However, the cause of such epilepsies can sometimes be determined, for example when seizures are the result of a specific genetic defect known to occur in certain breeds. Structural epilepsy is the diagnosis for seizures that occur because of observable damage to or malformations of the brain. For example, structural epilepsy can occur after an inflammatory disease of the brain, growth of an intracranial tumor, or after trauma to the head.
It can also be the result of congenital malformations or a vascular event, such as a stroke 5. The brain abnormalities seen with structural epilepsies can sometimes be detected using an MRI or by analysis of cerebrospinal fluid. Testing for structural epilepsy may be indicated if a dog exhibits neurologic abnormalities between seizures or if the dog falls outside the typical age range of onset for idiopathic epilepsy.
Interictal changes are less common in dogs with idiopathic epilepsy. Epilepsy of unknown cause is used to describe a condition in which a structural cause is suspected, but has not been identified on diagnostic evaluation. Reactive seizures, seizures which occur in response to specific stimuli such as a metabolic derangement or a toxin , are not considered to be a form of epilepsy, because they are not caused by an abnormality of the brain.
The Genetics of Canine Epilepsy. A large number of genetic mutations have been associated with epilepsy in both humans and mice. In humans, the inheritance of epilepsy is generally complex, meaning that it involves interactions of one or more genes with each other as well as potentially with environmental factors, and this is likely true of epilepsy in dogs as well.
However, the extent of inbreeding within specific dog breeds has allowed the identification of certain animals that are at particularly high risk of seizure development. No fewer than 26 dog breeds have shown at least some evidence of heritable epilepsies. Gene mutations have been identified, many of which include a group of diseases known as neuronal ceroid-lipofuscinoses.
These are storage disorders where mutations lead to the abnormal accumulation and storage of a cellular product within cells, eventually leading to the dysfunction or death of neurons 1. One gene for an inherited epilepsy has been identified in Lagotto Romagnolo dogs. That gene, LGI2, is similar to the previously identified human epilepsy gene LGI1, and scientists believe that a number of heritable epilepsies may have similar causes in humans and canines 1.
Research into potential similarities between dog and human epilepsies has also led to the identification of several candidate genes that may predict the effectiveness of anti-epileptic treatment in some breeds. It is generally believed that epileptic seizures are caused by an imbalance between excitatory and inhibitory activity in specific areas of the brain, leading to either excessive brain activity or activity that is unusually depressed.
However, in the absence of structural damage or metabolic insults, the causes of such dysfunction are not clear.
Further research into the specific causes of various forms of epilepsy is still needed; current understanding is incomplete. The information provided below is for information purposes only and cannot replace the advice of your veterinarian.
Do not give your dog any medications without a prescription from a veterinarian. Anti-epileptic drugs AED work primarily by inhibiting the action of excitatory neurotransmitters, stimulating inhibitory pathways, or altering ion channel function in the brain. Not all drugs work equally well in all animals, and their safety profiles are somewhat variable. A single, isolated seizure is not usually seen as a reason to begin treatment with AEDs.
Treatment with these drugs is usually indicated when multiple generalized seizures have occurred within a 24 hour period, a dog has had at least two seizures within a six month period, or a dog has unusual or severe signs during the postictal period 9. Once treatment has been declared necessary, the process of choosing the right drug requires balancing effectiveness and tolerability.
Although many short-term side effects can be managed by titrating medication dosages, some AEDs have the potential to cause significant adverse effects. Therefore, it is important for medications to be chosen and tested with care and to recognize that not all epilepsies are amenable to drug treatment.
Phenobarbital , a first generation AED, is one of the drugs most used in veterinary patients, because it is effective, relatively inexpensive, well-tolerated, and easily dosed 9. Serious side effects include blood cell loss cytopenias and liver toxicity. Other side effects include sedation, ataxia, and increased appetite and water consumption. Dogs can also develop tolerance to phenobarbital over time, and are susceptible to withdrawal effects as physical dependence can develop 9.
