Introduction
Seizures in dogs at night, also known as nocturnal seizures, are episodes of uncontrolled electrical activity in the brain leading to involuntary body movements and possible loss of consciousness. They often occur when dogs are resting or asleep. Nocturnal seizures are relatively common in dogs, with up to 5% of the canine population affected during their lifetime.
Nocturnal seizures can be alarming and disruptive for both dogs and their owners. While seizures occurring at night don’t necessarily indicate a more serious condition, they do require veterinary attention to determine the underlying cause and best treatment options.
Common Causes of Seizures in Dogs at Night
There are several potential causes for seizures in dogs that occur at night:
Idiopathic Epilepsy
Idiopathic epilepsy, meaning epilepsy with no known cause, is the most common cause of recurrent seizures in dogs. Epilepsy often develops in dogs between the ages of 1 and 5 years and may cause seizures during times of changing brain activity like sleep (Source).
Brain Tumors
Brain tumors can develop later in a dog’s life and provoke seizure activity. Brain tumors may disrupt normal brain cell activity and trigger seizures during sleep (Source).
Metabolic Disorders
Metabolic disorders like low blood sugar (hypoglycemia), kidney disease, and liver disease can trigger seizures in dogs. Metabolic disturbances may become more apparent at night.
Head Trauma
Head trauma from an injury or accident can cause brain inflammation and seizures. Seizures may occur immediately after head trauma or weeks/months later.
Poisonings
Exposure to toxins like lead, insecticides, or antidepressants can poison the brain and provoke seizure activity. Toxins may build up during the day and reach a threshold at night, triggering seizures.
Idiopathic Epilepsy
Idiopathic epilepsy is the most common cause of seizures in dogs, accounting for over 60% of cases [1]. The term “idiopathic” indicates that the exact cause is still unknown, but it is believed to have a genetic basis. Certain breeds like Belgian Shepherds, Beagles, Keeshonds, Golden Retrievers, Labrador Retrievers, German Shepherds, Italian Greyhounds, and English Springer Spaniels are predisposed to developing idiopathic epilepsy.
Idiopathic epilepsy usually develops between 1-5 years of age. The seizures are often generalized tonic-clonic seizures, which cause muscle rigidity and then jerking movements. Some dogs can also experience focal seizures that only affect one area of the brain and body.
The seizures from idiopathic epilepsy tend to happen spontaneously with no identifiable triggers. They can occur while the dog is awake or asleep. Dogs with idiopathic epilepsy usually appear normal between seizues and do not have any other neurological symptoms.
Brain Tumors
Brain tumors can cause seizures in dogs at night for a variety of reasons. Some key facts about brain tumors in dogs:
There are primary brain tumors that originate from the brain tissue itself, like meningiomas, gliomas, and pituitary tumors. There are also secondary brain tumors that have metastasized from cancers located elsewhere in the body, like hemangiosarcoma and melanoma [1].
Tumor location plays a role. Tumors in the forebrain, like frontal lobe masses, often cause seizures. Tumors near the limbic system, like meningiomas by the olfactory bulb, can also trigger seizures [2].
As a tumor grows, it puts pressure on surrounding brain tissue. This added pressure disrupts normal electrical brain activity and can provoke seizure activity. Brain edema or inflammation around a tumor can also irritate brain tissue and cause seizure activity [3].
Signs of a brain tumor in a dog include seizures, especially ones that seem to start suddenly in a middle-aged or older dog. Other signs can include head tilt, loss of balance, circling, vision problems, behavior changes, and more.
Metabolic Disorders
Metabolic disorders are a common cause of seizures in dogs at night. Hypoglycemia, or low blood sugar, is a particularly frequent trigger according to a study published in the Journal of Veterinary Internal Medicine (https://pubmed.ncbi.nlm.nih.gov/19939714/). The study found hypoglycemia accounted for 32% of reactive seizures in dogs. This often occurs when the dog goes too long without eating. The brain depends on glucose for energy and functioning. When glucose levels drop too low, it can lead to seizure activity.
Kidney and liver disease can also impact metabolism and electrolyte balances like calcium, potentially causing seizures (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7152292/). The liver helps regulate blood sugar, so liver dysfunction can lead to hypoglycemia. Kidney disease can cause electrolyte imbalances and an accumulation of toxins that may trigger seizures.
Treatment for metabolic causes of seizures focuses on correcting the underlying issue through diet, medication, or treatment for kidney/liver disease. Preventing long stretches without food and providing a consistent feeding schedule can help manage hypoglycemia. Your veterinarian may prescribe medications or IV fluids to stabilize blood sugar, electrolyte, and toxin levels.
