Canine and Feline Diabetes Mellitus: Nature or Nurture?

There is evidence for the role of genetic and environmental factors in feline and canine diabetes. Type 2 diabetes is the most common form of diabetes in cats. Evidence for genetic factors in feline diabetes includes the overrepresentation of Burmese cats with diabetes. Environmental risk factors in domestic or Burmese cats include advancing age, obesity, male gender, neutering, drug treatment, physical inactivity, and indoor confinement. High-carbohydrate diets increase blood glucose and insulin levels and may predispose cats to obesity and diabetes. Low-carbohydrate, high-protein diets may help prevent diabetes in cats at risk such as obese cats or lean cats with underlying low insulin sensitivity. Evidence exists for a genetic basis and altered immune response in the pathogenesis of canine diabetes. Seasonal effects on the incidence of diagnosis indicate that there are environmental influences on disease progression. At least 50% of diabetic dogs have type 1 diabetes based on present evidence of immune destruction of P-cells. Epidemiological factors closely match those of the latent autoimmune diabetes of adults form of human type 1 diabetes. Extensive pancreatic damage, likely from chronic pancreatitis, causes similar to28% of canine diabetes cases. Environmental factors such as feeding of high-fat diets are potentially associated with pancreatitis and likely play a role in the development of pancreatitis in diabetic dogs. There are no published data showing that overt type 2 diabetes occurs in dogs or that obesity is a risk factor for canine diabetes. Diabetes diagnosed in a bitch during either pregnancy or diestrus is comparable to human gestational diabetes.

Hereditary pancreatitis in a family of Aboriginal descent

Hereditary pancreatitis is an autosomal dominant condition characterized by recurrent episodes of acute pancreatitis, usually starting in childhood. We present a family who was ascertained when an 11-year-old girl presented with an episode of acute pancreatitis. Her father and other family members had also had recurrent bouts of acute pancreatitis. Genetic testing revealed a pathogenic mutation in the cationic trypsinogen gene in the proband, her father and her paternal grandmother. As far as we are aware, this is the first Aboriginal kindred with mutation-proven hereditary pancreatitis. Hereditary pancreatitis is an important differential diagnosis to consider in a patient with recurrent episodes of acute pancreatitis with no obvious precipitating cause. This family is of Aboriginal descent and the implications of the family's background are also discussed when considering the aetiology of the condition. We emphasize the need to ascertain a full family history from patients with a history of repeated episodes of acute pancreatitis and also emphasize the need to avoid ethnic stereotypes when assessing patients.

Molecular subtyping of feline immunodeficiency virus from domestic cats in Australia

Objective To determine the prevalent subtypes of feline immunodeficiency virus (FIV) present in the domestic cat population of Australia. Method Blood samples were collected from 41 FIV antibody positive cats from four cities across Australia. Following DNA extraction, polymerase chain reaction (PCR) was performed to amplify the variable V3-V5 region of the envelope (env) gene. Genotypes were assessed by direct sequencing of PCR products and comparison with previously reported FIV sequences. Phylogenetic analysis allowed classification of the Australian sequences into the appropriate subtype. Results Of the 41 FIV samples, 40 were found to cluster with previously reported subtype A isolates, whilst the remaining sample grouped within subtype B. Conclusions Subtype A was found to be the predominant FIV subtype present in Australia, although subtype B was also found. These results broaden our knowledge of the genetic diversity of FIV and the associated implications for preventative, diagnostic and therapeutic approaches.

Phylogenetic analysis to define feline immunodeficiency virus subtypes in 31 domestic cats in South Africa

Feline immunodeficiency virus (FIV), a lentivirus, is an important pathogen of domestic cats around the world and has many similarities to human immunodeficiency virus (HIV). A characteristic of these lentiviruses is their extensive genetic diversity which has been an obstacle in the development of successful vaccines. Of the FIV genes, the envelope gene is the most variable and sequence differences in a portion of this gene have been used to define 5 FIV subtypes (A, B, C, D and E). In this study, the proviral DNA sequence of the V3-V5 region of the envelope gene was determined in blood samples from 31 FIV positive cats from 4 different regions of South Africa. Phylogenetic analysis demonstrated the presence of both subtypes A and C, with subtype A predominating. These findings contribute to the understanding of the genetic diversity of FIV

Feline obesity: causes, consequences and management

Regulation of food intake and body weight involves a complex balance between long-term control of fat mass involving insulin, adrenal steroids and leptin signals to the CNS and short-term, meal-related signals. Cats will normally limit their food intake to their energy requirements. However, in some instances cats appear unable to regulate energy balance. Our research has demonstrated that despite elevated circulating leptin levels in obese cats associated with increased fat mass, they continue to overeat and gain weight. This paradox of increased leptin concentrations in obesity has been observed in other species and is hypothesized to be a consequence of 'leptin resistance'.