Ventilation

Respiratory disease is the second most common equine health problem after musculoskeletal issues, and poor barn ventilation is a primary contributing factor. Ammonia from urine, dust from hay and bedding, and mold spores from damp organic material accumulate in poorly ventilated stalls and damage respiratory epithelium. Studies from the University of Edinburgh showed that horses housed in enclosed barns have significantly higher rates of inflammatory airway disease (IAD) than horses with regular outdoor access or stalls with cross-ventilation.

Adequate ventilation means: at minimum one air change per hour in the stall space. Achieve this through windows on opposing walls that can be opened in warm weather, ridge vents or roof ventilators, and avoiding the common mistake of closing all openings in winter to "keep horses warm." Horses tolerate cold far better than ammonia and humidity -- a horse in 20 F weather with fresh air breathes better than a horse in 40 F weather in a tightly sealed, ammonia-laden stall. The exception is wind chill directly onto a wet or body-clipped horse; provide weather protection, not sealed air.

Bedding Management

Straw -- traditional; provides good cushioning, is relatively dust-free if stored dry, and composts easily. Horses may eat it, potentially causing impaction colic in horses prone to GI issues. Wet straw loses insulating value quickly. Requires daily removal of soiled material and complete stall strip weekly.

Wood shavings -- widely available; good absorbency; must be pine or cedar-free (aromatic terpenes cause respiratory irritation) or use kiln-dried shavings specifically labeled safe for horses. Fine-particle shavings are dustier than coarse ones. Deep-bed management (banking banks, adding rather than removing regularly, full strip monthly) is common with shavings.

Pelleted wood bedding -- highly absorbent; expands dramatically when wet (1 bag = several cubic feet of soft bedding). Less dust than loose shavings. Higher initial cost but often used in smaller quantities because of greater absorbency.

Rubber mats -- used under bedding, not instead of it. A 3/4-inch rubber mat reduces bedding requirements by 30-50%, reduces joint stress, and makes cleaning easier. Requires less bedding on top (2-3 inches vs. 6 inches on bare concrete), but mats must be lifted and cleaned beneath weekly to prevent bacterial accumulation.

Daily management: remove all manure and wet bedding. The presence of wet spots for more than 12 hours in a stall causes thrush (hoof bacterial infection) and ammonia buildup. Pick stalls at minimum once daily; twice daily in wet or high-traffic stalls.

Pest Control

Flies are a year-round problem in warm climates and a summer problem everywhere. They spread pathogens (pinkeye, Pigeon fever, summer sores from Habronema larvae), cause stress that reduces feed efficiency, and make horses miserable. Integrated pest management for barns:

-- Manure management is the single most effective intervention. Remove manure from the property or compost it in covered piles away from the barn. Fly larvae develop in manure; reducing manure is reducing fly source.

-- Fly predators (Spalangia and Muscidifurax parasitic wasps, available commercially) target fly pupae in manure. Release every 3-4 weeks from spring through fall. Non-toxic; complementary to other methods.

-- Fly spray or pour-on applied directly to horses. Pyrethrin-based sprays are effective short-term but break down in 12-24 hours; longer-lasting formulations (permethrin) last 7-14 days. Never use undiluted permethrin near cats -- it is acutely toxic.

-- Fly masks, sheets, and boots reduce stress in particularly sensitive horses.

Rodent control: secure all feed in metal or heavy plastic bins with locking lids. Poison baiting near horses carries secondary poisoning risk; snap traps and exclusion (filling gaps, hardware cloth on openings) are safer barn rodent management tools.