Some dogs are mad for food, while others absolutely love to chase a ball. But some dog owners aren’t always aware that there is actually a best – and worst – colour of ball to throw for your pup. This is because dogs are colour blind…
New research has revealed that dogs are red-green colour blind, meaning they cannot distinguish between the two colours. This can have obvious complications in a green field or park, if you throw a red ball for your pooch.
The study, published in the Royal Society journal Open Science, carried out a colour blind test specifically designed for dogs by scientists. Similar to the human colour blind test, the Ishihara’s test, where numbers are hidden amongst red and green dots, the dog test displays images of red and green dots with a picture of a cat hidden within.
It was previously thought that dogs simply had poorer vision than humans – up to eight times worse in fact. But the new research has delved into the specifics of colour vision.
Dogs in the wild are crepuscular. This means they are mainly active at twilight and therefore don’t need full colour vision. Although domesticated dogs are day animals, their eyes have not yet evolved to adapt to this lifestyle.
‘Overall, the direct demonstration that dogs are red-green colour blind is not only important for people directly involved in dog training but also for owners who want to improve their dog’s attentive skills during some activities such as play that is at the heart of a healthy owner-dog relationship,’ Dr Marcello Siniscalchi, of the department of veterinary medicine at the University of Bari, Italy, told The Telegraph.
‘If at the park you want to get your dog to catch a flying frisbee or to bring back a ball falling on the green grass it would be better if you thought of using blue instead of red toys.’
Your dog will struggle to see red items against a green background, such as grass, so frisbees and balls are better suited to being blue.
‘It would be reasonable to hypothesise that dogs also have difficulty in discriminating between brown and orange but we have not directly tested these colour shades,’ Dr Siniscalchi added.
