Lincoln Land Animal Clinic, Ltd

1150 Tendick
Jacksonville, IL 62650


Heartworm Disease & Prevention

Heart with heartworms at Lincoln Land Animal Clinic, ltd. Jacksonville, IL 62650 What is heartworm disease?

Heartworm disease is a serious and potentially fatal condition caused by parasitic worms living in the arteries of the lungs and occasionally in the right side of the heart.
~American Heartworm Society

How do pets get heartworms?

Pets get heartworms from the bite of an infected mosquito. The mosquito bites the unsuspecting pet and deposits the larvae into the animal.  The larvae migrates to the heart where it matures.  The adult heartworms then reproduce and their offspring (microfilaria) will be ingested the next time a mosquito feeds on the pet, starting the cycle all over again.

Is my pet really at risk?

Heartworm disease is transmitted by mosquitoes.  All pets are at risk, regardless of their lifestyle habits.  Both indoor and outdoor pets can get heartworm disease.  In the 2007 study conducted by the American Heartworm Society, Illinois veterinary clinics reported at least 6-25 cases per clinic, with even higher numbers in Southern Illinois.  

What damage do heartworms cause in pets?

The adult worm lives within the heart and can cause damage to the blood vessels and valves.  Unfortunately there is no test to determine how many heartworms your pet may have.  In order to determine how much damage has been done, we recommend taking x-rays of your pet's chest to see how enlarged the heart may be and what other damage might already exist.  We also recommend full blood work to see what damage may have been done to the other organs within the body.

My pet has been on heartworm preventative but still came up positive on the test.  Now what? 

The companies which manufacture these products offer various guarantees for certain diagnostics, treatments and future prevention.  Please contact our office for more information.

Treatment for heartworm disease:

We treat each patient differently depending on their condition, history, prior testing, and monthly preventative status.  If your pet has been on heartworm prevention we continue this medication for an additional three months before treating.  This medication will kill all the early stages of offspring and allow the older parasites, which are not susceptible to the preventative to grow old enough to be killed by the heartworm treatment.  This medication also helps to kill the female heartworm's offspring (microfilaria).

After three months of being on the heartworm medication, we admit your pet to the hospital to begin the adulticide treatment (killing of adult heartworms). Our hospital uses two different treatment methods for adulticide treatment; the veterinarian tailors the treatment for your pet based on history, physical examination, bloodwork, x-ray findings and overall condition.  Once the treatment  method is chosen, your pet is hospitalized and the treatment begins.

Where do the adulticide injections go and what to expect post treatment?

A small area on the your pet's back will be shaved and cleaned, this is where the injection is given.  The injection is placed deep within the back muscles on either side of the spine.  After the injection(s), your pet may be sore, swollen, and/or discolored.  In some situations we prescribe an anti-inflammatory to help with the discomfort. 

It is very important to keep your pet as quiet as possible during the treatment.  The heartworms reside within the heart and we do not want the heart to work any harder than it has to.  The heart is a pump; the artery the heart is trying to pump the blood through has a blockage (heartworms). Your pet's heart will work as hard as it can to get the blood where it needs to go.  We recommend that your pet is leash walked, that means no running off leash or in a fenced in yard, during and one month after treatment.  Your pet must continue on the heartworm medication monthly and be re-tested 5-6 months after treatment is completed.

Possible side effects of the adulticide treatment: 

If you see any of these possible side effects at any time during or after the treatment, please contact the clinic:  fever, cough, coughing up blood tinged material, lethargy, muscle stiffness and or soreness.


Your pet will need to remain on monthly heartworm preventative for the rest of their life and will need to be tested yearly.