I would suggest a thyroid test in addition to any allergy approaches you decide to try.
Hypothyroidism is common in Labs and older dogs in general. Since the itching is a new development and a dietary change didn't work, it's worth getting it checked.
The possible symptoms that can be caused or made worse by a thyroid imbalance are widely varied. Skin and coat are often affected. Usually dogs lose fur & get dry, flaky skin and icky lesions, but I HAVE also seen dogs get severely itchy with hypothyroidism.
The test is relatively inexpensive (about $45 where I live) and most vets should be able to do the test in-office. The meds are dirt cheap too (Soloxine).
Hypothyroidism is common in Labs and older dogs in general. Since the itching is a new development and a dietary change didn't work, it's worth getting it checked.
The possible symptoms that can be caused or made worse by a thyroid imbalance are widely varied. Skin and coat are often affected. Usually dogs lose fur & get dry, flaky skin and icky lesions, but I HAVE also seen dogs get severely itchy with hypothyroidism.
The test is relatively inexpensive (about $45 where I live) and most vets should be able to do the test in-office. The meds are dirt cheap too (Soloxine).