Cardiovascular System

Question 1

A puppy is having a “machinery-like” murmur that is best heard on the left side of the chest. What cardiovascular defect is most likely?

Answer 1

Patent ductus arteriosus.

Question 2

While examining a Doberman, you hear a rapid, irregular heart rate with pulse deficits. This arrhythmia is most likely:

Answer 2

Atrial fibrillation.

Question 3

An owner reports that her Weimaraner puppy is regurgitating undigested food every time the puppy eats. The puppy is losing weight and is coughing. What abnormality might this puppy be exhibiting?

Answer 3

Persistent right aortic arch.

Question 4

What is the reference range for heart rate in the dog?

Answer 4

60-180 beats/min.

Question 5

What amino acid do cats require in their diet to avoid cardiomyopathy?

Answer 5

Taurine.

Question 6

An adult Boxer was anesthetized for a routine castration. The physical examination and pre-surgery blood work was all within normal limits. During anesthesia induction, the technician noticed occasional ventricular contractions on the monitoring ECG. The surgeon terminated the procedure, and the dog recovered without incident. Repeat ECG studies on the awake dog showed normal sinus rhythm. The dog was adopted and was doing well in his new home. As the owner came home one evening, the dog became exited and experienced cardiac arrest and died.

1. Why did this happen to the dog?
2. Is it likely to happen again to another Boxer?
3. What could have been done to prevent this from happening?

Answer 6

1. Boxer dogs can carry the gene for Familial Ventricular Arrhythmia and show no outward signs of disease until they die suddenly. This gene predisposes them to fatal arrhythmias which can result at any time during the life of the dog. This is a conduction disease and not a disease of the heart muscle.
2. Since the disease is genetic, if you were to obtain a dog from the same breeding line, you may get a dog with the problem. If pays to research gene lines and ask questions when buying a Boxer dog.
3. Holter heart monitoring over a 24 hour period may show signs of the disease. There is nothing that can prevent this from occurring. Investigate any seizure-like occurrence, any surgical arrhythmias, or fainting that occurs in Boxer dogs.