Have I given my cats an overdose??

Thank you for all your advice and thoughts! I can’t really answer now, because I’m totally shocked. I’m not sure if the following information is correct, I’m not a vet, so I could have misunderstood something.

Kajsa was feeling very bad today. It started already yesterday, but it got worse today. She hasn’t left my bedroom at all. She has been laying on my pillow the whole day and is almost apathetic. She does react to sounds, but she’s too tired to care.

I’ve just read the package insert of the pills, and I’m shocked. I did see that those pills were for dogs, but the vet gave me these pills, so I trusted her. I just found out that the pills for dogs are 4 times as strong as the ones for cats, so I have given them an overdose. No wonder Kajsa is feeling bad! Tessa is surprisingly well, even though she was the one who immediately reacted to the pills. She’s been playing the whole day and is absolutely fine.

I try to leave Kajsa alone, because she doesn’t seem to appreciate my company. I’ve offered her some food and she has eaten a bit. I left more food and water on my bed, I hope she’ll manage to eat more.

I’ve tried to contact the emergency vet, but I didn’t get through the line yet. However, I’m not sure if it’s a great idea to take her somewhere tonight. She has gotten this overdose for some days now, the last one was almost 12 hours ago. It’s too late to empty her stomach, so I believe it’s best to avoid any additional stress. I’ll still try to speak to a vet today though.

As I said in the beginning: I’m not sure if this posting is correct, and whether she got an overdose. I “only” compared the package inserts for cats and dogs and I know for sure that the drugs for dogs is 4 times as strong. I’ve still given them the amount a cat should get (of the “cat pills”). Only good news: they never got the full dose, because they’ve always managed to spit parts of it.

I don’t really know how I feel. First of all, I’m very worried about Kajsa. I’m also angry, furious, that the vet gave me the wrong pills. I also blame myself that I didn’t react earlier – I knew the drugs were for dogs, but didn’t give it a second thought. I try not to blame myself. I got the pills from a vet, so it’s ultimately her fault and not mine. This knowledge doesn’t really help though when you see your cat suffering.

I’ll write an update as soon as something has changed. (Sorry, no pictures, no spell checking, but you understand why)

UPDATE
Well, I got to talk to a vet, but she wasn’t really helping. She said that I shouldn’t give her any more pills today, and that I should contact the vet of the shelter tomorrow morning. If I’m too worried about the cat / the cat is in a bad condition, I can come tonight to their clinic. Eh? I AM WORRIED. Of course I won’t give them any more pills tonight. I described her condition (very tired), so what is a bad condition?? Sigh. So I’m on my own, and I’ll go with my guts: leave this poor cat alone and give her a break. She needs to rest. The vet said that they’ve a long line, and I don’t want to be with Kajsa for ages in the waiting room.

UPDATE

Punapippuri and The 3 Cats helped me a lot. The overdose is most likely not dangerous. I’ll leave Kajsa alone and let her sleep. Thank you so much!