I have a 5 year old wirehair dachshund that was diagnosed with diabetes one year ago. He also has severe allergies and skin problems. He started out on steroids for his itching skin before being diagnosed with diabetes. It helped significantly, but now this is no longer an option. I have taken him my vet several times because he constantly licks his paws and scratches to the point of bleeding. The vet suggested allergy tests (which isn’t an option financially) and daily Benadryl. The Benadryl worked for a while, but is no longer working. We use special shampoo, which helps for a day or two. Is there anything I can do to keep him from scratching and licking his paws?
Prednisone and other steroids are commonly used against allergies in dogs. Sadly, prednisone can cause a number of side effects. It definitely exacerbates diabetes (and it may even trigger diabetes). Prednisone is contraindicated in diabetic dogs in all but the very rarest circumstances.
Fortunately, there are other options. Start by eliminating allergen exposure. Use a good flea preventative, even if you do not see fleas. Consider a hypoallergenic diet (but be aware that this may transiently interfere with regulating the diabetes). Gently cleanse his feet with a damp wash cloth after walks to remove pollen from his skin. Consider using omega-3 supplements (the use of these supplements in allergies is somewhat controversial, but they are not likely to cause harm).
Finally, if all else fails, consider using an alternative anti-allergy medication. Antihistamines such as Benadryl rarely do much to prevent skin allergies in dogs. However, a medication known as Atopica (cyclosporine A modified) is often as effective as prednisone, but it has fewer side effects and it is less likely to interfere with the diabetes. Atopica is more expensive than prednisone, but the price varies with the dose. Dachshunds take much smaller doses than Rottweillers, so hopefully the cost will not be prohibitive.