ANSWERS

Note that some of the questions in this section (those marked with an asterisk) are more advanced than required for the final V.N. exams. However, they are of interest to those already qualified, or studying for the Medical Diploma.

1. * State the approximate percentage of dogs that are affected by some form of heart disease during their life span.
   At least 11%.
2. List 10 signs which may be indicative of heart disease.
   • Lethargy.
   • Depression.
   • Variable appetite.
   • Exercise intolerance.
   • Respiratory distress/dyspnoea.
   • Coughing.
   • Collapse/syncope.
   • Ascites.
   • Weight loss.
   • Stunted growth in young animals.
3. List 6 techniques that may aid the diagnosis of a heart condition.
   • Mediate auscultation of the heart and lungs.
   • Measurement of pulse rate and depth.
   • Measurement of CRT & assessment of mucous membrane colour.
   • Echocardiograph (ECG) - a tracing of the electrical activity of the heart.
   • Radiography to assess the size and shape of the heart and the appearance of the lungs.
   • Ultrasound.
4. List and describe the common congenital heart defects seen in the dog and cat.
   • Patent ductus arteriosus (PDA) - The abnormal persistence of a duct between the aorta and pulmonary artery. Normally this duct closes shortly after birth, but if this does not occur, the left ventricle has to pump more blood than normal.
   • Pulmonic stenosis - A narrowing between the right ventricular outflow tract and the pulmonary artery. The resistance to blood flow means that the myocardium thickens.
   • Aortic stenosis - A fibrous, constricting ring develops at, above or beneath the aortic valve. The left ventricle hypertrophies in response to the resistance of blood flow.
   • Ventricular septal defect - The muscle/membrane separating the ventricles is incomplete. Blood flows from the left to the right ventricle due to the greater pressure in the left. The extra blood travels to the lungs and then back to the left side of the heart instead of to the body via the aorta and results in left sided failure.
   • Mitral and triscupid dysplasia - Deformity and incompetence of the valves that leads to regurgitation of blood and a systolic murmer.
   • Tetralogy of Fallot - A combination of pulmonary stenosis, interventricular septal defect, dextraposed aorta and hypertrophy of the right ventricular wall due to outflow resistance.
   • Persistent right aortic arch - Abnormal persistence of the right aortic arch instead of the left. This leads to ligamentum arteriosus lying across the dorsal part of the oesophagus while the remainder of the vascular ring around the oesophagus is formed by the pulmonary vein to the left, the aorta to the right and the heart base ventrally. The stricture interferes with swallowing and food becomes trapped in front of the vascular ring.
5. *What is the most common acquired cardiac abnormality in dogs?
   Chronic mitral valvular disease.
6. * What breed of dog is predisposed to mitral and triscupid dysplasia?
   The Golden Retriever.
7. * Name a common congenital heart defect in the dog?
   Patent ductus arteriosus (PDA).
8. * By what other name is chronic mitral valvular disease known?
   Endocardiosis.
9. List 6 dog breeds which are predisposed to chronic valvular disease.
   • Cavalier King Charles Spaniel.
   • Poodle.
   • Miniature Schnauzer.
   • Chihuahua.
   • Cocker Spaniel.
   • Dachshund.
10. What is endocarditis?
    Inflammation of the endocardium and heart valves; usually caused by bacterial infection.
11. What is an alternative name for myocardial disease?
    Cardiomyopathy.
12. What is the most common cause of heart failure in the cat?
    Hypertrophic cardiomyopathy.
13. Name the disease affecting the heart that is more common in dogs than in cats and is characterised by thinned heart muscle with loss of contractility.
    Dilated cardiomyopathy.
14. * Name 5 possible secondary causes of cardiomyopathy.
    • Malnutrition.
    • Taurine deficiency in cats.
    • Hyperthyroidism.
    • Hypertension.
    • Viral infection.
15. Which breed of dog is particularly susceptible to dilated cardiomyopathy?
    The Doberman.
16. Which breed of dog is predisposed to mitral insufficiency?
    The Cavalier King Charles Spaniel.
17. Name 5 countries in which heartworm is common.
    • America.
    • France (southern).
    • Spain.
    • Italy.
    • The Canary Islands.
18. List therapies that may be indicated in the treatment of heart disease.
    • Reduction of body weight if obese.
    • Low sodium diet.
    • Diuretics (to remove oedema and ascites).
    • Inotropes (to alter the force of contraction).
    • Vasodilators (to reduce valvular regurgitation and improve perfusion).
    • Antiarythmic agents.
19. List considerations to be taken into account when nursing an animal with a heart condition.
    • Keep the animal in a comfortable, warm, draught-free environment.
    • Restrict the amount of exercise.
    • Ensure that any drugs are given on schedule by the correct route, and that hospital records are kept updated.
    • Ensure that dogs are taken outside frequently if diuretics are being administered.
    • Avoid stress.
    • Monitor TPR regularly.
    • Oxygen therapy should be readily available in case of emergency.
    • Feed an appropriate diet.
20. Give 2 examples of prescription diets suitable for feeding to dogs with heart disease.
    • Hills Canine H/D.
    • Waltham Canine Low Sodium.
21. Describe the lead positioning when setting up for an ECG.
    • Red - right fore.
    • Yellow - left fore.
    • Green - left hind.
    • Black - right hind.
22. *What is the name of the serious tick-borne disease which destroys blood cells, affects only dogs and is particularly prevalent in France (especially south of the Loire valley)?
    Babesiosis.
23. State the 3 main causes of regenerative anaemia.
    • Acute haemorrhage.
    • Chronic haemorrhage.
    • Haemolysis.
24. List 5 common causes of acute haemorrhage.
    • Trauma.
    • Surgery.
    • Anticoagulant rodenticide ingestion.
    • Thrombocytopaenia.
    • Disseminated intravascular coagulation (DIC).
25. * Why will chronic external blood loss eventually cause iron deficiency anaemia?
    Due to the fact that the intestinal tract has a very limited capacity to increase iron absorption, even in the face of continuing iron losses.
26. State the 2 most common causes of iron deficiency anaemia.
    • Chronic bleeding from gastrointestinal neoplasms.
    • Chronic bleeding from gastrointestinal ulcers.
27. * What is the commonest cause of nontraumatic severe anaemia in the dog?
    Immune-mediated haemolytic anaemia (IMHA).
28. Give 2 examples of conditions that may cause oxidant damage to RBCs.
    • Ingestion of raw onions.
    • Paracetamol intoxication.
29. * Can you give 4 examples of factors outside of the bone marrow that can lead to the development of non-regenerative anaemia.
    • Chronic renal failure.
    • Hypoadrenocorticism.
    • Hypothyroidism.
    • Oestrogen toxicity.
30. What breed of dog is predisposed to von Willebrand's disease?
    Doberman.
31. What is the name given to the nuclear remnants that are present in increased numbers in strongly regenerative anaemia?
    Howell-Jolly bodies.
32. * What is the name given to the fragmented RBCs that are frequently found in animals suffering from haemangiosarcoma and DIC?
    Schistocytes.
33. * What is the name given to the spherical RBCs with a reduced diameter that are a frequent finding in IMHA?
    Spherocytes.