Company: FARNAM

FORMULATION: «tablets» for oral administration; may be chewable, flavored, coated, etc, depending on the country


CHEMICAL CLASS of the active ingredient(s):


PARASITES CONTROLLED (spectrum of activity):


Tablets for small dogs: 30 mg pyrantel + 30 mg praziquantel
Tablets for medium and large dogs: 114 mg pyrantel + 114 mg praziquantel

  • Dogs 6 to 12 lbs. 2.7 to 5.4 kg bw: 1 small tablet (equivalent to 11.1 to 5.6 mg/kg pyrantel and 11.1 to 5.6 mg/kg praziquantel)
  • Dogs 12.1 to 25 lbs. 5.5 to 11.3 kg bw: 2 small tablets (equivalent to 10.9 to 5.3 mg/kg pyrantel and 10.9 to 5.3 mg/kg praziquantel)
  • Dogs 25.1 to 50 lbs. 11.4 to 22.7 kg bw: 1 large tablet (equivalent to 10.0 to 5.0 mg/kg pyrantel and 10.0 to 5.0 mg/kg praziquantel)
  • Dogs 50.1 to 100 lbs. 22.8 to 45.4 kg bw: 2 large tablets (equivalent to 10.0 to 5.0 mg/kg pyrantel and 10.0 to 5.0 mg/kg praziquantel)
  • Dogs 100.1 to 150 lbs. 45.5 to 68 kg bw: 3 large tablets (equivalent to 7.5 to 5.0 mg/kg pyrantel and 7.5 to 5.0 mg/kg praziquantel)
  • Dogs 150.1 to 200 lbs. 68.1 to 90.7 kg bw: 4 large tablets (equivalent to 6.7 to 5.0 mg/kg pyrantel and 6.7 to 5.0 mg/kg praziquantel)

* Can be slightly different in some countries: read the product label!


  • LD50 (acute oral) in rats: n.a. for the tablets. >5000 mg/kg for pyrantel; 2840 mg/kg for praziquantel
  • Estimated Hazard Class according to the WHO: not applicable for veterinary medicines

Suspected poisoning? Read the articles on pyrantel safety and/or praziquantel safety in this site.

Never use on cats tablets approved only for use on dogs, and vice-versa. Never use on small dogs tablets approved for large dogs. Learn more about tablets and their safety.

You may be interested in the following articles in this site dealing with the general safety of veterinary products:


Risk of resistance development? YES, but rather low in Ancylostoma caninum.
There are reports on resistance of Ancylostoma spp to pyrantel in dogs and horses, but so far it does not seem to be widespread.

 Alternatives to prevent resistance through product rotation:

There are no reports on resistance of of tapeworms to praziquantel.

Learn more about resistance and how it develops.


Are the active ingredients of this product ORIGINAL* or GENERICS**?

  • Pyrantel: GENERIC (introduced in the 1960s)
  • Praziquantel: GENERIC (introduced in the 1970s)

*Meaning that they are still patent protected and generics are not yet available
**Meaning that they have lost patent protection and may be acquired from manufacturers of generic active ingredients other than the holder of the original patent.

COUNTRIES where this product is marketed: USA
GENERIC BRANDS available? YES, in many countries. This product itself contains generic pyrantel and praziquentel.

Click here to learn more about GENERIC vs. ORIGINAL drugs.


D-WORM COMBO is FARNAM's generic wormer for dogs with pyrantel and praziquantel, effective against roundworms, hookworms and tapeworms.

Pyrantel is a narrow-spectrum anthelmintic belonging to the chemical class of the tetrahydropyrimidines that was introduced in the 1960s (by PFIZER → ZOETIS). It is effective against roundworms and a few tapeworms (depending on the dose) in the gut, but not against those in other organs (e.g. the lungs, the skin, etc). It controls  important dog worms such as the roundworms Toxocara canis and Toxascaris leonina, the hookworms Ancylostoma caninum and Uncinaria stenocephala. It is used a lot in pets and horses but rarely in livestock. There are dozens of products for pets with generic pyrantel.

Praziquantel is a veteran isoquinoline anthelmintic introduced in the 1970s (by BAYER). It is still the most effective and most vastly used parasiticide against tapeworms, but without any efficacy against roundworms, fleas or ticks. Praziquantel adds efficacy against tapeworms (Dipylidium caninumTaenia pisiformis, Echinococcus granulosusEchinococcus multilocularis) but has no efficacy whatsoever against roundworms, hookworms or whipworms. It is the anthelmintic most vastly used against tapeworms on pets. There are hundreds of antiparasitic brands for pets containing praziquantel.

Pyrantel, praziquantel, all the benzimidazoles (e.g. febantel, albendazole, mebendazole, etc.), piperazine, and other anthelmintics have no residual effect, i.e. they act against the worms during a few hours after administration but are quickly metabolized and excreted. For this reason treatment must often be repeated for certain indications. This is in contrast with wormers containing macrocyclic lactones (e.g. milbemycin oxime, selamectin) that ensure efficacy against numerous roundworms during weeks after a single treatment.

For an overview and a list of the most popular pet wormers click here.


This article IS NOT A PRODUCT LABEL. It offers complementary information that may be useful to veterinary professionals and users that are not familiar with veterinary antiparasitics. 

Information offered in this article has been extracted from publications issued by manufacturers, government agencies (e.g. EMEA, FDA, USDA, etc.) or in the scientific literature. No guarantee is given on its accuracy, integrity, sufficiency, actuality and opportunity, and any liability is denied. Read the site's DISCLAIMER.

In case of doubt contact the manufacturer or a veterinary professional.