Page 129 - Clinical Small Animal Internal Medicine

12 Diabetes Mellitus in Dogs and Cats 97

Fructosamine is most often normal in cats with stress Short‐acting insulins are generally used in hospital for
VetBooks.ir hyperglycemia, but elevated in diabetic cats that have intensive blood glucose control, while intermediate‐
and long‐acting insulins are used both in hospital and at
been markedly hyperglycemic (>360 mg/dL; 20 mmol/L)
for at least 3–5 days. However, a normal fructosamine
protein source, insulins are human, human analog (syn-
concentration does not rule out prediabetes or diabetes home for long‐term, daily glycemic control. Based on
associated with more moderate hyperglycemia, whereas thetic insulin that is altered from the natural form but
Hb1c appears more sensitive. Home blood glucose mon- retains biological function), bovine, or porcine. Porcine
itoring with a meter calibrated for feline blood may also and canine insulin have an identical amino acid
assist in identifying prediabetic cats with persistent mild sequence, while bovine and feline insulin differ by just
elevation of glucose (>117–162 mg/dL; 6.5–9 mmol/L). one amino acid.
A typical work‐up for dogs or cats with suspected Traditionally, veterinarians have managed canine and
diabetes mellitus will include a complete blood count, feline diabetes with a variety of veterinary or human
chemistry profile with electrolytes, urinalysis, and urine insulins (Table 12.2). Veterinary insulins include porcine
culture via sterile collection. Some veterinarians rou- lente (Vetsulin/Caninsulin®, Merck), and protamine zinc
tinely use fructosamine or, less commonly, glycated human recombinant insulin (ProZinc®, Boehringer
hemoglobin to document persistent hyperglycemia. Ingelheim Vetmedica). Human insulins or insulin ana-
In dogs, if hypothyroidism or hyperadrenocorticism is logs include human‐origin lente (no longer available),
suspected, it is best tested after diabetes is regulated, neutral protamine Hagedorn (isophane, NPH, various
because of the effect of poorly regulated diabetes on manufacturers), glargine (Lantus®, Sanofi‐Aventis),
interpretation of tests. In intact female dogs, measure- detemir (Levemir®, Novo Nordisk), glargine 300 U/mL
ment of serum progesterone may also be helpful; elevated (Toujeo, Sanofi-Aventis) and degludec (Tresiba®, Novo
progesterone levels in diestrus or pregnancy increase Nordisk). Premixed combinations of short‐acting lispro
secretion of growth hormone, a counterregulatory hor- (Eli Lilly) or aspart (Novo Nordisk) insulin with longer‐
mone, leading to insulin resistance. In cats, a total T4 acting protamine insulin are also available as intermedi-
and feline leukemia virus/feline immunodeficiency virus ate‐acting insulins (Humalog® Mix 75/25 and Novolog®
(FeLV/FIV) test is warranted. Middle‐aged to older cats 70/30, respectively).
with polyuria/polydipsia, polyphagia, and weight loss The goals of treatment in canine diabetes include
should be screened for diabetes mellitus and hyperthy- resolution of polyuria, polydipsia and abnormal body
roidism, as the diseases cause similar clinical signs, and condition, while avoiding clinical hypoglycemia, dia-
may occur concurrently. For patients with atypical or betic ketoacidosis, urinary tract infections, and other
additional clinical signs, consider a thyroid panel (total or complications through excellent glycemic control. In
free T4 and thyroid‐stimulating hormone), insulin like dogs, American Animal Hospital Association guide-
growth factor (IGF-1), trypsinogen‐like immunoreactivity lines recommend the use of porcine lente, PZI, or NPH
(TLI), pancreatic lipase immunoassay (PLI), cobalamin insulins, and a complete and balanced diet that lacks
and folate, adrenal function testing, thoracic and abdomi- simple carbohydrates.
nal radiographs, and abdominal ultrasound as indicated A stable routine for meals, snacks, and exercise is cru-
based on the patient’s history and clinical exam findings. cial for good glycemic control; frequent changes in type
Cats with diabetes and blood glucose above the renal of food or amount fed should be avoided (Box 12.1). The
threshold have weight loss, and cats with a stable weight best diet for diabetic dogs is yet to be determined. Diets
or weight gain should be tested for acromegaly. If IGF-1 recommended include high‐fiber/restricted‐fat diets,
is in the normal range, but clinical signs are consistent which as a consequence are high in carbohydrate (>45%),
with acromegaly, test again after 6 weeks of insulin and diets with moderate fiber and restricted carbohy-
therapy. drate (<30% metabolizable energy [ME]), which as a
consequence are higher in fat and protein. High‐fiber
diets may help to delay glucose absorption from the
Therapy gastrointestinal tract and reduce postprandial hypergly-
cemia. A number of prescription canine diabetic diets
Nearly all veterinary patients with diabetes mellitus are are available with increased fiber, although most have
managed with a combination of insulin therapy, diet, and carbohydrate levels >45% ME. If used with NPH insulin,
weight management. these high‐fiber diets may exacerbate postprandial
Human and veterinary insulins are categorized both hyperglycemia in some dogs, because peak gastrointesti-
by onset and duration of action, and by protein source. nal glucose absorption occurs after peak insulin action,
Based on onset and duration of action, insulins are and in these cases are better fed 1–2 hours after insulin
short acting, intermediate acting, and long acting. administration. High‐fiber/moderate‐fat diets may cause