Cats get heartworm disease?
- Heartworms are carried by mosquitoes. The mosquito must first bite a dog with heartworms and ingests baby heartworms along with a blood meal.
- The mosquito flies around doing its thing while the babies grown up into "L3" larvae. They are like pre-teens.
- Now, when an affected mosquito bites your cat, some of these L3 larvae find their way into your pet's body.
- Most of these L3 larvae are dispatched by the cat's immune system, but some times they make it to the blood stream in about 3 months.
- They hang around for about 6 to 8 weeks, trying to figure out just where they are.
- Finally, some of the larva will find their way to the heart. Usually, they don't recognize it as a home and just continue to travel into the pulmonary artery and wander through the blood vessels into the lungs.
- Eventually, they reach the end of the line and stop. At that time, they are either recognized by lymphocytes, that initiate an immune response; or they are able to produce a chemical that keeps the lymphocytes away.
- If the lymphocytes are alerted, they cause a heightened immune response that causes a mild to severe pneumonia. Luckily, it is rarely fatal.
- If the lymphocytes are kept away, the larva can live for a couple of years. Although It will not mature to an adult, it will still grow and get larger.
- Ironically, when the larva dies, it stops producing the substance that fools the lymphocytes. The lymphocytes promptly recognize the dead larva, initiate a massive immune response that is usually fatal.
How can you tell if your cat has heartworms?
- There are two types of heartworm tests for cats.
- Antibody test: If positive it indicates that the cat has been exposed to heartworms. This does not mean that it has heartworms now, only that it was exposed sometime in the past.
- Antigen test: If positive it means that the cat is currently infected by an adult heartworm. These cases are very uncommon.
- Usually, these cases are diagnosed only after running X-Rays and exhaustive blood work.
How is heartworm disease treated in the cat?
- Treating is problematic. If the larva is killed, they can cause an exaggerated often fatal immune response.
- Because of this issue, treatment is symptomatic. The goal is to keep the cat as stable and comfortable as possible.
How is heartworm prevented?
- There is heartworm prevention for cats.
- Heartgard for cats is a monthly chewable treat that will prevent heartworms.
- In outdoor cats, it should be given for at least six months from late spring to autumn.