Monday Medical: Heartworm Treatment for Cats

As we mentioned last week, two summers ago we had quite a scare: Allie developed a croupy, dry cough and when examined, our veterinarian advised us to get her tested for heartworms. It was the first we'd ever heard that a cat might be susceptible to this parasite.

Allie gave us quote a scare a few years ago!

In last week's Medical Monday, Dr. Sara Huber of Leawood Plaza Animal Hospital talked to us about what heartworm disease in cats is and what symptoms you might see if your cat is infected.

Today, we continue our discussion with her, as she discusses treatment, possible complications, and the good news - it's completely preventable.


Click here to read
Heartworm in Cats, Part 1

Dr. Sara Huber of
Leawood Plaza Animal Hospital

A Tonk's Tale: So we learned one very scary statistic last week: there are more incidents of heartworm in cats than there are cats infected with FIV and FeLV. That was shocking to us - and made us even more determined to get the word out about it.

What can you tell us about heartworm treatment in cats?

Dr. Sara Huber:  To be honest, treatment for the disease can be frustrating. Studies suggest that 10-20% of infected cats die secondary to the death of the worm. Treatment to kill the adult worms is also, in and of itself, risky.

Infected cats are usually managed with supportive care for the pulmonary disease secondary to the infection (with drugs such as steroids, bronchodilators, ivermectin, etc.).

To make things even more confusing, heartworms can be infected with a bacteria called Wolbachia. Cats have a strong immune response to this bacteria and it is thought that the bacteria could play a role in the strong inflammatory response to infection.

ATT: So if the shock to a cat's system when the worm dies isn't enough, now we have to worry about a more pronounced reaction in our cats, because the heartworms may have this bacteria as well?

Dr. Huber: Yes. And for this reason, veterinarians will frequently treat infected cats with an antibiotic called Doxycycline.  Now I need to point something out here real quick: the use of Doxycyline tablets in cats has been associated with esophageal stricture - a narrowing or tightening of the esophagus which causes swallowing difficulties - and for this reason, the medication should be compounded to a liquid.

(Note: If you haven't read about the positive impact a compound pharmacy can have on your pet's health - and the danger we're in of losing this vital resource here in the U.S. please click here and add your voice to the petition!)

ATT: So what can we as cat owners do?

Dr. Huber: Prevention is key! It is very important for cats living in heartworm endemic areas to be on a preventative year round.

My favorite product (and I am in no way affiliated with the company that makes it, nor do I profit from recommending it!) is Revolution topical. In addition to preventing heartworm infection, it prevents several intestinal parasites, can treat ear mites, and prevents and treats fleas. It is a small volume of liquid that goes between the shoulder blades. Very easy to administer and based on what we previously talked about, worlds easier and safer than managing an infection.

Take a look at this map of the 2010 prevalence of heartworm infection in the US.

 
Keep in mind, this is only reported cases. I am confident that a number of cases go unreported every year. Also bear in mind, this is an older map. The mosquitoes that carry the disease are beginning to show up in many areas previously thought to be a low risk area.

As I said before...prevention is key!!!

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We thank Dr. Huber for helping us spread the word about the very preventable dangers of heartworm infection in cats. For more information, you can visit the American Heartworm Society at http://www.heartwormsociety.org.