Favorites and recent references stay on this device. No patient data is stored.
Choose the species
One selection filters the source overview, clinical facts, reports and dose calculator. Literature references are not species-filtered.
Choose one species for its overview and dose calculator, or all species to browse the full evidence.
Source overview
Recorded excerpts for one species. Each dose remains a separate source entry; no regimen is selected.
Choose one species to view its source overview. All-species evidence remains available below.
View full clinical evidence and sources ↓Clinical evidence
Pending clinical review (PROPOSED)Rule-based (RULE_BASED)— applies to the facts and dose entries in this species selection; individual source records retain their own status.
Indications3
Coccidiosis (Isospora/Cystoisospora) — the standard small-animal use; Neospora, Toxoplasma potential
DogCatExtra-label (EXTRA_LABEL)2 source records · View provenance
- Dog · Plumb's Veterinary Drug Handbook, 7th ed., p. 988–989 — Indications table · Not applicable · Extra-label (EXTRA_LABEL) · Pending clinical review (PROPOSED) · Rule-based
Original excerpt: Coccidiosis (Isospora/Cystoisospora) — the standard small-animal use; Neospora, Toxoplasma potential — Extra-label (equine EPM label — Sarcocystis neurona)
- Cat · Plumb's Veterinary Drug Handbook, 7th ed., p. 988–989 — Indications table · Not applicable · Extra-label (EXTRA_LABEL) · Pending clinical review (PROPOSED) · Rule-based
Original excerpt: Coccidiosis (Isospora/Cystoisospora) — the standard small-animal use; Neospora, Toxoplasma potential — Extra-label (equine EPM label — Sarcocystis neurona)
- Dog · Plumb's Veterinary Drug Handbook, 7th ed., p. 988–989 — Indications table · Not applicable · Extra-label (EXTRA_LABEL) · Pending clinical review (PROPOSED) · Rule-based
Sarcocystis neurona MARQUIS is indicated for the treatment of equine protozoal myeloencephalitis (EPM) caused by.
Species not recordedOn-label (ON_LABEL)United States1 source record · View provenance
- Species not recorded · SPL section 34067-9 (INDICATIONS & USAGE SECTION) · United States · On-label (ON_LABEL) · Pending clinical review (PROPOSED) · Rule-based
Dose regimens4
This calculator performs arithmetic only on the sourced dosing field shown for each result — it does not verify the field's accuracy, does not select which field to use for a patient, and does not replace a veterinarian's order. Not for clinical use. Confirm every result against the primary source before dispensing.
Choose one species above to view its dose calculator.
Adverse effects205
Loose feces (6× doses) — Dose-related GI
HorseNot applicable (NOT_APPLICABLE)1 source record · View provenance
- Horse · Plumb's Veterinary Drug Handbook, 7th ed., p. 988–989 — Side Effects / Adverse Effects table · Not applicable · Not applicable (NOT_APPLICABLE) · Pending clinical review (PROPOSED) · Rule-based
Rashes/hives/blisters, GI signs — Field-trial reports
HorseNot applicable (NOT_APPLICABLE)1 source record · View provenance
- Horse · Plumb's Veterinary Drug Handbook, 7th ed., p. 988–989 — Side Effects / Adverse Effects table · Not applicable · Not applicable (NOT_APPLICABLE) · Pending clinical review (PROPOSED) · Rule-based
Bitter taste — Compounded suspension acceptance issue
DogCatNot applicable (NOT_APPLICABLE)2 source records · View provenance
- Dog · Plumb's Veterinary Drug Handbook, 7th ed., p. 988–989 — Side Effects / Adverse Effects table · Not applicable · Not applicable (NOT_APPLICABLE) · Pending clinical review (PROPOSED) · Rule-based
- Cat · Plumb's Veterinary Drug Handbook, 7th ed., p. 988–989 — Side Effects / Adverse Effects table · Not applicable · Not applicable (NOT_APPLICABLE) · Pending clinical review (PROPOSED) · Rule-based
In the field study, eight animals were noted to have unusual daily observations. Two horses exhibited blisters on the nose and mouth at some point in the field study, three animals showed a skin rash or hives for up to 18 days, one animal had loose stools throughout the treatment period, one had a mild colic on one day and one animal had a seizure while on medication. The association of these reactions to treatment was not established. Post Approval Experience (2015): The following adverse events in horses are based on post-approval adverse drug experience reporting. Not all adverse events are reported to FDA/CVM. It is not always possible to reliably estimate the adverse event frequency or establish a causal relationship to product exposure using these data. The following adverse events have been reported: Neurologic deficits, primarily ataxia, have been reported to acutely worsen during the early treatment period. Although outcome was not always reported, in some horses the worsening of the neurologic deficits was transient. To report suspected adverse drug events, for technical assistance or to obtain a copy of the Safety Data Sheet (SDS), contact Boehringer Ingelheim Animal Health USA Inc. at 1-888-637-4251. For additional information about adverse drug experience reporting for animal drugs, contact FDA at 1-888-FDA-VETS or online at www.fda.gov/reportanimalae.
