Diluting Marquis Paste

Document Type:
Information Sheet
Infectious Disease
Canine and Feline

This information sheet shows how to use Ponazuril/Toltrazuril most effectively for treatment of coccidia in kittens and puppies.

The articles referenced below describe the use of toltrazuril and/or diclazuril for treatment of coccidia in kittens and puppies. Lloyd, et al found Toltrazuril at 30 mg/kg once or 15 mg/kg repeated daily for three days, then repeated again 10 days later was effective in clearing coccidial infection in experimentally infected kittens. A single dose of Diclazuril at 25 mg/kg did not clear infection in all treated puppies or kittens, but a repeated treatment was not tried in this study. Recontamination of the environment can be a problem and lead to reinfection. Daugschies, et al found that 10, 20 or 30 mg/kg of Toltrazuril suspension given to 4 week old puppies three days post infection successfully prevented shedding or development of signs in puppies. 4/6 untreated controls developed severe hemorrhagic diarrhea and died. The authors recommend prophylactic treatment of puppies at 3-4 weeks of age.

Ponazuril is a metabolite of Toltrazuril, and is available in the United States as Marquis Paste, produced by Merial.  Anecdotally, this drug has been used off-label successfully for treatment of coccidia at a dose of 15-30 mg/kg. A recent study by Lister, et al found the use of oral ponazuril at 50 mg/kg once daily for 3 consecutive days for the treatment of coccidiosis in dogs and cats to be effective.  A follow-up fecal flotation performed immediately after treatment is recommended, especially if the initial oocyst count is heavy.

Marquis paste is marketed for treatment equine protozoal myeloencephalitis (EPM) and administration to small animals is easiest when the paste is diluted. One tube of paste contains 127 grams (4.5 oz.) at 150 mg/gm (19,050 mgs total per tube) which is a 15% solution.

Although a single tube can be quite expensive, the ‘per animal’ cost is reasonable once diluted. Ponazuril is reportedly stable in suspension and can be mixed with water and VAL syrup or other suspensions to improve palatability.  The solution should be stored in a light proof container and thoroughly shaken before administration.  You may not want to make the whole tube up at once, in case of spills.

Ponazuril dilution instructions:

50 mls Marquis paste + 12.5 mls water + 12.5 mls syrup for flavor = 75 mls of 100 mg/ml solution

Or for a smaller amount at one time:

20 mls Marquis paste + 5 mls water + 5 mls syrup for flavor = 30 mls of 100 mg/ml solution

Dose at 25 mg/lb (~55 mg/kg) once at intake for all animals under 6 months of age and repeat again in 10-14 days

For animals testing positive for coccidia - dose at 25 mg/lb (~55 mg/kg) once daily for 3-5 days depending on severity of clinical signs

Dosing Chart:


Single tubes are available from various sources, e.g. Agri-med.com


  1. Darius AK, Mehlhorn H, Heydorn AO. Effects of toltrazuril and ponazuril on the fine structure and multiplication of tachyzoites of the NC-1 strain of Neospora caninum (a synonym of Hammondia heydorni) in cell cultures. Parasitol Res. Apr 2004;92(6):453-458. Epub 2004 Feb 2012.
  2. Lloyd S, Smith J. Activity of toltrazuril and diclazuril against Isospora species in kittens and puppies. Vet Rec. Apr 21 2001;148(16):509-511.
  3. Daugschies A, Mundt HC, Letkova V. Toltrazuril treatment of cystoisosporosis in dogs under experimental and field conditions. Parasitol Res. Oct 2000;86(10):797-799.
  4. Listler AL, Nichols J, Hall K, Camp J, Mohamed AS.  Use of ponazuril paste to treat coccidiosis in shelter-housed cats and dogs.  Veterinary Parasitology. 2014:202 pg. 319-325.