Fleas can cause a reaction in dogs much like hives. Are the areas she has the "hives" in one area or all over her body? Do you use any flea medicine or heart worm combined medicine? Does she have access to a recently treated grassy area, or recently cleaned carpet?
As far as your dog food goes Im wondering how much sugar is in it...it seems like alot of sugar (potato, apples, currants etc) and I would be concerned about the amount of mercury in the fish as well....
As far as bananas and mangoes go, in conjunction with the dog food having potato, apples and currants it seems like the sugar would be way too high.
Check with your vet about your dogs diet and the "hives" your dog is experiencing. The vet can determine best if the Hives are a contact rash or flea problem or something else completely. Good luck

Thanks Mazer....she is on flea and heartworm protection...we do not use any pesticides in our yard. We bought nematodes for the fleas out there...and will be using DE earth as well....both not harmful to the dog. We also use only non toxic in the house....and we don't have that much carpet. We are no longer going to be giving her bananas and we stopped the mango the first time I saw the hives. She will be going to the vet as well. She has the hives all over her sides. As for the food Orijen is supposed to be one of the best foods for dogs...I like it because it is completely made in canada with farm raised fish...I don't trust any food coming from China so where food is made is a big concern for me. I wish they had a red meat kind but the only other one they have I believe has chicken in it and as this dog seems to be allergic to stuff I'm not so willing to switch. My last bulldog was not allergic to anything...she ate everything. This little baby I'm going to have to watch. Orijen did recently change their formula (we have not gotten it since the change).

I just checked orijens site because I was concerned about the too much fish as well...and htey have a new red meat dog food. I am very very happy. :-)

You might want to switch your dog to a BARF diet. get some meat from grass fed beef, it is just a high in omega oils as fish is and does not contain the mercury.

We are actually considering going raw. It will have to wait until we get back from vacation though...we don't want to change her diet too much while we aren't around to monitor her.

I would not go back from a raw diet now - if you get a prepared one from a company you trust (ours come frozen in a plastic sausage sort of thing) it's not too much work. Our dog went from an indifferent eater of kibble (with gastric issues) to a dog who loves her food and is very healthy.

Ours loves bananas and has had no issues with them, but I'd give them sparingly as a treat.

Chances are the 'hives' are from the fleas, but it's certainly possible to develop an allergy to a food you were previously ok with. I'd try one thing at a time. Start dog on raw diet, see how it goes, introduce things one at a time.

Try this book:

Here is a link that might be useful: Natural nutrition for dogs and cats

Flea allergy dermatitis (FAD) is the most common veterinary dermatologic condition in the world. It begins with the bite of a flea. The saliva of the flea contains amino acids, aromatic compounds, fluorescent materials, polypeptides, and phosphorus. Some dogs are more allergic than others.

He/she would most likely benefit from Benadryl to help alleviate the hives until you find out what the culprit is.

Your dog could have sarcoptic mange mites. It's very contagious between dogs and your dog could have picked it up anywhere outside it's home. When I rescued my dog and his litter mates they had what looked like a rash on their bellies. Upon their first vet visit I learned it was mange. Is your dog scratching a lot?

It could also be a flea allergy or even an ant allergy. I had a little dog who was bit by one ant and her entire stomach was covered in a rash.

If you're treating for fleas with Frontline, Advantage or Revolution, then you maybe able to rule out fleas. Just a note, Revolution will kill mange mites.

Here is a test that works every time to determine if a dog has mange. The vets nor anyone else knows why this test works, but it does every time. If you scratch behind and around your dogs ear and it raises it's back leg to scratch it's side, it's mange mites. Don't laugh, it's absolutely fool proof. The itch reaction kicks in when the ears are touched.

When my vet diagnosed the pups she told me not to laugh but she wanted to try this test first before conducting the diagnostic lab work. Sure enough, all the back legs came up when the ears were scratched. Then of course the microscope confirmed the diagnosis.

You should consult a vet if the rash is not gone in a couple of days.