Why do Pets Urinate Inside the House?
All of a sudden my 14-year-old male has started
urinating the house. This has never been a
problem before. Why now? Does it have to do with
his age?
Linda
Topeka, KS
You do not say whether you have a cat or a dog. However, in both species the causes of inappropriate urination can be divided into two broad categories: medical problems and behavioral problems.
Medical causes of house soiling (as urination in the house is known) include bladder infections, prostate problems, hormone imbalances, bladder inflammation and syndromes such as diabetes (in cats and dogs) and kidney disease that cause increased thirst and urine output.
Behavioral house soiling is very frustrating. Stress or anxiety may cause pets to urinate inside the house. Cognitive dysfunction (senility) is a cause of house soiling in older pets. Some pets, especially those that have not been neutered, may urinate indoors as a natural territory marking behavior.
A veterinarian should assess any pet that urinates inappropriately. Blood and urine tests (and, on occasion, X-rays and ultrasound) can check for a medical cause of house soiling. If none is found, then behavior modification may be beneficial.
You have questions. 
Your cat? Your dog? Your son? (Now that’s a possibility Dr. Barchas didn’t consider in his answer!)
I had the same problem with my cat Nikie , the vet and I detrmined it was becaues he was senile (the cat not the vet) the cat did not seem to know where the litter box was and when he found it did not seem to know what to do so I ended up having to put him in, I eventualy had to put him down he was so confused he did not know who I was or where he was , I guess people don’t think animals get senile too.