Large Animal Cardiac Disease

Question 1

How can you diagnose VSD in a young calf?

Answer 1

A VSD can be auscultated on both sides but the best intensity is noted to be on the right side over the Tricuspid valve as a pansystoloic murmur.

Question 2

What is the most common arrythmia in a ruminant?

Answer 2

Atrial fibrillation is the most common arrhythmia noted in the ruminate and is often associate with an underlying gastrointestinal disease, metabolic alkalosis, and electrolyte abnormalities or toxemias (correct the problem to correct the afib). It is associated with increase in vagal tone complicated with sympathetic output, (pain) It is seen as irregular Q-T intervals and the absence of P waves.

Question 3

How is an ECG done in large animals?

Answer 3

ECG in large animals is best done by utilizing the base apex
-positive electrode on left thorax in the 5th IC space, (level of the elbow).
-negative electrode in the right jugular furrow 2/3 the distance from the
ramous to the thorax inlet.
-ground electrode can be place any site away from the heart. Often the ear works well.

Question 4

What is the pathogenesis of Bovine High Mountain Disease (BHMD)?

Answer 4

acute or chronic pneumonia, GI parasite (larval migration), high altitude hypoxia, locoweed

alveolar hypoxia to pulmonary vasoconstriction to pulmonary remodeling to pulmonary hypertension to RV hypertrophy to RV dilation to R heart CHF.

Question 5

What is the rule of 10 with brisket edema?

Answer 5

The amount of fluid seen can be multiplied by 10…

Question 6

What is the PAP (pulmonary artery pressure) test done for?

Answer 6

PAP scores of greater than 49 mmHg are high risk (for themselves and their offspring), cull.

Question 7

What is the etiology, pathogenesis, clinical signs of pericarditis (hardware disease)?

Answer 7

exudative fibrinous carditis from penetration, transudate seen in heart failure

pericardial effusion transudate or exudate
decreased venous return, atrial and ventricular filling, CO

2-5 days pospartum: decreased milk production, anorexia, odontopresis (bruxism), respiratory grunt

Question 8

What are some differentials for cardiomyopathies?

Answer 8

1. Gossypol poisoning
2. Vitamin E/selenium deficiency (diaphragmatic paralysis, Stiffness, Stilted Gait, Muscle Pain, Weakness, Recumbency, Elevated Muscle Enzymes: Creatine Kinase (CK), Aspartate Aminotransferase (AST), also white muscle disease)
3. Poisoning by ionophores (makes pores in memebran good and bad, can cause abmormal Na+ intake whihc then leads to Calcium is sequestered in mitochondria leading
   to failure of oxidative phosphorylation, ATP
   depletion, loss of Na/K pumps, and mitochondrial
   swelling and disruption.)
4. Sodium fluoro acetate
5. Plants containing cardiac glycosides
6. Staphylococcus aureus, Histophilus somni and Mycobacterium spp. are all known to cause myocarditis with subsequent cardiomyopathy.

Vitamin D deficienc: rickets

Question 10

How does heart failure present in horses?

right side? left side?

Answer 10

jugular distension and ventral edema, pulmonary edem with left sided heart failure

Left:
respiratory signs (tough, tachypnea, crackles)
resting tachycardia, murmur often present
may progress to right sided CHF due to pulmonary hypertension

Right:
ventral and subcutaneous edema
jugular venous distension
resting tachycardia
cavity effusions

Question 11

What cardiomyopathies can cause a continuous murmur?

Answer 11

PDA in young animals and Aortocardiac fistula (aortic root rupture into adjacent chamber (RA or PA)) in horses.

Question 12

What are the valves most frequently associated with endocarditis in our veterinary species and why?

Will you hear a heart murmur?

Answer 12

Has to do with organisms involved…

Equine: Streptococci, Actinobacillus
Bovine: Actonimyces pyogenes,
Porcine: Erysipolethrix
Canine: Strep, Staph

Equine: Aortic valve, mitral valve, tricuspid valve
Bovine: tricuspid valve, mitral valve
Porcine: AV valves
Canine: mitral valve, aortic, tricuspid

No murmur generally…

Question 13

What are some causes of myocardial disease in the equine?

Answer 13

myocarditis (viral, bacterial)
ionophore intoxication
Vitamin E/ Selenium deficiency
Snake envenomation
Hypervitaminosis D

Question 13

What are some diseases of the great vessels in horses?

Answer 13

Aortocardiac fistulae
Aortic or pulmonary artery rupture (sudden death, Fresion horses predisposed)
Aortoiliac thrombosis (long term managment on warfarin and clopidogrel, anti-thrombotic meds)