Head Trauma
Head trauma is another potential cause of seizures in dogs at night. Any injury to a dog’s head can result in brain inflammation and swelling that disrupts normal brain activity and leads to seizures. Some common causes of head trauma in dogs include:
- Falling from heights, such as falling off furniture or down stairs
- Being hit by a car or other moving vehicle
- Encounters with aggressive dogs or other animals that result in bites or blows to the head
- Blunt force trauma from being struck with an object or from forcefully hitting their head on something hard
The brain is very delicate, so even what may seem like a minor head injury can cause microscopic damage and bleeding in the brain. This interrupts normal electrical signaling between brain cells, which can trigger seizure activity. Seizures caused by head trauma may start soon after the injury or could be delayed for days or weeks.
If a dog experiences any sort of head trauma, it’s important to seek veterinary care right away even if seizures don’t start immediately. The vet can check for signs of concussion, bleeding or swelling in the brain through neurological exams and imaging tests. They may prescribe anti-seizure medications preventatively to reduce the chances of post-traumatic seizures occurring down the road.
Poisonings
Certain toxins, medications, and plants can trigger seizures in dogs, especially at night when dogs may accidentally ingest dangerous substances. Common toxins linked to seizures include caffeine, dark chocolate, mushrooms, theobromine, ethanol, and xylitol (Source). Theobromine, found in chocolate, is a stimulant that can overstimulate the central nervous system and induce seizures. Ingesting certain human medications like antidepressants, Adderall, opioids, or benzodiazepines can also spark seizure activity (Source). Finally, plants like sago palms, azaleas, and oleander contain toxins that are poisonous to dogs and may trigger neurological reactions.
If a dog has ingested a dangerous substance, immediate veterinary care is crucial to identify and treat the poisoning. Preventative measures include keeping human medications, toxic foods, and poisonous plants out of a dog’s reach.
Diagnosis
There are several tests vets perform to diagnose the cause of seizures in dogs:
Physical exam: The vet will do a full physical exam, checking the dog’s reflexes, balance, vision, hearing, heart, and abdomen. This can help identify any underlying issues like infections, organ problems, or neurological disorders.
Bloodwork: The vet will likely run a complete blood count and blood chemistry panel. These tests check for infection, liver or kidney problems, electrolyte imbalances, and other conditions that could cause seizures (https://vcahospitals.com/know-your-pet/seizures-general-for-dogs).
Imaging: X-rays, MRIs, or CT scans of the brain may be done. These can detect tumors, inflammation, trauma, or other brain abnormalities leading to seizures.
Spinal tap: A spinal tap collects and analyzes the cerebrospinal fluid. Inflammation or infection in the fluid can point to issues like meningitis or encephalitis as seizure causes.
Treatment
The main treatments for seizures in dogs are medications, surgery, and lifestyle changes.
The two most commonly prescribed medications for seizures are phenobarbital and potassium bromide, according to VCA Animal Hospitals. Phenobarbital is usually the first drug tried, but potassium bromide may be added if seizures continue. Other anticonvulsant medications may also be options. Medications can have side effects, so dogs on seizure meds should have regular lab tests.
Surgery may be an option if a brain tumor or other structural problem is causing the seizures. Removing the tumor or abnormal tissue may eliminate or reduce seizures. MRI or CT scans can help identify surgical candidates.
Lifestyle changes can also help manage seizures. Getting adequate exercise and rest, avoiding stimulants like chocolate, and maintaining a stable routine can all reduce seizure triggers. Natural supplements like melatonin may also be helpful additions to conventional treatment, according to WagWalking.
Prevention
There are several steps dog owners can take to help prevent seizures in dogs at night:
Safety measures like clearing clutter, padding hard surfaces, and removing objects near sleeping areas can help prevent injury during a seizure. Providing a comfortable, relaxing sleep environment may also help.
Avoiding toxins like lead, pesticides, mold, and blue-green algae can reduce the risk of toxin-induced seizures. It’s also important to be careful with medications, as certain drugs and dosages can trigger seizures.
Genetic testing may help identify dogs predisposed to epilepsy or other seizure disorders. This allows owners to be prepared and seek treatment early. Testing breeding dogs for epilepsy genes can also prevent passing seizures on to future generations.
Regular veterinary care ensures prompt treatment if seizures develop. Medications, nutritional supplements, acupuncture, and other therapies may help control seizures in susceptible dogs.