With rising human and pet life expectancies, the standard ‘1-to-7’ dog year ratio is becoming obsolete, according to MedicAnimal, Europe’s leading online pet retailer. While most pet owners stand by the “one size fits all” method to gauge their pets’ equivalent stages of life, the reality is more complex, and can negatively affect pet health further down the line.

The measurement has a long history, with a Judgment Day calculation inscribed at Westminster Abbey in 1268 declaring a ratio of 9 to 1 dog years to human years. In 1953, a French researcher named Lebeau categorised life-stage markers shared by humans and dogs - puberty, adulthood, and maximum lifespan - and established, for the first time, that dogs age 15 to 20 times faster than a human in their first year of life, then, as they age, gradually slow to a ratio of one to five (dog to human) years.

There are an estimated 1.3 million dogs and cats with dementia in the UK, with half of all cats aged over 15 suffering from dementia and 41 per cent of dogs aged over 14. This is partly as a result of rising life expectancy, which means pets are suffering from conditions they ordinarily wouldn’t have lived long enough to experience.

Andrew Bucher, Chief Veterinary Officer at MedicAnimal, the UK’s leading online pet healthcare retailer, said:

“Britain has long been touted as a nation of animal lovers, which was confirmed last year when we spent a record £6 billion on our pets, but as medical care becomes better, animals are living longer and this is contributing to a rise in old-age conditions that would have been rarer in the past. It largely depends on the breed and size of the dog in question, as seven years in one breed is not equivalent to seven years in another.”

“Putting an animal with dementia down does not have to be the only option, and with care, senile pets can live perfectly comfortable lives. However, extra vigilance is required if this course of action is taken, as there can be a range of things to watch out for, such as confusion moving around familiar objects or routes, disregard for previously learned training including soiling within the house, anxiety, lack of self grooming (fur may become matted) and notably changes in their sleep cycle such as night walking.

“It can be very tough for a vet to diagnose pet dementia in the course of a consultation, and this is why it is so important that pet owners are aware of the signs, and by using the simplified ‘1-to-7’ ratio people may not be aware of when they should start looking for signs of dementia or taking extra care.

“A better understanding of the ageing process of pets and how size and breed can influence this should be something that pet owners look into as standard when considering buying an animal.”