Epilepsy
Also described as convulsions, epilepsy, or “fits,” the term seizure is used to describe any onset of involuntary, and usually recurring, episodes of loss of consciousness, deranged consciousness, and loss of balance, increased voluntary muscle contractions or weakness.
The first order of business in diagnosis of the cause of a seizure is confirmation that the abnormal activity you observed was, in fact, a seizure. This can often be done when described in detail to your veterinarian, but occasionally partial seizures can be hard to differentiate from other disorders.
Grand mal seizures usually include collapse and loss of consciousness, dramatic muscle activity with paddling and snapping, loss of bladder and bowel control, and a slow return to normalcy. Partial seizures can involve any part of the body, abnormal behaviour, and can be easily confused with other disorders. In these cases having your veterinarian actually witness the event, or making a video-recording of the event may be necessary.
All seizure episodes have three periods: the first is the aura phase that is a prelude to the actual seizure. This period is often undetectable, but some dogs will display behaviours that can indicate a seizure is imminent: they may appear nervous, distressed, or dazed. The actual seizure, called the ictus, follows. When the seizure ceases there is a postictal period in which the dog is not actually seizuring, but has not returned to normal yet. Many dogs appear dazed and disoriented, but a few will be agitated, excited, or even aggressive. The length of the postictal period is highly variable, from less than a minute to hours long.
Treatment of seizures depends upon the origin. Not every dog that seizures require anticonvulsant therapy; remember that your veterinarian will be weighing the risks associated with having a seizure versus the risks caused by anticonvulsant medication. All anticonvulsants have side effects and if given on a routine basis, will require periodic monitoring of blood levels and serum chemistries to minimize chances of toxicity and permanent problems. Infrequent, brief, and mild seizures are usually treated with benign neglect; the risks associated with drugs will affect the dog more than the seizures. Prolonged, violent, frequent seizures, or “cluster seizures” (the seizures are brief but there will be more than one in the span of a day) warrant medication if underlying causes have been ruled out or brought under control.
You may need to make some changes in your basis husbandry for a dog that suffers from seizures. A seizure can evoke excited, aggressive behaviour in other dogs, so it is not recommended that a dog that is at risk of seizuring be kennelled with another dog that could potentially harm him if he has a convulsion. Keep the dog in his own run or tethered out of reach of neighbours. Unless all genetic causes of seizures have been ruled out, a seizuring dog should not be used for breeding and should be spayed or neutered.
Below is a description of some potential causes of seizures in sled dogs. It is by no means complete. A seizuring dog will absolutely need to be examined by your veterinarian; an emergency visit is warranted if a seizure persists for ten minutes or longer, or if cluster seizures occur.
Idiopathic Epilepsy:
By definition, idiopathic epilepsy is a seizure of unknown origin, and is only definitively diagnosed when all other causes of seizures have been ruled out. Epileptic dogs are completely normal on physical exam as well as normal on all routine screening tests. It is an inherited disorder in dogs; breeding a dog with this problem is likely to produce offspring with the same problem. It is frequently seen in various breeds of sled dogs, including hybrids. “Hybrid” sled dogs are often as tightly inbred as many registered purebreds, so it really isn’t surprising that problems like this should arise. Age of onset is usually in dogs less than five years old, although it occasionally will begin at a little older than that.
Also described as convulsions, epilepsy, or “fits,” the term seizure is used to describe any onset of involuntary, and usually recurring, episodes of loss of consciousness, deranged consciousness, and loss of balance, increased voluntary muscle contractions or weakness.
The first order of business in diagnosis of the cause of a seizure is confirmation that the abnormal activity you observed was, in fact, a seizure. This can often be done when described in detail to your veterinarian, but occasionally partial seizures can be hard to differentiate from other disorders.
Grand mal seizures usually include collapse and loss of consciousness, dramatic muscle activity with paddling and snapping, loss of bladder and bowel control, and a slow return to normalcy. Partial seizures can involve any part of the body, abnormal behaviour, and can be easily confused with other disorders. In these cases having your veterinarian actually witness the event, or making a video-recording of the event may be necessary.
All seizure episodes have three periods: the first is the aura phase that is a prelude to the actual seizure. This period is often undetectable, but some dogs will display behaviours that can indicate a seizure is imminent: they may appear nervous, distressed, or dazed. The actual seizure, called the ictus, follows. When the seizure ceases there is a postictal period in which the dog is not actually seizuring, but has not returned to normal yet. Many dogs appear dazed and disoriented, but a few will be agitated, excited, or even aggressive. The length of the postictal period is highly variable, from less than a minute to hours long.
Treatment of seizures depends upon the origin. Not every dog that seizures require anticonvulsant therapy; remember that your veterinarian will be weighing the risks associated with having a seizure versus the risks caused by anticonvulsant medication. All anticonvulsants have side effects and if given on a routine basis, will require periodic monitoring of blood levels and serum chemistries to minimize chances of toxicity and permanent problems. Infrequent, brief, and mild seizures are usually treated with benign neglect; the risks associated with drugs will affect the dog more than the seizures. Prolonged, violent, frequent seizures, or “cluster seizures” (the seizures are brief but there will be more than one in the span of a day) warrant medication if underlying causes have been ruled out or brought under control.
You may need to make some changes in your basis husbandry for a dog that suffers from seizures. A seizure can evoke excited, aggressive behaviour in other dogs, so it is not recommended that a dog that is at risk of seizuring be kennelled with another dog that could potentially harm him if he has a convulsion. Keep the dog in his own run or tethered out of reach of neighbours. Unless all genetic causes of seizures have been ruled out, a seizuring dog should not be used for breeding and should be spayed or neutered.
Below is a description of some potential causes of seizures in sled dogs. It is by no means complete. A seizuring dog will absolutely need to be examined by your veterinarian; an emergency visit is warranted if a seizure persists for ten minutes or longer, or if cluster seizures occur.
Idiopathic Epilepsy:
By definition, idiopathic epilepsy is a seizure of unknown origin, and is only definitively diagnosed when all other causes of seizures have been ruled out. Epileptic dogs are completely normal on physical exam as well as normal on all routine screening tests. It is an inherited disorder in dogs; breeding a dog with this problem is likely to produce offspring with the same problem. It is frequently seen in various breeds of sled dogs, including hybrids. “Hybrid” sled dogs are often as tightly inbred as many registered purebreds, so it really isn’t surprising that problems like this should arise. Age of onset is usually in dogs less than five years old, although it occasionally will begin at a little older than that.
