Have you ever wondered why we recommend preventives for heartworm for dogs and cats? It’s not a very popular disease here in the northeast, but with more and more dogs being adopted from the south, where it’s prevalent, we are seeing instances of it more often. This disease is transmitted by mosquitoes. All a mosquito has to do is feed off of an animal that is positive, such as wolves, coyotes, foxes or pets that are positive, and then feed on a pet that is not treated with heartworm prevention. This is why yearly heartworm tests are recommended and why monthly preventatives are recommended by your veterinarian. The CDC (Centers for Disease Control and Prevention) recommends it also.
When should I test my dog?
*Let’s say you adopt a cute 8 month old puppy from down south. You bring him home, fall in love and make him a member of your family. You get him established at your veterinarian’s office, your doctor recommends a heartworm test and he tests negative for heartworm disease. Great! Now your doctor says “I want to test him again in 6 month,” Why? you may ask. Answer: It takes at least 6 months for a dog to test positive after being infected.
*Or, you have an adult dog, not on prevention, but you want to start. Your veterinarian will want to test her before putting her on heartworm prevention, then test again in 6 months. Reason being the heartworms need to be at least 7 months old before the infection can be diagnosed. Another test will be needed at 12 months and, as long as she is on prevention all year, she’ll only need to be tested annually.
What are the signs and symptoms of heartworm in dogs?
In the early stages of the disease, dogs may not show any clinical signs at all. The longer the infection goes undetected, the more likely symptoms will occur. Here’s a snippet from www.heartwormsociety.org:
Signs of heartworm disease may include a mild persistent cough, reluctance to exercise, fatigue after moderate activity, decreased appetite, and weight loss. 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 sudden blockages of blood flow within the heart leading to a life-threatening form of cardiovascular collapse. This is called caval syndrome, and is marked by a sudden onset of labored breathing, pale gums, and dark bloody or coffee-colored urine. Without prompt surgical removal of the heartworm blockage, few dogs survive.
What are the signs and symptoms of heartworm in cats?
First of all, let’s mention that cats are an atypical host for heartworms. Most heartworms in cats do not survive to adulthood, however even immature worms can cause damage in cats. Unfortunately, the treatment used to rid the infection in dogs is not safe for cats. However, cats can be helped with monthly preventatives and good veterinary care.
Signs of heartworm in cats may be subtle or severe. Symptoms may include:
*lack of appetite
In more severe cases, an affected cat could have difficulty walking, have some fainting or seizures, or suffer from fluid in the abdomen. In some cases the first sign could be sudden collapse or sudden death.
How do you treat a dog that is heartworm positive?
First we need to confirm a diagnosis. After testing positive on the heartworm test, an additional blood test is needed. Treatment is expensive and complex, so we need to be sure the original test was not a false positive.
Dogs must be otherwise healthy in order to start treatment. Exercise has to be very limited! Over exertion can increase the amount of damage done to heart and lungs by the heartworms.
Treatment is done over the course of 90 days, with additional blood tests after that. If your dog tests positive, your doctor will go over the schedule that is to take place. The days of treatment require hospitalization for monitoring, to be sure there’s no side effects of the medication. The injection can be painful, so your dog may be given pain medication as well.
Here is a breakdown of cost to treat a heartworm positive dog (injections are based on weight) versus treating monthly with a preventative:
For a 24lb dog, the total estimated treatment would cost approximately $1500 which is equivalent to:
22 years of protection with Heartgard Plus chew tabs given once a month
20 years of protection with ProHeart6 injections every 6 months
6 years of protection with Revolution topical treatment given once a month
For a 49lb dog, the total estimated treatment would cost approximately $1800 which is equivalent to:
20 years of protection with Heartgard Plus chew tabs given once a month
19 years of protection with ProHeart6 injections every 6 months
7 years of protection with Revolution topical treatment given once a month
For a 75lb dog, the total estimated treatment would cost approximately $1950 which is equivalent to:
18 years of protection with Heartgard Plus chew tabs given once a month
15 years of protection with ProHeart6 injections every 6 months
8 years of protection with Revolution topical treatment given once a month
It is not fun to watch dogs go through the treatment of heartworm disease. It’s so much easier (and much more cost effective) to treat with prevention on a monthly basis.
More information can be found at https://www.heartwormsociety.org/pet-owner-resources/heartworm-basics or on our website at www.crossroadsanimal-hospital.com
As always, we are here for you if you have any questions or concerns about heartworm in your pet.