Stephanie Howe, DVM
By Stephanie Howe, DVM on Oct. 7, 2022

In This Article


PetMD’s medications content was written and reviewed by veterinary professionals to answer your most common questions about how medications function, their side effects, and what species they are prescribed for. This content shouldn’t take the place of advice by your vet.

What is Praziquantel?

Praziquantel is a type of medication called an anthelmintic, meaning that it treats parasitic worms. Praziquantel is effective in the treatment of tapeworms. There are a number of tapeworm types that can affect dogs and cats and this product takes care of several including Dipylidium caninum and Taenia pisiformis/taeniaeformis. In dogs it is also used in the treatment of a rarer species of tapeworms (Echinococcus granulosus and Echinococcus multilocularis).

How Praziquantel Works

The way in which praziquantel works against tapeworms is not entirely known, but it is suspected that it interferes with integrity of the worm's skin and causes paralysis. The deceased worms will either be defecated out or be digested with the rest of the ingested in the pet's digestive tract.

Praziquantel can be used as a standalone medication but is also used in combination with other products, like other anthelmintic products, but also in combination with flea or heartworm preventatives. Praziquantel and praziquantel combination products are available in many forms such as tablets, chews, topicals and as an injectable.

Praziquantel as a sole medication is available as a tablet (Droncit®) and as an injection (Praziquantel®). Common products that contain praziquantel along with other medications include: Interceptor Plus®, Sentinel®, Iverhart Max®, Profender®, Centragard®, Drontal®, and Virbantel®.

Praziquantel Directions

Because praziquantel is utilized in many different types of products, it is important to follow the directions on the drug label or as provided by your veterinarian. Your veterinarian may recommend giving this medication once for the treatment of tapeworms and they may recommend giving it twice–several weeks apart due to the nature of the tapeworm lifecycle in dogs and cats. If praziquantel is part of your pet's heartworm prevention medication–these medications are typically given orally once per month.

Dogs with an MDR-1 gene mutation (also called ABCB1) are at a slightly greater risk for an overdose. This product is safe for pets with this gene mutation at normal doses.

Missed a Dose?

If you forget to give a dose of praziquantel or a praziquantel containing product, give it when you remember. However, if it is almost time for your next dose, skip the missed dose and resume your normal dosing schedule. Do not give extra or double doses.

Praziquantel Possible Side Effects

Most pets do quite well with this medication. When seen, side effects may include:

  • Lack of appetite

  • Vomiting

  • Diarrhea

  • Lethargy

  • Drooling

  • Weakness

In addition to those symptoms, those pets receiving the injectable version of this medication can have soreness in the area the injection was given.

You may see dead tapeworms in your pet's stool if this medication was used to treat an active tapeworm infection; however it is more likely that you will not see any tapeworms in your pet's stool.

Human Side Effects

While praziquantel is also used as a human prescription medication there are different dosages and side effects that can occur in humans.  If you accidentally ingest a pet medication, call your physician or the national Poison Control Center hotline at 800-222-1222.


No specific monitoring is required for this medication, but your veterinarian may recommend routine testing depending on your pets' individual needs, other medications they may be on and/or the issue that initially caused your pet to be placed on this medication.

Call Your Vet If:

  • Severe side effects are seen (see above) or persistent vomiting or bloody diarrhea

  • You see or suspect an overdose

  • You have additional questions or concerns about the use of praziquantel

Praziquantel Overdose

Praziquantel overdoses are quite rare as this medication has a large margin of safety. Dogs with an MDR-1 gene mutation (also called ABCB1) are at a slightly greater risk for an overdose. This product is extremely safe for pets with this gene mutation at normal doses.

With large overdoses, in dogs and cats, vomiting, drooling, lethargy, trouble walking and even death can be seen if the overdose is large enough.

If you suspect an overdose, immediately contact your veterinarian or an animal poison control center. Consultation fees often apply.

Pet Poison Helpline (855) 764-7661

ASPCA Animal Poison Control (888) 426-4435

Praziquantel Storage

Storage recommendations will greatly depend on the product or combination product being used. Stand alone tablet versions of this medication are generally recommended to be stored below 77 F. With all tablet medications please keep the container tightly closed in order to protect from moisture and light.  

Keep out of reach of children and pets.

No vet writer or qualified reviewer has received any compensation from the manufacturer of the medication as part of creating this article. All content contained in this article is sourced from public sources or the manufacturer.

Featured Image: ignjatovic

Stephanie Howe, DVM


Stephanie Howe, DVM


Dr. Stephanie Howe graduated from the University of Florida College of Veterinary Medicine in 2011, after receiving a Bachelor of Science...

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