sick beagle

I have 6yr. old dog that seems to have some discomfort after 30 to 45 min. of running.
She lags behind and appears as if she is a little dizzy. It's her hips that sway
when she walks. She's a hunting dog, so as soon as the group finds another rabbit
she's off and running. She just started this recently when the weather got cold
so i'm wondering if this could be arthritis, if so can it be treated. I also gave
her a 7-1 shot and been worming her thinking she was sick but thats not the case,
stool is fine and she eats well. Any sugestions, thanks.

It could be a lot of things, from hip displaysia to heart problems, since you say she seems dizzy.

Please stop dosing her with meds she may not need and take her to the vet.

Take your dog in and have a check up. I agree no meds till you find out what the problem is.