This hot, rainy weather is great for umbrella sales and growing grass, but the stagnant puddles and stifling humidity make great breeding grounds for mosquitoes.
These blood-sucking parasites thrive this time of year and are known transmitters of many dangerous and potentially fatal diseases, including West Nile Virus.
Unfortunately, pets also are susceptible to many of these infections, which are difficult to diagnose and treat. However, there is one parasite that mosquitoes transmit that is easily diagnosed, treated and even better, preventable.
Heartworms are common parasites that do their damage in all 50 states. Dirofilarial immitus, the canine heartworm, is by far the most common blood-borne parasite affecting pets, accounting for tens of thousands of cases a year. Transmission of this worm is by a single mosquito: An infected canine, whether coyote, fox, wolf or dog, is bitten by a mosquito and the baby heartworm is ingested along with the blood meal.
The baby heartworm, called microfilaria, matures in the mosquito's body then is injected into our pets, a meal heartworms enjoy at Fido's expense. In roughly six months, the heartworms mature and migrate to the right side of the heart, where they can live for years and grow to six inches long.
With heartworms, initially, a little sluggishness is noted, easily overlooked in older pets or during this hot humid weather. But over time, the heart will begin to fail leading to a cough, fluid accumulation, collapse and eventual death.
Fortunately, if caught early enough, an infected dog can be treated to eradicate the parasite from their body. The unfortunate part is that it can be a lengthy and costly process. A controlled dose of an arsenic poison that will slowly kill the worms over time is injected by the veterinarian into the amimal.
Depending on how sick the dog is, the injections are given over a few days or may need to be spread out over a month to decrease the chance of complications. Following hospitalization, strict confinement for a month at home is needed to allow the patient to rid itself of the dead worms in the heart.
The pet needs to be rechecked in a few months to confirm successful treatment. Some pets may be candidates for a newer treatment performed only at a specialty hospitals: The heart is catheterized, similar to an angioplasty, and the worms are removed one at a time.
There is one thing much better than treatment of heartoworms: prevention. Heartworms are virtually 100 percent preventable with a monthly medication that prevents the worms from maturing in the body.
There are a couple of medications available on the market, but all have been around for 15-20 years and are extremely safe, effective and relatively inexpensive (usually less than a quarter a day for a 90-pound dog). All dogs should be on prevention medication -- period.
From a 2-pound Chihuahua to a 200-pound Great Dane and every breed in between, all are equally susceptible to the fatal affects of a heartworm infection.
Lifestyle is irrelevant; some of my worst mosquito "attacks" have occurred while I slept under the covers inside my air-conditioned house. So regardless if you have an outside dog or a toy breed that never touches the grass outside, dogs need to be on monthly prevention to avoid the harmful effects of this parasite.
Topical medications to prevent mosquito bites are not acceptable as prevention of heartworms. They are not effective at repelling mosquitoes nor are topical human products using pesticides such as DEET safe; many times dogs will lick these sprays off of themselves and ingest these dangerous compounds. Discuss with your veterinarian which is the best product for your pet.
Other species kept as pets also can become infected with heartworms. Ferrets are extremely susceptible to heartworm infections and should be on monthly prevention. Cats on the other hand are not a natural host to heartworms. Cats are unique in many ways, I am sure all owners will agree, as heartworms do not live long in cats as their body will kill the worms themselves. However, heartworms can cause a fatal embolism in cats without them showing any prior signs at home. Speak with your veterinarian if prevention is right for you and your cat.
We can not protect our pets from all infectious organisms that are outside, but with a simple monthly medication, usually disguised as a tasty treat, we can avoid an ugly worm from living inside our pets heart.
Dr. Brian Weitzman practices at Smith Mountain Lake Animal Hospital.