What you have astutely figured out is that many seizures start in the intestines – the intestines are considered our second brain as they have the same chemicals (neurotransmitters) as our official brain. So, chemical problems in the intestines can travel by the blood to the brain and cause whole body seizures.
By feeding the yogurt, you are providing an anti-inflammatory treatment (the probiotics in the yogurt are anti-inflammatory in some cases) to the intestines and stopping the production of the out of balance chemical – stopping seizures before the neurotransmitters hit the brain.
I’m so glad you found something to stop your dog’s seizures!! Do consider if the seizures start in the gut that your dog may have intestinal inflammation (also called leaky gut or dysbiosis) which, if treated, may make it that the pre-seizure episodes completely stop. Then, you only need to give yogurt for fun.