Large Animal CV Disease Flashcards
Most common cause of pericarditis in horses?
Idiopathic
What is the most common cause of pericarditis in cattle?
Septic
WHat are the 5 potential causes of pericardial disease?
> Septic (traumatic or embolic causes, most common in cattle)
Idiopathic (spontaneous and non-septic, eg. effusions, most common in horses)
1* bacterial pericarditis (pigs)
neoplastic (uncommon LA)
Viral (uncommon LA)
What is a sequalae to traumatic reticulo-peritonitis in cattle, but is now uncommon? what is this also known as?
- traumatic peritonitis
- known as hardware or wire disease
How does traumatic pericarditis appear on opening of the pericardium?
“bread and butter” cheesey fibrous exudate, adhesions and gas
What may also be found with traumatic pericarditis in cattle?
- reticular abscesses
- liver abscesses
- peritonitis
What may be a cause of hardware disease nowadays?
Chinese lanterns
Early signs of traumatic peritonitis?
- fever
- anorexia
- depression
- cranial abdo/reticular/thoracic pain
> elbows adducted, reluctant to move, grunting on movement
> positive WIlliams test (listen for grunt while ruminating) Bar and Pinch test for thoracic pain
Late signs of traumatic pericarditis?
- right sided (constrictive) heart failure
- venous congestion, peripheral oedema
CLinical signs of traumatic pericarditis on CV exam?
- tachycardia
- muffled heart sounds
- splashing washing machine murmer (sometimes)
- venous distension
- raised jug pulses and milk vein
- weak peripheral pulses
Diagnosing traumatic peritonitis, best methods? What is usually done
- radiography, US, pericardiocentesis under US guidance (only high value animals)
- usually culled
Tx of traumatic pericarditis?
- rumenotomy for wire removal
- marsupialise pericardial sac to debride and lavage
- magnet for prevention ( NOT multiple magnets! will repel!)
Which notifiable neoplastic disease in cattle may cause haemorrhagic pericardial effusion? Pathogensis?
- Lymphosarcoma due to bovine leukeamia virus (BLV) = leukosis virus
- Lymphoma masses in spine, RA wall (-> jugular distension), pericardium (-> haemorrhagic effusion, RCHF, neoplastic cells on cytology)
Which countries is BLV present?
US and Canada
What organism causes pericarditis in pigs? What is this disease commonly called?
> Haemophihlus parasuis
- Glassers disease
may also be caused by strep suis
CLinical signs of pericarditis in pigs?
- fever
- depression
- fibrinous polyserostiis (joints)
- CNS effusions
- pleural, peritoneal and synovial effusions
What are the majority of pericardial effusions in horses casued by? What are a minority caused by?
- majority idiopathic
- minority pericarditis due to
> EVA, influenza
> strep pnumoniae, E. Coli, Actinobacillus equuii
Appearance of pericardium in horses with pericarditis?
- bread and butter fibrinous effusion too
Drug tx of pericardial effusion in horses?
penicillin - potentially alter if something other than E. COli found as cause
What oes cytology show in horses with pericardial effusion?
Unremarkable
Clinical signs of pericardial effusion in horses
- venous distension and ventral oesema
- muffled heart sounds
- pericardial friction rubs -> squeaking (rarely heard)
- pleural effusion (dyspnoea, dullness on percussion, small lung field on auscultation)
Diagnosing pericardial effusions in horses, best methods?
> echo - fluid +- fibrin in pericardial sac - compression of cardiac chambers > electrocardiography - small complexes - main differential = obestiy > cytology of pericardial fluid (though risky!)
What colour would a fibrinous effusion be on ultrasound?
- effusion black
- fibrin white
Tx pericardial effusion in horses?
- repeated pericardial drainage and lavage +- Abx
- esp in RA collapsing (cardiac tamponade)
Why will pericardial effusions froth when drained?
Proteinacious, fibrinous
Prognosis for pericardial effusion in the horse?
- good providing tx is early and aggressive
- constrctive disease may occour in chronic cases (worse prog)
Which valves does baterial endocarditis affect and how is it caused?
any valves
- 2* to bacteraemia
Which animals is bacterial endocarditis most common?
- ruminants of and other farm animals (infection showers to the heart)
> metritis, liver abscess, traumatic reticulitis, metritis, mastitis, navel abscess, joint ill - horses less common but possible
> site of sepsis often not identified, spetic jugular thrombophlebitis from IV catheters possible
Why is propt tx of bacterial endocarditis necessary?
