Cocker Rage: A Complete Guide

May 27, 2022

Many Cocker Spaniel owners will have heard the phase "cocker rage" before but might be a little confused by what it means.

As someone who has had a Cocker Spaniel for six years, I was definitely part of this group.

This condition is quite surprising for anyone who owns or has spent any time with a Cocker Spaniel since they are widely known for a loving nature and keenness to please.

Cocker rage is a term used to describe bouts of uncontrolled aggression by Cocker Spaniels. It can be directed at people or animals and is generally unprovoked with no clear reason for it.

Now, before you start looking worryingly at your Cocker Spaniel let me just make clear that this condition is rare and only impacts around 10% of Cockers. It is definitely the exception rather than the norm.

Aggression is a dog owners worst fear. A serious concern for dog owners.

It is possible to misdiagnose cocker rage syndrome for other types of aggression. But we will get into this more later.

Keep reading to learn all about cocker rage and what you can do about it.

What is Cocker Rage?

As discussed briefly above cocker rage syndrome is a term used to describe vicious and sudden aggression from a Cocker Spaniel. The aggression could be aimed at anyone or another animal and you will be unable to control your dog.

It is a type of mental lapse aggression. Luckily, this behavioural condition only impacts a small number of dogs, around 10%.

There is no pattern to this behaviour and its impossible to predict in advance. This means its not possible to recreate the circumstances that cause it and work on it like other types of aggressive behaviour.

What Causes Cocker Rage?

Unfortunately there is no clear scientific explanation to what the cause of cocker rage is. Though there is a lot of speculation on what causes it and some patterns have been observed in specific dog traits where it is more likely to appear in.

Cocker Spaniel Temperament

Cockers are known for their delicate nature, more so than many other breeds. Some believe that this soft nature makes certain cocker spaniels more predisposed to this condition.

Personally, I feel this one falls into other type of dog aggression which we will get into later. It could just be a sign of fear or aggression from the dogs environment.


There is also some research that supports cocker rage being passed down through breeding. If true, this could mean that its a form of inherited disorder through breeding dogs which have exhibited signed of cocker rage in the past.

Bad breeding practices could play a role here with puppy mills generally having less focus on creating quality litters. More focused on profit over the the care of their dogs.

The majority of breeders aim to breed the kind natured Cocker Spaniels and don't breed dogs with an aggressive past.

Epilepsy or Partial Seizure

Another interesting theory is that it could be caused by epilepsy or a partial seizure. This theory might actually hold some weight since treatment for cocker rage can include a vet prescribing epilepsy medication.

Abused or Neglected Dogs

Another theory is that abused or neglected dogs have an increased risk of cocker rage.

This could be a bad owners or even just children who don't understand how to treat a dog or your Cocker Spaniel being left alone too long.

Personally I don't feel this theory is a cause of cocker rage and will be more likely be related to other types of dog aggression.

Lack of Early Socialization

Not being socialised effectively is another suspected cause of sudden onset aggression in Cocker Spaniels. This could be more related to fear than cocker rage and its more likely a sign of a dog who was not exposed to a wide range of situations as a puppy.

Low Serotonin Levels

Another interesting theory is that a lack or serotonin could be the cause of this syndrome .

Serotonin is believe to have a relaxing effect on the brain and a lack of it is associated with violent criminals.

Which is Most Likely?

As previously mentioned all ideas on what cause cocker rage are just theories. There is no conclusive evidence on what causes this condition.

That said, based on the current theories above I would say that the most probable cause is epilepsy given that its the type of medication used to treat it.

Of course, this is only speculation and we are yet to have an absolute answer for what causes it.

Cocker Spaniel Traits Likely to Display Cocker Rage

Yes. There are actually quite a few Cocker Spaniel traits that have been observed to be more common in spaniels with cocker rage.

Putting it all together would suggest that a solid coloured male English Cocker Spaniel bred for shows would be most likely to exhibit signs. Even in that granular view it would still be a rare condition to see.

Worth noting the difference between correlation and causation though.


There has been quite a few reports that suggest cocker rage was far more prevalent in full coloured Cocker Spaniels over blue roan or parti-coloured dogs.

Interestingly, there is also data that suggested solid coloured cocker spaniels have a higher chance of aggression in general.


Males are also more likely to be afflicted with this condition than female Cocker Spaniels. This could be related to testosterone.

English Cocker Spaniels vs American

It has also been observed that English Cocker Spaniels are more likely to be afflicted with this than their American counterparts.

Show Bred Cocker Spaniels vs Working

Working Cocker Spaniels are less likely to be affected with sudden onset aggression than show bred dogs. Perhaps due to their higher energy output?

How Can I Identify Cocker Rage Syndrome?

Now that we know what cocker rage what behaviours or characteristics should we look out for in our dog.

