Diabetes: Pets and People

Stone - Diabetes

November is American Diabetes Month. To highlight how veterinarians care for pets with diabetes, I thought I would tell the story of one of my patients, a fluffy, grey and white cat named Stone.

Stone is a youngster, just under two years of age. He came to see me because his owner had noticed weight loss and excessive drinking. Weight loss and excessive drinking are common clinical signs of diabetes, but Stone was much younger than the typical cat with diabetes. Hyperthyroidism can also cause weight loss and increased drinking, but typically occurs in older cats.

Another cause of weight loss and excessive drinking is chronic kidney disease, but again, typically in older cats. I wasn’t really sure what was wrong with Stone until the blood tests showed sugar in his urine and an elevated blood sugar.

Dogs and cats have different forms of diabetes. Dogs commonly have Type I diabetes, which is a total lack of insulin production by the pancreas. Cats have Type II diabetes which occurs most commonly in middle to older overweight cats. Unlike humans with Type II diabetes, cats require insulin injections where humans can often manage Type II diabetes with oral medications and diet. Strangely, with weight loss, insulin therapy, and a special diet, some diabetic cats will become normoglycemic again and no longer require insulin. This happened to my own cat and he stopped needing insulin for a year. Then became permanently diabetic and required insulin for the rest of his life. I think chronic inflammation of the pancreas (known as pancreatitis) was the likely cause of the diabetes.

Stone was in to see me just a few days ago. On twice daily insulin therapy, he has gained back some of the weight he lost and is eating his special diabetes diet with gusto. Blood tests indicate his blood sugar is well controlled and his owner notes it is getting harder for her to test his urine to measure the urine sugar level. I am suspicious he may be heading for a period of diabetic remission.

To help my readers understand the similarities between their own diabetes and that of their pets, I included a table below with a comparison of the common features of the disease.

Comparison of diabetes between people and their pets:

  Cat Dog Human
Occurrence 0.58% of cats 0.35% of dogs 9.4% of Americans
Type I diabetes No Yes Yes
Type II diabetes Yes No More than 90% of diabetes
Diabetic retinopathy No Rare Yes
Diabetic nephropathy No No Yes
Association with pancreatitis Yes Yes No
Oral treatments No No Yes
Insulin injections Yes Yes Yes
Spontaneous remission resolution Yes No No
Diabetic cataracts Rare Yes Yes
Linked to obesity Yes Yes Yes

Pancreatitis in Dogs

pancreatitis in dogsThe pancreas is a thin, elongated organ that is shaped a bit like a pounded piece of chicken tenderloin. The pancreas lies along the initial portion of the small intestine called the duodenum. As the bile duct leaves the gall bladder, it traverses the pancreas before it enters the duodenum. The pancreas is probably best known for producing insulin, the hormone deficient in patients with diabetes. The pancreas also produces digestive enzymes essential for breakdown of food into its nutrient component parts.

-itis = inflammation
When a body part is inflamed, the suffix “-itis” modifies the root word to indicate the disease process of inflammation. Tennis elbow is really inflammation of the elbow bone and in doctor speak is epicondylitis. Inflammation of the appendix is appendicitis. Inflammation of the pancreas is pancreatitis. Pancreatitis is the most common condition of the dog and cat pancreas.

Causes of pancreatitis in dogs
The exact trigger for pancreatic inflammation in dogs is elusive. High fat meals, such as one obtained illicitly from the kitchen trash can are often blamed. Miniature Schnauzers are a dog breed with an increased risk of pancreatitis. Some diseases, like diabetes, hyperadrenocorticism and hypothyroidism increase a dog’s risk for pancreatitis. Blunt force trauma, like an automobile accident or a fall from a height can injure the pancreas and set off the inflammatory cascade. Whatever the cause of the inflammation, it promotes release of the digestive enzymes from the pancreatic cells. The enzyme release worsens the inflammation and also the clinical signs.

Clinical signs of pancreatitis
Pancreatitis can be either an acute fulminant illness or a more insidious, chronic problem. The list of clinical signs attributed to pancreatitis is quite long: vomiting, anorexia, weakness, dehydration, abdominal pain and fever. Dogs may assume a “praying” position with their elbows on the floor and their rump held high. Veterinarians interpret this as a response of the dog to abdominal pain. Since the major signs of pancreatitis are nonspecific, vomiting and anorexia, a battery of blood tests, x-rays, and an abdominal ultrasound may be necessary to establish a diagnosis of pancreatitis.

Treatment of pancreatitis
There is no specific treatment for pancreatitis like there are antibiotics for bacterial infection. Veterinarians treat dehydration with fluids, control vomiting with anti-nausea medications, and manage pain with pain medications. We also rest the gastrointestinal tract of patients with pancreatitis by withholding food and water until the vomiting ceases, followed by a low fat, bland diet. Dogs may take several days to recover from a serious case of pancreatitis.

To help prevent pancreatitis, restrict your dog’s intake of human foods, especially fatty ones. There will be less dieting for him in the new year and hopefully no pancreatitis to spoil his fun.

Exocrine Pancreatic Insufficiency: Cats Get it Too!

Recently, I highlighted a common pancreatic disorder in dogs, pancreatitis. The following day, the New York Times "Well Pet" blog wrote about a much less common, but equally serious pancreatic disorder, exocrine pancreatic insufficiency (EPI). The article focuses on EPI in dogs, but cats also can suffer from this disease.

