Modern Worm Control for Horses: Test First, Treat Smart

Four main horse parasites - strongyles, tapeworms, ascarids, and bots - require a test-first, targeted approach. Use fecal egg counts (and tapeworm-specific tests when needed), dose by accurate bodyweight, maintain pasture and stable hygiene, quarantine and test new arrivals, and work with your veterinarian to choose drugs and verify efficacy. This reduces disease and slows anthelmintic resistance.

H2: Four parasite groups to know
Four parasite groups commonly affect horses and ponies: strongyles (including small strongyles or cyathostomins), tapeworms, ascarids (roundworms), and bots. In heavy infestations they can cause weight loss, colic, poor coat condition, and even death. Early detection and a vet-led control plan reduce risk.

H2: Test before you treat
Collect a fresh fecal sample and ask your veterinarian or an accredited lab for a fecal egg count (FEC). FECs identify active egg-shedding parasites and guide selective treatment. Tapeworms are often missed by routine FECs; ask about tapeworm-specific testing (serology or saliva ELISA) if you suspect them.

H2: Targeted treatment and drug choices
Treat based on test results, not automatic blanket dosing. Common anthelmintic classes include macrocyclic lactones (ivermectin, moxidectin), benzimidazoles (fenbendazole), pyrantel, and praziquantel (effective against tapeworms). Resistance to some drug classes - especially benzimidazoles against cyathostomins - is widespread, so work with your vet to choose drugs and to check efficacy after treatment with a fecal egg count reduction test (FECRT).

H2: Dosing and safety
Dose according to accurate bodyweight. Use a weigh tape or scale rather than visual estimates. Underdosing risks treatment failure and promotes resistance. Your veterinarian can recommend the correct product and dose for the parasite identified.

H2: Pasture and stable management
Parasites spread in manure. Reduce contamination by:

• Removing droppings from pasture at least twice weekly.

• Keeping feed and water off the ground and clean.

• Isolating and testing new arrivals before turning them out.

• Composting manure properly before spreading; fresh manure can spread eggs.

H2: Age-specific concerns
Foals and young horses are especially susceptible to ascarids and often need a different prevention schedule; discuss a foal-specific program with your vet. Adult horses with low FECs may need less frequent treatment if pasture contamination is controlled.

H2: Bots and timing
Bots are the larval stage of bot flies. Treatments that kill bots (macrocyclic lactones) are commonly given when adult fly activity ends in your area. Ask your veterinarian for timing specific to your region.

H2: Practical summary
Use fecal testing to guide treatment, dose by weight, manage pasture hygiene, isolate and test new horses, and review drug choices with your veterinarian. This targeted approach protects horse health and slows development of drug resistance.