When it goes wrong
The CNS is well protected, surrounded by multiple layers of tissue (the meninges), fluid (cerebrospinal fluid) and bones. “When damage does happen,” says Leticia, “it can trigger an inflammatory response, haemorrhage or lack of blood supply (ischemia), which can compromise the nervous function. “Clinical signs vary, depending on where the damage is. Abnormal behaviour, depression, sudden blindness, an abnormal position of the head, problems with balance, convulsions or asymmetries in the face are normally related to issues of the brain, stem cell or cranial nerves.” Generally, very severe lesions on the CNS will knock your horse to the floor. He will be unable to get up and may not survive. “Because of this, you should get your vet to check your horse after a severe trauma, especially if he’s been involved in a traffic accident, if he falls in the trailer, falls onto his back while rearing or hits his head severely,” advises Leticia. “Sometimes the consequences don’t appear immediately and changes are not seen until a few hours later.”
Plants and toxins
Some plants, if eaten, can damage the nervous system by releasing toxins in the bloodstream that reach the nervous tissue. Some get to other areas first, such as the intestine or the liver, then affect the nervous system later. Sorghum, clover and perennial ryegrass are just some examples of plants that can cause neurological alterations. “Make sure your fields are clear of poisonous plants. Take measures to avoid cross-contamination from neighbouring fields and check your forage is good quality and not mouldy, as this can also release toxins,” says Leticia.
Lack of oxygen can damage the neurons. “Horses are prey animals so, when a foal is born, his nervous system is almost fully developed in order for him to be able to escape danger,” explains Leticia. “Some newborn foals suffer from hypoxia during birth, which will slow reaction to stimuli.” These foals are called dummies and require intensive veterinary care to survive. So, if you have a foal and he is not standing up and suckling from his mother within four to six hours, call your vet.
Some breeds — Thoroughbreds and Warmbloods for instance — are prone to suffering from compression on the spinal cord, usually in the neck. This is due to joints between some vertebrae being looser than normal, also known as cervical instability. This can pinch the spinal cord, resulting in loss of co-ordination, which is why it’s called wobblers. XLVets Equine is a community of independently owned practices that work together to achieve the highest standards of veterinary care. For more information, visit xlvets.co.uk.
Some plants, such as clover, can cause liver damage
Wobblers can make your horse unsteady ▼
If your foal is slow to stand and suckle, call your vet