Rage Syndrome in Cocker Spaniels


The term “Rage Syndrome” is applied to serious uncharacteristic behaviour in certain breeds of dogs (particularly Cocker and Springer Spaniels).  The Cocker Spaniel Breed Council has never approved of the term “Cocker Rage” preferring to refer to uncertain temperament.  Rage is often misdiagnosed and used to justify euthanizing dogs.


It is not a new problem, indeed in an American book first published in 1935, Ella B Moffit wrote of certain Cockers having bad temperaments.  She expressed the view then that because breeders were not being selective enough and dogs and bitches with bad temperaments were being bred from, this resulted in poor temperaments reappearing three to four generations later.  Letters written from Elizabeth Barrett Browning to Robert Browning (1845-1850) included many references to the aggressively protective tendencies of her red Cocker called Flush.


Rage is often thought of as a variant of dominance aggression and is more common in solid coloured Cockers than in particolours (though it should be emphasised that cases are relatively rare).  An affected dog attacks suddenly and savagely, without any warning and during the attack the dog often has a glazed look and appears to be unaware of its surroundings. 


Dr Mugford, an eminent world authority on animal behaviour, wrote to the Daily Mirror in 1983 claiming that both Cocker and Springer Spaniels tended to be uncontrollable and some were prone to aggressive rages.  He reported that the most aggressive dog he had seen at Crufts that year was a Springer.  He was invited to speak at the Cocker Spaniel Club in the summer of 1984 on the behavioural aspect of Cockers with unsound temperament, accompanied by Geoffrey Skerritt (a veterinary surgeon specialising in neurology) who was asked to cover the medical aspect.


Dr Mugford had collected 200 pedigrees of affected Cockers, which enabled him to calculate their coefficient of inbreeding.  Three bloodlines occurred in over half of the patients he had seen, and the sample contained a 70:30 ratio of males to females.  At the meeting he presented four case studies that summarized the nature of the problem, and then went through the data.  One if his suggestions was that the Breed Club should operate a strict temperament testing regime on offspring that breeders had already sold to pet homes, when they were six, twelve, twenty-four and thirty-six months old.  If any of the offspring were then found to be unsound, then the parents should not be used for breeding again.  This caused much controversy at the meeting, which eventually broke up without any definite decisions being reached.


Dr Mugford claimed that Cockers (primarily the red and black) were the breed he was consulted most frequently about.  He had identified two leading kennels as being the sources of deranged solid Cockers and reported that the more champions there were listed on a Cocker’s pedigree, the more likely the dog would exhibit symptoms.  The affected Cockers, he said, were perfectly civil with strangers, and in the show ring, but tended to attack their owners savagely and unpredictably.  He concluded that solid Cockers in Britain and those exported to USA from Britain in the last ten to twenty years could be extremely dangerous dogs and he gave an extreme solution to the problem, advising against the breeding and selling of solid Cockers. 


During the early 1980s there were a number of articles in the national press relating to aggression in dogs in which Cockers were considered to be particularly dangerous.  There were similar references made on radio and television programmes at that time and this resulted in very bad publicity for the breed.


The Cocker Spaniel Breed Council established a Temperament Committee in the autumn of 1982 and its remit was to investigate the alleged temperament defects in the breed.  The aims of the committee were:


  • To clarify whether there were two separate problems, one being dominant animals due to lack of discipline and the other being so-called ‘rage syndrome’.
  • To research the cases of the defect or defects, calling in whatever specialist aid is required and where possible to recommend solutions.
  • To counter propaganda in the press and media contrary to the interests of Cockers.
  • To raise the necessary funds.


The Temperament Committee’s first meeting was under the guidance of Mr G Skerritt and it was decided to establish the incidence of abnormal behaviour by means of a questionnaire to be sent to as many Cocker “pet” owners as possible via the London Cocker Spaniel Society’s newsletter; this was subsequently extended to being sent to all embers of the British Small Animals Veterinary Association through their monthly journal.  The response to the detailed questionnaires was extremely good, resulting in information being provided on a total of 1,692 Cockers of which 258 showed one or more of eight different kinds of defined abnormal behaviours.  More dogs than bitches were found to display abnormal temperaments in each colour group and the frequency was higher in reds than blacks, and in blacks was higher than any other colour.


Dr Bruce Cattenach, a recognised geneticist and a breeder of Boxers, kindly arranged for a post-doctoral research worker at MRC Harwell to put the data on computer for statistical analysis and the findings were as follows:


  • There was no obvious environmental component other than all the dogs were ‘house’ dogs.  However, it might be the case that because they were house dogs the condition became detectable.
  • Because no environmental component could be found, and because reds were exposed more frequently than blacks, then a genetic component must be expected.
  • Although the abnormal temperaments could be due to a single gene, he thought it was more probable that a polygenic inheritance was more likely and if true should be discernable in pedigree studies.
  • He believed the type of approach needed to breed out the problem would be based on record keeping and listing of frequencies of pups with abnormal temperaments sired by ‘significant dogs’.  Although all extensively used stud dogs would be expected to sire some “abnormals”, if abnormal temperaments have a genetic basis he would expect the frequency to be higher for some dogs than for others.


