Diclazuril

Diclazuril is an antiprotozoal used for coccidiosis and equine protozoal myeloencephalitis. Its clinical roles include species-specific livestock or poultry products and a veterinary equine formulation for Sarcocystis neurona infection. The parasite stage affected and the treatment purpose differ among these products and diseases.

Group

Triazine antiprotozoal

Mechanism of Action

Diclazuril disrupts intracellular development of susceptible apicomplexan parasites, reducing successful multiplication and production of subsequent stages. Activity against coccidial sexual or asexual stages varies with species, while suppression of S. neurona merozoite production supports its equine application. The precise molecular target and relative contribution of individual cellular effects remain incompletely defined.

Dose Rates

Dogs

Use / stage	Dose	Route	Schedule	Instructions
Coccidiosis	25 mg/kg	PO	Once

Cats

Use / stage	Dose	Route	Schedule	Instructions
Coccidiosis	25 mg/kg	PO	Once
Kitten coccidiosis - low-dose alternative	0.625 mg/kg	PO	Once	Distinct source alternative: 1 mL of 2.5 mg/mL suspension per 4 kg. Not merged with the 25 mg/kg regimen.

Horses

Use / stage	Dose	Route	Schedule	Instructions
Equine protozoal myeloencephalitis	1 mg/kg	PO	Every 24 h	Up to 28 days; Top-dress oral pellets using the supplied cup.

Sheep

Use / stage	Dose	Route	Schedule	Instructions
Lamb coccidiosis	1 mg/kg	PO	Once	Preventive administration around 4-6 weeks when disease is expected; under high challenge a second treatment may be indicated about 3 weeks later.

Cattle

Use / stage	Dose	Route	Schedule	Instructions
Calf coccidiosis control	1 mg/kg	PO	Once	Source regimen is administered 14 days after entry to a high-risk environment; treat all exposed calves in the pen.

Indications

Treatment of equine protozoal myeloencephalitis caused by Sarcocystis neurona.
Prevention or control of coccidiosis due to susceptible Eimeria species in lambs or calves with an indicated product.
Prevention or control of coccidiosis in poultry with a corresponding formulation.
Extra-label treatment of selected companion-animal coccidiosis, with limited species- and regimen-specific clinical evidence.

Contraindications

Hypersensitivity; breeding/pregnancy/lactation safety for equine Protazil has not been established.

Interactions

Safety of equine concurrent therapies is not fully characterised.

Adverse effects

Occasional severe diarrhoea in highly susceptible lambs; equine adverse effects were uncommon in source trials.

Toxicity

Wide safety margins are reported, but overdose still warrants hydration and renal monitoring.

Preparations

Preparation	Form	Strength	Route
Protazil oral pellets 1.56%	Granules	15.6 mg / g	PO
Vecoxan oral suspension 2.5 mg/mL	Oral Liquid	2.5 mg / mL	PO

Monitoring and Administration

Shake suspensions. Treat group exposure and improve housing hygiene for calf/lamb coccidiosis.

For Protazil pellets use the supplied dosing cup; round up to the next weight graduation when the horse lies between marks.

Monitor neurologic response in EPM; parasite treatment does not guarantee complete neurologic recovery.