Florida has one of the largest mosquito populations in the United States, and these pesky bugs can transmit heartworms to your four-legged friend. Our Veterinary Medical Center of Indian River County team doesn’t want your pet targeted by these dangerous parasites, so we explain why your pet should receive year-round heartworm prevention.

#1: Mosquitoes are pervasive in Florida

Florida is home to more than 80 mosquito species, and many carry dangerous pathogens, such as heartworms. Mosquitoes not only transmit heartworms, but they also are necessary for the parasite’s life cycle. When a mosquito bites a heartworm-infected dog or wild canine, they ingest baby heartworms, called microfilariae. The young heartworms incubate inside the mosquito for two to three weeks until they reach an infective stage, when they can be transmitted to other pets and animals. When the mosquito snacks on your pet, they deposit the microfilariae in their saliva and the parasites swim through the bite wound to infect your pet. 

Also, consider the mosquito’s ability to enter your home. They can easily gain access through vents, open doors and windows, and torn screens. This means that if you have a pet that lives solely indoors, they are not protected from heartworm infection. Every pet needs year-round heartworm prevention to protect against these deadly parasites.

#2: Heartworms cause pets significant health problems

Heartworms cause significant health problems for pets, but they affect dogs and cats differently.

  • Vascular disease in dogs — Dogs are a natural heartworm host, which means the heartworms tend to thrive when parasitizing these pets. They can fulfill their entire life cycle, including mating and producing offspring, while living in your dog’s heart. The worms initially settle in the dog’s pulmonary vasculature, causing inflammation that leads to vessel thickening and constriction and creates a high-pressure area that limits the heart’s ability to pump blood throughout the body. Eventually, this results in congestive heart failure (CHF). Since the dog’s body is so amenable to heartworms, numerous worms can infect a single dog, and if enough worms accumulate in the heart, blood flow through the heart can be blocked, leading to a serious, life-threatening emergency condition called caval syndrome.
  • Respiratory disease in cats — Cats are atypical hosts for heartworms, and their immune system reacts strongly when parasites enter the body. This means that many young heartworms are cleared before they reach adulthood, although the immature parasites still can be extremely problematic for the cat. When the parasites reach the cat’s lungs, they trigger a severe inflammatory reaction, leading to a condition known as heartworm associated respiratory disease (HARD). In addition, some worms can grow to adulthood, and only one or two adult worms can cause severe problems for cats, since their hearts are so small.

#3: Many pets don’t exhibit heartworm disease signs

In the initial heartworm disease stages, most pets don’t exhibit signs, and significant heart and lung damage has typically occurred by the time signs do manifest. When signs are present, they include:

  • Dogs — Heartworm disease signs in dogs include lethargy, exercise intolerance, a soft, persistent cough, and weight loss. For dogs in CHF, fluid accumulation in their abdomen can give them a pot-bellied appearance.
  • Cats — In some cases, the first sign of heartworm disease is sudden death. Other potential signs in cats include increased respiration rate and effort, wheezing, open-mouthed breathing, and vomiting.

#4: Heartworm disease in pets can take months to detect

Tests available to detect heartworm disease are not able to detect the parasites until months after infection, which means the infection may be well-established before treatment can start. Options include:

  • Microfilariae test — A blood sample is concentrated and examined to look for circulating baby microfilariae, which can be detected six months after infection at the earliest.
  • Antigen test — This test detects a protein produced by the female adult heartworm. Heartworm antigen can be detected about five to seven months after infection.
  • Antibody test — This test detects the pet’s immune response to heartworms, and can detect infection as early as two months post-infection.

Currently, the American Heartworm Society recommends that dogs be tested annually using both the microfilariae and antigen tests. The antibody test is especially useful for testing disease in cats, because they often don’t carry female adult heartworms or circulating microfilariae. Chest X-rays and ultrasound are also helpful for diagnosing heartworm disease. 

#5: No heartworm treatment is available for cats

No drugs are safe for killing heartworms in cats, so treatment focuses on supportive care. This means that prevention is the only way to protect your cat from these dangerous parasites.

#6: Heartworm treatment for dogs is risky

Heartworm treatment for dogs is risky and must be performed in stages over several months to help prevent serious complications, such as anaphylaxis and blood clots. Treatment is extensive and involves:

  • Strict confinement — Physical activity can exacerbate the worms’ damage, and your dog must be strictly confined.
  • Stabilization — Since heartworm treatment is so risky, your dog’s condition must be stabilized to ensure they are healthy enough to undergo treatment.
  • Microfilariae treatment — We prescribe medications to clear the circulating baby heartworms.
  • Antibiotics — We prescribe antibiotics to treat a bacterial infection associated with heartworms.
  • Steroids — We may prescribe steroids to help reduce the inflammation caused by the parasites.
  • Adult heartworm treatment — To kill adult heartworms, your pet must receive a series of painful injections into their lumbar muscles.

#7: Providing heartworm prevention is easy

Providing heartworm prevention is easy and convenient, since you have numerous options, which include:

  • Chewables — Products are available as a tasty chew that can be administered once a month.
  • Topical — Products that you apply topically once a month are available.
  • Injections — If you can’t easily give your pet monthly medication, we can administer an injection once every 6 or 12 months to protect them from heartworms.

Spring, and the mosquitoes that go with the season, is here. Contact our Veterinary Medical Center of Indian River County team to schedule your pet’s annual heartworm test as soon as possible.