Although an uncommon occurrence, a brain tumor is a relatively more common form of cancer in dogs than a feline cancer. A head injury may result in accumulation of fluid in the brain or a cranial fracture - both of which may cause brain damage. Although both the conditions can be treated medically, irrespective of whether it is a typical case or a severe instance, brain surgery is required to relieve the pressure on the brain.
Brain tumors, however, are believed to have a genetic predisposition as they occur mostly in young cats. Brain tumors may be primary, occurring in the brain itself, or secondary, as extensions due to metastasis of a malignant growth in the nasal passage, skull or ear cavity and pituitary gland tumors.
Like all cancers, brain tumors do not show early symptoms. However, unlike the symptoms of liver cancer in dogs and cats that are non-specific, some of the symptoms of a brain tumor are specific and some of them are even indicative of exactly where the tumor is located.
- Loss of training
- Decreased activity
- Infrequent purring
Specific symptoms that indicate a tumor in a specific location in the brain:
- Cerebral Cortex - seizures
- Brain Stem - facial paralysis
- Cerebellum - tremors and/or wobbliness
- Hypothalamus or optic nerve - partial or complete blindness
- Olfactory system - loss of smell
Apart from these, the very presence of a tumor and the accompanying edema and inflammation can cause the following symptoms:
- Irritability and lethargy
- Compulsive walking and walking in circles
- Pressing the head against hard surfaces
- Loud meowing, mood swings and manic grooming
Before the advent of new imaging techniques like CT scan and MRI, brain tumors were assumed and rarely confirmed. The most common form of brain tumor in cats is a tumor arising in the meninges (one of three membranes that envelop the brain and spinal cord), which usually grows gradually and is sometimes malignant. If the tumor grows gradually and does not show specific symptoms, cat owners tend to get used to them after some time. This can further delay a diagnosis.
A biopsy remains the only way for ascertaining the benign or malignant nature of a brain tumor because even advanced diagnostic imaging cannot present a conclusive evidence of malignancy. Most brain tumors in cats remain a mystery until they are analyzed during an autopsy. The worrying part is that brain surgery is not common in veterinary medicine. It is a high risk surgery that requires the services of a neurosurgeon and specialty practices. Brain surgery is performed only if there is a reasonable certainty of removing the entire tumor and avoiding any collateral damage.