- large proliferatice vegetative lesions develop which limit propsect of return to normal valve function
Clinical signs of bacterial endocarditis
- congestive heart failure with murmur(s)
- fever, cardiac murmur, tachycardia, tachypnoea
> lab results - hyperfibrinogenaemia, anaemia, leucocytosis
- blood culture (3x repeated, ideally when pyrexic) [sterile procedure, do not use indwelling catheter]
Tx bacterial endocarditis
- Broad spec Abx based on culture sensititvty
- Tx of farm animals usually not viable economically
Prognosis of bacterial endocarditits?
Guarded even after bacteriologic cure (can limit further spread but damage to valve leaflets already done)
- in some horses return to performance is seen with some right sided lesions
- septic emboli may spread to distant sites (lungs from R heart, kidneys and joints from L heart) -> recrudescence
What condition may occour 2* to lung dysfunction? Pathophysiology?
> cor pulmonale
- leads to hypertrophy, dilation and ultimate failure of RV
- caused by chronic pulmonary disease, pulmonary vascular disease or high altitude (eg. cattel farmed in mountains) leading to vasoconstriction [also known as brisket or high altitiude disease]
- alveolar hypoxia -> pulmonary vasoconstriction -> pulmonary hypertension -> right ventricular failure
CLinical signs of cor pulmonale?
- subcut oedema (bottle jaw, brisket)
- jugular venous distension and pulsations
- dyspneoa and tachypnoea
- tachycardia and cardiac murmur
Prognosis of cor pulmonale
usually hopeless due to underlying chronic irreparable lung pathology and fibrosis
- exception: high altitude -> move cattle to lower pasture
What is EIPH?
Excercise induced pulmonary haemorrhage
Pathogenesis of EIPH?
- pulmonary haemorrhage during excercise
- volume varies from local pulmonary, tracheal bleeding or epistaxis
- seen in horses, dogs and human athletes
- haemorrhage from PULMONARY (not bronchial) vessels
- in horses haemorrhage usually from caudodorsal lung lobes
- pulmonary capillaries break as inevitable weak point (thin walled)
- even with these mega thin capillaries normal TBs become hypoxic and hypercapnic at excercise
> haemorrhage causes local inflam, ^ regional resistnance and pressure and ^ risk of vessel rupture
> viscous cycle!
Which circulatory vessels are affected by EIPH?
Pulmonary
not bronchial
Why are the caudo-dorsal lung lobes most commonly affected by EIPH?
- ^ blood flow
- v intrinsic vascular resistance
- displacment of diaphragm -> transient v alveolar pressure -> ^ transmural pressure -> rupture
- ^ mechanical forces
Predisposing factors for EIPH?
- young TBs
- BUT ^ prevalence with age due to fibrotic vessels
- conditions ^ pulmonary vascular resistance
> lower resp tract disease (eg. RAO)
> Upper resp tract disease (eg. RLN)
> Cardiac disease: atrial fibrillation, mitral valve disease
Does EIPH affect performance?
Rarely!
Clinical signs of EIPH?
- no clinical signs
- poor performance
- sudden onset excercise limitation
- swallowing after excercie
- epistaxis
- other signs of URT, LRT, cardiac disease (atrial fibrillation)
How can EIPH be diagnosed?
> clinical evidence - epistaxis only present in very limited cases > endoscopy > bronchoalveolar lavage - RBCs, haemosiderophages > radiograpy - not specific - localised regions of interstitial opactiy in caudodorsal lung lobes
Management of EIPH?
> ID and treat underlying URT, LRT, cardiac disease
break haemorrhage-iflammation cycle
- modify training to reduce episodes
- dust free (as RAO Tx)
- furosemide (v pulmonary capillary pressure - contentious!)
Why may furosemide not be indicated for EIPH treatment?
- against FEI guidlines so cannot be competed on it
What does furosemide do? What other drugs may be indicated for use with EIPH?
> diuretic
- v circulating volume
- weight loss (marginally)
vasodilator
- other vasodilators eg. NO, argenine, ACEI
- silver trialled as anti-inflam and anti-bacterial (not a “drug” so allowed by FEI)
Prognosis for EIPH?
Good to fair
- if spontaneous and minimal impact on perfomrmance
- or if asscoaited with resp infection or predisposing factor that can be identified and treated
Poor
- idiopathic bleeders with performance limitation
