Brain Tumors in Dogs

You find yourself looking back and micro analyzing all of those initial symptoms. The first time it happened, she was wobbly, and you thought arthritis. The second time around she got confused, you thought “she is just getting a bit older.” When she started pacing the house relentlessly, you took her to the vet and they sent her home with pain medicines saying it was arthritis. She went blind, so you thought, “well she must have cataracts or something”… I guess that’s okay. She forgot how to get back inside. Maybe it’s dementia? She may have had a seizure? “Doc, I thought she was going to die last night, the seizures were so violent!”  Do these things sound all too familiar?

That’s the thing with brain tumors, at first the symptoms can be so subtle. Diagnostically, they can mimic so many things that could be wrong or occurring in your pet.  Every pet that presents lameness is not going to be sent immediately for an MRI to rule out a brain tumor. Depending on your veterinarian, it may be the first thing they suggest be done, but many veterinarians will treat for arthritis or a soft tissue injury as it is much more common.

The brain is the powerhouse of the body. While the heart is responsible for pumping oxygenated blood to the body and deoxygenated blood to the lungs, the heart is just a muscle-  a pretty amazing and incredibly designed one. The brain is really the big boss, CEO, man or woman in charge. The brain drives the body for breathing, as well as drives the heart rate and blood pressure. It also recognizes and is responsible for coordination. Chewing, breathing, equilibrium, and the collection of information from the senses all occur here. So it is no wonder that symptoms can be varied, confusing, and involve multiple parts and functions of the body.

Reclusive behavior, weight loss, changes in appetite, loss of vision, head tilt, bumping into walls, standing in corners, getting stuck behind furniture, urinating and defecating inside – all are possible signs of a brain tumor. We may also see depression or an overall dull presence of just existing in our fur kids. Loss of balance and coordination, difficulty swallowing,  getting food or water in the mouth, dropping food or seemingly a loss of ability to lap water – all can be signs of something seriously wrong.  In some cases, instead of the dull depressed behavior, we will see panic and anxiety or even aggressive behaviors. Tremors and seizures, especially when they become more frequent and intense, can indicate progression of disease.

So let’s go back for just a minute here: Brain tumors are either primary (they originated from the brain or brain lining) or they can be secondary (caused by the spread of cancer). 

The most common forms of primary brain tumors in dogs include: 

meningiomas, gliomas, pituitary adenomas and adenocarcinomas (that pesky gland that can be responsible for Cushing’s disease). 

Meningiomas arise from the lining of the brain. Secondary tumors spread to the brain from somewhere else in the body. Examples of secondary brain tumors include: hemangiosarcoma, mammary carcinoma, and melanoma.  Therefore, depending on the location of the tumor, the symptoms will vary. Tumors of the fore brain will typically cause seizures and changes in mentation state or behavior. While tumors that affect the brain stem can impair the ability to walk, respiratory function, circulation, balance, and cranial nerve function such as control of face and mouth.

What to do if you think your pet has a brain tumor?

The hard reality is: Brain tumors are undetectable on x-rays and blood work. The brain needs to be imaged using magnetic resonance imaging (MRI) or computed tomographic (CT) scans.  Prior to these advanced diagnostics, a general workup is needed: a complete physical and neurological examination, routine blood work to rule out other problems, chest x-rays to check for the spread of cancer to the lungs, abdominal ultrasound to check for the spread of cancer to internal organs. 

While a CT or an MRI of the brain are the best choices to definitively identify brain tumors, they generally require anesthesia and are expensive.  CT & MRI scans are usually only offered at a specialty practice. The other big piece of this puzzle to take into account is that they are just INFORMATION, they are not therapeutic. If surgery, radiation, or chemotherapy are not an option for your pet or ultimately you choose not to purse treatment, is it worth putting the patient through this? This is not something I can answer. Every pet is different, every family is different. There is no right or wrong…. Not pursuing treatment can vary for several reasons, whether it be cost, the age of your pet, the stress your pet may experience at the vet, maybe another medical issue your pet may have, or simply, the risks to treat outweigh the quality by not treating.  

Brain tumors may be treatable, but sadly, they are rarely curable. The survival rates for pets treated with radiation averaged about a year. The ever tipping scale of quality vs quantity needs to be discussed with your veterinary oncologist in regards to treatment schedules, possible side affects, hospital stays etc etc.

Palliative care is also an option, and should not make you feel defeated and as if you are giving up on your pet. A dog with a brain tumor that is having seizures can be placed on anti-epileptic drugs such as Phenobarbital. Tumors that cause excessive fluid to accumulate and inflammation can respond to palliative treatment with steroids, such as prednisone, which has the potential to improve the quality of your pet’s life for a period of time. 

Lastly, there are times where a brain tumor can be caught early on and treatment is an option. Other times, the symptoms have become so severe, or quality of life is generally poor by the time the tumor has been discovered.  There should never be the sense of guilt, as stated in the article, symptoms can be so minuscule, a brain tumor may not be the first diagnosis.  Ultimately, being able to help our fur kids pass surrounded by love and support is the last act of helping them. We never want their last day to be their worst day.