Site Index



Dog Cognitive Dysfunction: Senility

Is your dog pacing at night? Or is she snappy with the kids? How could our beloved dog lose housetraining after all these years? Why is he staring into space and seems disoriented? Why is she howling? Our dog just lies around and ignores us! These are all important questions and concerns that owners of senior dogs frequently ask their veterinarians.

What Is Cognitive Dysfunction Syndrome?

Cognitive Dysfunction Syndrome (CDS), also termed Canine Cognitive Disorder (CCD), and commonly referred to as senility or "old dog" syndrome is a gradual, progressive loss of thinking (cognition) processes such as awareness, perception of surroundings, ability to learn, and memory. The family may note signs of this reduced cognition but not recognize the syndrome as a treatable disorder. This condition is not limited to extremely geriatric pets. A dog that is in the last one third of the normal lifespan can be affected. For the average dog, that is eight years of age or older.

When animals age, they lose mobility, have reduced immune system function, slower metabolism, loss of muscle and bone mass, and their senses of hearing, sight, and smell are reduced. These are all normal aging changes. CDS is characterized by behavioral changes that can lead to a break in the close bond shared between pet and family members as changes in temperament or loss of housetraining occur.

If you senior dog is showing any unusual changes, let your veterinarian know. They will ask for a complete history of the problem(s), and perform a thorough physical and neurological examination of the dog. Blood tests, urine analysis, X-rays or other tests may be recommended to help rule out any physical illness because these conditions can often produce the same signs that CDS does. Note that CDS may also occur in older pets with other illnesses; diagnosis in these instances can be very challenging since symptoms can overlap.

CDS Symptoms

  • Weight loss / Appetite changes
  • Confusion / Disorientation / Anxious look / Staring into space / Getting lost in the house
  • Altered pattern of sleeping and waking
  • Loss of learned behaviours such as obedience commands and housetraining
  • Change in relationship with family such as aloofness, aggression, apparent loss of recognition of voice and person
  • Abnormal vocalization such as howling, monotonous barking

CDS Treatments

If CD is identified, L-deprenyl is a prescription-only drug that can help to minimize symptoms by enhancing brain dopamine levels. Dopamine is a nerve messenger chemical and if it is depleted, may result in lower thinking ability. This drug also helps protect the neurons. Make sure your veterinarian is aware of changes in your pet's behavior so that proper assessment and treatment can be done. There is no cure for CDS, so the treatment goal is to provide a better quality of life and slow the progression of symptoms. Your veterinarian will know the right method of treatment for your pet.