The colour of a cocker spaniel can indicate its temperament. Photo / Getty Images
Few dogs have a more family-friendly reputation than the English cocker spaniel.
But owners of golden cockers should be wary – the colour of their coat indicates that their pet might suffer “cocker rage”, and they could even be more aggressive than a rottweiler.
The first scientific evidence has emerged that the dogs suffer a higher than expected level of aggression for the breed after data from more than 10,000 cocker spaniels in the UK were analysed as part of the VetCompass project by the Royal Veterinary College.
More than 4 per cent of cockers were found to show signs of aggression, as reported by their vet, which is similar to that of a chihuahua (4.2 per cent).
The team found that aggression levels varied by colour and coat pattern as well as gender in their study of more than 1400 cocker spaniels.
Golden cockers specifically have a tendency towards aggression, with one in eight of the tawny-coloured dogs found to have anger issues, making them the most likely of their breed to growl or bite.
Aggression levels recorded among golden cockers jumped to 12.08 per cent – higher even than the aggression level of a rottweiler (7.46 per cent).
The researchers found cocker spaniels of one colour, as opposed to a combination of two or three different colours, were more likely to be aggressive. Some 7 per cent of all single-coloured cockers were aggressive compared with 3.7 per cent of mixed colourations.
Among solid-coloured cockers, the prevalence of aggression was 12.1 per cent in goldens, 6.5 per cent in red cockers, 6.3 per cent in black dogs and 4.3 per cent in those of liver colouration.
Male dogs were also far more likely to be aggressive than females (4.95 per cent compared with 2.87 per cent).
However, unlike the feisty reputation of the diminutive chihuahua, the cocker spaniel is thought of as a child-friendly pet.
The breed is one of the most popular in Britain, with almost 30,000 puppies registered with the Kennel Club last year, which calls it the “merry cocker” due to its “ever-wagging tail and happy temperament”. The dog comes just behind Labradors and French bulldogs in popularity.
Experts are now trying to increase awareness of the dog’s behaviour so that families, especially those with young children, can select a pet that is right for them and avoid the cockers most prone to angry outbursts.
Dr Dan O’Neill, associate professor of companion animal epidemiology at RVC who led the project, told The Telegraph: “In the 60s and 70s there was a thing called ‘cocker rage’.
“Some people used to call it ‘cocker rage syndrome’ and it was recognised that some cocker spaniels would just flip and suddenly become very aggressive.”
This reputation faded, he said, but the data show that “aggression is still a bit of an issue for a dog that is meant to be a real loving family pet”.
How to avoid aggression in your cocker
Dr O’Neill added that people do not need to stop buying cocker spaniels, but they may wish to consider what type they get, and how they interact with the dog.
“If an owner is buying a cocker spaniel, and perhaps has some small children, maybe think about a female dog that might have a lower risk of aggression,” he said.
“Also to buy a multicoloured dog, so not a dog with a single solid colour, and certainly to avoid a golden cocker spaniel.”
He added parents should advise children to give their pet cocker spaniels some space, as children can eagerly hug and grab at the dogs.
Dr O’Neill said: “It is not absolutely certain that these dogs are going to have issues.
“It’s more for owners to be aware of and for them to be sensible about how the dogs are handled. It’s not that this is a huge immediate issue, it’s more awareness.”
He added that the aggression levels for cocker spaniels – solid gold ones excluded, for which the rate of aggression is one in eight – is not abnormally high, but is higher than befits a dog of its reputation.
“It’s not that cocker spaniels are more aggressive than every other breed,” he said. “There were breeds that are deliberately bred as guard dogs, German shepherds and rottweilers, for example, which show much greater aggression than even the golden cockers.
“But the point is, they’re not marketed as this really cute, friendly, family pet that can sleep in the bed with your children. They’re a different type of dog for a different type of owner.”
He added: “Cocker spaniels overall, are about average for aggression but we’re deliberately choosing them if we’re looking for a cute family-friendly pet, so ideally we would like lower than average aggression.
“Aggression becomes key because of the kind of family niche that cocker spaniel generally fits.”
Other dogs in this niche, such as Labradors (2.24 per cent), French bulldogs (2.15 per cent) and pugs (1.97 per cent), for example, have much lower aggression levels than the cocker spaniels, which sit at 4.01 per cent on average.
Where ‘cocker rage’ comes from
The reason for the “cocker rage” remains a mystery as the study looks at links, not causation. However, Dr O’Neill said: “The reason for the aggression has to be genetic because there’s no other reason.
“The exact mechanism we do not know, as it has not been elucidated, but it has to be genetic.”
Data from the study, published in Canine Medicine and Genetics, also found cocker spaniels are twice as likely as other breeds to have dental disease, which may be a result of their loose floppy lips.
They are also up to 50 per cent more at risk of sore ears, up to a third more likely to be obese and a third more likely to have anal sac infection, which leads to scooting behaviours.
All these things are easy to prevent and treat with either regular monitoring, daily teeth brushing, and quick vet visits.
Dr O’Neill said: “These are all things, to a degree owners can control, and aggression is something you have to look out for and be wary of and you can help that by choosing maybe a female or a non-golden to begin with.
“But all the rest of them are just slightly increased risks, but they’re manageable by humans – these are not baked into the dog.”