13-year-old dog in human years: age, stage and care

A 13-year-old dog is about 68 in human years if it is a small dog, 74 if it is medium, 79 if it is large and 90 if it is a giant breed. Bigger dogs age faster, so the same 13 calendar years add up to more human years the larger the dog is.

Thirteen is old for any dog. A small dog is entering its geriatric years, and a large dog has been in them for some time. For a number based on your dog's breed, use the pet age calculator.

How old is 13 in dog years?

Go by healthy adult weight for a mixed breed. The dog years to human years chart has the same figures for every age from 1 to 20.

How the number is worked out

The first year of a dog's life counts for 15 human years and the second for 9, which makes 24 at age two. Each of the next 11 years adds 4 for a small dog, 4.5 for a medium dog, 5 for a large dog and 6 for a giant dog. That gives 68, 74, 79 and 90, with the medium figure rounded up from 73.5.

The old multiply-by-seven rule gives 91 for every dog. That is close for a giant breed and far too high for a small one.

13 dog years in human years, the other way round

Some people mean the reverse: how old is a dog that matches a 13-year-old person? By the same formula, that is a puppy of about 10 months. A dog reaches the equivalent of 15 by its first birthday.

How old is a 13-year-old dog? Life stage by size

• Small dogs are just reaching the geriatric stage. A few long-lived small breeds, such as the Chihuahua, still count as seniors until 14.
• Medium dogs have typically been geriatric for about two years.
• Large dogs are well into the geriatric stage, and many are at or past the usual lifespan for their breed.
• Giant breeds rarely reach 13. One that has is exceptionally old.

These are typical ages, and breeds vary within each size. See when a dog is considered a senior for the breed-by-breed table. A year on, the numbers move again: a 14-year-old dog in human years is 72 to 96.

What is normal at 13

Most 13-year-old dogs show several of these. They are common with age, but tell your vet about any that are new or getting worse quickly:

• Sleeping more of the day and more deeply. See why old dogs sleep so much for where normal ends.
• Walking more slowly, and stiffness for the first few steps after rest.
• A gray muzzle and a thinner, duller coat.
• Duller hearing, and trouble seeing in low light.
• A bluish haze in the eyes. It is common in old dogs and often harmless, but cataracts can look similar, so let your vet tell you which it is.
• Thinner muscle over the back legs and spine.
• Needing to go out more often, and less tolerance of heat and cold.
• Soft lumps under the skin. Many are harmless, but have every new lump checked.

Normal for the age does not mean nothing can be done. Stiffness in particular is often arthritis, and a vet can often help make an arthritic dog more comfortable.

What to watch for

These changes are not ordinary aging and are worth a vet visit soon:

• Losing weight without a change in food. Our guide to weight loss in old dogs covers the usual causes.
• Drinking or peeing much more than before, or new accidents indoors.
• Eating less, being picky, or dropping food from the mouth.
• A cough, faster breathing at rest, or tiring quickly on walks.
• Confusion: pacing at night, staring at walls, getting stuck in corners, or not recognizing familiar people. Check these against the dog dementia signs checklist.
• Pain: panting at rest, licking a joint, reluctance to be touched, or a new limp.
• A lump that is growing, hard, ulcerated or bleeding.

Each of these can point to several conditions, some of them very treatable. Only an examination, and often blood and urine tests, can show which.

Call the vet today if

• Your dog has not eaten for a day, or is vomiting repeatedly.
• It collapses, faints, cannot get up or suddenly loses its balance.
• It is struggling to breathe, or its gums look pale, white or blue.
• Its belly is swollen or tight, or it retches without bringing anything up.
• It has a seizure.
• It is straining to pee or poop with little result.
• It cries out, trembles or cannot settle and seems to be in pain.

If your own clinic is closed, call an emergency clinic.

Care checklist for a 13-year-old dog

• Vet checks at least every six months. Vets often suggest seeing a geriatric dog more often than that, with blood and urine tests. Your vet will say what is worthwhile.
• Weigh your dog every month and write it down. Slow loss is easy to miss by eye.
• Review the food with your vet, especially if there is kidney, heart or weight trouble. See what to look for in a senior dog food.
• Ask about pain. Never give human painkillers such as ibuprofen, naproxen, acetaminophen or aspirin. They can seriously harm or kill dogs. Pain relief for an old dog has to come from the vet, who will check the kidneys, liver and other medicines first.
• Make the house easier: rugs on slippery floors, a ramp for the car or sofa, a thick bed that is easy to step onto, and a night light.
• Keep walking, but shorter and more often, at your dog's pace.
• Have the teeth checked. Sore mouths are a common reason old dogs eat less.
• Keep a simple diary of good days and bad days. It makes changes easier to see and gives your vet something concrete to work with.

This article is general educational information, not veterinary advice. The human-years figures are estimates based on averages for a dog's size, and they say nothing about how healthy an individual 13-year-old dog is or how long it will live. Changes in an old dog should be assessed by your veterinarian, who should also decide on any tests, diet changes or pain relief.