Diabetic cats and the challenges associated with their management intrigue me, which is why I have about 75 diabetic patients in my practice at any given time.
Successful management of a diabetic cat requires a multifaceted approach that begins with five principles:
• Tight control is not essential and probably not even desirable. Cats tolerate hyperglycemia without significant consequences better than humans or dogs do.
• Hyperglycemia is always better than hypoglycemia. The latter can be fatal.
• As long as the cat is not ketoacidotic, it is not critically ill. You do not have to get the cat regulated in the first week, or even in the first month, after diagnosis.
• Consistency is extremely important in maintaining regulation. The more things you can keep the same—diet, exercise, stress—the easier it is to regulate the diabetic cat.
• Monitoring clinical signs is vital in achieving and maintaining regulation. With few exceptions, if the clinical signs and the blood-glucose level conflict, believe the clinical signs.
What Can Be Done
Based on these five principles, here are four treatment steps:
• Client education. You are the coach on the sidelines. Your job is to instruct the quarterback so the plays are run properly. I recommend a client information handout that details the treatment plan.
• Treat other diseases. The most commonly associated diseases are chronic pancreatitis (50 percent incidence in newly diagnosed diabetic cats) and periodontal disease. After the diagnosis of diabetes is made, I recommend a urine culture and feline PLI1 as minimum diagnostics after the MDB (CBC, chemistry profile with electrolytes, FeLV/FIV test, urinalysis).
• I usually put my newly diagnosed diabetics on one to two weeks of broad-spectrum antibiotics, even if the tests are normal. If necessary, clean the cat’s teeth as soon as it is stable.
• Diet. A low-carbohydrate, high-protein diet is superior to others. Canned products have definite advantages, but most diabetics do well on dry products with this formulation. If the cat is reluctant to change its diet, gradually mixing in the new food is recommended.
• Insulin. Four products are used with varying degrees of success: protamine zinc2, glargine3, Vetsulin4 and Humulin N5. My first choice is protamine zinc. Upon final FDA approval, the product will be replaced by a recombinant PZI product that I have used in a clinical trial and found to be extremely efficacious.
Avoid glucose curves
I do not recommend glucose curves and have not done one in more than five years. I use a gradual regulation approach for non-ketoacidotic patients. I begin with a very low dose (about 0.5 u/kg) and send the cat home. I request a recheck weekly at about 12 hours post-insulin and make dosage adjustments based on clinical signs (most important) and glucose readings. My goals are to have the clinical signs resolved and, if possible, the glucose from 300 to 350 mg/dl.
About 20 percent of diabetic cats go into remission. This occurs because after resting, many pancreatic beta cells regain function and produce insulin again.
Therefore, the owner needs to know how to look for signs of the Somogyi Overswing, which may occur for up to one week before a hypoglycemic crisis. If hypoglycemic seizures occur, the cat should be given 50 percent dextrose intravenously to effect; the dose is usually about 1 to 2 cc/kg.
One should be aware that the bolus of dextrose lasts about three to six hours. After that, the cat may need to be supported with 5 percent dextrose IV or food.
The next step is to determine why hypoglycemia occurred. The most common cause is diabetic remission; however, it may be due to accidental overdosing of insulin or several days of anorexia. If a cause cannot be positively identified, insulin should be discontinued for two to three days, followed by a blood-glucose measurement.
If the cat is still diabetic, insulin should be resumed at about 50 percent of the prior dose and worked up gradually using the approach to a newly diagnosed cat stated above.
Don’t Overlook B12
The only common complication of feline diabetes is peripheral neuropathy, which results in a plantigrade stance of the rear legs. The vast majority of these cats regain neurologic function after two to six months of regulation. There is some anecdotal evidence that once- or twice-weekly injections of 1,000 mcg of Vitamin B12 can hasten recovery.
Home glucose testing has become popular with many veterinarians and cat owners. However, I do not share their enthusiasm. The home-testing approach generally results in the owner’s making dosing decisions based solely on blood glucose readings. (See Principle No. 5.) I realize that it is not always intended, but it does happen.
An alternative is for the client to call you with the glucose test results. However, that puts you in the position of managing a patient you are not examining and, often, doing so without payment for your expertise or time. The former puts you at risk for the consequences of some potentially poor decisions, and the latter does not make economic sense.
If the owner insists on home glucose monitoring, I insist they use a feline-validated glucometer6, log the readings, and bring the log and the cat in for periodic examination and consultation.
The main cause of death of diabetic cats is not hypoglycemia; it is euthanasia. This occurs because diabetic cats require a serious commitment from the owner. Insulin needs to be given twice daily in the vast majority of cats, special food is needed and the cat’s clinical signs need to be monitored almost daily by the client. Clients with irregular schedules may find this to be a commitment that is not feasible.
Although this is a frustrating end, the practitioner needs to be sensitive to owners, taking into account the quality of life of both the cat and the owner. Given my schedule, it would be very difficult for me to properly manage a diabetic cat of my own.
My intrigue with diabetic cats led me to develop a comprehensive approach to managing the disease. I know it works, because after more than 10 years of using it, my typical patient dies of another disease, usually after five to eight years of diabetes treatment.
On the Homefront
For diabetic humans, at-home readings and self-injected insulin are a routine part of managing the disease. For diabetic felines and canines, however, only veterinarians and technicians traditionally wield the tools. But the climate is changing as more owners of diabetic pets test blood-glucose levels.
Abbott Laboratories’ AlphaTRAK is one BG monitoring system designed for home use. Susan Li, senior product manager for AlphaTRAK, says testing a pet at home instead of a cold clinic is an advantage.
“In the home environment, animals are less stressed,” Li says. “If they’re stressed, their glucose levels will be changed.”
While some owners may be wary of pricking their pet to get a blood reading, Li says obtaining the sample is more helpful than painful.
Kathryn Sener, founder of the Diapetic Rescue care kit, says pet owners’ reluctance is temporary. Veterinarians who promote home testing typically train the owners to use a syringe, she says, and the Diapetic kit is used by some technicians to show customers how to help manage the disease. Owners learn to safely dispose of needles, test glucose through either urine or blood, and even give a honey stick to quickly raise low blood sugar.
Can veterinarians trust the readings of a non-professional?
The results are a “close number,” Sener says. “What they are is a good guideline of what (glucose levels) are at and how the customer’s pet is feeling.”
1. Pancreatic lipase immunoreactivity test available from GI Lab, Texas A&M University, (979) 862-2861.
2. PZI VET, IDEXX Laboratories, Greensboro, N.C., (800) 870-4264.
3. Lantus, Aventis Pharmaceuticals, Bridgewater, N.J. (800) 207-8049.
4. Vetsulin, Intervet/Schering-Plough Animal Health, The Netherlands, +31 485 587600.
5. Humulin N, Eli Lilly, Indianapolis, (800) 545-5979.
6. AlphaTRAK, Abbott Animal Health, Abbott Park, Ill., (847) 937-6088.