Procox for Dogs: Complete Guide to Dosage, How It Works, Collie Safety Warning & What It Doesn’t Treat

Procox is the only veterinary product that treats both intestinal roundworms and coccidia (Isospora) in dogs simultaneously in a single oral dose. This dual-action capability makes it particularly valuable in puppies and young dogs from breeding, rescue, or kennel environments, where mixed infections are extremely common.

But Procox also has important limitations and safety considerations — including a serious warning for Collie breeds and related dogs — that are worth understanding before use. This guide covers everything: how Procox works, the correct dose, what it does and doesn’t treat, and the environmental management that’s just as important as the drug itself.

What’s in Procox and How Does Each Ingredient Work?

Procox oral suspension (Elanco, formerly Bayer) contains two active substances:

Emodepside 0.9mg/ml — The Nematocide

Emodepside is a semisynthetic depsipeptide, derived from a natural compound produced by the fungus Mycelia sterilia. It works by a completely unique mechanism: it stimulates presynaptic latrophilin (CL-1) receptors on the nerve-muscle junctions of gastrointestinal nematodes. This causes sustained flaccid paralysis and death of the worm. Because emodepside targets a receptor not affected by any other dewormer class, it is effective against nematodes that have developed resistance to avermectins (ivermectin, selamectin) or benzimidazoles (fenbendazole, mebendazole).

Emodepside reaches peak blood concentrations in dogs approximately 2 hours after oral administration.

Toltrazuril 18mg/ml — The Coccidiocide

Toltrazuril is a triazinone derivative with potent activity against all intracellular developmental stages of coccidia, including both asexual (merogony) and sexual (gametogony) phases. This is significant because some older coccidiostats (like sulfonamides) are only effective against certain stages. Toltrazuril damages mitochondrial function and nuclear division in coccidia cells, causing death of the parasite at every developmental stage.

Toltrazuril is absorbed more slowly than emodepside, reaching peak concentrations approximately 18 hours after oral administration. It is primarily excreted unchanged in the faeces.

Why Both Together?

In practice, puppies frequently carry both roundworms (acquired from their mother) and Isospora coccidia (acquired from their environment) simultaneously. Before Procox, treating such puppies required two separate products: a standard dewormer for the nematodes and a coccidiocide for the Isospora. Procox eliminates this complexity with a single treatment, which is both more convenient and less stressful for young animals.

What Procox Treats — And What It Doesn’t

Procox IS effective against:

• Toxocara canis — the most common puppy roundworm; Procox targets mature adults, immature adults, and L4 larvae
• Uncinaria stenocephala — Northern hookworm (mature adults)
• Ancylostoma caninum — hookworm (mature adults)
• Trichuris vulpis — whipworm (mature adults)
• Isospora canis — canine coccidia
• Isospora ohioensis complex — including I. ohioensis, I. neorivolta, I. burrowsi

Procox is NOT effective against:

• Tapeworms (cestodes) — including Dipylidium caninum (the flea tapeworm) and Taenia species. For tapeworms, use praziquantel.
• Giardia — a flagellate protozoan, not a coccidian. Requires specific treatment (fenbendazole, metronidazole).
• Lungworms — separate treatment required.
• Heartworm — separate prevention required.

The Most Important Clinical Nuance: Procox Doesn’t Cure Existing Diarrhoea

This trips up many owners and even some breeders. Procox effectively eliminates Isospora coccidia and dramatically reduces oocyst shedding (clinical studies show 90–100% reduction) — but it does not resolve the diarrhoea and GI signs that are already established in an infected animal. An already-symptomatic puppy with profuse, watery diarrhoea from coccidiosis needs Procox to eliminate the parasite, plus supportive care: fluid replacement, electrolytes, probiotics, and sometimes additional medical management from a vet.

Procox is most powerful when used early — before or shortly after oocyst shedding begins — as a preventive or early-curative tool in at-risk puppies.

Procox Dosage Guide

The recommended dose is 0.5 ml per kg body weight orally, as a single administration.

• Minimum age: 2 weeks
• Minimum weight: 0.4 kg
• For nematode infestations: can repeat after 14 days if needed
• Shake the bottle well before use

⚠️ Critical Safety Warning: Collie Breeds and the MDR1 Mutation

This is the most important safety consideration for Procox and is frequently overlooked. Emodepside is a substrate of P-glycoprotein — the pump encoded by the MDR1 (also called ABCB1) gene that normally prevents drugs from accumulating in the brain. Dogs with the MDR1 (-/-) mutation lack functional P-glycoprotein at the blood-brain barrier, meaning emodepside can accumulate in the CNS at much higher concentrations than in normal dogs.

Breeds at risk for the MDR1 mutation include:

• Rough Collie and Smooth Collie
• Border Collie
• Shetland Sheepdog (Sheltie)
• Australian Shepherd
• McNab
• Old English Sheepdog
• White Swiss Shepherd
• Any cross or mixed breed containing these bloodlines

Procox is not recommended for known or suspected MDR1 (-/-) carriers. If you own one of these breeds, have the dog genetically tested for the MDR1 mutation (a simple cheek swab test is available) before using any emodepside-containing product. Consult your vet for appropriate alternatives.

Environmental Management — As Important as the Drug

Procox treats the parasites inside the dog. But Isospora oocysts in the environment are a constant source of reinfection, and standard disinfectants do not kill them. Environmental management is non-negotiable for effective coccidiosis control in kennels or breeding facilities:

• Remove faeces within 12 hours — Isospora oocysts sporulate (become infectious) within 12–24 hours at warm temperatures. Removing faeces before sporulation interrupts the transmission cycle.
• Treat the entire group simultaneously — leaving untreated dogs in the same environment guarantees reinfection of treated animals.
• Steam clean or use ammonia-based disinfectants on hard surfaces where possible — standard quaternary ammonium disinfectants are ineffective against sporulated oocysts.
• Reduce environmental humidity and temperature where feasible — damp, warm conditions accelerate sporulation.

Procox vs Other Parasite Treatments — When to Use What

Where to Buy Procox

Procox 7.5ml oral suspension is available from PetShopBoss.com with free worldwide shipping: Procox Oral Suspension 7.5ml (full clinical listing) | Procox 7.5ml (puppy & breeder listing)