Potassium bromide , or bromide, is another first generation AED that is often used to treat canine epilepsy. When used in combination with phenobarbital and other AEDs that are metabolized in the liver, dosages of those drugs can potentially be lowered to reduce the risk of liver damage.
Owners should maintain a log to document seizure occurrences and changes in medication administration. Adjustments in dosage often are based on the assessment of the seizure control in addition to blood drug concentration and drug side effects. It is important to have regular assessment of blood concentrations even at times when seizures are well controlled in order to monitor for toxic levels, especially for drugs with a greater potential for side effects i.
About percent of epileptic dogs achieve good seizure control when their therapy is carefully monitored. Dogs that are not well controlled risk euthanasia due to poor quality of life for the dog and their owners. Risk factors for euthanasia include younger age of onset, high initial seizure frequency, poor seizure control, and episodes of status epilepticus, or seizures that last longer than five minutes.
Approximately percent of dogs with epilepsy have one or more episodes of cluster seizures or status epilepsy, and a mean lifespan of only 8 years, compared to 11 years for those with epilepsy without episodes status epilepsy.
Epileptic dogs that have had cluster seizures are known to be significantly less likely to achieve remission with any treatment. Though life expectancy of the pet may not be affected, the odds of an epileptic going into complete remission and not requiring ongoing therapy are low: percent in dogs. Thus dogs with epilepsy usually require lifelong therapy and commitment from the pet owner.
Download as a PDF Epileptic seizures are defined as transient signs due abnormal excessive or synchronous neuronal activity in the brain, and epilepsy refers to at least two unprovoked seizures more than 24 hours apart. Clinical Signs Seizures in dogs with epilepsy can be either generalized or focal in onset. Sections of the mini-CBARQ relating to separation, attachment and attention seeking, and obedience and training behaviors were modified to include additional parameters for detecting anxiety based behavioral changes associated with different phases of the seizure episode.
This part of the questionnaire was only completed by clients with epileptic dogs. The terms prodrome, postictal, and interictal were not used on the questionnaire. Instead their definitions as outlined above were used so as to avoid confusion and ensure all owners could provide accurate responses. Veterinarians treating dogs with idiopathic epilepsy completed a brief questionnaire as well to identify and verify the diagnoses of each dog that participated in this study provided as Supplementary Material.
Veterinarians of dogs with idiopathic epilepsy were additionally asked to indicate when the diagnosis was made, the age of seizure onset, and the results of complete blood count, chemistry profile, serum bile acid testing if applicable , MRI of the brain, and cerebrospinal fluid analysis.
Owners of dogs that had been diagnosed with IE between 6 months and 6 years of age were asked to complete the questionnaire. The diagnosis of IE was based on the BMC Veterinary Research correspondence: International veterinary epilepsy task force consensus report on epilepsy definition, classification and terminology in companion animals Dogs with IE were included in this study only if they were found to have seizures with normal hematology as indicated by a complete blood count, normal serum biochemistry profile, and normal interictal neurological examination performed by a neurologist or resident in neurology.
The questionnaire was also distributed to owners presenting dogs of two other medical populations. One group consisted of dogs presenting for annual wellness examination and the other group consisted of dogs presenting for discomfort or neurologic deficits associated with IVDD.
Wellness examinations consisted of physical examination by a primary care veterinarian for the sole purpose of vaccination. The dogs composing of these two medical populations did not have a history of seizures. Owners of dogs presenting for IVDD were not asked if decompressive surgery had been indicated or performed in the past, nor was chronicity assessed.
Dog sex and neuter status, and dog breed were described using frequency and percentages. Dog age was presented as median, minimum, and maximum values given the non-normal distribution as assessed by skewness, kurtosis, normality plots, and Shapiro-Wilk test.
The signalment characteristics were statistically compared between populations using Fischer's exact test for dog sex and breed, and Kruskal Wallis test for dog age. Fischer's exact tests were utilized, to assess for differences in behavioral traits exhibited between the epileptic, IVDD and wellness groups.