In 1990 discussions commenced with the Companion Animal Research Group, Department of Clinical Veterinary Medicine at Cambridge University, where a three year research project was being embarked upon into aggression and other behaviour problems, including so called ‘rage syndrome’ and a possible connection with temporal lobe epilepsy.  In studies of this nature, it is important to distinguish between three different factors, which may influence the development of temperament:


  • Genetic factors
  • Early socialisation
  • Effects caused by the owner e.g. personality factors.


Members of the Temperament Committee visited Cambridge and met Dr James Serpell and his team.  Dr Serpell put forward the following proposals to investigate:


  • A vet had agreed in principle to examine at least 24 dogs, 12 showing typical symptoms of rage and a further 12 normal dogs, preferably of similar age, sex and colour to the affected animals.  The results would be sent to Cambridge for analysis.
  • To gather background information on as many raging and normal Cockers as possible for comparisons.
  • Send behaviour questionnaires provided by Cambridge, together with personality factor tests for the owners to complete.  The research team’s aim was to establish whether the owner’s personality played a part in the dog’s behaviour problems.


The total cost for the proposed research was estimated at just over £4,000 and the Cocker Spaniel Breed Council agreed to raise £5,000 by mid-summer 1991.


Two thousand questionnaires were distributed randomly via the Kennel Club to owners of purebred English Cocker Spaniels.  The findings were published in a paper [Anthony L Podberscek and James A Serpell (1996)] and whilst the information contained in it was scientifically based and some of the terminology not easy to comprehend I have tried to extract the most important points. 


A good representation of registered Cockers was achieved, as the distribution of coat colours of the survey of dogs compared well with the coat colours of Cockers registered in 1992 in the UK.  The solid coloured Cockers were significantly more likely to show aggression than the particolours in 12 out of 13 given situations, and the red/golden more likely to show aggression that the blacks.  .  Solid Cockers made up 38.6% of the sample and of these 47.9% black and 52.1% red/golden. 


The existence of significant behavioural differences between the different colour morphs of the breed is interesting in the light of Hemmer’s view that coat colour in domestic animals is often closely associated with temperament.  This theory was based on the fact that the pigment melanin shares a common biochemical synthesis pathway with the catecholamine group of neurotransmitters.  Because red Cockers have different pedigrees to particolours, it might be a genetic (polygenic) trait associated with lines more than colours.  There is to be a follow-up research on the study of pedigrees of a subset of aggressive and non-aggressive dogs.


There were similar numbers of males (49.1%) and females (50.9%).  Of the males, 82.7% were entire and of the females, 66,8%. 


  • Males were significantly more likely to show aggression than females, towards strange dogs, towards their owner or a member of the owner’s family, when disciplined and when reached for or handled. 
  • Females most commonly started to show signs of aggression at two months of age while the males started at around six months; the difference probably being related to the onset of puberty in males with its associated rise in testosterone secretion.
  • Neutered females were found to be more likely to show aggression towards children in the household.  A number of studies on neutered females have found that dominance aggression does increase significantly after neutering.
  • Neutered males were found to be significantly more aggressive than entire males.


Because the neutering effect was surprising, a follow-up study was carried out requesting further details of the age at which the aggression started (where appropriate), age the dog was neutered and the reason.  Results were collected from 149 neutered females and 73 neutered males.  The mean age at which aggression started was 11 months for both males and females.  From the statistics it was thought that neutering was probably the consequence of aggressiveness rather than the cause.


The results suggest a genetic and neuroendocrine basis for the differences in aggression.  Dr Podberscek carried out a  ‘cluster analysis’ (grouping together of aggression categories) which showed that there is some evidence that rage syndrome is an expression of social dominance, rather than being a separate or pathological phenomenon.  There are 2 main theories as to what this syndrome might be:


a)     An unusual form of dominance aggression

b)    Type of epilepsy – might be part of a group known as complex partial seizures.


The study provided important information on the prevalence of different types of aggression in the Cocker Spaniel.



Although rage syndrome has been studied for a number of years, it cannot be accurately predicted and can only be diagnosed by EEG or genetic testing and these tests are not conclusive.


The Chairman of the Temperament Committee informed me that things have come to a standstill over the last couple of years, the situation being that there has been a lack of affected Cockers coming forward for brain scans and it is difficult to progress any further.


Cocker Rescue is still occasional reporting temperament problems within the breed.


It is often very distressing and upsetting for the owners of dogs severely affected by true rage syndrome and not enough information is readily available.  They are often already very upset by the fact that their dog has attacked a family member without provocation and may feel a sense of guilt about the whole business.  The truth is there is probably not very much that could have been done to avoid the situation arising in the first place.  Owners of affected dogs should seek advice from a veterinary surgeon for possible referral of their dog to a professional behaviourist for assessment.


© Linda Ward 2002