Page 11 - Clinical Connections - Spring 2022

Research News

CHERRY EYE CONDITION – HIGH-RISK INTERVENTION REQUIRED FOR FRENCH
DOG BREEDS BULLDOGS
An RVC VetCompass project has revealed the true scale of RVC research has concluded that French bulldogs can no longer
prolapsed nictitating membrane gland (PNMG), commonly known be considered a ‘typical dog’ from a health perspective. A new
as ‘cherry eye’, in dogs and identified the breeds at most risk of the RVC study indicates the health of French bulldogs has strayed
condition. substantially from non-French bulldogs in the UK and is now largely
If left untreated, PNMG can cause discomfort and promote much poorer. The research suggests urgent intervention is required
complications such as dry eye, conjunctivitis and eye ulceration. to reduce the high rate of health problems experienced by the breed.
Surgery is usually required to treat the condition and reposition the The RVC VetCompass study compared the health of random
affected gland. samples of 2,781 French bulldogs and 21,850 non-French bulldogs.
The VetCompass study is the largest exploration of PNMG in A list of the 43 most common disorders across both groups of dogs
dogs in the world. The research team followed the anonymised revealed many of the differences in health risk between the two
veterinary health records of 905,553 dogs for a year and identified groups were closely associated with the extreme body shape that
that 0.20% (1,802 dogs) were affected. defines French bulldogs. This includes a grossly shortened muzzle,
Some breeds showed very high proportions of dogs affected a large head, skin folds and shortened spine/tail.
annually, including the Neapolitan mastiff (4.9%), English bulldog The French bulldog is hugely popular in the UK, with demand
(4.8%), Lhasa Apso (1.6%) and American cocker spaniel (1.5%). soaring in recent years. This demand has resulted in huge welfare
Importantly, some popular designer crosses of flat-faced breeds issues, particularly with reference to breathing problems and sore
were also highly affected, such as the puggle [pug and beagle] eyes that are common in the breed. Body exaggerations such as
(2.1%) and Jug [Jack Russell terrier crossed with pug] (1.2%), the flat face, big eyes and snuffly breathing that promote these
suggesting the recent craze for designer crossbreeds does not health issues are often perceived as ‘cute’ or ‘normal’ for the breed
eliminate health issues associated with the parental pure breeds. and, worryingly, ‘desirable’.
Additional key findings from the study include: Efforts to reduce demand for the breed include advice from the
• One in every 500 dogs (0.20%) overall in the UK suffer from UK Brachycephalic Working Group to ‘stop and think before buying
PNMG every year a flat-faced dog’. The Dutch Kennel Club has even gone as far as
• The median age at first diagnosis of PNMG was 0.6 years to ban the registration of new French bulldog puppies altogether
• Brachycephalic [flat-faced] dogs had 6.9 times the risk of (along with 11 other flat-faced breeds).
PNMG compared with dogs with medium skull length The findings of the new study revealed that French bulldogs had
Seventeen breeds showed increased risk of PNMG compared higher risk for 20 of the 43 (46.5%) common disorders compared
with crossbred dogs. The breeds with the highest risk included with a lower risk for just 11 of 43 (25.6%) disorders. Narrowed
Neapolitan mastiff (x 34.3), English bulldog (x 24.1), Lhasa Apso (x nostrils (stenotic nares) was the disorder with highest risk in French
12.4), American cocker spaniel (x 11.6), puggle (x 9.5), great Dane bulldogs, with the breed at 42 times risk of the condition.
(x 6.2), Saint Bernard (x 5.3) and jug (x 5.2). Other conditions with the ultra-high risk in French bulldogs
Sixteen breeds showed reduced risk of PNMG compared with included Brachycephalic Obstructive Airway Syndrome (BOAS)
crossbred dogs. The breeds with the lowest risk included the (x 30.9), ear discharge (x 14.4), skin fold dermatitis (x 11.2) and
German shepherd dog (x 0.03), West Highland white terrier (x difficulty giving birth (x 9.1).
0.06), English springer spaniel (x 0.07), Labrador retriever (x 0.12)
and lurcher (x 0.12). An infographic related to news pieces on this page can be
Purebred dogs had 1.4 times the risk of PNMG compared with downloaded from the following link.
crossbred dogs. Dogs aged under one year were at greatest risk of https://www.rvc.ac.uk/vetcompass/audio-visual-resources/
PNMG (x 10.8) compared with those aged from two to four years. research-infographics.

Research paper: O’Neill et al (2022) ‘Breed and conformational predispositions Research paper: O’Neill et al (2021) ‘French Bulldogs differ to other dogs in the
for prolapsed nictitating membrane gland (PNMG) in dogs in the UK: A UK in propensity for many common disorders: a VetCompass study’, Canine
VetCompass study,’ PLoS One Medicine and Genetics

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