Page 207 - ONLINE PROCEEDING BOOK WSAVA 2017
P. 207

WSVA7-0450
INTERNAL MEDICINE II
FELINE DIABETES - CAUSES AND HOW THEY AFFECT MANAGEMENT CHOICES
J. Rand1,2
diabetes is over-represented in Burmese cats in Australia, New Zealand, and the United Kingdom. The frequency of diabetes in Burmese cats is approximately 4 times higher than that of Domestic cats in Australia.
Age
Increasing age is also a risk factor for type 2 diabetes. Most cats are older than 8 years of age when diagnosed, with a peak incidence between 10 and 13 years of
age. Although 1 in 50 Burmese cats have diabetes, this increases to 1 in 10 for Burmese cats 8 years or older.
Obesity and physical inactivity
Environmental or lifestyle factors shown to be important in humans and probably in cats, include obesity, physical inactivity, dietary factors, and urban rather than rural residence. Exclusively indoor cats are usually less active than outdoor cats that hunt and defend territory. In humans and rats, exercise increases insulin sensitivity. Lack of exercise impairs insulin action, and adds to
the underlying level of genetically-determined insulin resistance.
Obesity associated with insulin resistance is an important risk factor in the development of type 2 diabetes in humans and cats. In a study where cats were allowed free-access to a highly palatable energy dense diet over 10 months and increased their bodyweight by 44%, their insulin sensitivity decreased by more than half. Following weight gain 25% of these cats had insulin sensitivity values within the range reported for diabetic cats.
Diet and type 2 diabetes
Overfeeding of highly palatable, calorie-dense food in cats with reduced physical activity, likely contributes to obesity, and hence diabetes. Recent evidence in cats suggests that a high carbohydrate diet increases the demand for insulin secretion when compared to
a low carbohydrate, high protein diet. In susceptible cats, this long-term demand for increased insulin secretion may lead to beta cell apoptosis and a decline is insulin secretory capacity, precipitating impaired glucose tolerance and diabetes, as hypothesized by the Carnivore Connection Theory. Ad libitum feeding of cats is not recommended except in the few cats which self-regulate food intake and maintain an ideal body condition.
Amyloid
Many, but not all cats and humans with diabetes, have amyloid deposition replacing islets cells. Amyloid deposition does not appear to be an essential component of type 2 diabetes in either species, but
is associated with beta cell loss and failure of insulin secretion.
Strong evidence for a genetic basis for the disease comes from the higher incidence of diabetes within some families of cats and ethnic groups of people. In humans, multiple genes are likely to be involved in predisposition to type 2 diabetes; genes controlling insulin secretion and action, and genes in uencing factors such as propensity to obesity.
Breed is also a risk factor in cats. The incidence of
An Urban Experience
1School of Veterinary Science, University of Queensland, Queensland, Australia
2Australian Pet Welfare Foundation, Brisbane, Australia
PATHOGENESIS OF FELINE DIABETES MELLITUS
Jacquie Rand BVSc, DVSc, MACVS, Dip ACVIM
Emeritus Professor Jacquie Rand BVSc, DVSc, MACVS, Dip ACVIM;
The University of Queensland, Brisbane Australia Executive Director, Australian Pet Welfare Foundation
Classi cation
Type 1 diabetes is uncommon in cats based on histological studies and absence of islet cell antibodies
Type 2 diabetes is the most common form of diabetes
in cats, based on islet histology, risk factors, and clinical behavior of the disease. Type 2 diabetes is characterised by inadequate insulin secretion and impaired insulin action (insulin resistance).
A substantial minority of diabetic cats have other speci c types of diabetes and include diseases causing insulin resistance, and those resulting from non- speci c destruction of pancreatic tissue. These include pancreatic adenocarcinoma, pancreatitis, acromegaly, and hyperadrenocorticism. Iatrogenic administration of megestrol acetate or long-acting steroids is associated with diabetes in cats.
Type 2 diabetes
In Type 2 diabetes insulin resistance is associated with genotype, obesity, physical inactivity, and some drugs.
Insulin resistance and obesity
Obesity causes insulin resistance and is a risk factor for the development of diabetes in cats, although not all cats with type 2 diabetes are overweight.
Genetics of type 2 diabetes
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