Cardiovascular diseases Flashcards
Most common congenital heart defects
Ventricular septal defect (VSD); (most common cardiac defect in calves)
Tetralogy of Fallot (almost always lethal; VSD + pulmonary stenosis + dextral position of the aorta that overrides both ventricles, plus secondary right ventricular hypertrophy);
Atrial septal defect (ASD);
Transposition of great vessels;
Patent ductus arteriosus (PDA) (rare as a single defect);
Inherited cardiac disease
White muscle disease
Bovine leukocyte adhesion deficiency (BLAD)
Bovine hereditary dilated cardiomyopathy
Clinical signs of congenital heart disease
Appear normal at birth; dyspnoea or poor growth, or both
Usually systolic murmurs, PDA may be continuous
Echo will allow confirmation
Treatment of congenital cardiac defects
Euthanasia or early slaughter
Eiesenmenger complex
Complication of a VSD
Can develop in calves or cattle between 1-3yrs
Sudden cyanosis and exercise intolerance due to increased pulmonary vascular resistance due to reversal of the shunt
White muscle disease
Deficiency of selenium and Vit E, which can cause myocardial damage among other muscle weakness
Specific cardiac signs of white muscle disease
variable, subtle or dramatic; arrhythmias;
persistent tachycardia (>120 bpm);
murmurs may be present;
exercise intolerance;
cyanosis;
dyspnoea (caused by cardiac lesions);
congestive heart failure signs;
acute death (e.g., spontaneously, after exercise or restraint);
Diagnosis of white muscle disease
Physical examination
Biochem - increased CK, AST, and LDH
Measurement of selenium levels or enzyme GSPH
Necropsy
Treatment of white muscle disease
Selenium and vitamin E intramuscular or subcutaneously
It may be necessary to repeat administration at 72 hours interval, up to a total of 3 or 4 treatments.
Keep calves in individual pens during convalesce to avoid them running freely and increasing the risk of precipitating further muscle damage.
Furosemide (0.5 – 1 mg/ Kg BW, SID or BID) in case of pulmonary oedema.
Treatment of concurrent aspiration pneumonia.
Prognosis: good for calves that survive 3 days after diagnosis.
Bovine Leukocyte Adhesion Deficiency (BLAD)
inherited autosomal-recessive trait in Holstein-Friesian cattle - fatal
results in neutrophils with deficient β2 integrin expression, prevents adherence to vascular endothelium and the capacity of subsequent migration into the tissue sites of inflammation
Onset early in life, poor growth, chronic or PI
Diarrhoea, pneumonia, ringworm lesions, persistent keratoconjunctivitis, gingival ulcer, loose teeth, tooth abscesses, poorly healing dehorning wounds
Neutrophilia, can do neutrophil function test, test of adhesion-dependent responses
Only palliative treatment
Bovine hereditary dilated cardiomyopathy
Type 1 - Cardiomyopathy in Hereford cattle
- rapid growth
- short curly coat
- sudden death
- dyspnoea, bloody froth from nose
- patchiness of myocardium
Type 2 - Cardiomyopathy in Japanese Black cattle
- death preceded by agonizing dyspnoea
- pulmonary oedema
- oedema, ascites, hydrothorax etc.
Type 3 - Dilated cardiomyopathy in Holstein-Friesian
- sudden onset congestive right sided heart failure
- oedema and engorgement of various areas
- signs of congestive heart failure
Diseases of the pericardium
Septic pericarditis
Idiopathic haemorrhagic pericarditis
Septic pericarditis
most commonly puncture of the pericardium by a metallic foreign body that originates in the reticulum
(could be fibrinous in septicaemic calves or cattle with severe bronchopneumonia (rarely see detectable fluid in pericardium))
detectable pericardial effusion and heart failure signs
Positive pain response to percussion of ventral chest or xiphoid
Traumatic reticulopericarditis - pericardiocentesis exam:
§ Purulent and foetid fluid
§ Commonly visible presence of fibrin clots that can obstruct needle;
§ Elevated protein and WBC with neutrophils as major component;
§ Bacteria easily detected in gram-stained smears;
Normal pericardial fluid: protein <25g/L; WBC £5000/mL with mononuclear cells as a major component;
Poor prognosis, attempt surgery for expensive cattle, medical treatment rarely cures
Idiopathic haemorrhagic pericarditis
Unknown aetiology
Jugular distention; severe submandibular and brisket oedema + acute reduction of appetite and milk production over 24 to 72 hours; mammary vein can be distended and turgid for the stage of lactation;
Typically, cattle are afebrile or low-grade fever; normal to mildly elevated heart rate and respiratory rate;
Heart auscultation: muffling heart sounds or a washing-machine type murmur
Treatment:
Corticosteroid administration (0.1mg/kg BW, over 3 days), alone or combined with pericardial drainage.
The combination seems to give the best long-term survival.
Antibiotic therapy (e.g., penicillin) is recommended in case of pericardial drainage
Good prognosis
Valvular diseases
Bacterial endocarditis
Bacterial endocarditis
Most commonly Trueperella
Most commonly affects tricuspid valve
persistent or recurrent fever; tachycardia; systolic heart murmur
can cause permanent distortion of valves
Treatment requires long-term antibiotic administration to cure bacterial endocarditis
Furosemide can be necessary in case of venous distention
Myocardial disease
Septic myocarditis
Toxins
Parasitic infections
Inherited myocardial disease
Cor pulmonale
Heart neoplasia
