Brain Tumors In Dogs

Besides humans, dogs are the only mammalian species in which spontaneous brain tumors occur.

Brain tumors may be primary or secondary tumors (metastasis - cancer spread). The most common form of primary brain tumor is a meningioma (50%) and a glioma (35%). Other less common brain tumors include ependymomas, choroid plexus tumors, gliomatosis cerebri, histiocytic sarcoma, and lymphoma.

Secondary brain tumors (SBT- metastatic brain tumors) originate somewhere else in the body and then spread to the brain. They represent approximately half of all canine intracranial tumors, including pituitary tumors, metastatic carcinomas, and haemangiosarcoma. These three account for almost 86% of SBTs in dogs.

Canine brain tumors account for 2-5% of all canine cancers. The estimated incidence reported is 15 cases per 100,000.

Brain tumors may occur at any age and both the sexes are equally vulnerable. However, most brain tumors occur in Middle aged-older dogs (average age>5 years).

Forebrain tumor symptoms:

• Seizures- younger dogs (Idiopathic epilepsy), older dogs (acute seizure disorder).
• Walking in circles - unable of walking in a straight path.
• Blindness in one or both eyes.
• Behavior changes- Irritable, seems lost, quiet, prickly, or may lose normal learned behaviors.

Symptoms of the back part of the brain tumors:

• Ataxia- Uncoordinated or wobbly walking
• Head tilt to the side
• Rapid, repetitive, involuntary movement or darting of the eyes (Nystagamus)
• Loss of vision
• Head/neck pain
• Nausea and vomiting
• Paresis: muscular weakness
• Hemiparesis- weakness on one side of the body
• Unsteady gait

• When your dog is diagnosed with a Brain tumor your vet may recommend surgery, chemotherapy, radiation, or a combination of these treatments.
• Surgery provides the best survival outcomes for brain tumors, along with adjuvant finely fractionated conventional radiation therapy.
• Meningiomas -median survival time (Surgery alone) for dogs is 6-9 months.
• Surgery followed by radiation therapy - Median survival time 1.5-2.5 years.
• Metastatic brain tumors - Surgery is not recommended.
• Chemotherapy can be considered in dogs after surgery if radiation therapy is not available.
• Chemotherapeutics that can penetrate the blood-brain barrier: carmustine, CCNU, procarbazine, temozolomide, melphalan hydroxyurea.
• Supportive medications: Anticonvulsants, omeprazole, and prednisolone.

Prognosis varies by case: The median survival time for dogs can be advanced to 20-24 months for meningiomas and from 12-14 months for gliomas (using a combination of treatments).

• Talk to Your Veterinarians, and oncologists and understand your pet's treatment options.
• Pain can be so subtle in dogs - access your dog's pain and watch out for any abnormal behavior.
• Don't forget even sick dogs need a few low-stress activities and a lot of rest.
• If you have considerations about your own health, talk to vets about how to keep yourself and your pet safe during the treatment.
• Get a good pet sitter! For those who could not spend enough time at the home, make sure you have a reliable pet sitter.

Modifiable risk factors for the prevention of Brain cancer.

1. You might be able to prevent brain cancer by avoiding certain lifestyle behaviors.

2. One of the most important changes you can make is reducing carcinogenic exposure such as pesticides, secondary smoking, and other chemicals.

3. Common carcinogens that lurk unknowingly in our households are:

• Benzene (adhesives, degreasers, rubber cement).
• Styrene (fragrances).
• Herbicides.
• Formaldehyde (plywood wood products).
• Asbestos sheet (roof shingles, ceiling tiles).

4. Industrial pollution and chemicals (arsenic, plastic, leather, textiles, dyes). Keep your dogs away from these carcinogenic risks.

5. Provide an organic, healthy diet with fruits and vegetables.

There is no breed, sex predisposition. However certain tumors are over represented.

Boxer, Golden Retriever, Doberman Pinscher, Scottish Terrier, Old English Sheepdog.

Some commonly occurring canine brain tumors are:

• Meningiomas: This is the most common primary intracranial tumor. These tumors are reported to arise from any of the three meningeal layers.
• Gliomas: they are the second most frequent tumor in dogs and the hardest to treat.

There are three types:

1. Astrocytomas - originate in astrocytes.
2. Oligodendrogliomas- originate in oligodendrocytes.
3. Undefined gliomas- unspecified or mixed glioma.

• Choroid plexus tumors - intraventricular tumors from the choroid plexus.
• Ependymoma- ependymal cells of the central nervous system.
• Haemangiosarcoma - blood vessel walls (vascular endothelium).

Causes of a Brain tumor in dogs: The definitive cause and risk factors of canine brain tumors are unknown. Although it is speculated that environmental, genetic, chemical, viral, dietary, immune system, and/ or traumatic factors may be involved.

Vets perform a few diagnostic tests that will help decide the type of brain cancer and how to proceed with the treatment.

• Urine, Blood, and/or spinal fluid samples - These are vital to evaluate organ function.
• CT scan/MRI - These play a crucial role in the management of a brain tumor.
• X-ray - Check for secondary tumors or metastases (spread of cancer).

Foods to avoid:

• Spicy foods, Greasy, fried foods and Allergens (gluten, soy, and dairy).
• eliminate colorings, preservatives, additives, and flavors from your pet's diet.
• Don't switch up food a lot but an occasional mix and match of foods are ok.

Vet's dietary decisions are based on a dog's type of cancer, any other conditions of the pet, and overall health.

• Reduce the carb and increase good fat foods for your dog.
• Include dog-safe spices like turmeric, ginger, cumin, and coriander.
• Foods that are often high on their lists for cancer-fighting properties are high-protein, Organic, and cruciferous foods.
• Generally, all ingredients should be fresh, easily digested, highly palatable with a good smell, and should be highly bioavailable.

The ratio would be:

35 to 50 percent protein + less than 25 percent carbs + 25 to 35 percent fat (including omega-3 fatty acids and arginine).

Some of the most popular include:

• Fresh, organic meats, either raw or cooked.
• Chicken.
• Fish.
• Organ Meat.
• Broccoli.
• Dark-green, leafy vegetables like spinach.
• Eggs.
• Antioxidant berries.

Omega 3 fatty acid foods (Sardines, Mackerel, Herring, etc,.).

The prognosis for brain tumors in dogs depends on the type of cancer and how early it was treated. The median (average) survival time is 2- 4 months with supportive care alone. However, with proper treatment, the survival time for dogs can be significantly increased.

Sadly, there is inadequate data in the veterinary literature to assess the effect of most brain tumors grade on clinical outcomes.

However, higher histological grades are prone to have a poor prognosis.