis where bacterial have adhered to the right AV valve
Treatment for bacterial endocarditis
- Long-term antibiotic therapy - minimum 3 weeks penicillin/amoxicillin
- Furosemide if CHF present
- Analgesia
Quite impractical and expensive. Hard to justify under responsible use of antimicrobials.
Prognosis for a cow with bacterial endocarditis
- Guarded if caught early - this is hard to do!
- Return to normal heart rate and sounds is a good prognostic sign.
- If signs of CHF -> poor prognosis and should euthanise.
- Animal may be fit to travel a short, stress-free journey, OR if severe signs/brisket oedema, should go for fallen stock.
Describe the incidence of congenital heart defects in cattle
- Uncommon
- About 0.2% of bovine heart affected
