Heartworm, Flea, and Tick Preventions

Heartworms: 

• Heartworms are transmitted by mosquitos. Once your pet is bitten by an infected mosquito  they get a small baby heartworm called dirofilaria. It takes 6 months for the dirofilaria to grow into adult heartworms. Since heartworms live in the heart and lungs, they can lead to heart and lung disease. Not all dogs with heartworms have symptoms of heartworm disease. 

• It is much easier and cheaper to prevent heartworms than to try to treat them.  Especially since the treatment of adult heartworms can have serious and potentially deadly side effects as the adult heartworms start dying. 

• Monthly preventions work by killing any dirofilaria  the pet contracted in the previous 30 days.  The monthly preventions do not work on the intermediate life stages or the adult life stages. Monthly preventions need to be given every month all year round to kill the dirofilaria transmitted by the mosquitos before they get an opportunity to grown into an adult heartworm. If prevention is missed, there is a possibility for dirofilaria to continue growing into the next life stages. 

• It is important to test for heartworms yearly to make sure the medication is working and to catch heartworm infection early before serious disease has occurred. 

• Heartworm test is a blood test involving a couple drops of blood and can often be performed in the hospital and takes approximately 10 minutes to run. 

For more information about heartworms: American Heartworm Society

CAPC (Companion Animal Parasite Council) provides up to date numbers on the prevalence of canine heartworms in the USA. 

As of March 2024, CAPC has reported that 1 out of every 100 dogs tested are positive for heartworms in the US. 

Fleas: 

• Fleas are found in the environment but spend their adult life on your pets. Once a flea gets a blood meal, they will jump off and lay eggs in their environment such as your house - in the carpet, bedding, clothing, etc. 

• The flea life cycle is about 3 months. This means that it can take 3 consecutive months of flea prevention and treating the environment to completely get rid of fleas. Treating all the pets in the house and the environment can help speed up the process of getting rid of the fleas. 

• Ideally, keep your pets on flea prevention all year round. 

• Fleas can cause multiple health problems including:  

  • Flea allergy dermatitis can look like hair loss, scratching, secondary skin infections - often in the "pants region" on your pet.

  • Tapeworms are spread via ingestion of an infected flea. Tapeworm segments look like grains of rice and are often found around the rectum or under the tail. They can lead to weight loss and nutritional deficits. 

  • Anemia can happen if the infestation is large enough, and the fleas have been on your pet long enough to cause enough blood loss to lead to diminished red blood cell count. It's possible the anemia could be severe enough to need a blood transfusion or death for your pet. 

  • Mycoplasma is a bacterial parasite spread by fleas that can cause destruction of red blood cells and anemia. Cats can also get fevers, lethargy, and weight loss. 

• Indoor pets are also at risk of getting fleas.  

• Flea prevention is recommended all year round. 

Ticks: 

• Ticks are parasites that live in the environment but will attach to your pet for a blood meal. After their blood meal, they will mate and lay thousands of eggs. 

• Ticks are easily missed on your pet and signs of tickborne disease can take  1-3 weeks or more to develop. 

• Ticks can live in wooded areas and also areas with tall grasses and shrubs. 

• Some ticks will also be out when the ground temperature is above freezing. 

• Ticks can carry multiple diseases that can cause fever, lameness, kidney disease, anemia, and low platelets. 

• Since ticks can be difficult to detect, it is important to keep your pets on monthly preventatives and vaccinate for Lyme disease when able. 

• Yearly testing for some tick borne diseases is recommended. This can be done at the same time as the heartworm test.

CAPC (Companion Animal Parasite Council) provides up to date numbers on the prevalence of canine tick borne diseases like Lyme disease, anaplasmosis, and ehrlichiosis in the USA.  

As of March 2024, CAPC has reported that 1 out of every 30 dogs tested are positive for Lyme disease, 1 out of every 15 dogs tested are positive for anaplasmosis, and 1 out of every 50 dogs tested are positive for Ehrlichiosis in the US. 

Ohio is considered high risk for Lyme disease and anaplasmosis according to the CAPC data.