Cardiovascular Flashcards
What are clinical signs of heart disease?
Edema, abnormal jugular vein, body cavity effusion, exercise intolerance, diarrhea, hepatomegaly, proteinuria, arrhythmias, murmurs, fever, death
What are differentials for edema?
Hypoproteinemia, lymphatic/venous obstruction, udder edema
What are differentials for abnormal jugular veins?
Thrombosis, phlebitis
How is heart disease diagnosed?
Cardiac auscultation, radiographs, pericardiocentesis, ECG, echocardiogram, BP measurements
What are normal heart rates for adult and neonate cattle and small ruminants?
Calves- 100-120bpm
Cattle- 60-80bpm
SR neonates- 120-140bpm
SR- 70-90bpm
Do cattle have benign arrhythmias? Do goats or camelids?
Cattle- no
Goats and camelids- sometimes sinus arrhythmias
Describe the appearance of a cow’s ECG
Positive P wave, upside-down QRS, T wave can be positive, negative, or biphasic
What congenital heart defects occur in cattle and how do they present?
VSD, ectopia cordis, PDA
Young animal with history of lethargy, weakness, exercise intolerance, with holosystolic, holodiastolic, or continuous murmur
What is the most common cardiac defect in cattle?
VSD
What breeds of cattle are predisposed to VSDs?
Limousine, Hereford
How does blood shunt in a VSD?
Left to right
What are the clinical signs of a VSD?
Loud harsh murmur heard loudest over tricuspid area and a little softer over the pulmonic valve area, lethargy, poor growth, dyspnea, exercise intolerance, atrial fibrillation
How are VSDs diagnosed and treated in cattle?
Echocardiogram
No practical treatment
Describe ectopia cordis cervicalis
Heart found in abnormal location (cervical, pectoral, abdomen), associated with multiple heart defects
PDA results in what direction shunting?
Left to right
What are the clinical signs of a PDA?
Continuous high pitched murmur louder on left, lethargy, poor growth, dyspnea, exercise intolerance
Can you treat a PDA in cattle?
No
What are differentials for right sided heart failure in a ruminant?
Lymphosarcoma (right atrium)
High altitude disease
Endocarditis
Mediastinal mass
What is brisket disease and where does it occur?
Occurs in high altitudes (>6000ft), pulmonary hypertension causing right sided heart failure (right ventricular hypertrophy), may have genetic component, occurs in calves and yearlings
Describe the pathophysiology of brisket disease
Pulmonary arteriolar constriction occurs in response to hypoxia, increased pulmonary vascular resistance and pulmonary hypertension occurs, pressure overload of the right ventricle leads to hypertrophy, dilation, and heart failure
What toxin can lead to high altitude/brisket disease?
Locoweed (swainsonine)
What are the clinical signs of brisket disease?
Edema, lethargy, weakness, bulging eyes, diarrhea, collapse, death, jugular vein distension, abnormal jugular vein pulse, dyspnea and tachypnea
How is brisket disease diagnosed?
History, location, PE findings, pulmonary hypertension (60-80mmHg)
How is brisket disease treated/prevented?
Move to lower altitude, decrease stress, select breeding stock with PAP scores <35mmHg at elevations of 5000ft
What is the heart valve most commonly affected by endocarditis?
Tricuspid
What are possible causes of endocarditis?
Degenerative changes, trauma, myocardial disease, inflammation, bacterial infection (Trueperella pyogenes, Strep, Staph, E. coli, Klebsiella)
What are the clinical signs of endocarditis?
Cardiac murmur, exercise intolerance, arrhythmias, weight loss, tachycardia, jugular vein distension, edema
How is endocarditis diagnosed?
Echocardiogram, CBC with stress leukogram, blood culture
What is the treatment for endocarditis?
Long term antimicrobials aimed and G+ species- penicillin; furosemide, prognosis guarded/poor if clinical signs present
What are causes of pericarditis?
TRP, sepsis, extension of thoracic infection, neoplasia
Describe the pathophysiology of pericardial disease
Bacterial proliferation in pericardial space -> inflammatory reaction -> neutrophil influx -> abscess -> inelastic pericardial sac and increased fluid pressure -> constrictive pericarditis
What are the clinical signs of pericarditis?
Fever, anorexia, depression, weight loss, peripheral edema, jugular vein distention, tachycardia, muffled heart sounds, splashing heart sounds
How is pericarditis diagnosed?
CBC and chemistry, radiographs, pericardiocentesis with >1.013 and protein >3.0g/dl, predominantly neutrophils and pH <7.3
How is pericarditis treated?
Poor prognosis- rumen magnet, rumenotomy, prolonged antimicrobial therapy, pericardiectomy and rib resection with pericardial marsupilization
What are causes of right to left sided heart failure?
White muscle disease
Ionophore toxicity
Gossypol toxicity
Myocarditis
Cardiomyopathy
Describe white muscle disease
Occurs in selenium deficient areas, usually affects calves 2w-6m old, weakness, dyspnea, coughing, ascites and sudden death may appear, treat by supplementing surviving calves
What is the mechanism of action of ionophores?
Alter sodium and potassium transport across cell membranes
Describe the pathophysiology of ionophore toxicity
Sodium influx into cells, intracellular calcium concentrations rise, mitochondria swell, cell osmolarity changes
What are the clinical signs of ionophore toxicity?
Anorexia, muscle tremors, diarrhea, sweating, weakness, arrhythmias, dyspnea
How is ionophore toxicity diagnosed?
Decreased potassium and calcium, increased BUN, AST, and CK, GI contents can be analyzed
Pale areas and areas of hemorrhage in myocardium, degeneration and necrosis of cardiac muscle with inflammation seen in necropsy
How is ionophore toxicity treated?
Remove feed
Possibly activated charcoal
