n The majority of dogs clear all heartworms with the standard treatment, but treatment is not always 100 percent effective. The label reads 90-99 percent effective; this is due to variation in each individual animal. One female worm could survive and cause the test to be positive.
Prognosis: heartworm treatment success rates
With the three-dose adulticide protocol described above, in conjunction with doxycycline and macrocyclic lactones as recommended by the American Heartworm Society, 98% of dogs will be cleared of heartworm infection.
early infection and starting life-saving therapy, as heartworms can cause significant damage to your dog's heart and lungs. Even after adulticidal therapy, in rare cases a dog will test positive again, requiring further treatment.
A positive test result confirms the patient has adult heartworms. It is likely these worms survived the adulticidal treatment, but their presence could also signal a new infection if the owner wasn't compliant in administering heartworm preventives during and after adulticide therapy.
Approximately 6 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.
The options for a dog that remains positive after treatment depends on the animal's health status and the stage of disease at the time of diagnosis. According to some veterinary cardiologists the treatment options are either to continue a monthly preventive for six months and retest, or do another round of treatment.
A newer drug is available that does not have as many side effects, allowing successful treatment of more than 95% of dogs with heartworms.
Dogs can live for at least six to seven months after becoming infected with heartworms. This is because it takes that long for adult heartworms to grow.
Because heartworms must be eliminated before they reach this adult stage, it is extremely important that heartworm preventives be administered strictly on schedule (monthly for oral and topical products and every 6 months or 12 months for the injectable).
Six months after your dog completes their treatment, you should retest for heartworms. And then be sure to continue with annual testing and a monthly heartworm preventative.
After treatment, the adult worms die and are carried by the blood to the lungs where they lodge in small blood vessels. There they decompose and are absorbed by the body over a period of several months. Reactions to the drugs are not uncommon, and there is always some risk involved in treating a dog for heartworms.
“No running, jumping, playing or high-impact exercise as these activities may cause the worms to break loose and cause significant harm to the pet being treated.”
As heartworm disease progresses, pets may develop heart failure and the appearance of a swollen belly due to excess fluid in the abdomen. Dogs with large numbers of heartworms can develop a sudden blockages of blood flow within the heart leading to a life-threatening form of cardiovascular collapse.
In most cases no reaction of any kind occurs when an ivermectin-based heartworm preventive is given to a heartworm positive dog. In fact, giving an ivermectin-based heartworm preventive to an infected dog is the first step in heartworm infection treatment.
Treatment for heartworm can cause serious complications for your pet's health and can be potentially toxic to the dog's body. Many dogs experience soreness and swelling at the site of their injections. The most severe side effects are related to a large number of worms suddenly dying.
Although there are fewer mosquitoes in the winter, there is still a risk that your pet could get heartworms if you stop giving heartworm prevention medication during this season. That's one reason veterinarians strongly recommend pets receive heartworm prevention medication year-round.
What percentage of dogs survive heartworm? With the traditional, 3-dose adulticide treatment and supportive medications, the survival rate of dogs treated for heartworm is 98%.
Stage 4 – Heartworms have caused severe damage to the animals heart, lungs, liver, and kidneys. In this stage, Caval syndrome is likely. Caval syndrome is when there is such a large amount of worms blocking blood flow to the heart that it creates a sudden life-threatening problem in need of quick surgical intervention.
Even if heartworm infection is treated, we all know it does serious, permanent damage to the body. This in-depth look at that damage will renew your commitment to consistent prevention recommendations for your veterinary patients.
Heartworms can also cause nosebleeds, pneumonia, high blood pressure, seizures, blindness, and excessive sleeping.
Dogs that have a high number of heartworms often develop symptoms such as pronounced and persistent coughing, difficulty breathing, and exercise intolerance. In more severe cases, dogs may also experience fainting or collapse, pale mucous membranes, weakness, elevated heart rate (tachycardia) and severe lethargy.
Though the dog's system has not displayed the ability to damage or dislodge adult worms, an otherwise very healthy dog may be able to outlive the worms, which can survive in the heart for five to seven years. The tests that can detect canine heartworm have increased in sophistication.
Myth #3: If my pet has heartworms, I will see them in her feces. Although many worm types, such as roundworms and tiny hookworms, are shed in your pet's feces, heartworms do not live in the gastrointestinal (GI) tract, and are not found in feces.
How long after heartworm treatment can a dog be active? According to Dr. Marteney, your dog will have to wait about six months after his diagnosis before he can get back to all his favorite activities.
All of the damage that the heartworms do while they're inside the body is permanent.