column By: Walt Cottrell, DVM | April, 18
Dear Dr. Walt:
I have a puppy that has seizures. They started a few weeks after we got her at 8 weeks and are hard to watch. What is the likelihood they can be controlled, and can she have a good life and be a bird dog?
Seizures are an ancient disease, and one of the most difficult to understand and treat. Even though they can occur in any breed, including sporting dogs, we can be grateful that this is not a common condition (cold comfort to you, I know). That said, some effort has been made to organize what is known about seizures as a way to describe what is happening, order the probability, possible causes and arrive at a prognosis.
Simply put, seizures are abnormal nerve activity in one or more locations of the brain; the character of the seizure is determined by the location(s). Seizures can be as mild as a transient change in mental status to complete loss of consciousness with muscular movements (convulsions) at variable intervals, which can range from partial to generalized to back-to-back seizures that do not end; this last called status epilepticus. As seizures occur, more neuronal damage also occurs, leading to a greater probability of more seizures and of status epilepticus. Some dogs seem to know a seizure is coming; this is called an aura and probably is a part of the seizure itself. More than a few patients experience increased seizure activity or severity with the onset of a full moon.
Seizures can be divided into those whose origins are in the brain and those that originate outside the brain. Those that come from primary brain disease include degeneration in the elderly dog. Parasitic, fungal, bacterial and viral infections, whether affecting the brain primarily or finding their way there from other parts of the body, can cause brain damage and seizures. Neoplasia (cancer) that affects adjacent tissue by pressure or actual tissue destruction can lead to seizures. Many environmental toxins readily alter normal brain function. Then there is the also large group of conditions called hepatic (of liver) encephalopathy (disease of the brain). Because the liver is so important in detoxifying the body, any dysfunction of the liver can also be at the root of a seizure. The neonatal liver can be small for the age and can require time to mature completely. It can also have abnormal vessel development. Because the brain has such an absolute requirement for glucose, abnormal biochemical pathways can also lead to seizures. The condition called Hunting Dog Hypoglycemia is probably an example of this. Seizures that have no cause identified are called idiopathic epilepsy.
Those are some of the things seizures are, and there are some things that they are not; that is, the list of alternative diagnoses. When there is malfunctioning of the heart and loss of blood (and oxygen) supply to the brain, alterations in visible brain function can be seen as fainting or weakness. This is called syncope. Abnormal repetitive behaviors from obsessive-compulsive disorders can appear as mild seizures. Narcolepsy, daytime sleepiness or unconsciousness, is not a seizure.
Because the prognosis depends in very large part on the diagnosis, how do we get that determination of cause and effect? Careful consideration of the age, sex, breed, history and physical examination can sometimes get us there. If further diagnostics such as response to antibiotics, blood work such as tick panels, brain assays, X-rays and MRI are employed, an answer may emerge. If none does, a label of epilepsy is logically applied.
But what can be done in any case, and to your question, with what end? Removal of an offending toxin or a responsive infection can restore good health. If conditions such as inoperable neoplasia, congenital liver disease or incurable infections are detected, the sad but humane way is clear. If epilepsy is the diagnosis and the seizures are not continuous, various medical therapies may be employed. Changing nutrition to a lower protein level and with different ingredients may be of benefit. Of the oral medications, phenobarbital and potassium bromide are often the first choices, and doses will need to be adjusted to the severity and frequency of the seizures. Acupuncture and Chinese herbal therapy can be very effective, either by controlling the seizures as the sole therapy or reducing the deleterious effect of the pharmaceuticals.
And what then for your sweet pup? You’ve already employed the more sophisticated diagnostics, and a diagnosis has not been made clear. I would offer that it is time to take stock of your (the most informed) assessment of the situation. Is there the kind of improvement that suggests a good outcome? Is it your opinion that she is a happy pup between seizures? Is the therapy a burden for you? Bring the answers to these questions to your veterinarian because he is the one who knows you both the best.