Diclazuril/Toltrazuril/Folic Acid Paste

Paste medications are thick and sticky, usually given by mouth using a syringe or tube. They’re often used for dewormers or other oral meds in horses, dogs, and cats. The key is to aim for the back of the mouth so your pet swallows the paste instead of spitting it out.

For Horses:

1. Set the dose on the syringe if it has markings (usually based on weight).
2. Stand beside your horse, not in front, and have someone hold them if possible.
3. Gently insert your thumb into the side of the horse’s mouth (between the teeth) to open it.
4. Insert the syringe into that gap and squirt the paste toward the back of the tongue.
5. Lift the horse’s head slightly and encourage swallowing by stroking the throat or gently blowing on the nostrils.
6. Watch for licking or chewing—that means they swallowed. If paste spills out, check how much was lost and contact your vet if unsure.
7. You can offer a little water afterward and reward them with a treat like a carrot if allowed.

For Dogs & Cats:

1. Gently open your pet’s mouth or slip the syringe into the side of it.
2. Aim toward the back of the tongue and squirt the paste in.
3. Hold the mouth closed briefly, and rub the throat or blow gently on the nose to encourage swallowing.
4. Give praise or a treat afterward to make it a positive experience.

Aftercare:

1. Wipe your pet’s mouth if needed.
2. Clean or recap the syringe as instructed.
3. Store the tube according to label directions.

Tip: Paste can feel weird to pets at first. For horses, try giving applesauce by syringe ahead of time so they get used to the sensation.

This compounded formulation combines active ingredients from different drug classes: diclazuril, an antiprotozoal; toltrazuril, an antiprotozoal; and folic acid, a B-vitamin. In compounding practice, clinicians may consider a multi-ingredient preparation like this to address more than one aspect of a patient's physiology at once. Your veterinarian determines whether it is appropriate based on your animal's diagnostic findings.

At a pharmacological level, diclazuril and toltrazuril function by disrupting the metabolic pathways of apicomplexan protozoa. Both agents target the apicoplast—a specialized organelle within the parasite—and inhibit enzymes involved in pyrimidine synthesis and the respiratory chain. This disruption halts the parasite’s ability to replicate and maintain its energy reserves. Folic acid is included in this specialized formulation as a metabolic supplement. Since some antiprotozoal protocols can interfere with the host’s folate metabolism, providing exogenous folic acid allows your veterinarian to manage the horse’s nutritional status during therapy. Your veterinarian will determine the appropriate application of this combination based on weight, the results of cerebrospinal fluid analysis and the specific clinical nature of the neurological presentation.

This description reflects the general pharmacology of the active ingredient's drug class; your veterinarian determines whether this approach is appropriate for your animal.

Prescription only. Use only under the direction of a licensed veterinarian. This information is not a substitute for veterinary diagnosis, prescribing or monitoring. Compounded drugs are not approved by the FDA for safety or effectiveness.

Commonly observed effects of diclazuril/toltrazuril administration include localized gastrointestinal changes such as loose stools or a temporary decrease in appetite. Some horses may exhibit a transient worsening of neurological signs, often referred to by veterinarians as a "treatment crisis," which is thought to be a metabolic result of the body’s inflammatory response to dying protozoa. Owners should watch for shifts in coordination, lethargy or behavioral changes. Because maintaining gastrointestinal health is vital during long-term protocols, your veterinarian will monitor for any persistent digestive upset. If you observe significant stumbling, physical distress or a complete refusal of food, contact your veterinarian promptly.

This medication is typically used with extra caution or avoided in animals with known hypersensitivity to triazinone derivatives. It is also carefully evaluated in breeding, pregnant or lactating mares, as the safety profile for developing foals is a point of ongoing professional observation. Before starting a protocol, ensure your veterinarian has a complete history of all other prescriptions and supplements your horse is receiving. Your veterinarian is the right person to design a comprehensive monitoring plan and provide guidance on the necessary duration of use to ensure the management approach remains suitable for your horse’s individual health status.