My 2 year old dog has been lethargic all day, spending the last 8 hours sprawled out on the floor next to me as I worked away from my office. He has only asked to go out for one potty break and that was 7 hours ago. (he had gone pee and poop though)
He ate his breakfast just fine, however close to supper time (he's fed twice a day) I tried to encourage him to get up and move some more, so I called him to the kitchen for a treat. He got up, VERY slowly and wobbled his way to the kitchen, almost like he was learning to walk on his lanky legs for the first time again.
Once he got there he took the treat and walked it to his bed like he usually does, but didn't eat it right away. After 15 minutes he ate it and then threw it up within a couple of minutes. Since then he's been REALLY lethargic and weak, like he can barely stand up or hold his head up. I sat down on the floor with him and let him lay no my lap, he did that for a bit and then since it was close to supper I got up and gave him a bowl of wet food (usually it's dry-only or a mix or wet and dry) to try and get him to eat and get some water into him as he wouldn't drink.
He ate about half of the bowl and then went into his bed to lay down. Within 15 minutes of eating he's showing improvement on the weakness and is now laying normally (as opposed to being sprawled out on the floor awkwardly) and is fully capable of lifting his head up with no issue to watch the cat walk around and such. So he's improving so I don't personally see a need in this moment for him to see a vet.
I'm just posting to ask opinions on what it could be if anyone's had a similar experience.
Side note: When he threw up it looked like enough food to be two meals worth potentially, so maybe his supper from the night before hadn't digested either along with his breakfast from that morning)
Thanks for reading!