Seizures in dogs can be a frightening experience for both the pet and their owner. While the image of a dog having a grand mal seizure—characterized by falling, violent jerking, foaming at the mouth, and loss of consciousness—is dramatic, seizures manifest in various ways and have diverse underlying causes. This comprehensive guide aims to demystify canine seizures, providing essential information for dog owners.
Types of Seizures
Seizures are broadly categorized into generalized and focal types.
Generalized Seizures
These seizures involve abnormal electrical activity affecting both hemispheres of the brain. The most well-known is the grand mal (tonic-clonic) seizure, described above. Other generalized seizure types include:
- Tonic: Stiffening and extension of limbs.
- Clonic: Rhythmic jerking of limbs.
- Myoclonic: Sudden, brief jerking of muscles.
- Atonic: Sudden loss of muscle tone, causing the dog to collapse while remaining conscious.
During a seizure, it’s crucial to ensure your dog’s safety by removing nearby objects that could cause injury and to avoid direct contact with their mouth to prevent bites. It’s also vital to time the seizure, as prolonged seizures can lead to a life-threatening condition.
Focal Seizures
Focal seizures originate in a specific area of the brain. They can manifest in subtle ways, such as repetitive “fly-biting” motions, jaw clacking (“chewing gum fits”), or twitching of an eyelid, lip, or ear. Consciousness is often preserved during focal seizures, and they typically do not require treatment. However, a focal seizure can sometimes evolve into a generalized seizure, so close observation is necessary.
Causes of Seizures in Dogs
Seizures can stem from a variety of underlying issues:
Reactive Seizures
These are caused by temporary, treatable conditions affecting the body’s metabolism or external toxins:
- Metabolic Disorders: Low blood sugar (hypoglycemia) or low blood calcium (hypocalcemia), liver disease, liver shunts, and kidney disease can all trigger seizures. If the underlying metabolic disorder is corrected, the seizures usually cease.
- Drug Reactions: Certain medications can lower the seizure threshold in the brain. Discontinuing the offending drug typically resolves these seizures.
- Toxins: Ingestion of substances like dark chocolate, caffeine, xylitol (a sugar substitute), antifreeze, rat poison, and alcohol can lead to seizures. Prompt identification and treatment of the toxin exposure are essential.
Structural Seizures
These result from abnormalities within the brain itself:
- Brain Lesions: Tumors, head trauma, inflammatory diseases (e.g., meningoencephalitis), and infectious diseases (such as rabies and canine distemper) can cause structural seizures.
Idiopathic Epilepsy
This is the most common cause of seizures in dogs, characterized by recurrent seizures of unknown origin. A diagnosis is typically made after all other potential causes have been ruled out. Idiopathic epilepsy often begins between 6 months and 6 years of age. Certain breeds, including Schnauzers, Collies, Basset Hounds, Cocker Spaniels, Labrador Retrievers, and Golden Retrievers, have a higher predisposition to this condition.
Diagnosis and Treatment
Diagnosing the cause of seizures involves a thorough veterinary examination, including a detailed medical history, physical and neurological assessments, and diagnostic tests such as blood work, urinalysis, and potentially advanced imaging like MRI or CT scans.
When to Treat
Veterinary professionals generally recommend starting antiepileptic drug (AED) therapy after the first seizure if the dog is between 6 months and 6 years old and exhibits certain risk factors, such as:
- Cluster seizures (multiple seizures within 24 hours).
- Particularly violent seizures.
- Seizures lasting 5 minutes or longer.
- A breed predisposition to difficult seizures.
For dogs experiencing seizures less frequently, a seizure log becomes crucial in determining when treatment is warranted. The decision to start medication is often based on the increasing frequency, duration, and severity of seizures, which can significantly impact a dog’s quality of life and that of their owner.
Medications
Several AEDs are available for dogs, with Phenobarbital, levetiracetam (Keppra), zonisamide, and potassium bromide being common first choices. Levetiracetam and zonisamide are often favored for their efficacy and minimal side effects.
- Refractory Epilepsy: Approximately 20% of dogs develop refractory epilepsy, meaning they require more than one AED to manage their seizures. Levetiracetam is frequently used as a second medication, though its short-acting nature necessitates three-times-daily dosing. Keppra XR, an extended-release formula, offers a more convenient twice-daily dosing schedule.
- Medication Tolerance: Over time, some dogs may develop a tolerance to their AEDs, requiring higher doses and potentially increasing the risk of side effects. Managing these cases can be challenging.
Home Management and Other Therapies
While medication is a cornerstone of seizure management, several other therapies and home-care strategies can be beneficial:
Emergency Seizure Medications
Your veterinarian may prescribe rectal diazepam (Valium) or intranasal midazolam for at-home administration during a seizure to help shorten its duration and reduce its severity. Pulse Keppra therapy, involving a few doses of short-acting levetiracetam, can also be used to prevent cluster seizures in prone dogs.
Adjunctive Therapies
- Vagal Nerve Stimulation: Gently pressing on your dog’s closed eyelids for 10-60 seconds may help lessen seizure duration and severity. This can sometimes even help stave off a seizure if recognized during its early stages.
- Traditional Chinese Veterinary Medicine (TCVM): Acupuncture and herbal remedies can complement conventional treatment, particularly for dogs with refractory epilepsy, potentially improving seizure control or allowing for reduced anticonvulsant dosages.
- Prescription Diets: Purina Pro Plan Veterinary Diet NeuroCare (NC) is a specialized diet containing medium-chain triglycerides (MCTs) that has shown promise in reducing seizure activity in epileptic dogs, especially when used alongside anticonvulsant medication.
Conclusion
Seizures in dogs, while alarming, can often be effectively managed with proper veterinary care, timely diagnosis, and a tailored treatment plan. By understanding the different types of seizures, their potential causes, and the available treatment options, owners can work closely with their veterinarian to ensure the best possible quality of life for their canine companions. Always consult your veterinarian for a personalized approach to managing seizures in your dog.
