Heart disease in cattle and sheep Flashcards
Focus on bacterial endocarditis and traumatic reticulo-pericarditis
Cardiac dz in farmed spp
- Cardiovascular disease moderately common in cattle
- Rare in other ruminants
- Acquired > congenital
– Congenital defects ~0.2%
Types of pericarditis
- Traumatic reticulo-pericarditis (TRP)
- Other types of pericarditis are uncommon and rarely cause signs of cardiac disease
– Sepsis in calves
– Severe BRD in adult cattle
– May be seen on PME associated with ‘pulpy kidney’ (C.perfringens type D)
– Idiopathic haemorrhagic pericardial effusion (IHP) (not seen in UK)
Traumatic reticulo-pericarditis (TRP) overview
- Cattle
– Most common pericardial condition in cattle - Septic pericarditis (see lots of pus and fibrin)
– Rarely reported in other species
– Hard wire/Hardware disease (“wire”) - Pericardium and reticulum are anatomically closely located
TRP - aetiology and pathogenesis
- Sharp linear metallic FB ingested
– Typically wires from tyres used to weigh down silage cover
– Associated with clamp silage feeding - FB penetrates reticular wall -> into pericardial sac (through diaphragm)
– Not always cranial direction
(with reticular contraction the wire moves, typically in cranial direct, but can go in other directions -> get inflammation of whatever other organ has been penetrated)
TRP - effects on cardiac function
- Cardiac tamponade
- Reduced cardiac output
– Forward failure - Progresses to CHF
– Backward cardiac failure
– CS related to this (e.g. oedema)
Why does TRP cause cardiac tamponade?
- Pericardial sac filled with pus and fibrin
- Heart won’t be able to beat effectively
- Get cardiac tamponade
TRP - history
- Typically non-specific
- Milk drop
- Non-specific illness 1-2 weeks prior to exam that appeared to resolve before recurring
- Inappetance
TRP - Presenting signs: early stages
- Pain
– Abducted elbows
– Withers positive
– Arched back
– Firm palpation - Rubbing/friction sounds on auscultation (pus still liquidy - heart moving around in this fluid)
- Tachycardia
- Pyrexia +/- associated BRD signs
- In the early (acute) stages, heart sounds can change daily
TRP - Presenting signs: later stages
- Muffled heart sounds (bilateral)
– Regular rhythm
– Splashing, squeaking, rubbing sounds - Difficulty palpating apex beat
- +/- pyrexia
- Signs related to congestive heart failure
– Jugular distension, ventral oedema, tachycardia, dyspnoea, injected scleral vessels - In the later (chronic) stages, heart sounds tend to be consistent
TRP - Clinical pathological findings
Non-specific
- Inflammation: Leukocytosis, Hyperfibrinogenaemia, Hyperglobulinaemia (TP ^)
- Infection/inflammation: neutrophilia
- Hepatic congestion (if CHF): Elevated liver enzymes
TRP - US
- Method of choice
- ICS3 – ICS5 on both sides
- Rectal scanner can be used
- Purulent fluid in pericardial sac (+/- fibrin)
- Hepatic congestion
TRP - Alternative imaging
- Radiography
– Lateral thoracic views (standing)
– Gas-fluid interface
– Metal wire may be identified
– Not often available
TRP - Pericardiocentesis
- Differentiate causes of pericarditis – NOT treatment
– Septic pericarditis
– Lymphoma (not in UK)
– Idiopathic haemorrhagic pericarditis (not in UK) - Potentially fatal risks
– Pneumothorax
– Cardiac puncture
– Contamination of pleural space
TRP - PM
- thickened reticular wall
- bruised pericardium (should be whitish colour)
- thickened pericardium
- potentially squished chambers
- lots of fibrin
TRP - Treatment and prognosis
Early stages (i.e. before fibrinous septic pericarditis has developed)
- Magnet
- Broad-spec antibiotics (e.g. amoxicillin, oxytetracycline)
Late stages (septic pericarditis has developed)
- Prognosis = poor to hopeless
- PTS on welfare grounds
- Pericardiotomy/percardiostomy and drainage are reported
– Poor outcomes
