Nearly 17-year old cat peeing everywhere

Question
We have a large breed cat turning 17 in a few months, but for the past year he has been peeing around our house, in many random spots.  We know he's lost most or all of his sight and has hyperthyroidism, but other than that our vet says he's a very healthy cat.  He's had a few loose and bloody stools, drinks a lot, and spends several hours of the day and night picking random spots around the house and giving deep, loud meows.
Is this something that happens a lot with senior cats?  The vet only ever says that his panels all come back fine, and he still enjoys his night-time canned food treat and snuggles, but it just feels like there's something not right.

Answer
Hi Jennifer,

You may want to do some research about Cognitive Dysfunction Syndrome (CDS), and see if any of these behaviors seems to fit your cat.  This is a condition similar to human Alzheimer's, and it affects older cats.  The most common problems noticed are failure to use the litter box and crying loudly at night.  As the disease progresses, most cats experience other changes that Alzheimer's patients do - mental confusion such as wandering aimlessly, staring into space, or appearing unfamiliar with people or places they know.  They may become depressed and lose appetite, stop grooming and even grow aggressive without being provoked.  Most people mistake these signs for regular old age moodiness when the cat is actually suffering symptoms of CDS.

There is no test for CDS, and diagnosis is made based on symptoms.  Treatment is generally Anipryl, a drug that is labeled for use in dogs, which has been used safely in cats for several years.  Many cats respond positively to the medication.  There is also a supplement called Novi-SAMe that may be helpful.

Best of luck!

Jessica