If you think your precious pooch has gone through a midlife crisis... well, you may be right.
The research, published in the journal Scientific Reports, found the personality of dogs changes in a complex way over their lifetime.
The conclusion was reached after researchers from Eötvös Loránd University in Budapest put 217 Border collies ranging from six months to 15 years through various tests to determine their personalities.
What they discovered was that the age of three (in human years) is the canine equivalent to the start of middle age.
And it’s around this age that a dog’s excitement and enjoyment for new situations starts to decline.
They also found that dogs’ attentiveness and ability to solve problems increase throughout early life, and then plateau at around six years old.
However, some traits remain unaltered by age.
For example, naturally active dogs remain that way all their life, while lazy pooches will always be, lazy.
Other finds were that dogs become a bit better at tolerating frustration with age, but they never really learn to deal with adversity and a sociable puppy will remain a social dog as they get older, while shy ones will remain shy.