Species not recordedOn-label (ON_LABEL)United States1 source record · View provenance
- Species not recorded · SPL section 34084-4 (ADVERSE REACTIONS SECTION) · United States · On-label (ON_LABEL) · Pending clinical review (PROPOSED) · Rule-based
These are counts of spontaneously reported events, not proven adverse effects, causal relationships, or incidence rates.
Bars compare report counts within each species; they do not show incidence.
More reportsFewer reportsCat
- Death11 reports
- Anorexia10 reports
- Dehydration8 reports
- Vomiting6 reports
- Agitation4 reports
- Death by euthanasia4 reports
- Gagging4 reports
- Hypersalivation4 reports
- Lack of efficacy (endoparasite) - roundworm NOS4 reports
- Lethargy (see also Central nervous system depression in Neurological)4 reports
- Ocular discharge4 reports
- Ataxia3 reports
Dog
- Diarrhoea18 reports
- Vomiting18 reports
- Death17 reports
- Other abnormal test result NOS13 reports
- Lethargy (see also Central nervous system depression in 'Neurological')12 reports
- Anorexia8 reports
- Death by euthanasia8 reports
- Lack of efficacy - NOS6 reports
- Bloody diarrhoea5 reports
- Pneumonia5 reports
- Weakness5 reports
- Ataxia4 reports
Monitoring1
Clinical: Fecal oocyst recheck ~1–2 weeks post-course; clinical diarrhea resolution; environmental hygiene (coccidiosis is a husbandry disease)
Species not recordedNot applicable (NOT_APPLICABLE)1 source record · View provenance
- Species not recorded · Plumb's Veterinary Drug Handbook, 7th ed., p. 988–989 — Monitoring Parameters · Not applicable · Not applicable (NOT_APPLICABLE) · Pending clinical review (PROPOSED) · Rule-based
Precautions6
Profile "not well established" outside horses — extra-label transparency with owners
Species not recordedNot applicable (NOT_APPLICABLE)1 source record · View provenance
- Species not recorded · Plumb's Veterinary Drug Handbook, 7th ed., p. 988–989 — Contraindications & Warnings table · Not applicable · Not applicable (NOT_APPLICABLE) · Pending clinical review (PROPOSED) · Rule-based
Coccidia game-changer: replaced the 7–20 day sulfadimethoxine regimens with a 1–3 day ponazuril course (or single 50 mg/kg dose) — the compliance differential is the whole story.
Species not recordedNot applicable (NOT_APPLICABLE)1 source record · View provenance
- Species not recorded · Plumb's Veterinary Drug Handbook, 7th ed., p. 988–989 — Clinical pearl · Not applicable · Not applicable (NOT_APPLICABLE) · Pending clinical review (PROPOSED) · Rule-based
Long half-life means short courses still work — steady accumulation does the killing.
Species not recordedNot applicable (NOT_APPLICABLE)1 source record · View provenance
- Species not recorded · Plumb's Veterinary Drug Handbook, 7th ed., p. 988–989 — Clinical pearl · Not applicable · Not applicable (NOT_APPLICABLE) · Pending clinical review (PROPOSED) · Rule-based
Don't forget the pen: oocysts survive in environment; treat the diarrhea AND clean it or re-infection recurs.
Species not recordedNot applicable (NOT_APPLICABLE)1 source record · View provenance
- Species not recorded · Plumb's Veterinary Drug Handbook, 7th ed., p. 988–989 — Clinical pearl · Not applicable · Not applicable (NOT_APPLICABLE) · Pending clinical review (PROPOSED) · Rule-based
Not for use in humans. Keep out of reach of children. For use in horses only. Do not use in horses intended for human consumption.