Just to stress it again don't start worrying that your dog has this condition as it is incredibly rare. If your dog does have this it would show up before they are an adult in most cases. Typically by eight months old.

In the lead up to an attack your dog can be quite well behaved and switch in an instant. It almost always takes the owner by surprise.

Cockers are often sleeping just before an attack and can be triggered by a unusual sound or even someone entering a room. It might even be their favourite human.

After its over your dog will quickly return to being calm and submissive. Even acting like nothing has happened at all.

It can often be mistaken for other types of canine aggression but we will get more into that soon.

Signs to look out for

  • Unprovoked aggression (most common)
  • Excessive drooling
  • Panting
  • Urinating inside
  • Temperamental
  • Staring eyes or dilated
  • Growling
  • Barking
  • Lunging at other dogs

Most of the behaviours listed above are not unique to this condition. Part of the reason its so easily misdiagnosed. There are more than a couple of videos on YouTube titled "cocker rage" which are actually just a hyper puppy being crazy.

Cocker Rage vs Standard Dog Aggression

Bearing in mind how uncommon this condition is you need to consider that any unexpected violent behaviour from your Cocker Spaniel is more likely a sign of another type of aggressive dog behaviour.

There are a few possibilities here to consider.

Firstly, this breed are known for having a high prey drive with a history of being bred as hunting dogs. Naturally a dog with this history have a high energy at times and can be a little crazy. It is really easy to get a cocker excited.

At times it can even happen for no apparent reason. This is just part of the fun of having a cocker spaniel.

Confusing Cocker Rage with other Behavioural Issues

As mentioned this impacts a low percentage of Cockers so another form of aggression is far more probable.

This could be:

  • Dominance aggression: Dog feeling challenged or threatened by owners actions
  • Resource guarding: Protective of food
  • Territorial related behaviours: Defensive of their home
  • Status aggression: Dog challenging place in pack
  • Just badly behaved: Poorly trained

Before concluding that your canine companion has cocker rage try to see how they behave around these areas. It is far more likely that one of these is the real culprit.

Try to create situations where you can test your dogs response to these situations. Keep a record of how your dog responds to these situations. Recording it can also be a good approach. All very useful if you have to speak to a dog behaviour specialist or vet later on.

Try to make detailed notes of everything has happens leading up to an attack while its still fresh in your mind. This will come in very handy if you need to speak with a specialist.

How Common is Cocker Rage?

Thankfully this condition is rarely seen amongst Cocker Spaniels. It only impacts roughly 10% of all Cockers.

What Age Does Cocker Rage Start?

If your dog is going to be affected by this condition the will usually be showing signs while still a puppy. On average signs tend to appear at around 6-8 months old.

It is really unlikely that an adult Cocker Spaniel with no previous history of cocker rage will be showing signs of it. Chances are if you are seeing behavioural change later in life it will be related to one of the other conditions listed above.

How do you Deal with Cocker Rage?

Found yourself in that unfortunate small percentage of people who own a cocker spaniel who has cocker rage? All is not lost there are still options available.

The first step you should take here is to ensure its not rooted in another form of aggression. See the section above on this for actionable tips on ticking that box.

You might be really lucky and find that its actually a training issue or something you can work through with a dog trainer.

Failing that book an appointment with your vet and voice your concerns. This is definitely the best person to speak to.

Run the vet through everything you have tried to treat this at home and any footage you have of it happening.

Can Cocker Rage be Cured?

If the vet confirms that your dog has cocker rage. There are still a few options on the table here.

First the vet might referred to an animal neurologist to get a better understanding.

In terms of treatment it is possible that your Cocker Spaniel could be prescribed epileptic medication. The response to medication will vary case to case.

If the aggression persists and no treatment is is effective there is unfortunately only one option left which is euthanasia. Of course, this is an absolute last resort but given the danger that it can pose, particularly to households with children it can be an option some have no choice but to consider.

Is this Condition Unique to Cocker Spaniels?

Though this condition is most commonly associated with this breed Cocker Spaniels are not the only dog who have been known to have it.

Several other breeds have had similar issues.

These include:

  • Golden retrievers
  • German shepherds
  • English springer spaniels
  • English bull terriers
  • Pyrenean mountain dogs
  • Chesapeake bay retrievers

All very rare though. Its thought this is more prevalent in Cocker Spaniels due to their sensitive natures.


Nobody wants to see their loving Cocker Spaniel being aggressive. Thankfully cocker rage is a very rare condition that is not commonly seen. When it does occur it can represent a very serious behavioural problem which can be quite dangerous.

This condition is often misdiagnosed in place of another variation of dog aggression. There are definitely ways to clearly test this though and understand the cause.

Like any problem with your dog be sure to speak with a vet if you have any concerns.

Allan  Noble
Hi, my name is Allan! I am the owner of Spaniel Advisor and I've got over seven years experience of owning Spaniels.  
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