Get Your Dog Care Questions Answered by Experts
Because you are seeing neurological signs along with the lethargy and fever, you need to find a vet today. Call around and see if any vets will allow you to post date a check or to make payments.
This could be something as simple as a parasite problem but it could be something big as well.
The only way to find out and get treatment is to see your vet.
Let me know if you still have questions.