The pet insurance you purchase for your dog will often provide allergy testing for your dog. The policy might NOT cover an allergy diet for dogs, but you can at least learn a bit more about your dog’s allergies. This is critical because you don’t want to put yourself in a situation where you don’t know enough about what your dog is allergic to.
You must start taking care of them based on their allergies right away.
It is still wise to take a pet insurance policy out to ensure that you are always covered no matter what kind of allergies your pet might have and how they can adjust to how they need to eat going forward. If you have the best knowledge possible of what your dog is allergic to, then you can plan their entire diet around these facts.
Keep in mind that some of the foods you might need to purchase for your dog may require you to get a prescription from your veterinarian. It is a requirement for certain types of food to be bought off of the shelves. Just bare this in mind and ask your vet about what you need to do to get that prescription.