Vet Blog

Heartworm Testing and Treatment

April 22, 2019

If you are the proud owner of a dog, cat, or ferret, you have probably heard of heartworms and know that this is one of a number of parasites that could affect your precious pet at some point in her lifetime if proper preventatives aren't provided.

However, there is still some confusion over heartworm testing and what it means for your pet, and how treatment for heartworm infection is carried out. To help you understand further, here is everything that you need to know about heartworm testing and treatment.

Annual Heartworm Testing

Since heartworms can have such a devastating impact on the health of our pets, most veterinarians in Helena, AL advocate yearly heartworm testing. Often this is done in conjunction with or recommended during her usual annual wellness exam, but it can be performed as a standalone appointment. The American Heartworm Society recommends annual testing for all dogs regardless of their age and location.

Testing for Adult Heartworms

Heartworm testing in pets takes the form of a simple blood test, which checks for the presence of specific heartworm proteins produced by adult female worms. These proteins are called antigens and as such, you may hear of heartworm tests referred to as antigen testing. Antigens can be detected between 6 and 7 months after an animal has become infected and positive results are possible for numbers as low as 1 to 3 adult females present in the heart.

Antigen tests may come up with a false negative in the following circumstances:

  • If the test is carried out too soon after infection, so while your dog is infected, it is too early for antigens to be produced.
  • If the worms are all male or all the females are still immature.
  • There are very low numbers of adult female worms and so the level of antigen is too low to detect.

Microfilaria Testing

If your dog's antigen test has shown a positive or weak positive result, your vet will likely proceed with a blood test that looks for immature heartworms, called microfilaria. If microfilaria is detected, this confirms that there are male adult heartworms present and treatment to kill adults and juvenile heartworms is required.

Occasionally, a microfilaria test may also flag up a false-positive result. This can occur if the worms are too immature to mate and produce microfilaria, if the worms are all of one sex and cannot mate or if there are too few microfilaria present.

Additional Testing

If all of the heartworm blood tests are found to be negative, but your pet is still showing symptoms of the disease, your pet may be required to undergo further testing in the form of x-rays and ultrasounds to check for abnormalities in the heart and lungs that could confirm the diagnosis.

Heartworm Treatment

Fortunately, it is possible to treat heartworms and the sooner treatment can commence, the better the outcome will be for your pet. There are various elements to the treatment process. These include:

  • Exercise restriction. Exercise puts strain on the heart and lungs, the two key areas affected by heartworms. Physical activity can increase the rate at which damage to these organs occurs and increases the likelihood of complications from heartworm infection. Therefore, you will need to start restricting your pet's exercise as soon as she is diagnosed until you are given the all-clear by your vet.
  • Medications to minimize the effects that the dying heartworm will have on your pet and improve her response to treatment. This includes antihistamines, anti-inflammatories, and antibiotics.
  • Heartworm preventatives that will destroy microfilaria before they can mature into adult heartworms.
  • Medications to kill the adult heartworms administered via injection.

Treatment usually takes place over a number of different appointments and your pet will be monitored closely to ensure that she doesn't experience a bad reaction at any stage. She may also need further supportive treatment as she recovers from her heartworm infection.

If you would like to schedule heartworm testing for your pet, or if you believe that she may need heartworm treatment, don't delay. Call (205) 621-2021 to speak to our veterinarians in Helena, AL today to get advice or schedule an appointment.