Hi there I'm Dr Goodall and I'd like to help.
I have some questions:
1) Is your dog itchy?
2) Is the red area weaping fluid/pus?
Is the rash only on the underside belly or elsewhere?
4) Does your dog lick his paws at all?
no it does not seem to bother him
no it does not
only on the underside
Is there any hair loss in the area? Is he currently on any other medications? Or have any other medical history?
yes he does lick his paws
no he does not take anything.no hairloss
he eats rice and chicken, which i cook.
Ok, has he always been on rice and chicken? Is the rash worse at particular times of year?
but he had it when he ate dog food.
The blackening of the skin is due to 'hyperpigmentation'. This is when more pigment is produced due to inflammation of the skin.
I suspect your dog will have 'atopy' - an allergic skin condition. This is common in dogs and is caused by allergies to things like grass, pollen, house dust mites, fleas etc etc. It can be literally anything. The only way to find out exactly what the dog is allergic to is to carry out a skin or blood test. If you know the allergy, it is possible to make a vacciantion which can control the condition (this isn't effective in all dogs however).
Sometimes atopy is seasonal to e.g. pollen, but other times the skin is inflamed all year.
The best way to manage atopy is a combination of medications. Regularly shampooing the dog with a special shampoo such as malaseb or allermyl can help as it removes the 'allergens' (things the dog is allergic to) as well as removing any bacteria on the skin which may be causing an infection too. Other medications may include antihistamines (often the human medication 'piriton'), skin conditioning tablets with omega fatty acids, and steroids. Steroid tablets/injections are a last resort though as they do have side effects. Steroids do come in sprays which are great as they don't have side effects. It may be that you have to use the spray on a regular basis to keep the skin condition under control.
I would highly recommend using a flea/mite/tick spot on medication monthly too, as parasites are often a contributor to skin problems.
It is also possible that your dog has a food allergy and that chicken and rice is included in the allergy. Try changing the diet to only pasta (a different carbohydrate) and white fish or lamb (any other protein but chicken) for 3 weeks and see if there is a deifference.
i will try that.thank you so much