We’re no strangers to insects in the south. But, did you know that 1 of every 18 dogs tested in Caddo Parish tests positive for heartworm disease? Louisiana’s accommodating climate for insect growth and reproduction makes parasite prevention a must for pets. Learn how to  protect your pet from heartworm disease in our latest blog post.

Thumbs up for a negative heartworm test

As the insect population increases, so do cases of the diseases they bring. However, with the many simple prevention options available, no pet should be exposed to these infections. To combat heartworm disease in your pet, brush up on these helpful facts on how the disease is spread, diagnosed, and treated.

#1: An infected pet does not transmit heartworm disease to another pet.

Most worms pass easily from pet to pet, but heartworms are atypical because they can only be transmitted by mosquitoes, not from contact with an infected pet. However, be aware that a heartworm-positive pet means heartworm-carrying mosquitoes that can easily infect additional pets are in your area.

#2: Heartworms require mosquitoes to grow and develop.

Without mosquitoes, heartworms would cease to exist. A mosquito must ingest heartworm larvae, or microfilaria, during a meal from an infected animal. The microfilariae only develop to the infective stage within the mosquito, then pass into the next victim’s bloodstream when the mosquito bites.

Dog heart Worm Life Cycle


#3: Mosquitoes are difficult to eradicate.

Mosquitoes used to be considered a summertime pest, allowing us freedom from their itchy bites in the winter. Unfortunately, that is no longer the case, and mosquitoes can easily winter in your home and can survive in harsher climates year-round.

#4: Even cats can get heartworm disease.

Heartworm disease has commonly been considered a dog-only disease, but any mammal can contract the infection, even humans. While the disease is seen less commonly in cats, it does occur. Cats with heartworm disease can react strongly to the microfilariae as their immune systems work to eradicate the threat, and may show respiratory signs similar to asthma attacks. Vomiting, weakness, and sudden death can also occur. No treatment is available for cats with heartworm disease.

#5: Diagnosing heartworm disease can be challenging.

An accurate diagnosis is difficult because of the heartworm life cycle and the limitations of the tests available. After an infected mosquito bites, it takes about six months for microfilariae to develop into adults, and a pet tested during this six-month period will test negative. Also, if the heartworms present are only male, or if there are too few females, a false-negative result is also possible. Any positive test at UVH is sent to a laboratory for confirmation, and the results can take 7 to 10 days.

Heartworm testing in the lab at UVH

#6: Treating heartworm disease is complicated.

Heartworm disease stages in dogs

Heartworm prevention is a cinch compared to treatment. Depending on the disease severity, heartworm treatment requires months to fully complete. Initially, we stage a heartworm-positive pet to determine the disease severity, which involves confirmation testing, blood work to check organ function, and X-rays to check for damage to the heart, lungs, and surrounding blood vessels. Once we can place a pet in the appropriate stage, we formulate a treatment protocol. At UVH, we pride ourselves on our protocol, which we adjust each time the American Heartworm Society makes recommendations. Typically, after 30 days of an antibiotic, a pet will receive one injection of an adulticidal compound and spend one night at UVH so our team can monitor for any reactions (pain, anaphylactic reactions, fever). One month from the first injection, a pet will receive two injections of the adulticidal compound given 24 hours apart and stay two days at UVH. The injections consist of a medication that will kill adult heartworms, and since the injections can cause pain and discomfort for the pet, UVH will start anti-inflammatory and pain medications before starting the injections. Hospitalization is required to ensure there are no adverse reactions—remember, we provide 24-hour care for our patients. Post-injection care is critical, and pets must be exercise-restricted for a minimum of 8 weeks during the entire treatment process.

#7: Every pet needs heartworm preventive. Every. Pet.

Since we know heartworms can infect any mammal and mosquitoes are skilled at surviving harsh conditions, all pets obviously should be protected from this devastating disease. Administer heartworm prevention to every pet, including house cats who never venture outdoors and lap dogs who only go outside for elimination purposes. Do not skimp on preventive and allow a mosquito to transmit this disease to any of your pets.

Proheart6 for dogs only

#8: Heartworm prevention is more cost-effective than treatment.

Most forms of heartworm prevention average $12 to $20 per month. The cost is higher if flea or tick prevention is included, but then your pet is completely protected. Monthly heartworm preventives often also include an intestinal parasite deworming medication. UVH recommends Proheart6 injections, because this medication provides continuous heartworm prevention for 6 months, and the injection is given by UVH. If your pet tests positive for heartworm disease, the cost for staging the disease, treatment, and follow-up care can be more than $1,200. Consider not only the financial burden but also the physical toll of this disease on your pet. It is OK to be scared. We are here for you and will outline every step of this process and communicate the life cycle, the staging process, and your pets individualized recommended treatment protocol.

Do you need to stock up on your pet’s heartworm preventive? Stop by our hospital and let us help you choose the best option for your furry friend.  Give us a call at 318-797-5522 and ask us questions! 


Dr. Alisha Spivey