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Global Insight Network

Do dogs really need heartworm prevention?

Author

Daniel Davis

Updated on April 30, 2026

Heartworm disease can be prevented in dogs and cats by giving them medication once a month that also controls various internal and external parasites. Heartworm infections are diagnosed in about 250,000 dogs each year. 1 But there is no good reason for dogs to receive preventives all year; it is just not needed.

Similarly, it is asked, do dogs need heartworm medicine in the winter?

Use Heartworm Prevention Medication Year-Round

Although there are a fewer number of mosquitoes in the winter, there is still a risk that an animal could contract heartworms if the owner stops giving medication during this season.

Subsequently, question is, how often do dogs need heartworm medicine? Year-round prevention is best! Talk to your dog's veterinarian to decide which preventive is best for your dog. The American Heartworm Society advocates to “Think 12." Give dogs 12 months of heartworm prevention and get them tested for heartworms every 12 months.

Beside above, how long can a dog go without heartworm pills?

The heartworm lifecycle is 6-8 months to go from mosquito bite to adult heartworms so missing one month should not cause any reactions. Your vet may recommend retesting in 6-8 months to make sure that he is still negative at that time.

How can you prevent heartworms in dogs?

Prevention of heartworm disease in dogs include Proheart 6; an injection administered in our hospital every 6 months as a scheduled appointment, Heartgard Plus; a monthly oral chew, or a monthly topical called Revolution.

Related Question Answers

Do dogs have to take heartworm pills every month?

If at the initial test, your dog is found to have heartworms, treatment will be needed before prevention can begin. However, if your dog is in the clear, he can be started on monthly medication to protect him from the disease.

Which flea and tick treatment is safest for dogs?

Frontline is one of the most trusted names in flea and tick prevention, and Frontline Plus is a great pick for your large breed. This easy-to-apply topical treatment offers 30 days of protection against fleas, ticks, chewing lice, and mites.

Do I need to give my dog flea and tick medication in the winter?

Yes! Keep your pets on flea and tick protection all year round! It is common today to hear people say “I don't give my pet flea and tick prevention in the winter there is no need, since it is so cold".

What months do dogs need heartworm pills?

Puppies under 7 months of age can be started on heartworm prevention without a heartworm test (it takes at least 6 months for a dog to test positive after it has been infected), but should be tested 6 months after your initial visit, tested again 6 months later and yearly after that to ensure they are heartworm-free.

Can I give my dog heartworm medicine without testing?

The preventatives will not kill adult heartworms, so the only way to be sure your pet is free of heartworm disease is to have the blood test performed.

Where can I buy heartworm medicine for my dog?

Petco carries prescription heartworm medication in chewable, tablet, and topical forms for your dog. Petco's full-service veterinary hospitals carry a wide range of heartworm preventatives as well.

What is the best heartworm prevention for dogs?

The Best Preventive Medicines for Heartworm In Dogs
  • Heartgard Plus is the top choice for a heartworm preventive.
  • Iverhart Plus (ivermectin/pyrantel) has been rated high for the effective protection it provides to dogs against heartworms, roundworms, hookworms and various other parasites.

What are the first signs of heartworms in dogs?

Signs of heartworm disease may include a mild persistent cough, reluctance to exercise, fatigue after moderate activity, decreased appetite, and weight loss. As heartworm disease progresses, pets may develop heart failure and the appearance of a swollen belly due to excess fluid in the abdomen.

How do you prevent heartworms in dogs naturally?

Have Conversations, Not Confrontations
  1. Avoid mosquito exposure. Because heartworms are spread by mosquitoes, advise owners to keep their pets indoors overnight and avoid pet walks at dusk or dawn when many mosquitoes are feeding.
  2. Eliminate standing water close to the home.
  3. Use natural mosquito repellents.

Is it OK to skip a month of heartworm medicine?

In this case, it would be fine to just resume giving your pet heartworm prevention medication as usual. What if my pet has missed a month of heartworm prevention? The simplest answer to those who miss a month of heartworm prevention is to give the dose immediately and restart the monthly preventative schedule.

Can I buy Heartgard without a vet?

Heartgard is a beef flavored soft-chew given once a month to prevent heartworm disease; the active ingredient in Heartgard is Ivermectin. Although Heartgard and other heartworm medicines require a prescription, at 1-800-PetMeds, we make the ordering process easy.

What does it mean if a dog is heartworm positive?

Coughing, exercise intolerance, weight loss, breathing difficulty, or sudden death can occur. Can Heartworm Disease Be Cured? It depends on the severity of heartworm disease in that particular dog. The heartworms can be eliminated in all dogs but if organ damage has already occurred, there may be continuing symptoms.

Can you do a heartworm test at home?

Product Description. VetScan Canine/Feline Rapid Heartworm Test Kit is a test for heartworm antigen in cats and dogs. Prior to initiating heartworm preventative medication, a heartworm test is required. This two-step kit only requires seconds of hands-on time, providing clinically accurate results in under 10 minutes.

How much does it cost to treat a dog with heartworms?

The average cost of heartworm treatment for dogs is often around $1,000. However, it can range from $500 to $1,100 or even more depending mainly on the size of your dog, veterinary bills, and the stage of the disease.

Does heartworm treatment shorten a dog's life?

This treatment does not actually kill the worms, however it does decrease their lifespan; keep in mind, however, that the average heartworm can live six years, so shortening that lifespan could still mean your dog having a heartworm infection for four more years.

Do dogs feel bad after heartworm treatment?

It's why dogs feel bad a week or so after they are treated. That's when the worms die and shift position. The dog may have a fever, cough, lose appetite, have trouble breathing, or cough up blood. Sometimes you don't see any of those things, but you can just tell that your dog doesn't feel good.

Do dogs poop out heartworms?

How do heartworms infect? The heartworm is one of the only mammal-dwelling parasites to be transmitted exclusively by mosquitoes. While other common parasitic worms are transferred via feces, heartworms cannot be passed directly from one host to another.

Is heartworm treatment painful for the dog?

Please contact your veterinarian about this, as human 0ver-the-counter products can be harmful to your dog. However, it sounds very much like your dog needs pain medication. The pain usually subsides in a couple of days, and most dogs don't have this type of reaction, but the ones that do get painful do need some help.

What do you give dogs for heartworms?

An injectable drug, melarsomine (brand name Immiticide®), is given to kill adult heartworms. Melarsomine kills the adult heartworms in the heart and adjacent vessels. This drug is administered in a series of injections. Your veterinarian will determine the specific injection schedule according to your dog's condition.