Monday, June 22, 2015

Managing diabetes in cats: new ISFM consensus guidelines

Being plus-sized predisposes cats to diabetes mellitus.
The International Society for Feline Medicine (ISFM) has just released guidelines on management of diabetes mellitus in cats, published in the Journal of Feline Medicine andSurgery.

The full text document is available for free and if you are an owner of a diabetic cat, or a veterinarian or student, these are worth downloading and reading in full.

Like all consensus statements this was put together by a panel of specialists who review the available literature and make recommendations based on current knowledge. Therefore the recommendations may change as further evidence becomes available. But these are definitely very helpful guidelines for those who need to make decisions around the management of diabetic cats.
Feline diabetes is on the rise, possibly due to an increase in the incidence of obesity, which is likely a result of ad lib access to premium diets and reduced outdoor access without associated reduction in calories.

The average age of survival of a diabetic cat is 13-29 months after diagnosis, however they tend to live longer if their diabetes is well controlled. I have certainly treated some cats that have lived for five years and over with diabetes.

Most cats with diabetes have a type of diabetes similar to type 2 diabetes mellitus (DM) in humans = due to pancreatic beta cell dysfunction and insulin resistance (fat increases insulin resistance, hence obesity is a factor). Aside from obesity, other risk factors include: being over 7 years old, being Burmese, being indoors and inactive, being male and desexed, and being on drugs that impact insulin metabolism, e.g. corticosteroids.

Living solely indoors, being a dude, being desexed and being Burmese are all potential risk factors for developing diabetes mellitus - but of course these risk factors can be managed by providing an appropriate diet, opportunities for activity and play.
The classic clinical signs of diabetes are polyuria (urinating a lot), polydipsia (drinking a lot), polyphagia (eating a lot), fatigue, and weight loss. Some cats also appear weak, wobbly or flat, and those with diabetic ketoacidosis or pancreatitis – or other concurrent disease like renal disease or hyperthyroidism - may be inappetent and vomiting.

Diagnosis is based on persistent high blood and high urine glucose (hyperglycaemia and glucosuria respectively). But the panel recommend performing a complete physical examination, complete blood count, serum biochemistry panel, serum fructosamine (this gives an indication of the average blood glucose over the previous week), serum thyroxine concentration and feline pancreatic lipase tests due to the high prevalence of concurrent disease like hyperthyroidism and pancreatitis (your pancreas is where those insulin producing beta cells live so it’s important in the aetiology of DM).

According to the panel, there are two key aims of treating cats with insulin:
  • To control blood glucose by keeping it under 14mmol/L (252mg/dl for our Northern hemisphere counterparts) for as much of a 24 hour period as possible;
  • To avoid clinically significant hypoglycaemia as this can be life-threatening.

Currently there is very little evidence supporting the use of oral hypoglycaemic agents to treat DM in cats. Use of a long-acting (e.g. glargine or detemir) injectable insulin is preferred. Two daily injections twelve hours apart may be very hard for owners to comply with. While this is ideal, the panel recommend allowing some flexibility with doses given 12 hrs +/- 2 hours apart, and missing doses outside of this window if occasional.

The guidelines go into detail on initial and long-term management of cats with DM, but one of the things strongly recommended is home monitoring of cats. While previously there have been mixed reports about home blood glucose monitoring, the panel supports this, along with assessment of daily wellbeing, daily water intake, daily urine production, weekly body weight and body condition score, urine glucose (using urine dipsticks) and where possible blood glucose.

They also recommend very regular in clinic monitoring. After initial diagnosis, 
cats should be re-evaluated in weeks 1,2-3, 6-8, 10-12 and 14-16 and then every 1-4 months (a good reason to invest in pet insurance).

There are now excellent resources for cat owners that can aid in monitoring diabetics via the iCatCare YouTube channel, so you can check out these very helpful links below.





Reference

Sparkes AH, Cannon M, Church D, Fleeman L, Harvey A, Hoenig M, Peterson ME, Reusch CE, Taylor S & Rosenberg D (2015) ISFM consensus guidelines on the practical management of diabetes mellitus in cats. Journal of Feline Medicine and Surgery 17(3):235-50. Doi: 10.1177/1098612X15571880