Could Your Senior Dog have Heart Worm?

Lindsey ZimmermanDog Health

dreamstime_xl_59605191All across America, vets begin testing dogs (and cats) for heart worm in April, which is why April is National Heart Worm Awareness Month. It used to be that heart worm was only prevalent in certain parts of the country. Unfortunately, it has now been detected in all 50 states, with the disease spreading to new regions of the country every year. For instance, after Hurricane Katrina, 250,000 pets with heart worm were sent across the country to be adopted.

What is Heart Worm?
Heart worm is a disease caused by foot-long worms (heart worms) that live in the heart, lungs and blood vessels of affected pets, potentially causing severe lung disease, heart failure and damage to other organs in the body. It can not only affect dogs and cats, but wolves, coyotes, ferrets and foxes as well. Heart worms live inside a dog, mature and mate, potentially causing several hundred heart worms in a dog.

How is Heart Worm Transmitted?
Heart worm is transmitted through infected mosquitoes. Once a pet is bitten it can take up to 6 months for the heart worms to grow. Heart worms can live for 5 to 7 years in dogs and up to 2 or 3 years in cats. Fortunately, humans can’t get heart worm from their pets.

What Are The Symptoms of Heart Worm?
In the beginning, dogs show few if any symptoms.  In fact, even a blood test will not detect heart worms initially. If you notice that your dog has a mild persistent cough, fatigue after exercise, a decreased appetite, or weight loss, you will want to get him tested as soon as possible. As heart worm disease advances, your dog could develop heart failure and a swollen belly from the excess fluid in his abdomen. If left untreated, heart worm can be fatal. The sooner the disease is detected, the better the chances the pet will recover.

How Is Heart worm Prevented?

  • The American Heart worm Society recommends that you get your pet tested every 12 months at your annual visit to the veterinarian. Annual testing is absolutely necessary, even when dogs are on heart worm prevention year-round, to ensure that the prevention program is working.
  • Give your pet heart worm medicine every year. You will probably need a prescription from your veterinarian. The decision of which preventative medicine to use should be discussed with your veterinarian based on what is best for your pet. Ideally puppies are started on monthly heartworm preventatives by 8 weeks of age.  There are monthly pills, monthly topicals that you put on the skin, and there’s also a six-month injectable product.

How Is Heart worm Treated?
If you dog has heart worm, your vet will do a complete physical exam, complete with x-rays, a urinalysis and blood tests.  Generally, the definitive diagnosis is usually made through the use of a heart worm antigen test or the Knotts test or Modified Knotts test. Treatment will depend on what stage of the disease your dog is experiencing. Generally it is a two-step process. The adult worms and the microfilaria are eliminated separately. No one medication kills both. The adults are treated first, then a different treatment is used to kill the microfilaria and migrating larvae.

Remember that heart worm is easy to prevent but difficult to cure.