Heartworms & Pets

Mosquitos are the single largest source of spreading disease and pathogens both to humans and to animals. The mosquito is responsible for millions of infections and over a million human deaths worldwide each year. While mosquitos can carry literally hundreds of diseases, the number one risk to pets is from heartworms.

Heartworms have a life cycle that depends on mosquitos as an intermediate host. It starts when a mosquito bites an infected host, like a dog. The infected dog’s blood has the juvenile form of the heartworm, called microfilaria. These enter the mosquito along with the blood meal and over the next 10 to 14 days, morph into the larval stage. The larvae are now able to infect a new host when it is bitten by the mosquito. In the new host, the larvae mature into adult heartworms and lodge in the heart and the blood vessels near the heart and lungs. The cycle begins again when these adult heartworms reproduce, and microfilaria are released throughout the bloodstream. As the cycle continues, the number of heartworms in an infected animal increases and the animal becomes sick to the point where it may die.

Did you know?

• Adult heartworms can live between 5-7 years in dogs and 2-3 years in cats.
• Early in the infection, many dogs show few to no symptoms at all.
• The first sign of heartworm disease in cats is often sudden collapse or death.

Dogs, wild relatives of the dog such as coyote, cats, and ferrets are all susceptible to heartworm infections. Signs of heartworm disease in dogs are progressive and include coughing, exercise intolerance, labored breathing, weight loss, and eventually heart failure. The blood flow in the heart may become blocked and cause a severe, life-threatening condition called caval syndrome.

Cats are more resistant to heartworm infection than dogs, but still at risk. A cat’s immune system may fight off heartworm infection, but they can still suffer from permanent damage from the heartworms in the form of chronic inflammation, heart disease, or heart failure. Unfortunately, there is no approved treatment for cats with heartworm infection making prevention critical for our feline companions.

Ferrets are also susceptible to heartworm infection. They suffer from the same symptoms as dogs, except that since a ferret’s heart is much smaller than a dog’s heart. Just one heartworm will cause a rapid onset of symptoms and may be enough to be fatal. Ferrets, like cats, have no approved treatment for heartworm infection. Treatment is aimed at reducing inflammation, stabilizing your pet, and developing a long-term management plan.

The good news is that heartworm is easily preventable. There are many products available to treat pets that are safe and effective, starting with puppies and kittens as young as 8 weeks old. Dogs, cats and ferrets should be on a year-round prevention program, even if you live in Michigan. One mosquito is all it takes to infect your pet. Mosquitos can find warm microenvironments, like inside your home, to survive in during Michigan winters. It is much easier and much less costly to prevent heartworm than it is to treat the disease. Ask your veterinarian about heartworm prevention. Your veterinarian can tell you about the preventative medications available for your pet and the relative benefits of each. At Blue Lake Animal Hospital we want to keep all our patients as healthy as possible and heartworm-free.