Practical Recommendations to Feed the Diabetic Cat

14. Practical Recommendations to Feed the Diabetic Cat

Format of the Food

Today, special diets for diabetic cats are available both as canned or dry food. Extrusion technology has been improved to such a degree where dry diets with high protein and low carbohydrate content have become available. Clearly, there is no indication whether a canned versus a dry diet offers a major advantage as long as the composition of the diet with a high protein and low carbohydrate content is controlled.

Method of Feeding

Most diabetic cats can best be fed twice a day, with insulin being injected just before or after meals. Obviously, this feeding regimen does not correspond to the natural feeding rhythm in cats which, when fed ad libitum, may consume up to 15 small meals throughout the day. Nevertheless, especially with the use of high protein diets, postprandial glucose levels increase only slightly compared to high carbohydrate diets (Kettelhut et al, 1980; Kienzle, 1994; Martin & Rand, 1999). Therefore, the timing of insulin injection relative to offering food, may seem less important. This was confirmed in an unpublished study indicating that the timing of insulin injection, which was supposed to be optimized for insulin action to occur (45 minutes before meal versus at the onset of the meal), had little effect on metabolic control (Alt, 2006). Hence, the composition of the diet is much more important than the timing of meals. It needs to be stressed, however, that food must be available once insulin action occurs to prevent life-threatening hypoglycemia.

Medical Checks

Caution must be taken to avoid hypoglycemia when insulin-treated diabetic cats are shifted to a high protein, low carbohydrate diet.

This point also stresses that throughout therapy, diabetic cats should be regularly monitored. This can be achieved by home monitoring for the blood glucose level with portable glucometers (Figure 27) (Reusch et al, 2006b) coupled with regular laboratory determination of serum fructosamine concentrations. Owners should also be aware of the possible clinical signs associated with hypo- or hyperglycemia. Throughout therapy, but also when insulin therapy is no longer necessary (transient diabetes mellitus), owners can easily check their cats for the recurrence of glucosuria using glucose sticks in fresh cat litter that is mixed with a small volume of water. This will provide at least some information to consider adjustment in the insulin regimen.

Figure 27. Home monitoring of blood glucose concentration in cats. (Courtesy of Prof. C. Reusch, Vetsuisse-Faculty University of Zurich).

Remission of diabetes mellitus is possible in many cats if the blood glucose concentration can be controlled with insulin therapy combined with a high protein diet. Therefore, many cats may not need lifelong insulin therapy. Insulin is discontinued with acquisition of glycemic control. It is recommended to maintain the high protein diet during remission. In addition, the cat should be regularly reevaluated to monitor for recurrence of clinical signs of diabetes mellitus. If or when the diabetes returns, specific treatment must be immediately reinstated.

Conclusion

Feline DM is a frequent metabolic disorder and its prevalence has increased over the last 30 years. This is most likely linked to the obesity problem in our pet population, especially in cats. However, at the same time treatment has become much more successful and the fatality rate in diabetes mellitus decreased tremendously over the last 10 - 20 years. Considering the major underlying pathophysiological disorder, i.e. the lack of insulin and insulin action, most diabetic cats have traditionally been treated with insulin. Insulin is still the treatment of choice because it is best suited to control metabolism and to help reduce glucolipotoxicity. This may result in complete resolution of clinical signs. Over the last few years, it has become very clear that insulin therapy should be supported by switching the diet of diabetic cats to a high protein (> 50%) low carbohydrate (<15%) diet. The remission rate has increased markedly since the introduction of these diets in the treatment regimen. Overall, feline DM clearly is a disease that can and should be treated.