Large Animal Cardiovascular Disease Flashcards
What are the causes of pericardial disease in large animals?
Septic pericarditis Idiopathic Primary bacterial pericarditis Neoplasia (uncommon) Viral (uncommon)
What might cause a septic pericarditis in large animals?
Traumatic and embolic causes
Which species is idiopathic pericardial disease most common in?
Horses
In which species is primary pericardial disease most common in?
Pigs
Explain the pathogenesis of traumatic pericarditis…
- Ingestion of wire which forces through wall of recticulum into pericardal sace
- Septic fluid, fibrous cheesy exudate, adhesions and gas occur in the pericardial sac
- May also have reticular abscess, liver abscess and peritonitis
What are the early clinical signs of traumatic pericarditis?
Fever, anorexia, depression
Cranial abdominal, reticular and/or thoracic pain
+ Stands with elbows abducted
+ Reluctance to move
What are the later signs for traumatic pericarditis?
RH heart failure
Venous congestion
Peripheral oedema
What clinical signs would you see during a CVS exam with traumatic pericarditis?
Tachycardia Muffled heart sounds \+/- splashing murmurs Venous distension Raised jugular pulse Weak pulses
How do you diagnosis traumatic pericarditis?
Clinical signs
Pericardiocentesis
Cytology
What is the treatment for traumatic pericarditis?
Most are culled
Surgical removal
How do you prevent traumatic pericarditis?
Magnets
Where may lymphoma masses develop in the heart of a cow? What signs might you see?
Right atrial wall - jugular distension
Pericardial infiltration -pericaridal effusion, CHF, cytology neoplastic cells
What pathogens cause pericarditis in pigs? What are the clinical signs?
Haemophilus parasuis (Glasser’s) and Strep suis
CS: Fever Depression Fibrinous polyserositis Effusions in CNS, pleura, peritoneum, synova
Describe the aetiology of pericardial effusions in horses.
Majority - Idiopathic Minority - Pericarditis due to: - Equine Viral Arteritis - Equine Influenza - Step pneumoniae - E coli - Actinobacillus equuli
CS is a fibrinous effusion and treatment is penicillin
What are the clinical signs of a pericardial effusion in horses?
Venous distension
Ventral oedema
Muffled heart sound
Dyspneoa, dullness on percussion
How would you diagnose pericardial effusion in horses?
Echocardiography
ECG
Cytology of pericardial fluid
What is the treatment for pericardial effusion in horses?
Repeated pericardial drainage and lavage alongside ABs
What is the prognosis for horses with pericardial effusions?
Good provided treatment is early and aggressive
Why does bacterial endocarditis occur in:
Ruminants
Horses
Secondary to bacteraemia
- Common in ruminants
- Liver abscess, traumatic reticulitis, metritis, mastitis, navel abscess, joint ill - Uncommon in horses
- Site of sepsis not identified or septic jugular thombophlebitis
Why is prompt treatment of bacterial endocarditis necessary?
Large proliferative ‘vegetative’ lesions may develop, limiting prospects for valve function to return to normal.
What are the causative organisms and areas of heart affected by bacterial endocarditis in:
a. Ruminants
b. Horses
c. Pigs
Organisms
a. Enterococci, step, actinomyces pyogenes
b. Pasteurella, actinobacillus, strep, rhodococcus equi
c. Staph aureus, actinobacillus suis, erysipelothrix
Areas:
a. Tricuspid + pulmonic valves
b. Mainly mitral and aortic, tricuspid only after jugular thrombophlebitis
c. Mitral, aortic
What are the clinical signs of bacterial endocarditis in LAs?
Congestive heart failure with murmur
Fever
Tachycardia
Tachypneoa
What do lab diagnostic tests show with bacterial endocarditis?
Hyperfibrinogenaemia, anaemia and leucocytosis
Blood culture
What is the treatment for bacterial endocarditis in LAs?
Broad spectrum ABs based on sensitivity
Treatment in farm animals not usually viable
What is the prognosis of bacterial endocarditis in LAs?
Guarded as permanent structural damage. Septic emboli may have shed to distant sites
What is cor pulmonale?
Hypertrophy, dilation and ultimately failure of right ventricle resulting from pulmonary hypertension
What are the causes of pulmonary hypertension that leads to cor pulmonale?
Pulmonary disease
Pulmonary vasculature disease
What is the pathogenesis of cor pulmonale?
- High altitude/chronic resp disease/acidosis
- Alveolar hypoxia
- Pulmonary vasoconstriction
- Pulmonary hypertension
- Right ventricle failure
What is the clinical disease seen in cor pulmonale?
Cattle with severe chronic respiratory disease
Doesn’t occur in horses
Clinical signs of heart failure
Prognosis usually hopeless
What is the pathogenesis of EIPH?
- Pulmonary haemorrhage during strenuous exercise
- Volume varies from local pulmonary, trace of tracheal, copious tracheal, epistaxis
- Haemorrhage from pulmonary, not bronchial vessels
- Typically originates in caudodorsal lung lobes
Describe effect of exercise on CO and pulmonary vascular pressures in horses
Increase CO and pulmonary vascular pressure 5-10 fold.
What is the failure point of equine pulmonary capillaries?
75-100mmHg
What are the caudodorsal lobes affected with EIPH?
Higher blood flow (low intrinsic resistance)
Displacement of diaphragm causes transient falls in alveolar pressure
Mechanical forces transmitted to lung greatest in caudodorsal loves
What are predisposing factors for EIPH?
Young TBs Increases with ages Conditions increasing pulmonary vascular pressure \+ LRT disease e.g. asthma \+ URT obstruction \+ Cardiac disease
What is the clinical significance of EIPH?
60-70% of horses endoscopically +ve following racing
<5% have epistaxis
What are the clinical signs of EIPH?
Often none Poor performance Sudden onset exercise limitation Swallowing after exercise Epistaxis Other RT and CVS signs
How is EIPH diagnosed?
Clinical signs Endoscopy BAL Radiography Sctintigraphy
What is seen on radiography of an EIPH horse?
Localised regions of interstitial opacity in caudodorsal in lobes due to chronic bleeding
Bronchial pattern
How do you manage EIPH cases?
Identify and treat underlying predisposing factors
Break haemorhage-inflammation cycle
+ Modify training
+ Dust free environment
+ Furosemide (reduces pulomary capillary pressures)
What medication can be used for EIPH?
Furosemide (reduces circulating volume and weight)
Vasodilators
What is the prognosis for EIPH?
Good if spontaneous and minimal impact on performance with resp infection or predisposing factor identified
Poor for idiopathic bleeders with performance limitations.
