Veterinarians used the “fast-kill” and “slow-kill” methods, the latter just involving long term use of a heartworm preventive to kill microfilariae and waiting for adult worms to die after five to seven years. The problem with this method is that worms can still continue to re-infect your dog, and significant damage can occur in a short amount of time. Therefore, the American Heartworm Society recommends the fast-kill method for dogs.
Dogs who are newly diagnosed need to start taking an oral heartworm preventive containing ivermectin, and they need to do this every 30 days while undergoing treatment to help prevent new infections. At the same time, an oral antibiotic known as doxycycline is prescribed for four weeks. It is used to kill tiny amoebae that live on the worms known asWolbachia.
During this time, you should begin trying to restrict some of your dog’s activity. After the first two months, your dog will be able to start theadulticide treatment. This is when your vet administers an arsenic-containing compound known asmelarsomine which kills adult heartworms.
Your dog’s class number will dictate if he requires the two-injection or three-injection protocol. Most dogs receive all three injections on the following days of treatment: day 60, day 90, and day 91. These injections can be extremely painful and cause lethargy for the first 24 to 48 hours. Your vet will recommend pain medications like NSAIDs or maybe steroids if your dog’s coughing is severe. Other pain medications like tramadol can be effective, and CBD oil may also be an option for comfort.
In rare cases, dogs can have an adverse reaction to treatment. Extreme exercise restriction is critical because fragments of dead heartworms can break up and act like blood clots, which can be life-threatening if they obstruct major arteries. Playing and running are not permitted, and any dog who goes outsidemust be on a leash at all times.
Follow up testing occurs around four to six months after the injection protocol is complete. However, veterinarians are always finding new information about variations to this protocol. For example, new evidence suggests thatmoxidectin, the active ingredient in topical Advantage Multi, may be an effective way to treat heartworm disease in dogs1.
Caval syndrome patients can only be treated via the emergency surgical removal of heartworms. The surgery is extremely risky, and unfortunately, most patients do not survive.