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Chelmsford Animal Hospital

Parasite Control

Parasites such as fleas, ticks, heartworm, roundworm, and hookworm can be detrimental to your pet’s health. Prevention is key and should be taken year-round.


Parasites are no fun for your pet or humans. Not only are they a nuisance, but their presence can result in serious consequences. Parasites can diminish the quality of life and even cause life-threatening health issues.

Common internal parasites include heartworms, roundworms, hookworms, whipworms, and tapeworms. The most frequent external parasites include fleas and ticks. Your pet should be free from parasites, both internal and external, which we can help with through preventative measures.

Why are parasites dangerous?


Fleas are small, wingless, brown, fast-moving insects you can see in your pet’s fur. Some animals are allergic to the saliva of fleas, which can cause inflammation and more discomfort. If ingested while your pet is grooming themselves, fleas can transmit an intestinal parasite called tapeworm. Flea infestations can lead to anemia and fleas are also capable of transmitting serious diseases.


Ticks are members of the spider family and live in cracks and crevices in the home or outside in grass, woods, brush, and weeds. Some tick bites only cause mild irritation or swelling at the site, but other tick bites can infect your pet with serious illnesses. If left untreated, these diseases, such as Lyme, can lead to more severe health problems or even be fatal.

Note: If you see a tick and cannot remove it, we will gladly help you. Call us immediately to limit the impact of the tick's attachment. It’s much safer to have one of our trained professionals remove the tick for you. Make an appointment with us immediately to limit the impact of the tick.

To track tick activity in your area, visit Tick Talk


Heartworms are transmitted when an infected mosquito bites your pet. Heartworms are parasites that live in the heart and surrounding blood vessels. The adult heartworm produces offspring called microfilariae, which circulate in the pet’s blood. Unrecognized and untreated heartworm infections can be fatal.

When should I seek treatment for parasites?


If your pet is showing signs of fleas such as continuous scratching, gnawing, or licking, schedule an appointment immediately. Additionally, flea dirt, the by-product of fleas that look like coffee grounds or pepper, can usually be seen by looking at your pet’s abdomen or by combing your pet’s coat with a fine-tooth comb.


If you see a tick on your pet, we recommend calling us to limit the impact of the tick. If you notice the tick outside of business hours, follow this tutorial to safely remove the entire tick: The Best Way to Remove a Tick

Prevention is key when it comes to ticks. One of the most common and effective prevention methods is a monthly oral medication. Chat with us today to explore the options.


Heartworm prevention may not be necessary in all cases, please discuss with the Veterinarian your pet’s risk factor.

The parasite is transmitted through mosquito bites and usually, the pet shows no signs for months. Later symptoms include difficulty breathing, coughing, weight loss, tiring easily and listlessness. In many cases, pets do not show outward signs until advanced stages of the disease. An annual blood test is recommended to screen for heartworms. This disease can be treated if found early, but it can be costly.

How can I prevent parasites?

Our veterinary team is happy to help you choose the correct preventive regimen based on your pet’s risk factors and health status. It is important to discuss with us yearly which pest control products are ideal for your household based on the everyday life of your pet.

Parasites such as fleas and ticks can be detrimental to your pet’s health. Prevention is key and should be taken year-round.