ANSWERS

1. Which hormone is produced in excess in Cushing's disease?
   Cortisol.
2. By what other name might Cushing's disease be known?
   Hyperadrenocoticism.
3. What is the name of the hormone that is released from the pituitary gland and is responsible for stimulating the production of cortisol from the adrenal glands?
   Adrenocorticotrophic releasing hormone (ACTH).
4. List 6 clinical signs of Cushing's disease.
   • Polyuria/polydipsia.
   • Alopecia/thin skin/comedomes (keratin and sebum plugs).
   • Lethargy.
   • Polyphagia.
   • Obesity.
   • Muscle weakness/atrophy.
5. *Would you expect the following haematology parameters to be raised or lowered in animals suffering from Cushing's disease: eosinophils, neutrophils and lymphocytes?
   • Eosinophils - lowered.
   • Neutrophils - raised.
   • Lymphocytes - lowered.
6. *Which biochemistry parameters might you expect to display abnormalities in an animal suffering from Cushing's disease?
   • ALP - raised.
   • ALT - raised.
   • Cholesterol - raised.
7. What is the name of the specific test used to diagnose Cushing's disease?
   ACTH stimulation test.
8. When taking blood for an ACTH stimulation test, a pre and post ACTH sample are required. How long following injection of ACTH should the second blood sample be taken?
   1-2 hours. Some vets may take the second sample at 30 minutes after administration.
9. If an animal has Cushing's disease, would you expect to see an increase or decrease in circulating cortisol following injection of ACTH?
   An increase (grossly exaggerated).
10. What therapy is required following bilateral adrenalectomy?
    Lifelong mineralocorticoid therapy.
11. What is the name of the cytotoxic drug used in the treatment of Cushing's disease?
    Trilostane.
12. In hypoadrenocorticism, insufficient cortisol and aldosterone are produced. By what other name might this disease be known?
    Addison's disease.
13. In which species and sex is Addison's disease most common?
    The bitch (usually large breeds).
14. By what name might acute Addison's be known?
    Addisonian crisis.
15. How do the symptoms of acute and chronic Addison's differ?
    The signs of chronic Addison's tend to be vague and non-specific whilst animals with acute Addison's will suffer from vomiting, anorexia, weakness, collapse and shock.
16. Why are Addisonian animals usually hyponatraemic and hyperkalaemic?
    Due to low aldosterone levels.
17. What is the name of the glucocorticoid supplement used in the treatment of Addison's disease?
    Dexamethasone.
18. What is the name of the mineralocorticoid supplement used in the treatment of Addison's disease?
    Fludrocortisone (Forineff).
19. List 12 clinical signs that may be evident in a hyperthyroid cat.
    • Weight loss.
    • Polyphagia.
    • Hyperactivity.
    • Restlessness/aggression.
    • Moderate elevation of body temperature.
    • Tachycardia (possibly with a variety of cardiac arrhythmias/murmers).
    • Increased frequency of defecation (abundant bulky stools passed).
    • Polyuria/polydipsia.
    • Occasional vomiting.
    • Panting.
    • Hyperaemia (reddening of the mucous membranes/skin).
    • Matted, greasy and unkempt coat.
20. What tests may be used to aid a diagnosis of feline hyperthyroidism?
    • Total T4.
    • Liver enzymes (usually raised in hyperthyroid animals).
    • ECG.
    • Palpation of the thyroid glands.
    • Mediate auscultation of the heart.
21. What is the name of the drug commonly used to treat hyperthyroidism in cats?
    Neo-Mercazole.
22. What biochemistry blood parameters must be measured for 3 days following thyroidectomy?
    • Calcium.
    • Phosphorous.
23. What drug is commonly used to treat hypothyroidism in dogs?
    Soloxine.
24. Name the 2 types of diabetes insipidus?
    • Central diabetes insipidus
    • Nephrogenic diabetes insipidus.
25. What is the name of the hormone that is deficient in cases of central DI?
    Antidiuretic hormone (ADH).
26. What are the most common signs of DI?
    Polyuria and polydipsia.
27. What urine specific gravity range would you expect to see in an animal suffering from DI?
    1.002 to 1.008.
