Although it is relatively uncommon, dogs and cats can develop brain tumours just like humans. Our pets can’t tell us how they’re feeling, and brain tumours often cause some worrying signs which can be scary for owners to witness.  

The good news is that veterinary medicine has advanced hugely in recent years meaning brain tumours can be diagnosed earlier and treated more effectively. A brain tumour doesn’t necessarily mean an animal should be put to sleep immediately as it’s possible to achieve a good quality of life with management for months or even years after diagnosis. 

What actually is a brain tumour? 

A brain tumour is an abnormal growth of cells within or around the brain. Tumours can arise directly from the brain tissue itself, or they may be a spread from other cancers elsewhere in the body.  

We generally divide brain tumours into two different types: 

  • Primary brain tumours – tumours originating from the brain itself or its surrounding structures, including the meninges (the thin, protective layers around the brain). 
  • Secondary brain tumours – tumours spread to the brain from another part of the body, or those that have invaded from a nearby tissue such as the nasal cavity. 

Brain tumours can be benign (slow growing and less invasive) or malignant (aggressive and invasive). However, even benign brain tumours can cause serious problems as they increase pressure on the brain within the skull, which is a closed space.  

How common are brain tumours in pets? 

Overall brain tumours are considered relatively rare in cats and dogs, but they are more commonly found in dogs than cats. We most often see brain tumours in older dogs. Certain breeds including Boston Terriers, Bulldogs, Boxers and Golden Retrievers appear to be predisposed.  

What are the symptoms of brain tumours? 

Symptoms of a brain tumour will depend on the size and location of the tumour. Signs often develop gradually over time, although some pets will appear to worsen suddenly. 

Seizures 

One of the most common brain tumour symptoms in dogs is seizures (fits), especially if they develop seizures for the first time in middle or old age (idiopathic epilepsy is a much more common cause of seizures in dogs up to 6 years old).  

A seizure usually involves: 

  • Collapse 
  • Paddling limbs  
  • Twitching 
  • Hypersalivation (drooling) 
  • Loss of consciousness 
  • Involuntary urination and/or defecation 
  • Temporary confusion afterwards 

Cats may show more subtle signs such as facial twitching, odd vocalisation or sudden episodes of staring into space or apparently losing consciousness.  

Check your pets symptoms
Symptom Checker

Behaviour changes 

Owners also sometimes notice personality changes in their pet before other physical symptoms arise. Pets may become: 

  • Disorientated 
  • Withdrawn 
  • Irritable 
  • Restless 
  • Clingy 
  • Anxious or confused  

Abnormal movement 

Brain tumours can also affect balance and coordination, resulting in changes to the way an animal moves around. Pets may: 

  • Walk in circles 
  • Stumble  
  • Tilt their head to one side 
  • Drag their feet  
  • Appear weak on one side  

Some animals struggle to judge distances as well or start bumping into furniture.  

Vision Problems  

Some tumours can press on or interrupt the visual pathway, causing dilated pupils or blindness.  

Other possible symptoms 

Additional signs of a brain tumour might include: 

  • Changes in appetite 
  • Weight loss  
  • Excessive sleeping 
  • Abnormal eye movements 

It’s easy to see how some of the above symptoms could be confused with an older animal simply becoming clumsy or senile with old age, so it’s important to get your pet checked if they develop any of them.  

How are brain tumours diagnosed? 

Brain tumours need special equipment to properly diagnose them. We can sometimes make a presumptive diagnosis based on history, neurological exam and ruling out other causes first. 

Your vet will need to perform a neurological examination to help localise the problem or find out whether the issue is coming from the brain, spinal cord, nerves or somewhere else in the body. 

Baseline blood tests can help rule out metabolic diseases that can mimic certain neurological conditions, such a liver disease or electrolyte imbalances.  

The most definitive way to diagnose brain tumours is advanced imaging; usually an MRI or CT scan, as the brain isn’t visible on normal x-rays. Advanced imaging will usually be carried out at a specialist centre with veterinary neurologists and advanced imagers, so your vet will likely need to refer your pet for this. MRI scans also require general anaesthesia to keep the pet completely still. However, although these imaging modalities are great at picking up lesions in the neurological system, they can’t always identify the specific type of mass.  

