Hmm, I haven't got any experience with this but buckling at the knees is a symptom of Narcolepsy. Does he seem to fall asleep at times that aren't normal, and then this happens?
If a horses collapses at rest, it is often because there is a problem within the nervous system. If the brain is not sending the right messages, the body can't respond and will tend to topple over. |
Narcolepsy is one such syndrome. This is a rare, incurable sleep disorder of the central nervous system characterised by uncontrolled episodes of loss of muscle tone (cataplexy) and sleep.
The disease has been reported in Shetland and miniature foals (called the fainting disease) and Welsh ponies, as well as the Thoroughbred, Quarter Horse, Morgan, Appaloosa, and Standardbreds.
Narcolepsy is the classic cause of a horse flopping to the floor, as opposed to a fit or seizure. With a fit, the affected animal is likely to be stiff and rigid with involuntary twitches and paddling of the limbs.
With narcolepsy, there is usually a rapid onset of collapse, or sometimes excessive drowsiness and head droop. Horses may buckle at the fetlock and knees and stumble. Sometimes they will sink to the ground, but others will appear to wake up and regain their feet. They may have difficulty moving and are hard to lead because they are unco-ordinated, as if they are sleepwalking.
It's possible ta be that but it might be from lack o' REM sleep too. Does he lay down and sleep at all? Because horses can doze while standing but must lay down ta get REM sleep. If he's lackin this then he could be startin ta go inta REM and therefore falling. I am no expert in this area though.