azzaaah

One of mine retrieving a staffy alive back to hand.

Yes...he is more than capable of mating and producing at that age.

Did your vet, empty the dogs anal glands? Also skin scrapes rarely show anything, full allergy tests/bloods are a better way of diagnosis, but can be expensive, if you are not covered by insurance, I would also go for STRONGHOLD as opposed to frontline, it has an ingredient(selamectin) which is the only effective preventative treatment for sarcoptic mites (mange), and effective in the treatmnet of flea allergy dermatitis I would also remove bedding, and clean kennel area, and maybe use vet bed for the mean time. Keep the diet the same, and try to feed a good quality, natural source of food.

It always best to take time out at feed time, and go throught he routine with him, instead of giving him the food on the floor, make him come to u, feed him with the bowl in your hands, and raise it slighly, so he has to reach up a little to eat, then simply raise the bowl to a higher level, tell him to sit and wait, then lower the bowl again, for him to continue eating, this way he assosiates sharing the experience of eating, he must be in close proximity to you, to get what he wants (the food) and he will associate you in the equation in a positive manor, as the food is seemingly coming from

Eukanuba is indded one of the more expensive dry feed, but holds alot of un natural ingredient and is higher in derivatives, JWB as suggested is a superior higher quality diet, well worth the money, with natural ingredients, it's widely used for dogs with digestive and allergy problems, as it does not contain a bulk of the ingredients that dogs are more commonly allergic to, one being corn, which alot of the cheaper diets include. A BARF diet is the best and most natural diet, with JWB and Burns being the better dry diets.