My cat Dale is 10yrs. 6mos. Old and is usually very active but the last couple of days he's been very unresponsive and just lays in one spot but will get up and move positions, he hasn't been drinking much water or eating and I haven't seen him use the cat box either. Dale is a indoor/outdoor cat. I took him to the vet the other day and they couldn't find anything wrong with him, his temp was 1 degree higher and the vet doctor didn't feel any mark on him from another cat. The vet gave him a shot of Convenia 80mg/ml/3.6mg in case he had a infection but he's still the same, unresponsive. The vet wanted to do a blood panel to see if anything came back but we thought we would wait 2 days to see if the shot they gave him worked, it hasn't. Any idea's? We are going to take me to hospital tonight once my husband gets home from work.

Go ahead with the blood panel. That test will be very helpful in determining the problem. Many cats this age can start having some degree of organ failure. Organ failure is not alawys fatal since many meds can help.

Do you think Dale might of gotten posioned? I know our neighbors had sprayed for rats in their yard but Dale is good at just staying in our yard, he's not one to wonder in other yards.

Anything is possible, but I agree with Ballengerb the blood panel will be very informative. Older cats can begin to have age related problems such as thyroid disease, kidney disease and the like, a CBC would also show if there is a problem like infection or anemia, by all means do the bloodwork.
I wish the best outcome for you and your cat.