Just as with humans, untreated diabetes in cats can lead to a number of complications. These include pancreatitis, diabetic neuropathy (walking on the hocks), diabetic ketoacidosis, hypoglycemia and kidney failure. Research in humans and mice has shown that organ damage begins to occur when the blood sugar is above 140 (7.8). Many of these studies can be found here: Research Connecting Organ Damage with Blood Sugar Level. Several of the more common complications are described below.
Pancreatitis is a condition that causes severe inflammation of the pancreas. The pancreas is already damaged, to varying degrees, by the time our cats are diagnosed with feline diabetes (FD). Dr. Hodgkins states in her book Your Cat, Secrets to a Longer, Stronger Life, cats with FD typically have at least low-grade pancreatitis. As a result, when a cat comes along that is not achieving expected results with insulin, initial thoughts should turn to the likelihood of pancreatitis. Pancreatitis may be acute or chronic. Acute pancreatitis is a sudden inflammation of the pancreas, where chronic pancreatitis refers to a long-standing inflammation of the pancreas that alters its normal structure and functions. Both forms of pancreatitis can cause serious complications for our cats, some more severe than others. Mal-absorption of food, internal bleeding, damage to tissue, infection, cysts, fluid accumulation, enzymes and toxins entering the bloodstream, damage to the heart, lungs, kidneys, and/or other organs may occur if left untreated. It is now suspected that pancreatitis in cats may also cause FD. Mal-absorption of food is a very common outcome in humans with pancreatitis, as is diabetes. Diabetes develops because insulin-producing cells (the islet cells) of the pancreas become damaged.
Diabetic Neuropathy (Walking on the hocks)
Diabetic neuropathy results from damage to the peripheral nerves due to high blood glucose levels. As a result of nerve damage, cats will experience the following symptoms:
- Weakness of hind legs
- Feet slipping out from under him/her on the floor
- Walking on the hocks in back (see image below) and/or the wrists in the front
- Lying down more frequently, especially after short walks
Key in preventing and treating this condition is achieving good control of blood sugars. Diabetic neuropathy has also been treated successfully in many cases using a supplement of methylcobalamin B12 (note: not to be confused with cyanocobalamin). Methylcobalamin is active in spinal fluid, and as a result, is able to help heal the damaged nerve cells. Treatment may be required for weeks or months, but improvements are usually seen quickly in most cats treated with methyl B12. Join the forum to read about our members’ experiences with diabetic neuropathy.
Diabetic Ketoacidosis (DKA)
This potentially life-threatening condition is a result of a buildup of ketones in the blood. Ketones (organic acids) are formed when the body burns fat for fuel rather than glucose. In the case of diabetics, a lack of insulin renders the body unable to metabolize glucose (sugar) and thus the body turns to fat reserves for energy. Ketones are normally filtered out by the kidneys and excreted in the urine, however, if an excess of ketones build up, this will cause electrolyte imbalance. In addition, the pH level of the cat’s blood becomes dangerously acidic.
- Excessive drinking of water
- Excessive urination resulting from water consumption
- Weight loss
- Increased respiratory rate
Ketoacidosis is a medical emergency. If you suspect Diabetic Ketoacidosis, get your cat to a vet immediately. If your cat has more than a mild case of Ketoacidosis, he will likely need intensive care, including intravenous re-hydration, correction of electrolyte imbalance, and reversal of high ketones and metabolic acidosis. You can test for ketones using inexpensive urine test strips, and should routinely do so until your cat’s blood sugar levels are regularly below 11.1/200. In a diabetic cat, any level of urinary ketones above “trace ketones” or trace ketones with symptoms listed above, are reason to call a veterinarian immediately. More information and experiences with DKA can be found on the forum.
Hypoglycemia, defined as abnormally low blood sugar, occurs when the blood sugar becomes low enough to deprive the brain of fuel (glucose). Symptoms of hypoglycemia include:
- Loss of coordination
- In severe cases, seizure and coma
Hypoglycemia is usually caused by an overdose of insulin. Cats on the tight regulation protocol do not have clinical hypo. Dr. Elizabeth Hodgkins explains: “This can happen at many different levels of blood glucose, sometimes a cat will have these signs at levels that are not that low, say 70 (3.8 mmol/L), and other cats show absolutely no signs whatsoever at blood glucose levels as low as 20(1.2 mmol/L)! Therefore, the absolute number is not the whole story, not by a long shot. The cat’s liver is just as important to the control of blood glucose as the pancreas is. The liver and pancreas work together, with the pancreas keeping the blood glucose from going too high and the liver keeping the blood glucose from going too low. The cat on high carbohydrate foods loses both its normal liver function and its normal pancreatic function. This loss of normal liver function is what causes the signs of hypoglycemia. When a diabetic cat is consuming low carb foods instead of high carb foods, the liver resumes its ability to make enough glucose to meet the brain’s needs, and signs of clinical hypo DO NOT OCCUR. Low carbohydrate-feed cats have tremendous resistance to hypo signs because their livers work to keep this problem from occurring.” For more info on DCH’s opinions and experiences with low numbers, please join the forum.
Diabetic Neuropathy (Renal or Kidney Failure)
Diabetic neuropathy occurs when high levels of glucose damage the glomeruli, which are the filtering structures, in the kidney. The damaged kidneys can no longer remove waste and extra fluids from the blood stream. Eventually, protein will leak out of the kidneys into the urine. Along with achieving regulation of blood sugars to prevent further damage to the kidneys, treatment for kidney failure may involve treatment with drugs such as Benazapril (an ace-inhibitor), intravenous fluid therapy, and phosphorus binders. Join the forum for more information on how diabetic kidney failure is managed in conjunction with tight regulation.
Hepatic Lipidosis is a serious complication affecting the liver. More common in overweight cats, Hepatic Lipidosis occurs after a period of not eating. The body starts to break down fat for energy and if too much fat is broken down, it begins to accumulate in the liver, causing it to swell. Symptoms include refusing to eat, vomiting, weight loss, lethargy, and jaundice (often indicated by a yellowish look to the whites of the eyes, gums and inside the ears)
It is essential that cats with Hepatic Lipidosis eat. This may involve giving appetite stimulants, or inserting a feeding tube if the cat refuses to eat. While Hepatic Lipidosis is rare, it is usually fatal if not treated.
In addition to the above complications, diabetic cats may also experience vomiting, diarrhea and other stomach upsets. Susceptibility to infections is also common in diabetic cats due to high levels of glucose in the blood and urine. Cats may experience frequent urinary tract infections (UTI), dental and skin infections and delayed wound healing.
For more information and members’ experiences with the above complications, and any other issues that affect our diabetic cats, please join the Diabetic Cat Help Forum.