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HEARTWORM IN THE DOG

What is it?

Heartworm is an infection in dogs caused by long, threadlike worms which live in the dogs heart and large vessels in the lungs. The most common signs are a chronic cough, weight loss, and loss of appetite, but early in the infection there are usually no outward signs.

 

HEARTWORM DISEASE PREVENTION General Information Highly effective medication is available to prevent heartworm disease. Mosquito control is certainly helpful but should never be the sole means of prevention. Preventive Medication Milbemycin oxime (Interceptor®): This drug is also comes in chewable tablets to give once per month. It has the advantage over ivermectin in that it also kills hookworms and whipworms which can be an insidious intestinal parasite that could be developing in the dog during the winter months, by itself a good reason to give these tablets year-round. In geographic areas where mosquitoes are present throughout the year, dogs must be treated year-round to prevent heartworm infection. Monthly heartworm preventatives work by killing certain stages of heartworm larvae in the skin and muscles. Heartworm larvae need 2 1/2 months to mature from a tissue form to a blood larval form. The monthly medication is only in the animal's system for one day. It does not remain in the animal for an entire month. Important Points in Treatment Weigh your dog monthly during the treatment period. A change in your pet s weight might require a change in dosage. These drugs must be given on the prescribed schedule to be effective. You must not skip doses or give the pill late. Call the doctor if you are having trouble adhering to the prescribed schedule. Stickers for your calendar are available to help remind you of the monthly schedule. Mosquito Control Screen outdoor kennels, especially in areas where heartworm is prevalent. Keep your pet indoors during the early morning and evening hours, when mosquitoes are most active. Electronic insect killers can be positioned near kennels. Premise sprays are available for treatment of the environment. Mosquito repellents can be used for short periods of exposure. Be sure your pet does not lick off the repellent.

How does your dog get it?

The infection is transmitted by the mosquito. The mosquito picks up the infection from an already infected dog (it sucks up microfilaria produced by adult female heartworm that circulate in the blood) and after a short time in the mosquito, the mosquito can infect another dog with it's bite. In six to nine months the infection can reach the dogs heart where the worms mature.

How is it diagnosed?

By Blood Test.
Discuss with your veterinarian the best testing schedule for your dog.

 
Can heartworm be treated?

If your dog is found to be infected with heartworm, it is not necessarily fatal. The infection can be treated, but it must be done both carefully and in a step-by-step procedure. First, the adult worms must be destroyed by injections, involving two to three days of hospitalization, normally. Secondly, any immature forms in the bloodstream, if present, must be eliminated four weeks later. A dog who already has permanent body damage from heartworm infection may die of these complications even with intensive treatment.

Your pets activity must be severely restricted for up to 8 weeks after treatment. Short on-leash walks are the only exercises allowed. No rough play, extended barking or other excitement. Call the Doctor if ANY changes in behavior or attitude arise at home.

Can heartworm be prevented?

There are preventive medications available which can keep your dog from getting heartworrn. However, before your pet can be given this medication, a blood test may need to be taken to detect existing infection. Preventive medication is generally given monthly. The monthly medication we prefer - Interceptor® helps control several common intestinal worms and may be used year-round. Yearly heartworm testing is still required, unless you are giving the monthly preventative year-round and have two consecutive negative yearly heartworm tests -- then testing can be done every other year. (Note: we have no way to insure owner compliance or that the animal did not spit out, vomit or poorly absorb the medication.) Also, if your puppy is still growing, weigh it monthly BEFORE giving the medication to be sure he gets an adequate dose.

Mosquito control:
1. Screen outdoor kennels,
2. Keep pets indoors during the early mornings and evening hours when mosquitos are most active,
3. Electronic insect killers can be placed near outdoor kennels,
4. Premise sprays are available for treatment of the environment,
5. Mosquito repellents can be used for short periods of exposure. But be sure your pet does not lick off the repellents.
   
   

What other animals get heartworms?

While the animal most commonly infected is the dog, it has also been reported in cats, ferrets (for which heartworm preventative is also recommended) and found in foxes, skunks. Extremely rare cases have been reported in man.