How do I check the age of a cat I have rescued?

I think that this is a good question. It is the question that a person asked on the Reddit.com social media website. They wanted to figure out the age of a tabby cat that they had rescue. The picture of the cat is below.

Rescue tabby cat about 12 months old? That's my guess. Image: Reddit.com.

The first point to make is that this cat is not full-sized. This is not an adult cat. We all of us know what an adult cat looks like and therefore we can measure the size of the cat that we've rescued against what we know is the size of an adult domestic cat. This, I think, is a good starting point.

We also know that domestic cats become adults at about 18 months of age. So, if a rescue cat is smaller than adult cat and indeed looks a little bit juvenile because they do look juvenile when not fully grown, we can work backwards from that 18 months and decide from the relative size their approximate age. In this instance I have decided that this cat is about 12 months of age because they are a sub-adult both in facial appearance (juvenile) and size.

Once a cat has become adult you will have difficulty in deciding the age if you've rescued a cat. The domestic cat's appearance does change as they become older. They do indeed look older but the changes are subtle. I think you can bracket an adult cat's age between about two years and eight years and then eight years onwards to a senior cat; that is two brackets which is very general indeed.

It is easier to figure out the age of a young cat before they become adults. Indeed, you can do it very accurately and/or veterinarians can by checking their teeth. Deciduous teeth i.e. baby teeth are gradually replaced by permanent adult teeth. At 3-4 months of age the incisors (the small teeth at the front between the canines) erupt followed at 4-6 months by the canine teeth, premolars and molars.

By seven months of age the cat's adult teeth are fully developed. Knowing this sequence, you can then work out fairly accurately the age of a kitten.

It is difficult to work at the age of a cat through wear and tear of the teeth. This is something that can be done for horses because they grind and wear down their molars but for cats it doesn't really work because they sheer flesh with a scissor-like action. Their teeth do not grind and masticate food.

However, the general condition of the mouth in terms of oral health will give a clue. A cat of around 8-10 years of age may have some gum disease i.e. inflammation of the gums, some tartar and calculus at the border between the teeth and the gums as well. If you see oral health which is not excellent and some build-up of debris and bacteria around the teeth then you can be sure that the cat is not young but somewhere in middle age.

In old age, domestic cats move more slowly. They sometimes become thin due to hyperthyroidism. They might have arthritis which affects the way they move. They sleep more. They are static more often. And therefore, they are less active. All the signs indicate that the cat is elderly and therefore in the age bracket of about 12-18 years of age.