Diabetic ketoacidosis is a dire diagnosis


Michelle Gerhard Jasny, V.M.D. has been practicing veterinary medicine on the Vineyard since 1982 and writing the Visiting Vet column for more than 25 years. She lives and works in West Tisbury. She can be reached at drjasny@comcast.net.

Yves had always been a cat who liked to eat. A seasonal resident, I saw him every summer.  When he was four years old, I suggested reducing the amount he was being fed. At six, I advised a prescription weight loss diet. It was a difficult regimen for his owners to maintain. Yves lived strictly indoors and didn’t get much exercise, and the other cat in the household had different health problems, requiring different food. By 11 years old, Yves was tipping the scale at 21 pounds.

“He’s at risk for all kinds of diseases, especially diabetes,” I said, not unsympathetically, considering how many years I have struggled with my own battle of the bulge. His family committed again to helping him lose weight and last winter we sent them off with more diet food, recommending monthly weigh-ins with their winter veterinarian.

Spring arrived. Seasonal folks began returning. Memorial Day weekend, Yves’s mother called. “We’ve been here two weeks,” she said. Yves had been fine until yesterday. “I am worried he might have some kind of blockage. He’s been vomiting and crying and he’s not eating.”

“He’s still an indoor cat?” I asked. Cats who go out have greater risk of ingesting things that may upset their tummies, anything from mice to antifreeze, but Yves never ventured to the great outdoors.

“Any flowers like lilies in the house?” I asked. Ingestion of houseplants is a common cause of gastroenteritis for indoor cats and lilies in particular are extremely toxic to cats, leading to potentially fatal kidney failure.

“No, no flowers,” his mom said. “He does like to eat some garlic chives we have in a pot.” Uh-oh. Garlic, onions, chives, all members of the Allium family,  can cause a serious reaction in cats called hemolytic anemia. It was too much to figure out by phone, so I suggested they bring him in.

When Yves arrived, it was apparent he was very sick: he lay listlessly on the exam table. He was dehydrated, despite the fact he had been drinking lots of water. He seemed almost too weak to stand and cried softly when I gently palpated his abdomen. His bladder felt full and tense.

Could he have a urinary tract blockage? This common problem in neutered male cats can lead to similar symptoms, though usually owners report frequent trips to the litter box and straining without producing any urine.

Or could it be allium toxicity from those chives? The whites of his eyes looked slightly jaundiced. Or something else?

I put him on the scale and did a double take. Last time I had seen Yves nine months back he weighed 21 pounds. Today he weighed 14. He had lost a third of his body weight.  Had his family finally succeeded with the diet? This was a pretty dramatic change. I asked his owners to leave Yves with me for a few hours so I could run some tests.

Diabetes is a disorder of metabolism caused by an insulin deficiency. Insulin is necessary to move glucose (a form of sugar) from the blood into the cells, where glucose fuels the body.  When an animal does not produce sufficient insulin to properly utilize glucose, this leads to the classic diabetes symptoms of increased drinking, urination, and appetite, combined with weight loss. If an owner notices these signs and goes to the veterinarian, the diagnosis is usually made fairly easily and appropriate treatment instituted, such as dietary changes and insulin injections to correct the deficiency.

But Yves had been on a strict diet, so his weight loss hadn’t seemed unexpected. Of course he acted hungry. He was on a diet. And monitoring water consumption and urine output in a house with multiple cats isn’t easy. So, not surprisingly, his diabetes went undiagnosed.

When a diabetic animal goes untreated, the body starts breaking down its own tissues in an effort to “feed” itself. One of the byproducts of this is the production of substances called ketones which build up in the blood. Eventually the untreated diabetic cannot maintain proper fluid, electrolyte, and acid-base balance and develops what is called diabetic ketoacidosis. Abbreviated “DKA,” it is a true medical emergency. Symptoms include excessive drinking and urination, muscle weakness, depression, loss of appetite, vomiting, liver enlargement, jaundice, abdominal pain, seizures, and eventually death.

Yves’s laboratory tests were consistent with a diagnosis of DKA. His blood sugar was high. He had ketones and glucose in his urine. Many DKA patients have other underlying illnesses such as bacterial infections or heart disease that contribute to the onset of the crisis. In Yves’s case, his liver enzymes and bilirubin levels were very elevated, indicating serious inflammation of the liver and bile ducts called cholangiohepatitis. Up to 90 percent of cats with DKA will present with liver disease, pancreatitis, cancer, kidney failure, or other such issues.

Treatment is challenging. Fluid and electrolyte imbalances need to be corrected and carefully monitored. The patient needs insulin. Blood glucose levels have to be checked frequently, sometimes as often as every one to two hours. Any and all underlying problems must be identified and addressed.

“You should consider taking him to a referral  hospital,” I advised. Further testing could evaluate the severity of his liver disease. Round-the-clock nursing and access to specialists might give the best chance of recovery. “If he makes it, he will likely need daily insulin injections,” I added.

The statistics are sobering. One study reported the mean hospital stay for DKA cats to be a costly five days, and of those that survived, almost half had a recurrence later. I have seen DKA described as a “very complicated multifactorial metabolic nightmare that even the best vets have a hard time getting under control.” Considering all these factors, especially Yves’s age and not wanting to prolong his suffering, his owners decided it was time to let him go — a sad but compassionate choice when faced with this complex and often deadly disorder.