Heartworm Disease: An Increasing, Year-Round Problem
Written By Dr. Gary Holfinger
Heartworm disease is transmitted by mosquitoes. No direct contact between pets is needed to pick up the disease. A positive dog will serve as a carrier to any pet in a one to two mile range, acting as the "typhoid Mary" source for the neighborhood. After years of maintaining control, we're seeing the number of heartworm cases increasing in our area. There seems to be two new aspects that are escalating the problem:
First, pets are being shipped from area to area in a worthy attempt to find homes. The most notable example is the dogs saved in New Orleans after Hurricane Katrina. Over 50% of those animals were positive for heartworm disease, which quickly spread the problem throughout the country. We also suspect that the increase in wild coyotes is adding to the spread.
Secondly, we see that less people are keeping up with preventive medication year round. Mosquitoes do typically hibernate in the winter but they can be active as soon as the temperatures get around 50º, and the weather here in the Midwest has been inconsistent, to say the least. For that reason, the need to stay on preventive medication through the entire year is real and even more important. The newer medications that include flea control and intestinal parasite protection are a wise mechanism to reduce potential risk.
The problem isn’t reserved for the canines. Many clients do not realize that cats can also get heartworm. While incidence is not as high as in dogs, we know that the problem does occur in our area. Unfortunately, diagnosis is not as easy as in dogs, and clinical signs are minimal. Sadly, the most common presenting sign is acute death with no warning or problems apparent to the owner. There is monthly prevention for cats which will also prevent intestinal parasites and ear mites.
Heartworm treatment for either species is difficult and time consuming, often taking several months. The worm is eight to twelve inches long and resides in the pulmonary artery. Problems with transient lung disease are an expected side effect and pets need to stay inactive through the treatment process. It’s really a situation where an ounce of prevention is better than a pound of cure so take care of your furry family members and give them the preventive medication they need year round.