Heartworms are a serious problem that dog owners need to be aware of. These parasites actually live in a dog’s heart and can cause serious problems. However, many dogs have a small number of these parasites already, and we don’t know it. That’s because they have to multiply out of control to make your pet sick. We don’t want to think about dogs and heartworms in the same sentence, but doing so could save your pet’s life.

In dogs with compromised immune systems or active and working dogs, heartworms can end up being fatal. What can we do about them and how can we keep them from hurting our pets?

Preventing Heartworms

The first line of defense with heartworms is prevention. These parasites are transmitted through mosquito bites, not via exposure to other dogs, even if the other dog has heartworms. This means that preventing your dog from being bitten by mosquitos is an important defense mechanism.

Keep your pet indoors at night when you can, and try using a mosquito repellent on your dog’s coat whenever you take your pet outside and mosquitos are a risk. One effective natural repellent is eucalyptus oil diluted in water, rubbed around areas where mosquitos are likely to bite.

You can also administer ivermectin – an anti-parasite drug used in many animals – during the time when the infection is most likely. This drug is sold as Heartgard and several other brand names in the US. Other medicines used to prevent heartworm infections include milbemycin (Interceptor and Sentinel) and moxidectin (ProHeart).

Some of these drugs can also prevent or kill mites, ticks, and fleas, as well as heartworm. All of them are highly effective.

When given properly, they’ll protect ninety-nine percent of dogs from infestation. Most cases where these preventative medicines “don’t work” are actually caused by owners who don’t keep their dogs treated during the infectious season. While some of these drugs do continue to protect outside of their ideal effective period, that’s not a guarantee.

At one time, heartworm infections were confined to the south, in the US. However, this parasite can now be found nearly everywhere mosquitos are present. Heartworm is also a problem in Canada, South America, the southern parts of Europe, Japan, Southeast Asia, Middle Eastern countries, and Australia. Anywhere mosquitos are present, heartworm is a danger.

Heartworm Infection

Heartworms go through several stages of life before they can infect an animal, and require mosquitos to finish their life cycle. Heartworms can’t be transmitted at low temperatures, and are not a risk in colder months. That means that in colder areas, your dog is less likely to suffer from heartworm, though transmission can still occur in the summer.

Once a pet is bitten by a mosquito, the heartworms take six to seven months to grow to adulthood and start living in the heart. They develop under the skin near the bite at first, then migrate to the abdominal muscles to grow further. At about seventy-five to a hundred twenty days after infection, heartworms enter the bloodstream and are carried to the heart.

By the time they reach adulthood, they can start reproducing, and the problem can spread. If an infected dog is bitten by another mosquito, heartworm larva in its bloodstream can be carried to another animal.

During the six-month-long preadult (prepatent) period while the worms are growing, most dogs will show no signs of problems. In fact, the majority of pets won’t even show signs after the worms reach adulthood. Animals that don’t get much exercise and have a mild infection may not appear to be affected. But more serious cases of heartworms or heartworms in very active animals may cause real problems.

Symptoms Of Heartworm Disease

Dogs infected with heartworms may suffer from a cough when exercising, get tired early, and begin losing weight. In advanced cases, where the problem goes untreated, dogs may faint, lose significant amounts of weight, cough up blood, or suffer heart failure and death. It’s clear that heartworm isn’t something you can ignore, but what can you do about it?

Treatment For Heartworm

Dogs that have been diagnosed with heartworm have to be evaluated. It’s important to make sure that they have proper heart, kidney, and liver functions because treatment can be a huge strain on the body. Often, adult worms are killed using a heartworm medication based on arsenic. The currently approved type of heartworm medicine in the United States is Immiticide or melarsomine dihydrochloride. It works much better and has fewer problems than the older drug, Caparsolate. That makes it safer for dogs with serious heartworm problems.

After being treated, it’s important to keep dogs from too much activity. The dead worms must be absorbed by the body. Too much exertion can cause the dead parasites to travel to the lungs and cause respiratory failure. Several weeks later, a heartworm test will be given. If the dog tests negative, heartworm medicine is a success. In severe cases where heartworm medication doesn’t work, surgical removal may be considered.

Some vets also use high doses of Ivermectin to kill heartworms. However, this takes a long time and is less effective than conventional heartworm medicine. Natural cures are sometimes sold, but so far, none of them has a testable track record for curing heartworms. That means that preventative heartworm medicine and conventional treatments are the best options for dogs.

Any responsible pet owners will take the time to have their dogs against heartworms. The alternative could be a painful, life-threatening infection and many heart problems. Preventative medication is easy to get and inexpensive. It’s definitely worth it if you want to keep your dog safe from this serious condition.