Over a long time, it was believed that one dog year equals seven human years. But that’s not correct as large breed dogs have a much shorter life expectancy compared to smaller dogs. Here is a more accurate approach to calculating your dog’s age!
Dog years run faster
A common rule of thumb to calculate a dog’s age in human years used to be the “multiply by seven” rule. But this doesn’t seem to be accurate in the light of new scientific studies. Interestingly dogs are ageing faster when they are a puppy. As all dogs regardless of the breed reach puberty under the age of one year.
A 2019 study suggests a new formula to calculate your dog’s age. For nerds who want to do the maths, it’s human age = 16 ln(dog age) + 31. Here is your dog’s age based on the formula:
Dog Age Chart Based on Epigentic Clock
| Dog Years | Human Years |
|---|---|
| 1 | 32 |
| 2 | 42 |
| 3 | 48 |
| 4 | 53 |
| 5 | 56 |
| 6 | 60 |
| 7 | 62 |
| 8 | 64 |
| 9 | 66 |
| 10 | 67 |
| 11 | 69 |
| 12 | 70 |
| 13 | 72 |
| 14 | 73 |
| 15 | 74 |
| 16 | 75 |
| 17 | 76 |
This calculation is based on the so called epigenetic clock. Which can be used to estimate a mammal’s life expectancy by looking at DNA methylation patterns.
This converting method seems to be much more accurate than just multiplying by seven. But does it live up to the variety of dog breeds which all have different life expectancies? No, it doesn’t. The American Kennel Club recently published a table discriminating between different dog types. This gives us a much better idea of our dog’s age.
Dog Years in Human Years by Dog Type
| Dog Years | Small Breed | Medium Breed | Large Breed | Giant Breed |
|---|---|---|---|---|
| 1 | 15 | 15 | 15 | 12 |
| 2 | 24 | 24 | 24 | 22 |
| 3 | 28 | 28 | 28 | 31 |
| 4 | 32 | 32 | 32 | 38 |
| 5 | 36 | 36 | 36 | 45 |
| 6 | 40 | 42 | 45 | 49 |
| 7 | 44 | 47 | 50 | 56 |
| 8 | 48 | 51 | 55 | 64 |
| 9 | 52 | 56 | 61 | 71 |
| 10 | 56 | 60 | 66 | 79 |
| 11 | 60 | 65 | 72 | 84 |
| 12 | 64 | 69 | 77 | 93 |
| 13 | 68 | 74 | 82 | 100 |
| 14 | 72 | 78 | 88 | 107 |
| 15 | 76 | 83 | 93 | 114 |
| 16 | 80 | 87 | 93 | 121 |
| Dog Years | Small Breeds | Medium Breeds | Large Breeds | Giant Breeds |
What is the Life Expectancy of my Dog?
As mentioned above your dog’s breed has an influence on his life expectancy. A simple rule of thumb is the larger the dog the shorter it’s lifespan. Studies have shown that every 2 kg of body mass reduces a dog’s life by one month.
While body mass influences a dog’s life expectancy there are breed-specific features that play a role too. Cavalier King Charles Spaniels, for instance, have a much shorter lifespan than many larger breeds. So don’t choose your dog by bodyweight only when you’re looking for a companion who will be around for long.
Life expanctancy of popular breeds
| Breed | Expectancy (in years) |
| Labrador Retriever | 12,6 |
| German Shepherd | 10,3 |
| Irish Setter | 11,8 |
| Jack Russell Terrier | 13,6 |
| Lurcher | 12,6 |
| Great Dane | 8,4 |
| Springer Spaniel | 13 |
| Border Collie | 13 |
| Boxer | 10,4 |
| Cavalier King Charles | 10,7 |
| Dachshund | 12,2 |
| Golden Retriever | 12 |
| Chihuahua | 15 |
| Rottweiler | 9,8 |
| West Highland White Terrier | 12,8 |
| Yorkshire Terrier | 12,8 |
| Beagle | 13,3 |
The Impact of Overweight on the Lifespan
It wasn’t surprising what a group of scientists published in 2018 – The Body Condition Score is negatively correlated with a dog’s life span. Meaning the fatter the dog, the shorter his life! The most significant difference was seen in Yorkshire Terriers, who have a 2,5 years shorter life expectancy when being overweight.
Why do overweight dogs die earlier?
A high body condition score causes a large number of diseases. Your dog gets lazy and enjoys walking and playing less – a vicious circle! The result is inflammation in the joints, called arthritis, and many other internal diseases such as diabetes.
Signs that Your Dog is Aging
We’re all getting older so are our canine friends. After several years of companionship, they may show the first signs of getting old. Some are just normal physical changes others may be indicative of a disease process.
Common symptoms that may need veterinary work-up:
- Slowing down
- Limping
- Difficulties in Jumping or Taking Steps
- Bad Breath
- Weight Loss
- Lumps
- Being more Vocal
- Difficulties finding Comfort
- Changes in Appetite
What to do to keep your Aging Dog Fit?
Regular veterinary check-ups including dental examinations are the most important things you can do. Keep all the vaccinations up to date and have a yearly blood check done.
Your vet will help you with all your pet’s needs. The diet may have to be changed, modifications may have to be made around your house and preventive treatment can be taken into consideration.
Recommended Posts on Ageing Dogs:
- Arthritis in Dogs. Signs, Diagnosis, and Therapy.
- Home & Exercise Adaptions for Dogs with Arthritis
- Pressure Points for you Dog with Osteoarthritis
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– Felix