Page 320 - Problem-Based Feline Medicine

312 PART 6 CAT WITH WEIGHT LOSS OR CHRONIC ILLNESS

hyperglycemia is stress-induced. Alternately, the owner calorie intake to no more than 75% of maintenance
can be asked to test the cat’s urine for the presence of requirements and monitoring for changes in insulin
glucose when it is at home. requirement. Aim for no more than 2% weight loss per
week.
Assessing serum fructosamine or glycosylated hemo-
globin concentrations will give an indication of how Dietary modification – all cats with diabetes benefit
high the blood glucose concentration has been during from being fed a well-balanced diet on a regular, con-
the preceding 2–3 weeks, and 1–2 months, respectively. sistent, feeding schedule.
● Obese cats may benefit from being fed a low-calorie,
Many cats with diabetes have mild to moderate
high-fiber diet to help them lose weight. However,
increases in serum concentrations of cholesterol and
a low-carbohydrate, high-protein diet may be more
liver enzymes. However, more severe changes such as
beneficial to minimize demand for insulin secretion
bilirubinemia, acidemia, uremia and electrolyte disor-
and minimize post-prandial hyperglycemia.
ders are unlikely to be present in a cat that is maintain-
● Non-obese cats benefit from being fed a low-car-
ing a good appetite, that is, a cat with uncomplicated
bohydrate, high-protein diet. The choice of diet
diabetes.
may be affected by concurrent illness, especially
Ketones may or may not be present in the urine. Their renal disease.
presence further confirms the diagnosis of diabetes. By ● Regular feeding is essential. Cats on once-daily
the time a cat has developed diabetic ketoacidosis it is insulin are usually fed just before their morning
unlikely to be maintaining a good appetite (see page 355, insulin, then again in the early evening. Cats on
The Thin, Inappetent Cat). twice daily insulin are usually fed just before both
insulin injections. Free-choice feeding can be bene-
ficial, but it is important to monitor the amount of
Differential diagnosis food eaten on a daily basis.
These include most of the other causes of weight loss Oral hypoglycemic agents act to increase insulin
with a good appetite. However, since cats with diabetes secretion, decrease peripheral insulin resistance, and/or
develop polyuria and polydipsia, hyperthyroidism and decrease absorption of glucose from the intestinal tract.
renal disease (particularly protein-losing nephropathies) They may successfully control some non-ketotic,
should be considered as important differentials, as should uncomplicated diabetic cats, either temporarily or
underlying causes of diabetes, such as acromegaly and longer term, particularly when given in conjunction
hyperadrenocorticism. with dietary modification. There are several different
types of drugs that have been shown to be at least some-
what effective in cats.
Treatment
● Sulfonylureas, e.g. glipizide (0.25 mg/kg PO q
Treatment consists of various combinations of 8–12 h, adjust dose as needed). Side effects include
weight loss, dietary modification, oral hypoglycemic vomiting, anorexia and hepatopathy. Periodic
agents and insulin administration. checks for serum biochemistry and hematology are
● While the signs of diabetes in obese cats may recommended. It may take a few weeks of medicat-
resolve with dietary modification alone, most cats ing to see the full effect of the drug.
need at least temporary medical intervention. ● Alpha-glucosidase inhibitors, e.g. ararbose
● Oral hypoglycemic agents may be successfully (12.5–25 mg/cat with meals). Side effects include
used in some cases of uncomplicated diabetes, or flatulence, soft feces and diarrhea.
once glucose toxicity has resolved following insulin ● Transition metals, e.g. vanadium (0.2 mg/kg/day
therapy. in food). Side effects include anorexia, vomiting,
● Insulin is required for most diabetics, at least ini- diarrhea and renal disease; chromium (200
tially. μg/cat/day PO). Side effects are unknown.
Obese cats usually benefit from weight loss. Insulin: There are a number of different types of insulin,
However, this should be done very gradually, restricting and the choice is often based on personal preference.