Auburn, CA dog with heartworm.

Heartworm disease is spread by mosquitoes. While this fact doesn’t endear anyone to them, mosquitoes are just doing what’s in their nature—sucking blood. They don’t discriminate and, in fact, perceive every mammal as a potential meal. The problem is, mosquitoes pick up microscopic heartworm larvae from various fur-covered prey, and subsequently deposit the worms into the bloodstream of their next victim. Staying on top of prevention is an absolute must, but heartworm testing is equally important. Why?

The Whole Picture

All animals are vulnerable to mosquitoes, but those on heartworm prevention medication have a layer of protection against the disease. While not all mosquitoes are vectors of heartworm, it’s best not to play those odds. They have the ability and opportunity to prey on various species, including raccoons, deer, coyotes, foxes, and, of course, cats and dogs. 

Heartworm Dosage

Traditional heartworm preventatives are given once monthly. It’s easy to miss doses, especially during the colder weather when mosquitoes are rarely seen. It is recommended to maintain heartworm prevention year-round, as not all mosquitoes are killed by chilly weather, and dogs may live in or travel to warmer states

If a mosquito bites a dog that receives their monthly dose all year long, any larvae deposited into the bloodstream will be quickly eradicated by the medicine. Without regularly scheduled doses, the larvae move to the lungs and heart where they cause major problems. 

Two Sides, Same Coin

Heartworm testing and prevention are parts of the same strategy against the disease. If a dose is missed or skipped, or a dog has never received heartworm prevention medication before, heartworm testing is required. A positive result can lead to earlier treatment and a better outcome (instead of waiting for symptoms to develop), while a negative result will allow us to prescribe the right medication for your dog’s age, size, and lifestyle

Giving a dog their heartworm preventative too long after their last dose can cause serious health problems, and can even be deadly, if they have worms developing in the body. Killing the worms by way of preventative medication can actually cause anaphylactic shock. 

Heartworm Testing and Your Dog

Heartworm disease can be effectively treated if caught early on. If worms are left alone to mature inside the heart and lungs, they can be very difficult to kill or remove. Heartworm testing your dog annually is simply part of a strong defense against this terrible parasitic infection. 

An Eye on the Weather

Mosquitoes carrying heartworm disease are a year-round threat to your dog’s health and wellness. Early or warm springs, long summers, and falls that extend much closer to winter all impact the reach of mosquitoes. Monthly preventative medication, along with annual heartworm testing, are the best defense. 

We’re In This Together

A simple blood test checks for heartworms, whereas an antigen test can detect heartworm proteins in the blood released by adult female worms. Because it takes some time for the microfilaria (microscopic heartworms) to develop inside the host, the earliest that antigens can be caught is about 5 months after infection. In contrast, because it takes about 6 months for larvae to mature and reproduce, we can test for microfilaria in the bloodstream half a year following infection.

Heartworm Prevention

There are chewable and non-chewable pills to dose out once a month, or we can inject the medicine twice a year. 

Whatever you decide, year-round parasite prevention is key to your dog’s overall health and wellness. Please call us at (530) 924-5639 with any questions. Our team is always here to help at Bowman Veterinary Hospital.