28. What is the name of the specific test used to diagnose DI?
    Water deprivation test.
29. For how long must water be withheld during preparation for a water deprivation test?
    15 hours or if the patient loses more than 5% of their starting body weight.
30. A water deprivation test should not be performed if what blood biochemistry parameter is elevated?
    Blood urea.
31. *Describe how a water deprivation test is performed.
    • Preparation - starvation for 12 hours, water withheld for 15 hours.
    • Bladder emptied by catheterisation first thing in the morning.
    • Weight of the animal recorded.
    • Recatheterisation every 2-4 hours and measurement of urine SG and weight taken each time.
    • STOP when more than 5% of body weight lost or dehydration evident.
    • Perform ADH response test (if still no concentration - likely nephrogenic DI as the kidney is not responding to the ADH).
32. If urine becomes concentrated during a water deprivation test, what explanation could you give for the initial low SG?
    The animal is probably a compulsive drinker (perhaps related to stress).
33. *By what other name might compulsive drinking due to stress be known?
    Pyschogenic polydipsia.
34. What treatment might be used in cases of DI?
    Administration of ADH by injection or nasal drops (Desmopressin). Chlorothiazide diuretics and a low sodium diet may help).
35. Briefly describe the 2 types of diabetes mellitus.
    • Type 1 - Insulin dependent: insufficient insulin is secreted in response to hyperglycaemia.
    • Type 2 - Non-insulin dependent: Animals become resistant to the effects of insulin (common in man, rare in the dog but probably more common in the cat).
36. List the 4 main functions of insulin.
    • Slows down glucogenesis (glucose creation) in the liver.
    • Slows down glycogenolysis (breakdown of glycogen) in the liver.
    • Slows down lipid and protein catabolism.
    • Helps the cells to absorb glucose.
37. Which organ produces insulin?
    The pancreas.
38. What is often the first sign of DM?
    Polydipsia.
39. List 4 conditions that may precipitate DM.
    • Obesity.
    • Pancreatitis.
    • Oestrus.
    • Drugs (glucocorticoids and megoestrol acetate).
40. Why might an animal suffering from DM show hepatomegally?
    As a result of increased fat storage.
41. What condition of the eye is commonly seen in diabetic animals?
    Cataracts.
42. What causes ketotic breath?
    Acetone.
43. Why is regular insulin normally only used in the treatment of ketoacidotic dogs?
    It has a rapid onset (30 minutes).
44. What is the name of the insulin that has a maximum action of 14-20 hours and duration of 24-36 hours?
    PZI insulin.
45. Where should insulin be stored?
    The refrigerator.
46. List 3 signs of hypoglycaemia.
    • Muscle weakness.
    • Twitching/fitting.
    • Lethargy.
    • Recumbency.
47. What action should be taken in the case of hypoglycaemia?
    Initially, oral administration of Hypostop. If Hypostop is unavailable any sugary substance such as honey or jam may be substituted. If no improvement is observed within 30 minutes, intravenous dextrose fluids may be required. Insulin dosage will need to be decreased.
48. *Why do animals with ketoacidosis vomit?
    Due to excess ketones that stimulate the emetic centre of the brain.
49. Why are diabetic cats often more difficult to stabilise than dogs?
    • Collecting a urine sample may prove very difficult for owners.
    • Regulating food intake is often difficult in multicat households.
    • Exercise regulation is difficult in cats that have access to the outdoors.
    • Cats may resent injection more than dogs and may be more difficult to restrain.
50. List 5 possible causes of hyperglycaemia in a diabetic dog.
    • Inadequate dosage of insulin
    • Excessive food consumption.
    • Obesity.
    • Infection.
    • During the period following the season in bitches.
51. List 3 possible causes of hypoglycaemia in a diabetic dog.
    • Insulin overdose.
    • Lack of food.
    • Over-exercise.
52. Why should special care be taken when using Caninsulin?
    Caninsulin is administered with special syringes that have a different scale to the international units that are used with other types of insulin.
53. Give an example of a prescription diet suitable more feeding a diabetic dog of normal weight.
    Hills Canine W/D, or any other high fibre diet e.g. Chappie.