The statistics are in. Over one million dogs are infected with heartworm disease in the United States, and more than half of pet owners leave their veterinarian's office without heartworm preventive (Veterinary Team Brief). While many pet owners skip heartworm prevention to save money, what they do not consider is the cost of treating their pet if they test positive for heartworms. Dr. Emilee Alms at Shoreview North Oaks Animal Hospital can help you choose the best preventative and/or course of treatment for your pet.
What Happens if My Dog Tests Positive for Heartworm Disease?
No one wants to hear that their dog has heartworm. The good news is that most infected dogs can be successfully treated. The goal is to first stabilize your dog if he is showing signs of disease, then kill all immature and adult worms while keeping the side effects of treatment to a minimum.
What to Expect:
Confirm the diagnosis. Once a dog tests positive on an antigen test, the diagnosis should be confirmed with an additional—and different—test. Because the treatment regimen for heartworm is expensive and complex, your veterinarian will want to be absolutely sure that treatment is necessary.
Restrict exercise. This requirement might be difficult to adhere to, especially if your dog is accustomed to being active. Your dog’s normal physical activities must be restricted as soon as the diagnosis is confirmed, because physical exertion increases the rate at which heartworms cause damage in the heart and lungs. The more severe the symptoms, the less activity your dog should have.
Stabilize your dog's disease. Before actual heartworm treatment can begin, your dog’s condition may need to be stabilized with appropriate therapy. In severe cases of heartworm disease, or when a dog has another serious condition, the process can take several months.
Administer treatment. Once your veterinarian has determined your dog is stable and ready for heartworm treatment, he or she will recommend a treatment protocol involving several steps. The American Heartworm Society has guidelines for developing this plan. Dogs with no signs or mild signs of heartworm disease {such as cough or exercise intolerance}, have a high success rate with treatment. More severe disease can also be successfully treated, but the possibility of complications is greater. The severity of heartworm disease does not always correlate with the severity of symptoms.
Test (and prevent) for success. Approximately six months after treatment is completed, your veterinarian will perform a heartworm test to confirm that all heartworms have been eliminated. To avoid the possibility of your dog contracting heartworm disease again, you will want to administer heartworm prevention year-round for the rest of his life.
What if My Cat Tests Positive for Heartworm Disease?
Like dogs, cats can be infected with heartworm disease. However, there are differences in the nature of the disease, how it is diagnosed, and how it is managed. Sometimes the infections will resolve on their own because cats are not the ideal host for a heartworm. However, even if the infection resolves on its own, it can leave cats with respiratory system damage. Heartworms in the circulatory system also affect the cat’s immune system and cause symptoms such as coughing, wheezing, and difficulty breathing. Heartworms in cats may even migrate to other parts of the body, such as the brain, eyes, and spinal cord. Severe complications such as blood clots in the lungs, and lung inflammation can result when the adult worms die inside the cat’s body.
Here’s what to Expect:
Diagnosis. While infected dogs may have thirty or more worms in their heart and lungs, cats usually have less than six -- and may have just one or two. While the severity of heartworm disease in dogs is related to the number of worms, in cats, one or two worms can make a cat very ill. Diagnosis can be complicated, requiring a physical exam, an X-ray, a complete blood count, and several types of blood tests. An ultrasound may also be performed.
Treatment. Unfortunately, there is no approved drug therapy for heartworm infection in cats, and the drug used to treat infections in dogs is not safe for cats. Nevertheless, cats with heartworm disease can often be helped with good veterinary care. The goal is to stabilize your cat and determine a long-term management plan.
Monitor your cat. Heartworm-positive cats may experience spontaneous clearing of heartworms, but the damage they cause may be permanent. If your cat is not showing signs of respiratory distress, but worms have been detected in the lungs, chest X-rays every six to twelve months may be recommended. If mild symptoms are noted, small doses of prednisolone may be administered to help reduce inflammation.
Provide veterinary care. If the disease is severe, additional support may be necessary. Your veterinarian my recommend hospitalization in order to provide therapy, such as intravenous fluids, medicine to treat lung and heart symptoms, antibiotics, and general nursing care. In some cases, surgical removal of heartworms may be possible.
Maintain prevention. A cat that has developed heartworm disease has demonstrated that it is susceptible to heartworm infection {outdoor and indoor cats are at risk}.
*Information shared here is sourced from The American Heartworm Society