Persistent pet maladies

This month we look at two unfortunately common maladies in dogs and cats. While
heartworm is easily preventable, diabetes may not be.

Whether in people or pets, when we talk about diabetes it is mostly diabetes mellitus (DM), a problem related to insulin, the hormone that assists the cells in taking in glucose, our fuel. In DM, either the body cannot make enough insulin, or the insulin is rendered less effective.

Of the three classifications of DM, two are big players in our pets. Dogs commonly
have Type I (“insulin-dependent” in humans). That means the pancreas is not
making enough insulin, either because of genetic issues or possibly environmental
factors. Low levels of insulin in the blood mean blood sugar goes way too high. This
is treated most successfully in dogs with insulin injections under the skin.

Cats diagnosed with DM most commonly have Type II (“non-insulin dependent”).
This is usually a case of insulin resistance, or an inability to secrete enough insulin, because of obesity, genetics, or other factors. Diet seems to play a role, though we don’t know if it is a cause of the disease or just exacerbates the problem.

In both dogs and cats, the most common signs of diabetes are increased thirst,
urination, and weight loss. Dogs commonly form cataracts at some point, but cats rarely do. Cats many times will have pancreatitis (inflammation of the pancreas)
or liver disease, but dogs rarely do. Cats may also develop neurological signs, seen as an abnormal stance in the rear legs not often seen in dogs. Low blood pressure may also be associated with DM.

The disease can be very complicated, with a long list of symptoms and suspected
causes. If you suspect your animal might have diabetes, have it checked quickly. This
is a disease that can be treated successfully if caught early, and devastating if ignored.

Heartworm disease is another frustrating condition, all the more so because it is
preventable. We have very good testing for the disease, and we know quite a bit about the parasite that causes it. Yet the percentage of dogs (and cats to some  degree) with newly acquired infections has remained steady for years.

This dangerous parasite has evolved a very sophisticated lifecycle. Young worms
called microfilariae born in the cardiovascular system of infected dogs are “sucked
up” by a feeding mosquito, then transmitted when the mosquito feeds. Heartworms
can be found in cats and other mammals like wolves, coyotes, ferrets, foxes, and
even sea lions. They have even been found in humans!

The microfilariae undergo a transformation in the mosquito that allows them to mature and infect the next victim. The worms find their way into the bloodstream, and eventually end up in the arteries, lungs, and occasionally the right side of the heart. It is not the worms themselves that cause problems, but the damage they do to those organs that make dogs so sick.

Prevention is easy: Give one of the effective monthly medications. There is also an injection back on the market that works for six months at a time. No dogs are completely safe from the risk of developing heartworm disease, so you need to discuss the risk with your veterinarian and find the right preventative for you.

Daniel Levenson operates the Southwest Veterinary Medical Center at the south end of Corrales Road. Visit his website at mysouthwestvet.