In some cases, vets may take a sample of cerebrospinal fluid (CSF – the liquid circulating around the brain and spinal cord). Occasionally a biopsy is required, but most cases are diagnosed based on imaging and clinical signs.  

Aggressive types of tumours can spread around the rest of the body (metastasise) and these may be picked up on imaging done by your first opinion vet, for example on chest x-rays or abdominal ultrasound scans. Your vet may also want to carry out these tests afterwards if a brain tumour is diagnosed, to see if it has spread elsewhere.  

Can brain tumours be treated? And if so, how? 

Treatment really depends on a few different factors: 

  • The type and typical behaviour of the tumour 
  • Tumour location 
  • The pet’s age and overall health  
  • Financial considerations 
  • Overall quality of life 
  • Owner expectations and goals for quality of life  

There are a few different options for treatment and some involve a combination of methods.  

Medication 

Medical treatment of brain tumours is usually aimed at reducing the symptoms, rather than attacking the tumour itself. The brain is a very protected organ with its own special blood supply, so it is very difficult for most drugs to penetrate it. Steroids can be helpful in reducing the swelling and inflammation caused by the tumour while anti-seizure drugs aim to reduce the frequency and severity of any seizures. Medication can make a huge difference and dramatically improve an animal’s quality of life overall, but it can come with side effects which your vet will discuss with you. This is usually the most low-cost treatment option but it doesn’t treat the tumour directly and may only provide relief for a short time. 

Radiation therapy 

Radiotherapy is one of the most effective treatment options for many types of brain tumour in dogs. Targeted radiation can shrink tumours and improve neurological signs while minimising the damage to the surrounding tissues. Therefore, the potential benefits of this treatment can outweigh the risks. However, there is still the possibility of side effects. Radiation therapy targets the tumour directly and is more likely to provide a good quality of life for a longer period than medication alone. Nevertheless, radiation rarely treats the tumour entirely. Average remission times are 8 to 14 months before the tumour grows back.  

Surgery 

Surgery may be an option for certain tumours, especially meningiomas in dogs and cats. Unfortunately, it is not often possible to remove the whole tumour from a brain and not all brain tumours are able to be approached surgically at all. Surgery on a brain tumour will usually be aimed at removing as much of the mass as possible, helping the other treatment methods to hopefully work better as well as relieving some of the symptoms. This should also allow a sample of the tumour to be taken for a better diagnosis. This is often the most expensive option and still comes with risks attached to the surgery but if it goes well, it may provide the longest period of good quality of life. 

There is no right or wrong treatment plan and any options should be discussed in depth with you vet. They will ensure you feel that you are making the right choice for your pet as an individual, as everyone’s situation is different.  

What is the prognosis? 

Prognosis varies enormously depending on the type of tumour and the treatment pathway chosen.  

Without any treatment at all, survival may only be a few weeks to months once neurological signs become severe and impact an animal’s quality of life. However, other pets may go on relatively comfortably for much, much longer. 

With treatment, some pets may be kept comfortable for a few months on medication alone and pets treated with surgery or radiation may survive for several years.  

Unlike human cancer treatment, animal cancer treatment is focused on extending their life rather than treating the cancer completely. When it comes to pets, we consider quality of life the most important factor, more so than survival alone. Many owners choose treatment if it means their pet can continue to enjoy their normal activities and stay involved in family life.  

A brain tumour diagnosis can feel overwhelming and many owners worry about whether their pet will suffer as well as uncertainty about the future and what that might look like. Plenty of pets will enjoy a good quality of life for meaningful periods after diagnosis. Your vet will be able to help tailor any treatment plans around you and your pet’s needs.  

Simple adjustments at home can help to make your pet feel safer and more comfortable, such as reducing disruption at home, careful monitoring and restricting access to stairs or unfamiliar environments.  

Above all, owners know their pets best. Changes in their personality or quality of life should be noted and discussed regularly with your vet.  

Conclusions 

So yes, dogs and cats can unfortunately get brain tumours, particularly as they age. Although the condition is serious, modern veterinary medicine offers far more options than many people realise.  

Recognising the symptoms early and seeking prompt veterinary attention can improve outcomes, comfort and extend life times.  

Further Reading: 

Primary Brain Tumours – NDSR 

Brain Tumours – Vet Specialist Factsheet