Did you know that our dog and cat friends can get diabetes, just like people?
What is diabetes mellitus?
Diabetes mellitus occurs when the body either cannot produce adequate levels of insulin or it cannot respond normally to the insulin that is produced.
Insulin is a hormone secreted from the pancreas that is responsible for promoting uptake of glucose (sugar) from the bloodstream into the cells of the body. Without insulin, the glucose is stuck in the bloodstream and the cells cannot get the energy they need.
What does the body do to fix this situation?
Most of the glucose in the bloodstream comes from food that our pets eat, but since the energy-hungry cells cannot get access to the glucose circulating in the blood, they begin to signal other parts of the body to release alternative energy sources.
Stored proteins and carbohydrates are broken down to form glucose, which only adds to the ever-growing glucose level trapped within the bloodstream. And, in severe cases, fats are also broken down into an energy source called ketones (more about these later).
Unfortunately, without the insulin that is responsible for blood glucose uptake into cells, mobilizing more glucose does not solve the problem; the cells continue to starve despite the blood glucose level continuing to rise.
What clinical signs should I look for to know if this is happening to my pet?
There are two classic groups of clinical signs that the vast majority of diabetic pets will show:
- Weight loss despite an increased appetite
- Increased thirst and increased urination
Why? Well, the cells of the body are starving and still don’t know that it’s the insulin that’s the problem, not a truly low blood glucose level. This results in signals to the brain to keep on eating in a misguided attempt to increase the blood glucose.
In addition to the mobilized protein and carbohydrate stores, this increased appetite will further increase the blood glucose level. As the blood glucose level gets higher and higher, it will spill out into the urine as the body tries to get rid of some of the excess sugar. The sugary urine causes an osmotic draw of water into the urine, thereby increasing the volume of each urination. Because diabetic patients are peeing more, naturally they are more thirsty and drink more!
Is there anything else to watch out for?
There are a few other clinical signs you may see at home, including:
- In dogs, cataracts
- In cats, a crouched or sunken stance, particularly in the hind limbs
What about those ketones?
When the body finally turns to fat stores as a method of providing an energy source for cells, the fat is broken down into a substance called ketones.
Ketones may be a potential energy source for cells, but they ultimately cause more harm than good. When there are excessive levels of ketones in the bloodstream, they, like the glucose, will spill over into the urine, pulling even more of the body’s water with them. They also pull important electrolytes with them into the urine
Ketones still in the bloodstream cause the body to become more acidic than usual, which in turn will effect other normal body functions.
Overall, the body becomes dehydrated, acidic, electrolyte-depleted … and still has a high blood glucose level! This situation can be life-threatening, and is called diabetic ketoacidosis (DKA). DKA is most likely to occur when there is something else going on in the body in addition to diabetes, such as an infection, pancreatitis (inflammation of the pancreas), kidney disease or cancer.
Between all that drinking, peeing and DKA, it’s time we talk about TREATMENT!
Once a pet is diagnosed with diabetes, treatment can be started. Of course, it makes sense that any good treatment would get right at the heart of the matter – the insulin.
It sounds simple: Provide the body with the one component it needs to get all that much-needed glucose from the bloodstream into the cells. However, in reality, this can be a tricky process. Finding the right amount and type of insulin can be difficult, as there is some variation in dosing from pet to pet.
Finding the right amount of insulin often involves multiple vet visits, blood draws and blood glucose curves (where your pet’s blood glucose will be tested throughout the day to be sure that it never drops too low or gets too high during the time period when the insulin is effective).
Additionally, your pet’s insulin needs may change over time, and he or she will require frequent monitoring to check blood glucose and screen for other commonly seen and potentially dangerous health problems in diabetic animals, particularly urinary tract infections.
How is insulin administered?
Insulin comes in a liquid form that is most commonly administered one to two times daily as a subcutaneous (under the skin) injection. This is not for everyone! Most pets will tolerate the injections, but it can be scary to learn how to do at first.
Don’t worry: Every parent of a newly diagnosed diabetic pet will get special instructions on administering these injections.
Very rarely, cats can be effectively treated with an oral medication, but there are no oral treatments available for dogs.
How long do diabetic animals need to be treated?
For most pets, insulin therapy is a lifelong commitment. In addition to the insulin injections and regular monitoring with your veterinarian, there are other lifestyle changes that need to be made, including starting a diabetes-friendly diet and providing regular exercise.
Now, this is where some cats just get lucky! Depending on the cause of their diabetes in the first place, some cats can enter into a remission of their diabetes, and no longer require insulin administration. The diabetes may come back, particularly in the face of certain other illnesses, but treatment may again be temporary. Unfortunately, remission does not occur in our canine friends.
Ultimately, taking care of diabetic pets does require a lot of work, but if you are dedicated to their treatment, it can be rewarding! As always, talk with your veterinarian if you have any concerns or questions about your pet’s health.
dr. emily young
By Emily Young, VMD, VCA San Francisco Veterinary Specialists, a member of our 2014-2015 intern class