Separation means no shared noses or kit
A quarantine stable across the yard from the residents, or a paddock fenced with a clear gap from the nearest field, is the starting point — nose-to-nose contact over a door or fence defeats the whole exercise. Nothing travels between your horse and the others: his own water buckets, feed bowl, haynets, headcollar, grooming brushes and a dedicated fork and barrow. Colour-tape his kit if the yard is busy, because equipment drifts back into communal use unless it is obviously claimed. If he must use a wash box or tie-up area, he goes after the residents and it is cleaned down afterwards.
Handle him last, every time
Order your day so the resident horses are fed, mucked out and turned out before you touch the new arrival, and he is always the last job. Hands are washed after handling him, and boots and yard coats that have been in his stable stay out of the other boxes. It sounds fussy for a fortnight, but most yard infections travel on people and equipment rather than through the air, and the routine costs nothing but sequence. Tell everyone on the yard the rule and where his kit lives — quarantine fails through helpfulness, when someone kindly lends his bucket to another horse.
The daily check that makes quarantine worth doing
Take his temperature at the same time each day and note it: a resting horse normally sits around 99 to 101.5 degrees Fahrenheit, and a reading above his own normal, especially with a dull manner, is an early warning worth acting on. Watch his appetite — hay left, feed refused, water barely touched — and look for coughing, discharge from the nose, swollen glands, loose droppings or simply a horse quieter than the one who arrived. Jot the observations down daily rather than trusting memory; a three-day drift in appetite is invisible day to day and obvious on paper.
Vet thresholds during quarantine
Call the vet the same day, and keep him isolated, if his temperature rises, discharge appears, he coughs repeatedly, stops eating or develops very loose droppings — during quarantine those signs are treated as contagious until a vet says otherwise, and the yard manager should hear about them from you immediately rather than discover them. Do not move him out of isolation to see if he perks up, and do not borrow the residents' thermometer mid-examination. Most quarantines end with nothing found, which is the point: the routine is cheap, and the outbreak it prevents is not.
Ending quarantine properly
He joins the yard fully only when the yard's stated period — often around two weeks, but the yard's rule is the rule — has run with clean daily checks throughout. Introduce him to turnout neighbours over a fence first if he has been stabled alone, and keep using his own kit in shared areas until the staff say otherwise. File the quarantine notes with his other records, so the next yard or the next vet visit starts from facts.
Keeping his vaccination history, worming dates and those daily quarantine notes together in his KinsLe Pet Passport gives the yard manager and the vet the whole picture in one packet, instead of a paper hunt through old messages.