Heartworms

A couple of weeks ago, we discussed intestinal parasites of dogs and cats, Today, we are going to discuss the heartworm, which is a parasite found in the heart and bloodstream of dogs. Heartworms are transmitted by mosquitoes from one dog to another. A microfilaria, which is an immature stage of a heartworm, is picked up from the bloodstream of a dog when the mosquito is taking a blood meal. This stage of the heartworm goes through a stage of development in the mouth of the mosquito. This second stage is called a larva. The larva enters another dog when the mosquito bites the other dog.

The larva works its way through the dog where it finally finds its way to the heart of the dog. This journey takes about six months to complete. The larva then develops into an adult heartworm that can be several inches in length. If there are at least one female worm and one male worm present in the heart, they will reproduce more microfilaria that can infect other dogs.

A single dog can be infected with so many heartworms that the heart can become clogged. The heart doesn't pump blood as well as it should so the dog becomes tired very easily. Fluid starts to accumulate in the dog's lungs causing the dog to cough. Fluid can also accumulate in the dog's abdomen causing the dog to swell. Because of the decreased blood flow, the kidneys and liver of the dog start to fail. Finally, heartworms result in death of the infected dog.

Heartworms can be prevented from ever developing in your dog if it is put on medication given monthly or daily depending on the type of medication used. If your dog is over six months of age, it should be tested by a veterinarian for heartworms before being placed on a preventive medication.

If the test done by the veterinarian indicates that your dog has heartworms, all is not lost because heartworms can be treated. However, some dogs can become very sick during the treatment. So, as you can see, preventing heartworms makes a lot more sense than trying to treat a dog with heartworms.