Older dogs are likely to develop an increasing number of medical and degenerative problems as they age. Any of the organ systems can be affected and play a role in the development of a wide variety of behaviour problems. For example, diseases of the urinary system and kidneys can lead to house soiling. Diseases of the endocrine organs such as the thyroid gland and pituitary gland can lead to a variety of behavioural and personality changes. A decline in the senses (hearing and sight), painful conditions, and those that affect mobility may cause the dog to be more irritable or more fearful of approach and handling. Ageing pets may develop many of the same changes as are seen in Alzheimer’s disease in people.
Regardless of age, every behaviour case must begin with a complete veterinary physical examination and a clinical and behavioural history. In addition, blood tests and a urinalysis may be needed to rule out organ disease and endocrine imbalances. Additional tests or perhaps a referral to a specialist may be appropriate depending on the initial findings.
Should multiple behaviour problems develop and these changes progress, the condition may be consistent with senility or dementia of the Alzheimer’s type (cognitive dysfunction).
In many cases the answer is yes. If there are medical problems contributing to the behaviour changes, the problem may not be treatable. The key therefore is to report changes and bring in your pet for assessment as soon as new problems arise.
In cognitive dysfunction, depletion of brain dopamine levels may be responsible for many of the behaviour changes. Drugs are available that can help treat some forms of cognitive dysfunction in dogs. These drugs help to normalise the brain dopamine levels, help to protect against nerve cell deterioration and have few side effects. Many of the behaviour problems listed above will show marked improvement and overall these dogs may become more attentive, playful and affectionate. It is important to note however that once new habits are learned, retraining and changes to the environment may also be needed to resolve the problem. For example, in addition to drug therapy, dogs that have begun to eliminate indoors will need to be retrained much like a puppy that has begun to eliminate indoors.
Dogs that develop behaviour problems due to underlying medical conditions may need alterations in their schedule or environment in order to deal with these problems. If the condition is treatable and can be controlled or resolved (e.g. Cushing’s disease, infections, painful conditions) then, as discussed, you must be prepared to retrain your dog, since the new habit may persist. For example, the house-soiling pet may have less duration of control due to his or her medical problems. If these conditions cannot be controlled, then your dog’s schedule (more frequent trips outdoors), or environment (installing a dog door, paper training) may have to be modified.