You should seek the advice of your veterinarian if your pet is ill as only he or she can correctly advise on the diagnosis and recommend the treatment that is most appropriate for your pet.

Very few studies have been conducted into behavioural disorders in old cats

According to one report (Geriatrics and Gerontology of the Dog and Cat (1995) by Goldston and Hoskins, p58  Saunders)  the following behavioural problems have been reported to occur most frequently in geriatric cats (mainly over 10 years of age) :

• Inappropriate urination
• Inappropriate defecation
• Urine spraying
• Aggression towards other cats
• Hyperactivity *
• Excess vocalisation *
• Scratching furniture
• Inappetance and anorexia

(* These can be signs of hyperthyroidsim)

In recent years reducing exercise and reluctance or inability to jump as well has been associated with the presence of osteoarthritis

Of course this list probably represents owner concerns, or the spectrum of cases requiring referral to a behavioural specialist rather than the true distribution of age-related behaviour problems in old cats. 

Updated January 2016