Brand: CESTEX ®

Company: ZOETIS

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


CHEMICAL CLASS of the active ingredient(s): ISOQUINOLINE


PARASITES CONTROLLED* (spectrum of activity):


USA and other countries

  • Dogs: 2.5 mg/lb (≈5.5 mg/kg)
  • Cats: 1.25 mg/lb (≈2.25 mg/kg)

Dosage schedule: Tablets of different sizes containing 12.5 mg, 25 mg, 50 mg, and 100 mg epsiprantel/tablet

    • Dogs 5 lbs. ≈ 2.25 kg bw: 12.5 mg epsiprantel
    • Dogs 6 - 10 lbs. 2.7 - 4.5 kg bw: 25 mg epsiprantel
    • Dogs 11 - 20 lbs.  5.0 - 9.0 kg bw: 50 mg epsiprantel
    • Dogs 21 - 40 lbs. 9.5 - 18.2 kg bw: 100 mg epsiprantel
    • Dogs 41 - 50 lbs. ≈ 18.5 - 22.7 kg bw: 125 mg epsiprantel
    • Dogs 51 - 60 lbs. ≈ 23.0 - 27.2 kg bw: 150 mg epsiprantel
    • Dogs 61 - 80 lbs. ≈ 27.7 - 36.3 kg bw: 200 mg epsiprantel
    • Dogs 81 - 90 lbs. ≈ 36.7 - 40.8 kg bw: 225 mg epsiprantel
    • Dogs 91 - 100 lbs. ≈ 41.3 - 45.4 kg bw: 225 mg epsiprantel
    • Dogs >100 lbs. ≈ >45.4 kg bw: 2.5 mg/lb rounding up to the next whole tablet combination
    • Cats <10 lbs. bw: 12.5 mg epsiprantel

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


  • LD50 (acute oral) in rats: >5000 mg/kg for epsiprantel a.i.
  • Estimated Hazard Class according to the WHO: not applicable for veterinary medicines

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? NO

There are no reports on resistance of tapeworms to epsiprantel after decades of use.

Learn more about resistance and how it develops.


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

  • Epsiprantel: GENERIC (introduced in the 1980s)

*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, Canada, etc.
GENERIC BRANDS available? NO, in most countries

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


CESTEX is ZOETIS' veteran anthelmintics against tapeworms for dogs and cats with epsiprantel. It is an alternative to the most vastly used praziquantel

Epsiprantel is a narrow-spectrum anthelmintic introduced in the 1980s (by PFIZER - ZOETIS), effective only against tapeworms, not against heartworms, roundworms, hookworms or whipworms. It is a well tolerated anthelmintic belonging to the chemical class of the isoquinolines. It is not used In livestock or in agriculture.

Epsiprantel has no residual effect, i.e. it acts against the worms during a few hours after administration but is quickly metabolized and excreted. For this reason treatment must often be repeated for certain indications. 

In some countries ZOETIS markets formulations of epsiprantel together with other anthelmintics (e.g. pyrantel).

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.