Heartgard Plus is a heartworm preventive treatment that also controls and treats various other worm infections. It also treats hookworms and roundworms.

The FDA Provides Answers to Frequently Asked Questions About Animal Drugs

  

What is an approved animal drug?
How does an animal drug get approved by FDA?
What are the benefits of FDA's drug approval process?
Are approved animal drugs the only drugs that can be legally used in animals?
Can a drug for people be legally used in animals?
What does extra-label use mean?
Where can I find information about a drug my veterinarian prescribed for my pet?
Why can't I find information about a drug in Animal Drugs @ FDA?
My dog had a bad reaction to a drug. How do I report this side effect?
How does FDA get an unsafe or ineffective animal drug off the market?
Is a generic animal drug as safe and effective as the brand name animal drug?
Is it safe to give my pet a pain reliever for people, such as aspirin, ibuprofen, naproxen, or acetaminophen?
Why does a veterinarian have to examine my pet before prescribing a drug?

What is an approved animal drug?

An approved animal drug has gone through FDA's drug approval process. During this process, the agency reviews information, submitted by the drug company, about the animal drug. If the information meets the requirements for approval, the agency approves the animal drug. FDA's approval means the drug is safe and effective when it's used according to the label. FDA's approval also ensures that the drug's strength, quality, and purity are consistent from batch to batch, and that the drug's label is truthful and complete.

Back to the top


How does an animal drug get approved by FDA?

The approval process for an animal drug is a collaborative effort between the drug company and FDA. In a nutshell, the steps of the approval process are:

For more information about the approval process for an animal drug, please see From an Idea to the Marketplace: The Journey of an Animal Drug through the Approval Process.

Back to the top


What are the benefits of FDA's drug approval process?

The benefit of FDA's drug approval process is the assurance that an approved animal drug is safe, effective, and high-quality. The drug company has shown that the drug is safe and effective in a specific animal species when used according to the label. The label is written specifically for that species and includes all necessary information to use the drug safety and effectively, including the risks associated with the drug. The drug company has also shown that the manufacturing process consistently produces a high-quality drug.

Another benefit of the drug approval process is FDA's continued monitoring of approved animal drugs after they're on the market. Sometimes, the agency's post-approval monitoring uncovers safety and effectiveness issues that were unknown at the time of approval. FDA also continues to monitor the drug's labeling, the drug's manufacturing process, and the company's marketing communications related to the drug.

Back to the top


Besides approved animal drugs, there are two other categories of legally marketed animal drugs that can be used in animals, depending on the situation. These two categories are: (1) conditionally approved animal drugs; and (2) indexed animal drugs. Only drugs for minor species or for a minor use in a major species can be conditionally approved and only drugs for certain minor species can be indexed.

FDA classifies horses, dogs, cats, cattle, pigs, chickens, and turkeys as the seven major species. All other animals, such as sheep, goats, and hamsters, are minor species. A minor use in a major species is the use of a drug in a major species for a condition that occurs:

For example, the use of a drug to control pain in dogs with bone cancer is a minor use in a major species because relatively few dogs get bone cancer each year.

Conditional Approval

A conditionally approved animal drug has gone through FDA's drug approval process except the drug has not yet met the effectiveness standard for full approval. FDA's conditional approval means that when used according to the label, the drug is safe and has a "reasonable expectation of effectiveness."

The conditional approval is valid for one year. The drug company can ask FDA to renew the conditional approval annually for up to four more years, for a total of five years of conditional approval. During the 5-year period, the drug company can legally sell the animal drug while collecting the remaining effectiveness data. This early marketing is good for two reasons: first, the drug is available sooner to be used in animals that may benefit from it; and second, the company can recoup some of the investment costs while completing the full approval.

After collecting the remaining effectiveness data, the company then submits a New Animal Drug Application to FDA for full approval. FDA reviews the application and, if appropriate, fully approves the drug.

For more information, please see Conditional Approval Explained: A Resource for Veterinarians.

Indexing

An indexed animal drug is a drug on FDA's Index of Legally Marketed Unapproved New Animal Drugs for Minor Species, referred to simply as "the Index." Although technically unapproved, a drug listed on the Index has legal marketing status. It can be legally marketed for a specific use in certain minor species. Indexing is allowed for drugs for:

Indexing a drug is quite different from the drug approval process. Indexing relies heavily on a panel of qualified experts outside FDA. The experts review the drug's safety in the specific minor species and the drug's effectiveness for the intended use. All experts on the panel must agree that, when used according to the label, the drug's benefits outweigh the risks to the treated animal. If FDA agrees with the panel, the agency adds the drug to the Index.

For more information, please see Drug Indexing.

Back to the top


Can a drug for people be legally used in animals?

Yes. Veterinarians can legally prescribe an approved human drug in animals in certain circumstances. This is called an extra-label use.

Back to the top


What does extra-label use mean?

Extra-label use means using an approved human or animal drug in a way that isn't listed on the drug's label. It's sometimes called off-label because the use is "off the label"

In 1994, Congress passed a law that allows veterinarians to prescribe approved human and animal drugs for extra-label uses in animals under specified conditions.

For more information, please see The Ins and Outs of Extra-Label Drug Use in Animals: A Resource for Veterinarians.

Back to the top


Where can I find information about a drug my veterinarian prescribed for my pet?

Ask your veterinarian

Your veterinarian is your best resource for information about a drug he or she has prescribed for your pet. For more information, please see Medications for Your Pet; and Questions for Your Vet.

