My dog recently started having seizures, should I stop using an e-collar?

I don't know that I can give you a definitive answer. Why is your dog having seizures? Is it linked to a medical condition, reaction to flea/tick/heartworm medication or other outside substance, epilepsy, etc??

With that said, a quality ecollar is like a TENS unit that my chiropractor uses so I don't expect it to cause or aggravate a seizure condition. Still, I am NOT a health care professional or veterinarian and without knowing all the details you'll have to decide what is best for your dog and situation. I wish you and your dog all the best and hope he remains seizure-free.