Canine DementiaFebruary 12, 2010
Canine dementia, or senility, is a common problem seen in many elderly dogs. Dementia is the name given to a group related conditions which destroy brain cells and lead to a progressive decline in mental function. There are many similarities in the changes affecting the brain seen in dogs and Alzheimer’s disease in people, not least the laying down of protein plaques in the brain. For us these plaques are large and focal, whereas in dogs they are small and diffuse. This difference is important with respect to the progression of the disease as, in man, no treatment has so far been shown to delay or reverse the condition to any significant degree. In dogs, however, the outlook is more positive as behavioural signs of dementia can be temporarily reversed and the progress of the disease can be dramatically slowed down with appropriate therapy.
The signs to look out for:
Typical problems include going to the wrong house or staring at things that have been there for a long time and even possibly not recognising people. Other signs that may be noted include barking for no reason, staring in to space for extended periods or standing in corners.
• Interaction changes
An older dog may show a lot less enthusiasm when greeting us or when playing. Affected dogs are also more likely to become anxious and develop phobias such as noise. This may lead to an elderly dog becoming less able to cope with new experiences leading to them becoming more irritable or demanding reassurance from us. Sadly, other dogs may recognise the odd behaviour and show aggression towards the elderly dog.
• Sleep disorders
Affected dogs often sleep during the day, but are unable to sleep or settle at night. They may pace, howl or bark and act in a confused manner.
• House-soiling or loss of previously learned commands
This may start with the dog going to the toilet in unusual places (for example on the patio rather than the grass) and then progress to house soiling. In some cases the elderly dog may sit by the wrong door to be let out and we as owners then fail to recognise what our dog is asking for. In addition to house-soiling, dogs may lose their ability to respond to commands and lose their previously learned inhibitions (for example they may start snatching food from a person’s plate).
Affected dogs may show one or a combination of these signs, and it may be quite subtle in the early stages. One study found that at least one of these signs was present in a third of 11-12 year old dogs. By the time dogs reach 15-16 years of age this increased to two-thirds. Many owners write of these changes as “just old age” and are not aware that treatment can help.
So what can we do to help?
As with all degenerative problems, once the condition has started, it is not possible to stop the process completely. The aim of treatment then is to delay the progression of the disease, restore mental function and retrain lost behaviour so as to re-establish relationships with people and other animals in the household. As with all therapies, if started early in the progress of the disease it is more likely to have an effect. These therapies in clued both behavioural treatment and the use of medications.
Behavioural therapy aims to try and re-establish previously known behaviours, such as house-training and recognition of simple commands. Short training sessions – such as two to three minutes at a time – with big rewards are a help. It can help to use strong, unambiguous commands, such as exaggerated hand signals and the use of a clicker. Visual markers may also be useful, such as placing a paper cross on the door leading to the outside so the dog knows which door to wait by when it wants to go out. Ringing a bell when the dog’s food is ready may also be helpful. As well as retraining, it is important to provide a consistent, moderate amount of mental stimulation and exercise. Short, frequent periods of interaction for play or exercise (at no more than five to ten minutes at a time) are beneficial. Simple games, such as ball and recall games, with rewards and encouragement are ideal.
There are now also a variety of medications that available that help to delay the progress of the changes affecting the brain. They need to be used alongside the behavioural therapy but have been shown in studies to improve learning significantly. In this way they can help with the re-training of elderly dogs which have a reduced short-term memory span. They are also helpful for those elderly dogs that have developed fear and anxiety-related disorders. Signs of improvement are usually seen after two to three weeks, with a full response seen after two months of therapy. Other therapy seeks to help to increase the amount of oxygen arriving at the brain and there are even diets now that specifically target this type of problem.
As with all these treatments, the early appreciation of any deterioration is essential. Senior dogs (those over 10 years of age) tend to be checked slightly more often at Veterinary Centres for this reason. Recognising these subtle changes in the early stages is, as always, the key to a much happier time for our dogs in their ‘autumn years’.
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