Why Heartworm Preventatives Need a Prescription

Heartworm disease is a serious and potentially fatal condition that can affect dogs and cats. The disease is caused by a parasitic worm transmitted through mosquito bites. $500 loan online. Heartworm preventatives are medications designed to prevent this disease by killing the heartworm larvae before they can mature into adult worms.

One thing that may surprise pet owners is that all heartworm prevention for dogs and cats requires a prescription from a veterinarian. Many people wonder why this is the case, and there are several good reasons.

  • Heartworm preventatives are medications designed to be given to dogs and cats for a certain period, usually monthly. Like all medications, they can have side effects and interactions with other medications. By requiring a prescription, veterinarians can ensure that the medication is safe for your dog or cat and that it will not interact with any other medications they may be taking.
  • Heartworm-preventative medications are designed to be effective at specific dosages based on the animal’s weight. Overdosing or underdosing can result in the medication not being effective or causing harm to your dog or cat. By requiring a prescription, veterinarians can ensure the correct dosage is given to each pet.
  •  Heartworm preventatives are prescription medications because they are regulated by the FDA. The FDA regulates all medications, including those for pets, to ensure they are safe and effective. By requiring a prescription, the FDA is able to ensure that heartworm medications are being used in a safe and effective manner.

Why Does my Dog or Cat Need a Heartworm Test?

The American Heartworm Society and most veterinarians recommend an annual heartworm test before prescribing a heartworm preventative. Blood testing ensures that the medication is effective, the pet is not already infected with heartworms, and there are no adverse effects of the medication. Heartworm-preventative medications kill immature heartworm larvae and prevent them from maturing into adults, which causes illness. These medications do not kill adult heartworms.

  • A dog or cat that is infected with heartworms will require a different treatment plan. Starting medication without testing can put the pet at risk of serious complications.
  • Preventatives are highly effective, but your dog or cat can still become infected with heartworms even while taking the medication. Blood testing detects any new infection and allows for prompt treatment.

If you have any questions or concerns about heartworm prevention for your dog or, talk to your veterinarian. They can recommend the best medication for your dog or cat so they receive the best protection from heartworm disease. Learn more about heartworm disease in dogs and cats on our blogs.


This information is not intended to diagnose or treat any disease and is purely educational. Please seek advice from your pet’s veterinarian with any questions regarding your pet’s health. 

Heartworm Disease in Cats: Prevention is Treatment

Commonly, we consider heartworm disease as one that only affects dogs, not cats. However, cats are at the same risk of contracting this serious disease. Just like dogs, cats can get heartworms when they are bitten by an infected mosquito.Cats that go outdoors are more likely to be exposed, however, a mosquito can easily get into the house and infect the cat. Different from dogs, most heartworm larvae in cats do not grow into adult worms, because the cat is not the ideal host. Yet, heartworm larvae can create permanent damage to the lungs and blood vessels, and affect the immune system. Adult worms take up residence within the heart, clogging blood vessels and interfering with the heart valves.

Signs & Symptoms

Cats infected with heartworm disease may show little to no symptoms or experience serious complications. Diagnosis can require an exam, blood tests, and X-rays to confirm infection. Symptoms may include the following:

  • Coughing
  • Wheezing
  • Difficulty breathing
  • Asthma-like attacks
  • Loss of appetite and/or weight loss
  • Fainting or seizures
  • Sudden collapse or death

Treatment and Prevention

Prevention equals the best medicine. Currently, no treatment or drug therapy exists for cats infected with heartworm disease. Heartworm preventative medications kill immature worms and keep new infections from developing if an infected mosquito bites your cat again. All heartworm medications require a prescription from your veterinarian, for the purpose of annual blood testing to be sure your cat is not infected. Preventative medications are highly effective, but cats may still become infected. Even with a single missed dose. Giving heartworm medication to infected cats may lead to serious reactions.

April represents National Heartworm Disease Awareness Month, but this disease does not follow a season. Because heartworm disease has been diagnosed in all 50 states, the American Heartworm Society recommends that you “think 12:” (1) get your pet tested every 12 months for heartworm and (2) give your pet heartworm preventive 12 months a year.

VetRxDirect has a variety of heartworm and parasite preventative treatments for cats. Because these require a prescription, choosing the right medication for your cat should be done with the help of your veterinarian to make sure they have the best protection.

Heartgard for Cats at VetRxDirectHeartgard for Cats

  • Kills heartworm larvae in cats
  • Eliminates adult and immature hookworms
  • Tasty chewable
  • Give once a month
  • Safe for cats six weeks and older

 

Revolution for Heartworm Disease Prevention at VetRxDirectRevolution for Cats

  • Kills fleas and controls flea infestations
  • Eliminates hookworm and roundworm
  • Prevents heartworm disease
  • Treats and controls ear mites
  • Convenient monthly topical treatment

 

Advantage Multi At VetRxDirectAdvantage Multi for Cats

  • Prevents heartworm disease
  • Kills fleas and controls flea infestation
  • Eliminates hookworms and roundworms
  • Treats and controls ear mites
  • Broad spectrum, monthly topical treatment