In at least one regard, cats have been great at following the lead of humans, only to suffer unwanted consequences.
As with humans, increasing numbers of cats are living with the effects of diabetes. In many cases, the root cause is all too familiar–advancing years and a sedentary lifestyle, which fosters weight gain and, eventually, obesity.
For people and for cats, “This body condition predisposes to diabetes,” says Margie Scherk, DVM, Dipl. ABVP (feline), founder of Cats Only Veterinary Clinic in Vancouver, British Columbia, and immediate past president of the American Assn. of Feline Practitioners.
The good news? Feline diabetes can be highly manageable and need not shorten Kitty’s life.
Be consistent with treatment and diet, as well as attentive to the cat’s blood glucose curves and frutosamine values, Dr. Scherk advises colleagues and clients alike.
“We will get your kitty’s condition stabilized over two to three months,” she tells cat owners. “Be patient, because it does take some time.”
Scherk says her 2,500-client practice sees about three new diabetic cats a month, and it’s common for clients to be fearful and a bit overwhelmed about what lies ahead.
“They’re concerned about the unknown costs associated with the ongoing condition,” she says. “They want to be reassured that they CAN do this and that their kitty will feel better.”
Insulin choices available to veterinarians have fluctuated recently. In April, Idexx Laboratories announced it was discontinuing production of its PZI VET (Protamine Zinc Insulin) product. PZI was derived from bovine and porcine pancreatic glands, and the company says it had exhausted its supply of the raw material.
At the same time, Intervet’s Vetsulin product (porcine insulin zinc suspension) recently has been licensed for feline use in the United States.
"Vetsulin is a lente insulin of porcine origin. As an intermediate insulin, most cats will need BID therapy,” says Holly Brianceau, DVM, a technical services specialist with Intervet/Schering-Plough who consults with practitioners on diabetes treatment.
Previously, it was thought that porcine-derived insulin was better for dogs and bovine-derived better for cats.
“We need to retrain on that,” Dr. Brianceau says.
"Pork insulin is identical to canine insulin, and bovine insulin differs from feline insulin by one amino acid. While differences in amino acid sequencing can cause anti-insulin antibody formation in dogs and potentially lead to insulin resistance, anti-insulin antibodies are rare in cats despite the three amino acid difference between porcine and feline insulin."
For more than 15 years, Vetsulin has been used with success internationally (under the name Caninsulin) for managing feline diabetes, Brianceau adds. Scherk has used Caninsulin in her Canadian feline practice for 10 years, “So I have a great degree of comfort through experience with it.”
Another option is Lantus (glargine), a human insulin that is also widely available.
“The key point is that whatever insulin is used, the correct syringes must be used to match the insulin concentration,” Scherk says. "Vetsulin requires U40 syringes, Lantus (glargine) a U100 syringe. Use of the wrong syringe can result in potentially fatal mistakes.”
For clients, the fear of giving injections twice a day is a hurdle practitioners often have to help them clear. With consistent support, clients usually gain confidence quickly, Scherk says.
“Once they get through the first few weeks, they start to feel proud of their new-found skills,” she adds.
To help foster that confidence, Scherk says she and her colleagues stage their teaching. They also recommend support-group websites such as Felinediabetes.com, Petdiabetes.org and Sugarcats.com.
Once a diagnosis of feline diabetes is made and confirmed by a fructosamine test, Scherk sets up a consultation-demonstration appointment for the client to come in without his or her cat. She explains the condition, how insulin works, dietary requirements and introduces the client to blood glucose curves. The first curve is scheduled for 10 to 14 days later.
Then a nurse or technician teaches the client how to handle insulin, how to draw it into a syringe and, using saline and one of the clinic cats, how to give an injection.
The client also learns how to fill out diary sheets that further empower him or her to be a partner in the cat’s care. Clients are asked to record the date, time and dose of insulin, the amount the cat ate and drank as well as the number of urine clumps produced. They also chart the character of the stool, the cat’s activity level and any other comments they want to include.
“This first session is really about establishing a relationship,” Scherk says.
For the next few days, someone from the clinic calls daily “to be sure things are going well or, if there are any problems, to nip them in the bud,” Scherk adds.
The client brings the completed diary sheets to the next appointment, when a blood glucose curve is taken as soon as the cat comes in, with curves repeated every hour. At discharge, any changes to the insulin dose are discussed and the client is taught how to do ear pricks to measure blood glucose at home.
“I want them to check BG every time they give insulin–not for dose adjustment but so they gradually learn how to do this themselves and so at the very least they know how to check BG if the cat seems ‘off,’” Scherk says.
“We also emphasize to the client how proud they should be for what they’re accomplishing.”
Ten to 14 days later, at the next in-office blood glucose curve, fructosamine also is checked and the client is encouraged to perform the next curve at home on a day off about 10 days later. Thereafter, the client faxes or e-mails curve results to the office, and Scherk makes adjustments based on those values and the client’s observations.
If things go well, Scherk sees the cat in two months and four to six months thereafter. As signs of improvement appear–energy increases as urine output and water intake wane–“Clients feel they’re being successful, and their confidence grows,” Scherk says.
Likewise, practitioners should be confident they have the tools and knowledge to effectively manage feline diabetes, she adds.
“The most common mistake is trying to avoid using insulin,” Scherk says. “As long as Kitty is lacking insulin, he or she is at risk for glucose toxicity as well as exhaustion of the pancreatic beta islet cells.
Scherk and other veterinarians say that in the past five years, there have been a number of changes in the way feline diabetes is managed. For instance, these days there’s a greater emphasis on diets lower in carbohydrates rather than higher in fiber.
“We recommend a high-protein, low-carb diet,” says Brianceau. “It’s important to understand that as obligate carnivores, cats have very different needs from those of dogs.”
In addition, fewer veterinarians are recommending the use of oral hypoglycemics for cats, Scherk says. “They’re getting on with insulin, and this has helped with treatment, as there is no evidence for oral hypoglycemics working well in cats.”
“Diet in conjunction with earlier insulin treatment has resulted in more cats being better controlled than was previously the case,” Scherk notes.
"Intervet offers supportive tools for veterinarians to use when regulating diabetic patients, Brianceau says. “Our website, www.vetsulin.com, provides information for both veterinarians and pet owners."