Balance is maintained whenever the head or body moves because the vestibular system, including the inner ear, has tiny nerve endings bathed in fluid which sense the movement and transfer information to the brain. The position of the body can then be adjusted to ensure that balance is maintained and this process of movement and resetting is occurring all the time at thousands of times a second so that the process of maintaining balance is smooth rather than jerky.
No one understands why vestibular syndrome occurs. It may relate to a spasm in the blood supply to the inner ear or an infection there, but often it is termed idiopathic which means it just happens. In humans, Meniere’s disease is a similar problem affecting balance.
Dogs typically suffer vestibular syndrome in middle to old age. Cats are only rarely affected. The symptoms will come on suddenly, without warning. The animal will tilt its head to one side and lose balance so that it falls repeatedly. The eyes will be flicking from side to side, which is sometimes quite subtle – this is called nystagmus. Motion sickness will be experienced and often result in physical vomiting. Commonly, affected dogs can panic and keep trying to move around. This is a very distressing condition for owners to witness.
Traditionally, this condition has been referred to as a “stroke”. However, we must come away from this terminology as it is not the same as a stroke, or cerebrovascular accident, in humans where the patient has a blood clot blocking an artery to the brain or a ruptured artery in the brain. These do occur in dogs but are more subtle owing to the fact that the dog does not use the same areas of the brain for movement as a human does and therefore paralysis is not so much of a feature. We need to change the terminology used as vestibular syndrome causes signs which are much more likely to be reversible than a true stroke and the prognosis is much better. Whilst vestibular syndrome and strokes may share some similar symptoms, they are not the same and owners are usually reassured when they know their dog has not had a stroke.
The diagnosis is usually straightforward – there are certain tests we carry out to distinguish between dysfunction of the inner ear and dysfunction of the components of the vestibular system within the brain.
The prognosis for full recovery in a few days is very good for most cases. Nonetheless, it is distressing for owners to watch their pet during this time. Generally, the symptoms peak in the first few hours and, over the next few days to a week, the pet will regain its balance and begin to eat again. Occasionally, the head tilt may persist, but usually without consequence.
As far as treatment goes, the truth is that there is a very little that you or your vet can do to alleviate the problem other than make the dog comfortable and allow time to pass. Some vets use medications to improve blood flow to the inner ear. Most dogs will benefit from anti-sickness drugs which will help with nausea even if vomiting is not actually physically present. Sedative can be used to calm the patient.
It is common to receive the advice to turn off the lights and keep the pet in a darkened room. Whilst this may help to reduce anxiety at first, after the first 12-24 hours it is now thought that it is a good idea to assist the dog to try and walk. The affected inner ear will start to adjust back and will be helped by the inner ear on the other side which will compensate to some extent. This process is felt to occur quicker if the pet is encouraged to regain activity and challenge the systems a little, albeit ensuring this is done in a safe environment.
In conclusion, vestibular syndrome is a distressing condition to witness but it usually has a very good prognosis. It is important that house-sitters are aware of the disease and not to term the problem as a “stroke” when speaking to their clients who may be away and receiving the news over the phone. Make arrangements for affected dogs to see the vet. Mark Maltman BVSc CertSAM CertVC MRCVS
Maltman Cosham Veterinary Clinic, Lyons Farm Estate, Lyons Road, Slinfold RH13 0QP (Due to open March 2011)
H: 01403 256840
M: 07540 983648
mark.maltman@maltmancosham.co.uk
www.maltmancosham.co.uk