Look up the drug in Animal Drugs @ FDA

Animal Drugs @ FDA is an online database that includes most FDA-approved and conditionally approved animal drugs. You can search this database in several ways, such as by the drug's proprietary name (also known as the trade name or brand name) or active ingredient. Indexed animal drugs aren’t listed in Animal Drugs @ FDA.

Read the Client Information Sheet

Some approved animal drugs have a Client Information Sheet written specifically for pet owners in a user-friendly, question-and-answer format. The handout gives you detailed information about your pet's medication and the side effects it can cause, helping you use the medication as safely and effectively as possible for your pet. You can get a Client Information Sheet from your veterinarian.

Not all approved animal drugs have Client Information Sheets available. Generally, they're written for medications where owner involvement is important for safe and effective use.

Look up the drug's label

You can also find drug information by searching for the label in one of two online databases: the FDA Online Label Repository and DailyMed, a website run by the National Library of Medicine. You can search both databases in several ways, such as by the drug's proprietary name or active ingredient.

Look up the drug in the Index

The Index of Legally Marketed Unapproved New Animal Drugs for Minor Species contains information about every indexed animal drug.

Read the drug's Freedom of Information Summary

Every approved, conditionally approved, and indexed animal drug has a Freedom of Information (FOI) Summary. This summary is a public document describing the safety and effectiveness information that supports the agency's decision to approve, conditionally approve, or index the animal drug. The document includes summaries of studies that were done and explains the basis for the agency's decision. Links to the FOI Summaries for animal drugs can be found in Animal Drugs @ FDA and on the Index of Legally Marketed Unapproved New Animal Drugs for Minor Species.

Back to the top


Why can't I find information about a drug in Animal Drugs @ FDA?

There are several reasons why you might not find a certain drug in Animal Drugs @ FDA:

Back to the top


My dog had a bad reaction to a drug. How do I report this side effect?

FDA encourages pet owners to work with their veterinarian to report problems with any animal drug. Problems include undesired side effects associated with a drug and product defects. Undesired side effects are called adverse drug experiences. Adverse drug experiences also include a lack of effectiveness (the drug doesn’t do what it's supposed to do) and unfavorable reactions in people who handle the drug. Product defects are problems such as defective packaging or the drug has an abnormal appearance.

By reporting undesired side effects and product defects with animal drugs, you help FDA more easily identify and correct problems.

For more information, please see How to Report Animal Drug Side Effects and Product Problems.

Back to the top


How does FDA get an unsafe or ineffective animal drug off the market?

Under federal law, FDA has the authority to remove an approved, conditionally approved, or indexed animal drug from the market if the agency later finds the drug to be unsafe or ineffective.

The agency follows specific regulations and policies for removing an approved animal drug from the market. In most cases when FDA withdraws the approval for an animal drug, it's at the request of the drug company because the company no longer manufactures or markets the drug.

If FDA finds that a conditionally approved drug is unsafe, the agency can deny the company's request for an annual renewal. (Remember, a conditional approval is valid for only one year. To legally sell the drug after one year, the drug company must ask FDA for an annual renewal. The company can receive up to four annual renewals, for a total of five years of conditional approval.) Under certain conditions, the agency can also remove a conditionally approved animal drug from the market outside of the annual renewal process.

If FDA finds that an indexed animal drug is unsafe or ineffective, the agency removes the drug from the Index and the drug company can no longer legally sell it.

For more information, please see Process for Withdrawal of Approval of a New Animal Drug Application.

Back to the top


Is a generic animal drug as safe and effective as the brand name animal drug?

Yes. FDA requires a generic drug to have the same quality, performance, and intended uses as the already-approved brand name drug. The generic drug must be bioequivalent to the approved brand name drug. This means that the generic drug is absorbed by and performs the same way in the animal's body as the brand name drug.

FDA also requires that the generic drug be manufactured under the same strict manufacturing standards as the brand name drug. The manufacturing process for the generic drug must consistently produce a product that is equivalent to the brand name animal drug in identity, strength, purity, and quality.

For more information, please see Generic Animal Drugs: Approved or Unapproved?

Back to the top


Is it safe to give my pet a pain reliever for people, such as aspirin, ibuprofen, naproxen, or acetaminophen?

When you see your dog or cat limping or showing other signs of pain, it's common to think about giving him or her an over-the-counter pain reliever for people. But a pain reliever for people isn't a good alternative to a pain reliever approved for animals.

Even if data show that a non-steroidal anti-inflammatory drug (NSAID), like aspirin, ibuprofen, and naproxen, is safe and effective in people, the drug may not be safe and effective in dogs because the drug may:

These differences may lead to toxic effects in dogs, such as stomach problems as well as liver and kidney damage.

You have to be even more careful with cats. Cats are more sensitive than dogs to the side effects of NSAIDs because they aren't able to break down the drugs as well.

Acetaminophen (brand name Tylenol) is not an NSAID and doesn't have much anti-inflammatory activity. Acetaminophen is fatal to cats. Cats should never be given acetaminophen because their liver cannot safely break down the drug.

Even if your pet seems to be in pain, don't give him or her anything in your medicine cabinet until you talk to your veterinarian.

For more information, please see Get the Facts about Pain Relievers for Pets.

Back to the top


Why does a veterinarian have to examine my pet before prescribing a drug?

Many states have laws governing the practice of veterinary medcine, and these laws may require a veterinarian to have a valid relationship with both the patient and the client before he or she can prescribe a drug for an animal. Depending on the state, such a relationship may include a physical examination. Your veterinarian is the best person to determine which drug is best for your pet's condition and to make sure it's used appropriately. For more information about the veterinary medicine practice laws in your state, contact your state's veterinary medical board:

Back to the top

All information provided by the U.S. Food and Drug Administration