Over one million dogs are infected with heartworms in the United States! The unfortunately thing about heartworm disease is that it is completely preventable and sadly more than half of clients leave the veterinary clinic without heartworm prevention. Heartworms can infect dogs, cats, ferrets and rarely humans.
Heartworms are transmitted from pet to pet from the bite of a mosquito. The infected mosquito deposits the larvae (baby heartworm) under the skin of its next victim. It takes the larvae about six months to mature into an adult worm and reach the heart. An adult heartworm is about 12 inches in length. These adults then start producing more baby heartworms that circulate in the blood stream waiting to catch the mosquito train and infect the next victim. Because heartworms can live five to seven years in a dog and two to three years in cats, each season can lead to an increase number of worms in the heart.
Heartworm disease is very often a silent killer, as many animals do not show clinical signs until it is too late. This is why yearly heartworm testing is so important. Common symptoms in dogs include coughing, exercise intolerance, decreased appetite, weight loss and, in severely infected dogs, congestive heart failure. Recently, it has been discovered that heartworm disease in cats primarily causes respiratory disease. The movement of the heartworm through the lungs can reduce the airway by 50% therefore causing respiratory symptoms similar to feline asthma.
Heartworm treatment protocol depends on the severity of the infection but involves a series of injections followed by strict rest for 30 days. Immiticide is an injectable medication which is used to kill adult heartworms in dogs. Unfortunately in cats, there is no treatment available at this time, diagnosis can be difficult and many time infection results in sudden death.
The great news is that heartworms can easily be prevented by giving an inexpensive monthly preventative all year around. Heartworm preventatives are very effective but are eliminated quickly from the pet’s body and it does not protect your pet from future infections. The medication works to kill a certain stage of the larvae so they can’t continue to mature into adults. Both oral and topical heartworm preventative are available. Ask your veterinarian which is best for your pet.
Please e-mail me with your questions at ACoffin@aol.com and put “Ask Dr. Anna” in the subject line or mail your questions to 123 West Harrison Guthrie, OK 73044.