Heartworms. You probably know about them. You probably pick up heartworm prevention at the vet whenever you think about it. You probably know they’re not a super great issue for your pet to have, but you also probably think it would never happen to your pet. Since the topic of transmittable disease is all we hear about these days, let’s take a break from coronavirus and check out heartworms!
Those awful little buggers you hear about at the vet’s office are parasitic worms known as Dirofilaria immitis. They are transmitted by mosquitos who have fed from infected animals. The incidence of heartworm disease is highest in the Gulf coast area. Since mosquitos are the unofficial state bird of Louisiana, it makes sense. Mosquitos essentially suck up tiny heartworm offspring (microfilariae) and those babies will become infective while inside the mosquito, sort of like a foster parent situation. The mother will give birth, but it takes someone else stepping in to help the children realize their full potential.
Then as the larvae grow, they’ll migrate to the mosquito’s mouth parts so during the mosquito’s next blood meal, they can enter another animal through the bite wound. These heartworm children will then move through the body of the animal as they age, first through the tissues and eventually into the blood vessels. When they reach the lung blood vessels, they are ready to fall in love, get married, and have babies. And they will. Their tastes aren’t very discerning, so it’s not a far leap to assume they’ll pick a sibling they grew up with. Then more microfilariae will be released into the animal’s bloodstream, ready to be picked up and carried off by the next hungry mosquito. Keep in mind that mature heartworms can be 4 to 12 inches long. That’s a foot-long spaghetti noodle living rent-free in your pet’s heart! And they’re almost never alone. The number of heartworms living inside an animal, known as the “worm burden,” can be up to 250 at a time. Worm Burden is admittedly a great band name, but heartworms are the opposite of rock & roll.
Heartworm disease progresses through four stages, ranging from mild symptoms to severe. Stages 1 and 2 will mostly exhibit mild symptoms such as an occasional cough and tiredness after moderate activity. Stage 3 is when your pet will start to look sick; he’ll have trouble breathing, a persistent cough, and signs of heart failure. Stage 4 (also known as caval syndrome) is deadly. Caval syndrome occurs when there are so many worms in your pet’s heart that they physically block blood flow. Not good, right?
If left unchecked, heartworms WILL cause death. Treatment is available if your pet does get heartworms, but it’s expensive and very hard on the animal. It includes a month of taking antibiotics to weaken the heartworms, a series of injections to gradually kill the heartworms, and very strict cage rest for the duration of treatment. This part is most important to the recovery of the animal, but also the hardest to follow. Let me get real: too much movement during treatment could jostle the dead and dying worms into breaking apart, forming a clot, and then causing a stroke. It’s all very intense and NOT GOOD. Thankfully, prevention will keep you from ever having to go through heartworm treatment with your pet.
Talk to your vet about which heartworm preventative is best for you and your pet. Your cat may even need prevention, because they’re not immune from heartworm disease. Ferrets aren’t either, so all you ferret-heads out there may need to talk to your vet as well. The doctor will need to perform a simple blood test to check for heartworms before starting or switching preventatives, or if you’ve missed a dose. We receive a lot of guff from clients who think this is unnecessary, but if your pet is already heartworm positive, the preventative could send them into shock. Remember, the staff here at Gill Bright is always happy to discuss your heartworm prevention or treatment options, so please give us a call if you have any questions.