Age of my cat

Question
A couple months ago, while on a walk i was adopted by a tiny tabby cat my husband named Charity. She was roughly 9-10 inches long, not even a foot. After posting everything from an add on the Internet to posters all over our neighborhood and getting no response for 2 months we decided it was time to get her vaccinated. We went to a local Petco and asked the vet there if he could tell us her age. However, Charity has a bad habit of chewing on our thick wood table... when the Vet checked her teeth for wear he estimated her to be about three years old. That did not seem to fit, however seeing her size when we found her. Is it possible for her chewing habits to effect the wear on her teeth? If so, could the vet be mistaken on her age?

Answer
Hi Samantha.  Guessing the age of a cat is very far from an exact science.  There are a number of things that can fool the vets when making an estimate.  Likewise, there are a number of things that can stunt a cat's growth so badly that they appear much younger than they are.  Your kitty's teeth certainly could be worse for the wear than usual due to her strange teething habits.  Some cats also get a condition called juvenile stomatitis, an early onset type of gingivitis.  Juvenile stomatitis occurs before the age of one year.  If the vet noticed that she had some periodontal disease and based part of his conclusion about her age on this, it's possible that she could be suffering from juvenile stomatitis.

But starting before birth, influences such as nutrition and early infections can cause a cat to age more quickly than their years.  I had a cat who was deprived of taurine and suffered a distemper infection as a baby.  I got her when she was confirmed just 6 weeks, so I knew her to be 4 years old at an appointment when a vet told me she was at least 10.  Viral infections not only cause lasting gum disease, but nutritional deficiencies early in life can also cause poor tooth condition as well as early changes in appearance of the eyes.  They also may cause severely stunted growth which the cat never makes up for, so some cats will appear kitten-like all their lives.  

If you haven't had the kitty tested for the feline AIDS and feline leukemia viruses, this would be a really good idea.  These two illnesses speed up the aging process, especially the AIDS virus, and young cats can appear old when examined.  If she is positive for leukemia, she will need to stay inside and away from all other kitties.  The disease spreads through bite wounds, mutual grooming and sharing food and water bowls.  If she is positive for AIDS, she should stay indoors, since this virus can spread through bite wounds.  In a friendly household, this disease is not likely to spread, so I have kept AIDS positive cats with negative ones for many years and have never had the disease move from one cat to another.

At any rate, cats have all their adult teeth in by the age of 6 months or so, so you know she is at least this old judging by her teeth.  If she continues to grow, you know she is under the age of three years.  Most cats stop growing at around a year old, but some individuals, mostly large breed cats, can continue to develop up until the age of three.

Congratulations on your new family member!

Jessica