Dog have magnificent brains. If you see evidence of brain disease, get the dog to the vet as soon as possible.
Brain tumors in dogs are difficult to diagnose without an MRI. They can develop at any age. Some tumors are benign growths, while others are cancerous masses inside the cranium. Secondary tumors in the brain are especially bad, as they signal a spreading cancer. Signs of brain tumors in dogs include loss of learned behavior, depression, a sharp increase or decrease in appetite, loss of vision on one side that leads to bumbling, and seizures. Surgeries and cancer treatments may be the only courses for relief.
Cerebellar degeneration is typically an inherited disease often stemming from an infection the mother contracts while pregnant. Some breeds are especially prone, including many types of setters, collies and terriers. As the name suggests, the disease eats away at the cerebellum. Like tumors, cerebellar degeneration is difficult to detect without a diagnostic such as an MRI. Symptoms include an abnormal, goosestepping walk, swaying, muscle tremors, loss of coordination and odd posture or stance. No treatment exists.
Inflammation of the Brain
Encephalitis is an inflammation of the brain, often caused by infection. Bacteria that enter the circulatory system and make their way to the brain, such as bacterial endocarditis, can cause bacterial encephalitis. Infections stemming from foreign matter, from porcupine quills to fungal spores, can lead to various types of brain swelling. Symptoms include confusion, constant circling, wandering, pacing, head pressing, excessive vocalizing, vomiting, diarrhea, dark urine and loss of appetite. More serious symptoms include seizures, coma and sudden aggression. Antibiotics usually alleviate the issue.
Problems with the brain often stem from problems in a dog's liver. This is called hepatic encephalopathy, and it occurs when the liver -- charged with removing toxins from the blood supply -- breaks down and creates improper blood flow. The result is unfiltered blood coursing through a dog's body. Hepatic encephalopathy is typically inherited and can begin at any age. Symptoms include those found in encephalitis victims. Your vet will likely hospitalize your dog while she treats his liver functions.