Last night my 4.5-month-old toy poodle woke up from a nap and collapsed. She was then sick and collapsed on her side again with her legs stiff, and when I picked her up and tried to give her water she again collapsed and couldn't walk. We immediately took her to the emergency vet where they put her on a drip and some kind of toxicity antidote (lipids I think?) as they were fairly sure it was something she had eaten in the park. I think it may have been her flea medication though –I gave her Simparica Trio on Saturday (the day before) and yesterday morning she was a bit off her food, which is super unusual. She ate it when I hand fed her, so I brushed it off and just thought she couldn't be bothered to eat it from the lickimat I'd given it to her in. Then in the park in the afternoon, she was running around like normal but was also trying to eat grass, which I read is sometimes done when dogs are trying to make themselves sick. She's never eaten grass before. I did some reading online about Simparica Trio and it seems like there are a lot of reports of side effects like this and I'm at a loss as to why the vet would prescribe it (there's actually a note on the box saying that they have switched brands due to supply issues caused by brexit...) Has anyone else had this experience with Simparica Trio? The vet is sending off samples (urine, vomit) for further testing to see if they can find out what it was, and if that comes back clean then they said it may be the Simparica. I'm so worried for my pup and any long term effects. The vet said she is doing a lot better today and that her neurological symptoms subsided at around 2am, although she still hasn't eaten anything since yesterday lunch. Thankfully, we should be able to pick her up later this afternoon, but it was just so awful yesterday, I thought she had died when she collapsed and she was so limp on the way to the vet. Any advice / other people's experiences would be greatly appreciated. Thank you