Pancreatic function

The pancreas has two main functions: first to produce the hormone insulin to control blood sugar and second to produce digestive enzymes. Production of insulin is the pancreas’ endocrine function and production of digestive enzymes is an exocrine function. Deficiency of insulin is called diabetes.

Deficiency of the digestive enzymes has a much more descriptive name – exocrine pancreatic insufficiency.

What a cat with EPI looks like

The classic cat with EPI is skinny, greasy, and has bad diarrhea. The absence of digestive enzymes prevents the gastrointestinal tract from breaking food down into it components, and if they are not broken down, the nutrients cannot be absorbed. If your cat has this disorder, he will eat lots of food and lose weight rapidly. Cats with EPI are greasy because they cannot digest fats without pancreatic enzymes and all the undigested fat in their stool gives them nasty diarrhea.

The causes of feline EPI

This disorder is thought to be inherited in certain dog breeds, most commonly German shepherds. Cats never want to be like dogs. Exocrine pancreatic insufficiency in cats does not appear to have a genetic component and is more likely to be the result of chronic damage to the pancreas from long standing pancreatitis. These cats may also be diabetic if the pancreatic damage is severe enough to prevent production of both digestive enzymes and insulin.

Testing the skinny cat

When I see a cat with weight loss, I commonly collect blood for what The Animal Medical Center (AMC) calls a GI panel. This quartet of tests looks at the digestive function of the pancreas and small intestine. One of the tests measures trypsin-like immunoreactivity and is the diagnostic test of choice for feline EPI. Another important test on this panel measures vitamin B12 or cobalamin. A study of feline EPI cases at The AMC and Purdue University found all cats with EPI were deficient in this important vitamin.

Replacement therapy

Once lost, the pancreas do not typically regain exocrine pancreatic function. Management of EPI requires lifelong supplementation with pancreatic enzymes and vitamin B12. Vitamin B12 supplementation is simple: a small injection given under the skin once a week. Pancreatic enzymes come as a powder and are sprinkled on the food. This is where cats can be challenging since many cats refuse food that has been embellished. Raw pancreas (which contains the digestive enzymes) has been recommended, but I haven’t tried it on any patients, yet. The good news is our study of feline EPI showed most cats will respond to therapy.

Resources on pancreatic disease

Exocrine Pancreatic Insufficiency

Pancreatitis

Texas A&M University

WebMD

IDEXX Laboratories

Pancreatitis: Systemic Effects of an Unhappy Organ

One of my friends was in the hospital last week. Not a human friend, but a dog friend. Happily, I have dog friends who are not dog patients and Decoy is one of those. This lovable lab is a member of a family who are friends of my family.

Under the weather

I saw Decoy’s name on the overnight admission list which is emailed to all the veterinarians at The Animal Medical Center at about 5:30 every morning. Decoy came to The AMC ER for vomiting and limping. The ER doctors found abdominal pain, a fever and an elevated heart rate. On my way into the hospital, I stopped by his cage to say hello, but could tell my normally tail-waggin’ friend was a hurtin’ pup; Decoy was living up to his name by looking more like an inert, stuffed dog than a real one.

In the blood tests

Blood tests for AMC patients are available online. To help with interpretation, abnormal results are displayed in red, normal results in black. Decoy’s reports were shockingly red. His illness was impacting his liver, his blood calcium level, and dramatically increasing his infection-fighting white blood cells.

Inside the abdomen

Because Decoy’s blood tests indicated multiple organs within the abdomen were affected by whatever was making him sick, his internal medicine specialists ordered an ultrasound of his abdomen. Ultrasounds let veterinarians look at intra-abdominal structures in a different fashion than x-rays allow. X-rays show bones and lungs very clearly, but we can only see the outline of abdominal organs like the liver and kidneys. The pancreas cannot be seen using x-rays and we rely on ultrasound to help make a diagnosis of pancreatic disease. Because pancreatic disease could account for Decoy’s clinical findings of vomiting and diarrhea and his multiple blood test abnormalities, an ultrasound was done and confirmed the suspicion of pancreatic inflammation or pancreatitis. The ultrasound showed pancreatic swelling. The swollen pancreas displaced the colon out of its normal position and was even causing a small amount of fluid to accumulate in the abdomen.

On the road to recovery

There is no antidote to stop pancreatic inflammation. Veterinarians provide what we call supportive therapies while the inflammation subsides and then we try to decrease risk factors for recurrence. Decoy received intravenous fluids, antiemetic agents, and antibiotics in case the pancreatitis was turning into an abscess. Every day he improved a little bit and he was discharged from the hospital a few days later.

Follow up

To help prevent another bout of pancreatitis, Decoy’s doctors made several recommendations to his family. First, overweight dogs are at greater risk of developing pancreatitis. I suspect a diet will be on Decoy’s list of New Year’s resolutions. High-fat diets increase the risk of pancreatitis. This means he may need to eat a special low-fat diet and certain dog delicacies like bacon will no longer be a menu option for him. In the future, his doctors will avoid certain medications to prevent provoking another serious case of pancreatitis.

Pancreatitis is a common disorder of dogs and it can become a recurrent problem. In Decoy’s case, the problem was quickly corrected, but when pancreatitis becomes a chronic problem, seeking input from an internal medicine specialist is a good idea.