Heartworm Infection on the Rise

The March 2019 data ranks San Francisco as second highest percentage increase heartworm infection in the US. Even if you don't treat your cat or dog for heartworm every month, as recommended, please try to this year, and be sure you don't miss the next few months. 

Heartworm is transmitted through the bite of an infected mosquito. Unfortunately, our wet spring has resulted in a dramatic increase of the mosquito population which then has led directly to an increase in the documented cases of heartworm infection.

Heartworm disease in dogs is serious and can be fatal. From the time a dog is bitten by an infected mosquito to the time a positive test confirming infection can be achieved is 6 to 7 months. During this time, damage to the infected individual begins. The adult worms that develop reside in the heart and in the pulmonary artery leaving the heart on the way to the lungs. The presence of these adult worms in these locations is responsible for the clinical signs that include coughing, lethargy, excercise intolerance and weight loss. This can progress to heart failure in some of its worst forms.

Cats respond differently to the few adult worms that develop and present essentially with asthma which can be severe. Unlike dogs, cats cannot be treated for heartworm infection, which makes a good case for prevention.

Even indoor pets are at risk. Studies have shown the percentage of heartworm infected mosquitoes is higher in the indoor population versus the outdoor population of mosquitoes. Heartworm infected mosquitoes understandably seek out the less challenging environment of the indoors.

Heartworm disease in dogs is treatable, but has many difficulties. The treatment occurs over several months, requires multiple drugs that can be costly, and some come with their own risks. The primary drug used to kill the adult worms is an arsenical derivative. Most dog owners, as well as veterinarians, would prefer not to find themselves in a situation where such a drug is necessary. Needless to say, prevention is far easier, more affordable and comes with essentially no risk to your pet.

Obtaining heartworm prevention is easy. It does require that dogs be tested for heartworm and, if negative, we start them on a preventative. Heartworm testing can be arranged simply by calling the hospital and making an appointment for a heartworm test. Or, we'd be happy to arrange for a veterinary technician to come to you.

If ever there was a case of ‘an ounce of prevention is worth a pound of cure,’ this is it. With heartworm infection on the rise locally, we encourage the use of preventatives for the health of your pet.