The following article appeared in the Telegraph recently about dogs being colour blind. Experts have known for some time that dogs have poor vision, and are up to eight times worse than humans at seeing things in detail.
In the wild, dogs are a crepuscular species, meaning they are most active in dawn or dusk, for which colour vision is not needed. But through domestication, pets are awake mostly in the daytime, for which their eyes have not yet evolved. But until now, nobody knew why. Now scientists have developed a test for dogs and found that they struggle to tell red and green apart, much like colour blind humans, a condition known as deuteranopia.
The researchers used a modified test of colour vision in humans, known as Ishihara’s test, where numbers are hidden in a circle of red and green dots. People who are red-green colour-blind cannot see the numbers. For the new test, the researchers developed a similar experiment, but used an image of a cat instead of numbers.
It showed that dogs exhibited a behavioural response similar to that of red–green blind human subjects suggesting that dogs struggle to distinguish between red and green colours; so it would also be reasonable to hypothesise that dogs also have difficulty in discriminating between brown and orange but these colour shades have not been directly tested.
Dr Marcello Siniscalchi, of the department of veterinary medicine at the University of Bari in Italy, said dog trainers may want to avoid red clothing or shoes if working on grass, because animals will struggle to see their movements. If outside 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. 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.
I personally would have thought that a dog’s sense of smell would compensate for any poor eyesight/colour blindness. After all, if we can smell a stinky, slobbery ball or tuggy held at arm’s length, then I’m sure a dog would easily sniff it out in the grass with their eyes closed!
Holger Volk and his team at the RVC are doing a study into the long-term influence of a medium chain fatty acid diet on canine idiopathic epilepsy – LifeTIME (Long Term remission Mct Epilepsy) study and are interested in the recruitment of dogs diagnosed with epilepsy. They are inviting owners of dogs with epilepsy aged over 6 months, of all breeds and cross-breeds to complete this survey. www.surveymonkey.co.uk/r/LifeTIMEtrial.
If you are selected for enrolment in the study they will contact you after completion of this survey using the contact details provided. They are looking for dogs with recurrent seizures, but which have not had any history of cluster (more than 1 seizure in 24 hours) or status epilepticus (prolonged seizure activity). If in doubt, please do fill in the questionnaire, which is estimated to take 10-20 minutes. If you have any queries regarding the questions asked or details of the trial, please contact the Clinical Investigation Centre at the RVC (email@example.com)
Epilepsy is the most common chronic neurological brain disease seen in first opinion practice for domestic dogs; so why get involved? Medical advances in prevention, detection and management of diseases in veterinary and human medicine depend on clinical trials. Clinical trials are essential to determine if a new test or management works and is safe. Their study is looking at the effects of a diet on their seizure activity and behavioural comorbidities of canine epilepsy.
What they would like from you as part of the trial
1. A complete clinical history of your dog’s epilepsy.
2. Willingness to change your dog’s diet for 1 year and keep a seizure diary.
3. You are able to make five appointments at the Queen Mother Hospital at the RVC in Hertfordshire at day 1, then 3, 6, 9 and 12 months later.
What do you get out of it?
1. A free veterinary check up with clinical and neurological examination at each appointment
2. Free clinical tests at each appointment including haematology, biochemistry, and serum drug levels
3. Free brain scan (MRI) if you adhere to the protocol
4. Free diet for you dog for the duration of the study