Canine Diabetes Mellitus

Question 1

How does diestrus/ pregnancy lead to diabetes mellitus in the dogs?

Answer 1

there is increased progesterone secretion –> stimulate growth hormone secretion from the mammary glands
- both progesterone and growth hormone antagonize the action of insulin

Question 2

What’s the main concern with insulin deficiency?

Answer 2

• lack of utilization of glucose, amino acids, and fatty acids in the blood stream
• leading to hepatic gluconeogenesis and glycogenolysis
• breakdown of muscles for amino acids –> hepatic gluconeogenesis
• breakdown of fat for fatty acids –> transported to liver for beta oxidation –> Acetyl CoA –> too much –> converted to ketone –> ketoacidosis

Question 3

How does diabetes lead to PU/PD?

Answer 3

Too much glucose in circulation –> exceeds renal capacity for resorption –> excreted in urine –> hyperosmolar, increases water excretion –> stimulates thirst

Question 4

How does diabetes lead to polyphagia?

Answer 4

Inability to use glucose, tissue catabolism, and some caloric loss from glycosuria = polyphagia

Question 5

How does diabetes mellitus lead to hyperlipemia and hepatic lipidosis?

Answer 5

The increased amount of fatty acid that goes to the liver –> more very low density lipoprotein and triglycerides made –> hyperlipemia and hepatic lipidosis

Question 6

what are some of the most common presenting complaints for dogs with diabetes mellitus?

Answer 6

• PU
• PP
• weight loss
• sudden blindness (cataracts)
• ravenous appetite
• signs of DKA: lethargy, anorexia, vomiting, weakness

Question 7

What are some diet recommendations for dogs with diabetes mellitus?

Answer 7

If not underweight, high fiber diets –> watch for constipation, flatulence, increased frequency, and watery poop
- diet should NOT have significant amounts of simple sugars
- aim for low-fiber, high caloric density

Question 8

Why is exercise good for dogs with diabetes mellitus?

Answer 8

• it can help insulin distribution
• upregulates insulin transporters (esp GLUT4)
• obesity can have insulin resistance effects
• exercise should be consistent
• can decrease insulin dose if sporadic strenuous activity is going to happen

Question 9

What are some examples of the different types of insulin used in diabetic dogs?

Answer 9

• usually start with intermediate acting insulins (0.25U/kg SQ BID)
• ex. lente, human recombinant (NPH)
• the long acting ones will start with a lower dose (0.1U/kg BID)
• ex. glargine (pH is important, do NOT dilute, Detemir (can be diluted), PZI (human recombinant)

Question 10

What are some common concurrent illness that can contribute to insulin resistance?

Answer 10

other endocrine issues:
- Cushing’s
- hypothyroidism
- chronic pancreatitis
- diestrus
- CKD
other drugs:
- glucocorticoids
- progesterone

Neoplasia

Infection
- oral
- UTI

Question 11

What’s the pathogenesis of diabetic cataracts?

Answer 11

glucose is metabolized to sorbitol and glactitol. Increased levels of them in the lens –> hyperosmolar –> influx of fluids –> swelling –> ruptured lens fiber –> cataracts

Question 12

What kind of neuropathy is more typical of canine diabetes mellitus?

Answer 12

distal polyneuropathy
- weakness, muscle atrophy, hyporeflexia, hypotonia

Question 13

What’s the most common form of diabetes in the dog?

Answer 13

type 1

Question 14

Should treatment of diabetic dogs aim for normal or near normal blood glucose level?

Answer 14

Not recommended (it is in cats thought)

Question 15

What is the treatment goal for diabetic dogs?

Answer 15

resolution/ improvement of clinical signs
- PU
- stable/ acceptable body weight
- normal social interactions