Not all horses can or do swim; the occasional horse that is walked into an equine swimming pool makes no attempt to swim and ends up walking underwater until hauled up by the attendants.
Horses don’t swim as they run – they use a modified trot. Their stride rate is also much slower than it would be on land due to the water resistance.
Horses can swim at around 1-3mph (1.6-4.8km/h)
Horses breathe differently when swimming. They breathe much more slowly. They also (sensibly) often close their nostrils. Their breathing is also quite noisy.
Fit horses are surprisingly buoyant considering they have low body fat.
Swimming pools for horses are almost always cooler than the horse, and so they keep the horse’s body temperature down. As a result the heart rate (indicator of workload) is often lower than expected.
Swimming can be used for heart and muscle fitness whilst not placing impact on the joints, tendons, bones or feet.
Foals can swim within hours of being born.
Normal swimming sessions in pools for horses are of the order of 15-30 minutes, but in 2016, an Australian racehorse named REBEL ROVER spooked on the beach, unseated his rider and swam out to see. He swam for 2h and covered 11km before being rescued.