If a significant difference between the groups was detected, then post-hoc testing with Fischer's exact tests for pairwise comparisons was performed and a Bonferroni correction was applied to reduce the rate of false discovery due to multiple comparisons.
A subgroup analysis was performed for dogs in the epileptic group, this involved assessment for associations between seizure severity, seizure frequency, and seizure therapy mono- or polytherapy using Fischer's exact tests. As before, when a significant difference was identified post-hoc testing with pairwise comparisons using Fischer's exact tests utilizing a Bonferroni correction was performed. The Bonferroni correction was applied again to reduce the rate of false discovery due to multiple comparison.
The effect of seizure phase on behavior was assessed in the epileptic group through generation of new variables with subtraction of one seizure phase behavioral trait score from the other.
The new variable non-zero scores reflected a change in behavioral trait score between the two different seizure phases. The scores for the new variable were assessed as frequency and percentage of dogs. One hundred and two dogs were included in this study. Thirty dogs met the inclusion criterion for the wellness disease category, 37 dogs met the inclusion criterion for the epilepsy disease category, and 27 met the inclusion criterion for the IVDD category.
A summary of signalment characteristics are included in Table 1. A summary of anticonvulsant therapy within the epileptic group can be found in Table 2. No other survey questions assessing other behavioral characteristics were identified as significantly different between the three populations evaluated in this study.
The median range seizure severity score reported in the epileptic group was 7. Increasing seizure frequency was defined as an average number of seizures occurring more frequently at the time of the questionnaire was performed than at the time of initial diagnosis. No other survey questions were identified as significantly associated with seizure severity. The median range seizure frequency reported in the epileptic group was 4 range: 1— times per year.
No other survey questions were identified as significantly associated with seizure frequency. No other survey questions were identified as significantly associated with monotherapy compared to polytherapy. A Fisher's exact test was performed on questions pertaining to separation, attachment and attention seeking, and obedience and training behaviors to investigated if an association existed between seizure phase and different behavioral traits.
This analysis identified behavior changes across the varying seizure phases in 14 of 37 total epileptic dogs in a majority of questions presented questions 22—25, 28—31, 34— This indicates that seizure phase is associated with behavior changes, although one specific seizure phase was not more likely to produce behavior changes than another. Additionally, differences in behavior were noted between patients with IE receiving polytherapy vs.
No specific seizure phase was associated with increased anxiety in the present study as it has been seen with humans. The goal of investigating behavioral changes is to better assess QoL, which has become a growing area of interest in the veterinary community.
This could be a side effect to the medications, as most of these dogs were on drug therapy for seizure control or pain relief. Or rather, this could be attributed to the disease itself. Dogs with idiopathic epilepsy and IVDD suffer from acute episodes of seizures and pain, respectively. Similarly, patients undergoing orthopedic surgery may experience similar anticipatory pain. While dogs with IE and IVDD showed evidence of fear and anxiety when approached by an unfamiliar dog, no other parameters were statistically significant in regard to anxiety related behaviors when comparing all groups.
It is possible that further correlations were not made between behavioral comorbidities and differing medical populations due to the limited sample size.
Seizure phase has been associated with changes in anxiety related behavior in humans 5 , 6. Our cohort of patients showed a similar phenomenon. Jerry Klein about seizures in dogs to find out what you should do if you witness one. Klein explains. Other causes of seizures in dogs include electrolyte or blood abnormalities, such as low blood sugar, severe anemia , cancer , brain tumors , trauma to the brain, metabolic diseases, and exposure to toxins.
While these are easier to spot, some seizures may be localized, such as a facial tremor, or present as a sudden onset of rhythmic movements or actions, like unusual barking. Following these tips will help keep you and your dog safe until the seizure is over:. Compare Breeds Compare up to 5 different breeds side by side. Dog Name Finder Browse our extensive library of dog names for inspiration.
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