Species not recordedOn-label (ON_LABEL)United States1 source record · View provenance
- Species not recorded · SPL section 34071-1 (WARNINGS SECTION) · United States · On-label (ON_LABEL) · Pending clinical review (PROPOSED) · Rule-based
Interactions1
None significant documented — —
Species not recordedNot applicable (NOT_APPLICABLE)1 source record · View provenance
- Species not recorded · Plumb's Veterinary Drug Handbook, 7th ed., p. 988–989 — Drug Interactions table · Not applicable · Not applicable (NOT_APPLICABLE) · Pending clinical review (PROPOSED) · Rule-based
Pharmacokinetics4
Mechanism — Triazine — inhibits apicoplast/mitochondrial function of coccidia (kills intracellular stages)
Other speciesNot applicable (NOT_APPLICABLE)1 source record · View provenance
- Other species · Plumb's Veterinary Drug Handbook, 7th ed., p. 988–989 — Pharmacokinetics table · Not applicable · Not applicable (NOT_APPLICABLE) · Pending clinical review (PROPOSED) · Rule-based
Horse PK — 30% oral bioavailability, t½ ~80 h → accumulation to steady state over ~1 week
Other speciesNot applicable (NOT_APPLICABLE)1 source record · View provenance
- Other species · Plumb's Veterinary Drug Handbook, 7th ed., p. 988–989 — Pharmacokinetics table · Not applicable · Not applicable (NOT_APPLICABLE) · Pending clinical review (PROPOSED) · Rule-based
DMSO co-formulation — Enhances bioavailability (2.2 mg/kg in DMSO ≈ plain 5 mg/kg levels)
Other speciesNot applicable (NOT_APPLICABLE)1 source record · View provenance
- Other species · Plumb's Veterinary Drug Handbook, 7th ed., p. 988–989 — Pharmacokinetics table · Not applicable · Not applicable (NOT_APPLICABLE) · Pending clinical review (PROPOSED) · Rule-based
1-6 7 8 Sarcocystis neurona in vitro max max max max The activity of ponazuril has been demonstrated in several Apicomplexans. Lindsay, Dubey and Kennedyshowed that the concentration of ponazuril necessary to killwas 0.1 to 1.0 μg/mL. Furr and Kennedyevaluated the pharmacokinetics of ponazuril in serum and CSF in normal horses treated daily at 5 mg/kg for 28 days. The time to peak serum concentration (T) was 18.20 (±5.9) days and the maximum serum concentration (C) was 5.59 (±0.92) μg/mL. The terminal elimination half-life for serum (calculated using Day 28 to 42 data) was 4.50 (±0.57) days. In CSF, Twas 15.40 (±7.9) days and Cwas 0.21 (±0.072) μg/mL. A pharmacokinetic study was conducted in eight horses to collect serum and cerebrospinal fluid (CSF) levels of ponazuril after a single dose of 5 mg/kg body weight. The estimated parameter values were used to model time concentration profiles for ponazuril in serum and CSF. The model results were used to estimate the size of the loading dose needed to support the achievement of steady state serum and CSF levels after the first dose. The appropriate loading dose, calculated on the basis of the accumulation ratio (i.e., the fold increase in serum drug concentrations once steady state conditions have been achieved) was 15 mg/kg (6.81 mg/lb) body weight. This dose represents the range of estimated accumulation ratios of 2.3 to 3.3. Thus, a three-fold loading dose (3*5 mg/kg) was selected, leading to achievement of steady state blood levels in horses after one or two days of ponazuril administration.
Species not recordedOn-label (ON_LABEL)United States1 source record · View provenance
- Species not recorded · SPL section 34090-1 (CLINICAL PHARMACOLOGY SECTION) · United States · On-label (ON_LABEL) · Pending clinical review (PROPOSED) · Rule-based
Pregnancy / lactation considerations1
6× mare dosing: uterine epithelial edema on histopath — avoid in pregnancy where alternatives exist.
Species not recordedNot applicable (NOT_APPLICABLE)1 source record · View provenance
- Species not recorded · Plumb's Veterinary Drug Handbook, 7th ed., p. 988–989 — Pregnancy & Lactation · Not applicable · Not applicable (NOT_APPLICABLE) · Pending clinical review (PROPOSED) · Rule-based
Literature references19
References are linked to this drug. Species applicability is not recorded here, so the species filter does not narrow this list. Imported dates do not retain their original precision; confirm dates in the original citation.
- Bioanalytical RP-HPLC method for the determination of ponazuril in plasma.
Study summary not available in the imported record. Open the original citation to review the study.
- Pharmacokinetics of oral ponazuril in kea (Nestor notabilis) support its use as a preventative for sarcocystosis.
Study summary not available in the imported record. Open the original citation to review the study.
- Toltrazuril sulfone (Ponazuril) residue depletion in pig tissues and estimated withdrawal intervals.
Study summary not available in the imported record. Open the original citation to review the study.
- Ponazuril: Clinical efficacy, ultrastructure, and histopathology studies of in vivo anticoccidial action against Eimeria tenella.
Study summary not available in the imported record. Open the original citation to review the study.
- THE PHARMACOKINETICS AND PHARMACODYNAMICS OF ORAL PONAZURIL IN THE TREATMENT OF SYSTEMIC ISOSPOROSIS IN PASSERINE BIRDS.
Study summary not available in the imported record. Open the original citation to review the study.
Sources: DailyMed, U.S. National Library of Medicine; PubMed, National Library of Medicine; openFDA, U.S. Food and Drug Administration; Plumb DC. Plumb's Veterinary Drug Handbook. 7th ed. PharmaVet Inc; 2011.
Owner information handout
Plain-language medication information to review with the owner. Open the handout to print it or download a PDF.