Nutrition for the diabetic cat

Introduction

Diabetes mellitus is probably the most common feline endocrinopathy, with type 2 diabetes being much more frequently encountered than type 1, being diagnosed in up to 95% of diabetic cats. Each new feline patient that presents with diabetes is a challenge for both the veterinarian and the nutritionist, because it requires us to take into account many different factors with the ultimate goal of achieving euglycemia and improving both the patient’s quality of life and life expectancy.

Not only does the correct medical treatment – with a long-acting insulin – need to be initiated, the nutrition and the overall management of the feline patient must be adjusted in order to both reduce (and, ideally, eventually eliminate the need for) insulin dosage and enable the cat to reach its ideal body weight. All these changes have to be implemented in agreement with the owner’s abilities and the cat’s preferences; otherwise compliance with the proposed alterations is unlikely to be successful. As both a practicing veterinarian and a board-certified nutritionist, I hope to supply you with hints, gained from my experiences throughout the years dealing with such patients, in a way that will help you to tackle such cases with more confidence in the future.

Obesity and diet

Many cats with type 2 diabetes have a mild to severe form of obesity (Figure 1). It is therefore necessary to change their diet to a food which is specifically designed to make them lose weight; however, it is essential that weight loss is achieved in a controlled manner, so that the cat remains healthy, yet the diet chosen must limit the glycemic load. Such a diet is typically low in energy, high in fiber and protein, and low in soluble carbohydrate; it should also be enriched with anti-oxidants and L-carnitine. A diet that is low in energy will allow the owner to feed a larger volume of food, which will help to maintain satiety between meals; this is aided by the increased amount of insoluble fiber in the diet. The soluble fiber fraction in the food will slow the uptake of nutrients, thus helping to control the glycemic load. The high-protein content is necessary to avoid muscle breakdown due to the caloric restriction in the food; this has a synergistic effect with increased activity levels (see below) which together helps improve lean body mass development. Anti-oxidants will counteract the negative effects of obesity-related chronic inflammation, and L-carnitine will facilitate the use of fat – rather than glucose – as an energy source by the cells.

The choice between a dry and a wet diet should be made in consultation with the owner, and should take into account the cat’s preferences and habits prior to the diagnosis. In general, wet diets are often better at achieving satiety; so moisturizing kibble may be a good option if a cat does not like pouches or pates. Another advantage of moisturizing kibble or using wet food is that urinary health may improve, as recurrent cystitis is a common comorbidity in diabetic and/or obese cats. However the most important thing is to ensure that the cat has a consistent, predictable food intake (which for some cats might only be achievable with a dry diet).

The amount to be fed should be calculated using an estimation of the cat’s ideal bodyweight, and as a starting point the aim should be to supply 293 kJ (= 70 kcal) per kg metabolic bodyweight: ideally the cat should lose between 0.5 and 2% of its body weight each week once on the new diet. Weight assessment should therefore be done during each follow-up consultation (Figure 2) and adjustments to the ration made in accordance with the weight loss.

Feeding regime

Meal supervision is also a crucial factor in managing these patients, and feeding should be tailored around the insulin injections. In practice this means that two larger meals (2x 30% of daily amount) should be fed at 12-hour intervals, offered before the insulin injections, with the remainder of the feed given between times in smaller portions.

When the patient will only eat wet diets, the owner’s time schedule will dictate feeding times, as the food should be given fresh, but if the cat will eat kibble, investing in one (or more) automatic feeders is a must. These will enable the cat to be fed multiple small meals throughout the day, thus mimicking its natural behavior (Figure 3). The advantage of having more than one automatic feeder is that the cat has to exercise more – i.e., it has to move between the feeding stations. Importantly, however, it is essential to alter the schedule each day, so that the cat does not know which feeder will open at which time. Failure to do so means that the cat will simply wait in front of the feeder it knows will open next.

Activity stimulation

As mentioned before, it is necessary to stimulate physical activity in these patients, and in many cases a cat’s activity levels can be increased by simply altering the way in which it is fed. Some of the options available include:

• Advising the owner not to feed their pet on the floor but rather to provide the food on a raised area, so that the cat has to jump up to feed (Figure 4). This should however take into account the cat’s abilities to jump; this should be discussed with the owner and, if necessary, the place chosen to feed the cat may need to be altered as the cat loses weight. The more weight the patient loses, the harder it should be made for the cat to reach its food.
• Encourage the owner to distribute the food throughout the cat’s living area, rather than just supplying it in a single bowl. This can easily be done with both kibble and wet diets.
• Suggest that the owner uses feeding toys so that the cat has to expend more energy getting to its food (Figure 5).
• Enrich the cat’s living environment in any way possible; this will encourage the cat to explore its surroundings and will provide both mental and physical stimulation. (Figure 6).

In summary, each cat with type 2 diabetes should have its feeding regime reviewed and, if necessary, be prescribed a diet which is specifically designed to achieve healthy weight loss, facilitate glycemic control and reduce the time required to reach euglycemia. Along with simple alterations to the cat’s lifestyle and environment, this will improve the cat’s quality of life and aid in delivering the desired weight loss.