New research from the RVC has revealed that flat-faced dogs and spaniels, amongst other breeds, are more prone to a disease that causes dull and lacklustre eyes that can lead to blindness if left untreated. The disease called keratoconjunctivitis sicca (KCS) is more commonly known as “dry eye”. The findings of the study are an important step in helping owners to identify the signs of dry eye and to seek veterinary help to minimise pain and long-term issues.
The shine and “sparkle” in a dog’s eyes are taken as a sign of health and happiness due to the liberal covering of tears maintaining a permanent gloss. However, dogs with dry eye are unable to produce enough tears (or tears of good enough quality) to keep their eyes lubricated and functioning as expected of a healthy eye. This leads to sore eyes, eye infections and eye ulcers that are hugely painful. As a result, some dogs go blind or may even need to have their eyes removed. In cases where dry eye is diagnosed in time, dogs will require lifelong medication to maintain their sight.
The study was led by the RVC’s VetCompass Programme and is the largest study using anonymised veterinary health records to explore dry eye in dogs. The study included 363,898 dogs that were followed for a year to identify 1,456 dogs affected with dry eye.
Although one in every 250 dogs overall is affected with this condition, the study also confirmed that certain breeds are especially prone to dry eye and the complications that can be associated with the condition. The worst affected breeds include American Cocker Spaniels (one in 17 dogs affected), English Bulldogs (one in 55 dogs affected), Pugs (one in 110 dogsv) and Lhasa Apsos (one in 54 dogs affected). Flat-faced (brachycephalic) dogs and spaniel breeds overall had greater risk of dry eye.
The good news is that owners of breeds that are highly prone to this disease can now be on the lookout for signs of recurring eye problems in their dogs and then seek immediate veterinary attention. Understanding which breeds are most at risk also allows The Kennel Club and breeders to target health programmes at these high-risk breeds and to breed away from extremes of facial conformation such as protuberant or exposed eyes that are more prone to dry eye and its resulting complications.
Additional key findings include:
- One in every 250 dogs (0.4 percent) overall suffers from dry eye.
- The frequency of dry eye was very high in certain breeds including American Cocker Spaniel (5.90 percent) (i.e. one in every 17 dogs), West Highland White Terrier (2.21 percent), Cavalier King Charles Spaniel (1.91 percent), Lhasa Apso (1.86 percent), English Bulldog (1.82 percent), English Bull Terrier (1.65 percent) and English Cocker Spaniel (1.60 percent).
- Twenty-two breeds showed increased risk of dry eye compared with crossbred dogs including: American cocker spaniel (x 52.33), English Bulldog (x 37.95), Pug (x 22.09), Lhasa Apso (x 21.58) and Cavalier King Charles Spaniel (x 19.79).
- Two breeds showed reduced risk of dry eye compared with crossbred dogs: Labrador Retriever (x 0.23) and Border Collie (x 0.30).
- Flat-faced (brachycephalic) breeds had 3.63 times the risk of dry eye compared with mesocephalic breeds.
- Spaniel breeds had 3.03 times the risk of dry eye compared with non-spaniel breeds.
- Breeds with bodyweight at or above the mean for their breed and sex had 1.25 times the risk of dry eye compared with dogs weighing below the mean for their breed and sex.
- Dogs in lower bodyweight groups had higher risk of dry eye: dogs weighing 10.0 to < 20.0 kg had 5.49 times the risk compared with dogs weighing 30.0 to < 40.0 kg.
- Dogs aged ≥ 12 years had the highest risk of dry eye (x 29.44) compared with dogs < 3.
The authors of the study have made recommendations to veterinary professionals to help reduce the frequency and impact of KCS by testing for the adequacy of tear production as part of the annual physical examination of all dogs but especially for the list of predisposed breeds as they approach advanced age.
Dr Dan O’Neill, Senior Lecturer, Companion Animal Epidemiology, at the RVC, and author of the paper, said:
“We all love those glossy puppy dog eyes, but this study shows that sadly not every dog enjoys good eye health. This research identifies that flattened faces in some breeds makes these breeds more prone to this painful dry eye condition. Work is urgently going on to improve the health of many of these flat-faced breeds, but in the meantime the message from everyone who cares about dogs is to ‘stop and think before buying a flat-faced dog.”
Rick Sanchez, European Specialist in Veterinary Ophthalmology says:
“Taking a fresh dip into an old, dull looking disease like KCS has shown us there is more for us to learn than we thought. Ultimately, all of us, clinicians, nurses, researchers, breeders and dog owners are, in one form or another, care givers for our beloved animals. All of us need whatever new information we can set our eyes on to inform our next steps in improving canine ocular health. There’s no better eye opener than evidence-based scientific findings. I hope this research helps all of us raise awareness about canine KCS and that it helps us keep those animal eyes looking fresh and healthy, as they should.”
Bill Lambert, Health, Welfare and Breeder Services Executive at The Kennel Club commented:
“These findings are important to help us to identify which dogs are most at risk of developing dry eye. Ultimately, this should help owners that may need support in spotting the initial signs, as well as ways to treat affected dogs and how to prevent it occurring in the future. The data from this fascinating research will also be used to collaboratively create strategies to tackle health priorities with the breed clubs of affected breeds.
“We hope this research, funded in part by The Kennel Club Charitable Trust VetCompass grant, helps to improve dog welfare across the board, raise awareness of KCS and reduce the impact of this disease.”