My new shelter dog has some skin issues?

My vet doesn't know what is causing him to itch so much, so he gave him a cortisone shot. My dog is on Sentinel for fleas, and we've given him three baths in case it is fleas. Yet he still itches like crazy.What should we do for him?

It could be allergies. This time of year has lots of pollen so animals with allergies will react often with skin problems. Did the shelter note anything about skin issues while he was with them? Did they ever have him in the spring time?If he never had any allergies in his past it could be an allergy to something in your home such as laundry detergent. This can be hard to eliminate, but you can just wash all of your dog's bedding without detergent, and hang it to dry. This will eliminate his contact with the possible allergen. It could be food allergies. Has he changed diet since he has been with you? What was he on before? Did he have issues on the food he was on before? I know this may be hard for you to figure out since he is new to you, and the shelter may have very little information on him. You may want to start first by putting him on a high quality diet. Wellness Core is a pretty good diet that comes in cans and kibble. If you are open to try other types of diets, a raw diet (there are many frozen raw diets that are sold in natural pet food stores) would be a great way to go. With a raw diet you automatically remove all grains which is something many animals are allergic to. You can then start with a certain meat (something different than what is normally fed even if it was in kibble form) and only feed that meat source for a few weeks. Then try another meat source. Frozen raw foods come in a variety of meats such as beef, chicken, turkey, boar, venison, lamb, rabbit, etc. Poultry tends to be a source of allergens, but each animal is different. Duck is often used in hypoallergenic diets, so you can give that a try as well. By feeding different meats you can find if there are any allergies there depending on the increased or decreased itching.After going on about allergies, the other thing it could be is a behavioral problem if your dog is anxious. Some dogs will use itching as a way of trying to get out of doing something or getting out of a stressful situation. Being in a new home, your dog may have some anxiety. Try giving him more exercise to tire him out and keep him happy so that he won't feel the need to itch. If you are around you can try to keep him busy with chew toys or stuffed kongs.Good luck!