In this VETgirl online veterinary continuing education blog sponsored by Purina® Pro Plan® Veterinary Diets, Dr. Andrew Bugbee, DACVIM discusses how you can help improve the outcome of your diabetes mellitus feline patients. By focusing on factors that you as a veterinary professional can improve, you can improve this common feline endocrine disease! Please note the opinions in this blog are the expressed opinion of the author and not directly endorsed by VETgirl.
Improving Outcomes for Diabetic Cats: Focus on Factors that Can Be Controlled
By Dr. Andrew Bugbee, DACVIM, Associate Clinical Professor of Internal Medicine
Co-Founder/Director, UGA Veterinary Diabetes Clinic, College of Veterinary Medicine, University of Georgia
Diabetes mellitus in cats is a complex disease process, with plenty of challenging questions for clinicians:
• Why do some overweight cats develop diabetes and others don’t?
• How likely is a prediabetic cat to develop diabetes?
• What are the odds a diabetic cat can achieve remission—and maintain it?
While some factors associated with feline diabetes are beyond the control of veterinarians and owners, appropriate and timely actions can mitigate other factors and have an important and positive effect on patient outcomes.
Which cats draw the diabetes short straw?
“Obese cats” is typically the first answer that comes to mind, but there’s more to the development of diabetes in cats than simply being overweight. Adipose tissue is a metabolically active tissue that produces adipokines such as leptin that are linked to insulin resistance, as well as inflammatory mediators that perpetuate insulin resistance, leading to beta cell dysfunction, injury and loss. As beta cells are overworked and blood glucose remains increased, the cells effectively declare “I’m not getting paid enough for this,” and retire from insulin producing service. Once they retire, it’s hard to get them to come back to work and eventually they are permanently lost.
However, while being overweight is a significant risk factor for cats, being a fat cat is not the only dynamic in the pathogenesis of this complex condition. Feline diabetes is caused by the interaction of multiple factors over time. These include genetic predisposition, body weight/body condition, activity level and the presence of co-morbid conditions that collectively—and cumulatively—lead to insulin resistance. The more risk factors a cat has and/or the longer insulin resistance persists in a cat, the greater the likelihood that diabetes mellitus will develop. As a result, some fat cats get lucky and avert diabetes development, while some skinny cats develop diabetes as a complication of conditions such as pancreatitis.
Can I keep a prediabetic cat from developing diabetes?
Prediabetes is a state of hyperglycemia that occurs before overt diabetes develops. What’s key is to detect glucose intolerance early in the process of pancreatic beta cell dysfunction. These cats tend to run slightly more hyperglycemic than healthy cats and may have more profound hyperglycemic responses to meals or a true glucose challenge. While the exact number suggesting a prediabetic state in cats varies from study to study, recent research suggests that a senior cat with a persistent fasted glucose concentration above 189 mg/dL should be considered prediabetic.
Detecting a prediabetic state in a cat, however, may be easier said than done, due to the stress hyperglycemic response encountered in cats, especially when they are being evaluated in the veterinary hospital. A single glucose measurement, especially in a stressed cat, may not be helpful in determining if prediabetes is present. This response can occur within a matter of seconds when cats become stressed by their surroundings, and it can be difficult to get cats to calm down for several hours in the hospital environment in order take several repeated samples.
A better alternative is to periodically monitor the cat at home by training owners to use a glucometer to screen blood glucose. Rather than asking the owner to purchase a glucometer, veterinarians can send one home from the clinic.
Once a clinician diagnoses a patient with prediabetes, the two most important steps that can help prevent overt diabetes from developing are (1) implementing a weight-loss program if the patient is overweight; and (2) transitioning the cat to a high-protein/low-carbohydrate diabetic diet. Dietary therapy alone is possible at this point. If the owner needs an incentive to commit to their cat’s diet change, the veterinarian can stress that feeding a diet to manage cats with diabetes now might keep them from having to inject insulin twice a day down the road.
Can diabetic cats achieve remission—and retain it?
Imagine that your client has been told her cat has diabetes. She researches the condition online and learns that diabetes remission rates in cats can range from 8% to 100%, depending on which study is cited. What the owner may not realize is that if her cat has developed diabetes over time due to insulin resistance, the odds of remission are much lower than if the cat had developed diabetes secondary to something like steroid therapy. For natural disease in the United States, a more realistic percentage of cats that can achieve remission is 26-30%, based on reports from feline practitioners and veterinary endocrinologists. Factors that improve the likelihood that patients can achieve remission include the following:
• Absence of concurrent conditions, such as kidney disease, especially advanced kidney disease. Both diabetes and renal disease tend to occur in older cats, and concurrent disease can complicate patient management. High-protein, low-carbohydrate diabetic diets are inappropriate for patients with advanced kidney disease; in such cases, the clinician typically needs to feed the cat a renal diet and rely on insulin injections to manage the diabetes.
• Weight management. Achieving and maintaining an ideal body weight increases the odds of achieving remission. A high-protein, low-carbohydrate diet, coupled with appropriate caloric intake, is the best nutritional strategy.
• Exercise and activity. Owners may initially scoff at the idea of exercising their cats, but it’s important to remember that incorporating activity into the cat’s day doesn’t have to involve enormous lifestyles changes. Little things, like moving food and water bowls—perhaps to different floors in the house—will get the cat moving a little more. Spending just 10 minutes a day engaging the cat in play, whether the cat is chasing a laser pointer or a fluffy ball, is something most owners can do, and it can have an important and beneficial impact on the cat.
Unfortunately, remission isn’t always permanent, and cats may relapse within a year or two of discontinuing insulin injections. In such cases, a second remission is possible to achieve but is less likely.
The bottom line: While we as clinicians can neither control every factor involved in the development of feline diabetes nor some of the complications that ensue, there is much we can control through identification of prediabetic cats, weight management and dietary therapy.