In dogs and other vertebrates, nerve cells -- called neurons -- transmit signals that enable the brain to regulate the body's functions. When a disease process interferes with the neurons ability to do that, the central nervous system, which consists of the brain and spinal cord, malfunctions, potentially causing a wide range of disorders. Some are more common among certain breeds and bloodlines, suggesting genetic and hereditary links. If you suspect your pet has a neurological problem, see your vet right away.
Symptoms to Watch For
Specific conditions have their own sets of symptoms but according to the Veterinary Neurological Center of Phoenix, confusion, loss of muscle control and abnormal movement patterns are all typical signs of neurological disorders in dogs. If a dog starts to walk strangely, dragging a leg, losing his balance, trembling or shaking, the normal channels of communication between his brain and body could be disrupted. If a dog is stumbling into things, his vision might be affected. Collapsing and losing consciousness, seizures and involuntary loss of bowel and bladder control are further warning signs. Difficulty with swallowing and chewing, muscle spasms in the jaw and crying out in pain for no apparent reason also may indicate neurological impairment.
Wobbler Syndrome Affects Large Breeds
Wobbler syndrome, which causes dogs to walk with an unsteady or "wobbly" gait, is most common among large and giant dog breeds, especially Great Danes and Dobermans, says veterinary neurologist Ronaldo da Costa of Ohio State University. Painful spinal cord compression in the neck region compromises the dog's ability to walk and stand; left untreated, this can result in paralysis of all four legs. In early stages, affected dogs might slip on smooth surfaces or appear unsteady only when they walk slowly. In more advanced stages, their legs can buckle and they might have difficulty getting back on their feet. Treatment may include anti-inflammatory drugs and restricted physical activity but surgery can improve or stabilize wobbler syndrome in about 80 percent of cases, da Costa says.
Seizures and Epilepsy
Seizures can be brought on by a number of conditions, including brain inflammation and tumors, head injuries and strokes, but the cause of epilepsy, a chronic seizure disorder, is idiopathic, or unknown. This neurological disorder is characterized by episodic convulsions that last between 30 and 90 seconds and can be alarming to witness. Usually, an affected dog collapses, his body stiffens, he drools profusely, paddles all four legs, vocalizes and may urinate and defecate. Age of onset may be as young as 6 months or as old as 6 years. Some breeds are more susceptible than others, including border collies, Shetland sheepdogs, Australian and German shepherds, beagles, golden and Labrador retrievers. Vets treat idiopathic epilepsy with anticonvulsant drugs, which affected dogs must take for the rest of their lives.
Canine Cognitive Dysfunction: Doggy Dementia
Canine cognitive dysfunction, also known as "doggy dementia," corresponds closely to Alzheimer's disease in humans. In both species, a buildup of protein deposits in the brain is believed to be a major contributing factor. "Not all dogs develop signs of cognitive dysfunction, much as all people don't develop senility," says veterinary behaviorist Gary Landsberg. For dogs who do, symptoms such as disorientation, anxiety, agitation, sleep and activity changes, might come on as early as age 6 or as late as age 11. Medications and dietary changes seem to help relieve symptoms in some dogs but not others. Sticking to regular routines for feeding and walking, and uncluttering the environment to reduce the number of obstacles a confused dog might have to find his way around, are among Landsberg's recommendations for home care.