The Arbors at Dogwood Creek

In our area the snake most likely to bite a dog is the Copperhead.
But the good news is that the Copperhead is the least venomous of all the viper snakes in Texas, and a healthy dog is very likely to recover from a bite in short order.

Check with your local vet, who will usually recommend simply administering Benedryl (an anti-histamine) to control swelling and perhaps an antibiotic for possible infection.

Benadryl Dosage For Dogs:

The usual dosage for treating dogs is 1 mg/lb every 8 hours (three times daily) but can be doubled to 2mg/lb if needed.
Example: If your dog weighs 25 lbs, you would administer 25 mg (one regular strength pill) of diphenhydramine up to three times daily.

For liquid dosage, use the Children’s Liquid Benadryl formulation, which is alcohol free. At standard concentration, every 5 mL (or 5 cc) of liquid contains 12.5 mg of diphenhydramine and can be given to dogs at a dosage of 0.4 mL/lb. For reference a US teaspoon measurement is 5 mL.
Example:
If your dog weighs 25 lbs, you would administer 10mL (10cc or 2 tsp) up to three times daily.

(The suggested dosage is for Benadryl with the active ingredient "diphenhydramine". Make sure the formulation you’re using contains either "diphenhydramine" or "cetirizine" as the only active ingredient before giving it to your pet. For small pets use the Children's Benedryl for more accurate measuring)

http://www.veterinaryplace.com/dog-medicine/benadryl/