As a veterinarian that witnesses seizures, I understand how unsettling this event can be to you, the owner. I can only imagine the fear and uncertainty that your pet experienced. I feel it is important to give you information on seizures and this may be repetitive to the information your veterinarian sent home with you.
A seizure is any abnormal electrical disturbance in the brain. Seizures can vary in length from several seconds to minutes. Our pets may experience a seizure as a one-time event in their life or seizures can occur as a repeated event over weeks or months. We refer to this repeated event as epilepsy. You may hear the term status epilepticus which is a seizure that is continuous and does not end without intervention. It is a dangerous state and may result in death due to hyperthermia, circulatory collapse, loss of oxygen or an imbalance within the body’s systems. Fortunately, we do not see this severity routinely.
Seizure activity is divided into two categories, generalized and partial seizure activity. When generalized seizures occur, the owner may notice changes in consciousness, limb motions, urination and/or defecation, salivation (drooling), dilated (wide) pupils and vocalization. Partial seizures are characterized by abnormal limb movements on one side of the body and there may or may not be any of the other symptoms of a generalized seizure.
There are different stages of seizures:
1. Pre-ictal stage (aura)-this is the time prior to the seizure where owners may notice a change in the pet’s behavior. The pet senses that something is coming and the owner can predict a seizure is coming.
2. Ictal (seizure) stage-this is the true seizure and often lasts from a few seconds to a few minutes followed by a period of disorientation and sometimes the loss of site.
3. Post-ictal-this is the recovery period after the seizure. This period may not be noticed or could be very prominent lasting from a short period of time to a lengthy time span depending on the pet.
Epilepsy is a common finding in pets between the ages of 1 and 5 years of age. Epilepsy can be separated into two categories: primary and acquired. Primary epilepsy is the most common form of seizure activity and is directly related to the abnormal electrical activity in the brain. Acquired epilepsy is a result of damage to the brain from previous infections, trauma, or brain development that occurs at some point in the pet’s life.
When a pet has a seizure, it is common that veterinarian’s, upon examination, will find a pet to be normal. We recommend, as was the case in your pet, to run bloodwork, to identify any underlying conditions. There are numerous causes of seizure activity including, but not limited to, heart abnormalities, liver diseases, toxins, bacterial or viral infections, internal parasitism, congenital defects, hypoglycemia (low blood sugar), storage diseases, fungal infections, kidney disease, trauma, neoplasia (cancer), etc. Additional baseline testing veterinarian may recommend would include fecal (stool) examination, urinalysis, and survey radiographs.
While chemicals could be a cause of the vomiting and seizures, the lack of exposure in the history would make this less likely. The age of your Chihuahua would be consistent with true epilepsy. However, this presumptive diagnosis would only be suspected if the bloodwork, fecal, urinalysis and survey radiographs came back normal. The clinical symptoms we see with seizures are rather diverse from no fever, increased eating, ataxia (uncoordinated), barking, salivation, weight loss, blindness, behavior changes, tremors, increased drinking, disorientation, circling, convulsions, collapse, inappropriate urination, etc.
As you can see, seizures occur for a variety of reasons and only diagnostic testing can begin to determine an underlying cause. Ultimately, pets may require examination from a neurologist with the ability to perform advanced diagnostics, ie MRIs, to attempt to determine the ultimate cause of your pet’s seizures.
At this time, be sure to follow your veterinarian’s recommendations to the best of your ability. Keep a record of the seizures documenting as much information as possible. Date of occurrence? Was there a pre-ictal phase and how long did it last? Did the seizure start on one side of the body or was it the entire body at once? How long did this phase last? What happened during the seizure? What occurred during the recovery phase and how long did the recovery phase last? The more information you can provide the better for your pet’s veterinarian.
Remember, your pet may never have another seizure during their lifetime. I commend you for running the initial tests and hope they come back normal. I hope this information helps you and let us know if we can be of further assistance. Always keep a good line of communication open with your veterinarian so they understand your concerns and can answer your questions. Your veterinarian and you can decide the appropriate course of diagnostic testing and treatment for your pet.
What type of food are you feeding your dog? There are several tainted commercial foods such as Nutro with excess zinc levels which cause vomiting and diarrhea and signs that mimic pancreatitis and epilepsy. Many more foods including Royal Canin have been recalled and may or may not be the underlying culprit. You might check the list of recalled pet foods to see if yours is on the list. Also review the type of treats you have been feeding as many are also tainted with chemicals including melamine and have been recalled such as many of the chicken jerky treats. Pigeon droppings are also a possible cause of seizures and if you live in a rural area or even if you have a bird feeder, the bird seed contaminated with droppings are very attractive to pets and can lead to seizures. Lawn and fertilizer chemicals need to be ruled out as well. Nestles cookie dough was also recalled last week due to bacterial contamination with E-coli which causes severe diarrhea leading to dehydration which if severe could initiate a seizure. I would look to the most obvious sources and as a veterinarian for many years, checking everything you have fed your dog would be very worthwhile.
Dr. Carol Osborne, DVM