Why did my dog just have her very first seizure?

You should take the dog to the vet for care, seizures are nothing to mess with or just let go. https://www.akc.org/expert-advice/hea...source=FB-keywee&utmmedium=SocialRetentionMarkets&kwp0=768242&kwp4=2982303&kwp1=1257576

The AKC article posted is a good one. I work as nurse in a large 24 hour small animal (cat/dog) hospital and in my experience most seizures are not related to food/diet unless the animal is eating something completely inappropriate for their species. Some pets (and people) go through a post ictal phase immediately following a seizure, which can be whining, crying, stumbling or any combination of abnormal behaviors. This can last a few minutes to a few hours and varies with each case. If the seizure was a single event, you can take her to her regular veterinarian for the beginning workup. If there are multiple seizures in a short period, this is an emergency and the animal may need IV drugs to control the seizures. Multiple seizure events can cause brain damage. dangerously high body temperature and injuries from harm caused during convulsions.