Heartworms are parasitic roundworms spread through mosquito bites that can infect both dogs and cats. One in 200 dogs become infected with heartworm each year. Heartworms are very common, but heartworm treatment for dogs and cats and prevention prescribed by a veterinarian will significantly reduce the risk of your pet contracting the parasite.
Dogs are natural hosts for heartworms. Once infected, the developing parasites may complete their entire life cycle. As the heartworms grow inside the host, they make their way into the heart, lungs and blood vessels. It’s possible for your pet to be infected with hundreds of heartworms and these parasites can grow up to a foot long. Cats are atypical host for heartworms so most heartworms do not survive to the adult stage; therefore, cats usually have one to three worms in their heart. However, even immature worms can cause significant damage to the lungs. Cats infected with heartworms can get heartworm associated respiratory disease (HARD). Unlike dogs, there is no heartworm treatment for cats so prevention is the only way to protect your cat. Heartworms can bring about severe health complications and even death if not treated properly. This is why it’s imperative that pet parents keep their pets on regular heartworm prevention medicine.
Heartworm Diagnosis & Treatment Process
Below, we have outlined the diagnosis and treatment process for you, so that in the event that your pet does contract heartworm disease, you’ll know what to expect.
Step 1: Heartworm Antigen Test
First, we will test your pet for heartworm with a heartworm antigen test. This is the most common and accurate form of testing for heartworm.
Step 2: Microfilariae Test
Next, if your pet does test positive on the heartworm antigen test, then we will test for microfilaria (immature developing heartworms in the bloodstream). If your pet is heartworm positive, a confirmatory test will be sent to the lab because we want to make absolutely sure before beginning treatment.
Step 3: Assess Overall Condition
Last, we’ll need to assess your dog’s overall condition by performing chest X-rays, Complete Blood Count (CBC) and blood chemistry test. In more severe cases, we may recommend an echocardiogram (sonogram of the heart). Based on your pet’s unique condition, other tests may be necessary.
Step 4: Start Heartworm Prevention
Your dog will be started on heartworm prevention right away. If your dog has a high microfilaria burden, then they will be monitored in the hospital for the day after receiving the first dose of heartworm prevention. This is to make sure they don’t have any adverse reactions. Heartworm prevention must be given for 2 months prior to administering the first heartworm treatment.
Step 5: Start Doxycycline Antibiotics
This is an adjunct therapy given before heartworm treatment begins. Doxycycline therapy is for 4 weeks to eliminate Wolbachia, an endosymbiont bacteria which lives inside the heartworm. By treating with Doxycycline, it reduces the adverse reaction the dog may experience as the worms die during heartworm treatment and to weaken the heartworms.
Step 6: Heartworm Treatment for Dogs and Cats
The treatment process for heartworms is determined on a case-by-case basis, but most pets are treated with the following protocols over several months:
- First heartworm treatment: Melarsomine injection will be given to your dog to eradicate adult heartworms. Your pet will be hospitalized for the day to closely observe for any side effects and to control pain. Oral Prednisone will be prescribed for 4 weeks, and pain medication will be prescribed to use if needed. Your pet will need to rest completely for 30 days.
- Second Melarsomine treatment: After 30 days, the second injection will be given to your dog. Your pet will be hospitalized again for the day to closely observe for any side effects and to control pain. Prednisone will be prescribed again for 4 weeks and pain medication will be prescribed to use if needed. Return in 24 hours to complete the third and last heartworm treatment.
- Third Melarsomine treatment: A third and final injection will be given to your dog. Your pet will be hospitalized for the last time for the day to closely observe for any side effects and to control pain. Your pet will be sent home and given instructions for home care.
- Recheck in with your veterinarian in one month to make sure your pet is doing well.
- Recheck in 6 months to repeat heartworm test.
Step 7: Home Care During Heartworm Treatment
- After each heartworm treatment for dogs and cats, you will need to monitor for any side effects: injection sight swelling, pain, coughing, labored breathing, lethargy, decreased appetite, vomiting or diarrhea. If you see any adverse side effects, please immediately call your veterinarian.
- Strict rest is imperative for 6-8 weeks. This means that your pet can be leashed walked outside to urinate and defecated, but must come back inside to rest. Do not allow your pet to run, jump, climb stairs, or play rough with other dogs or children. When your pets are not supervised, they should be crated to prevent activity.
- Please complete all medications that are prescribed for your pet even if your pet is feeling well and appears healthy.
At Vetsavers Pet Hospital we follow the American Heartworm Association guideline for heartworm treatment to ensure your pet will get the best possible care and successful outcome.
Download the American Heartworm Association Guideline for heartworm treatment today!