Good Morning and welcome. I am Dr. Loretta, a licensed veterinarian and I am happy to answer your question.
This odor is caused by this allergc reaction that is causing a secondary pyoderma or skin infection. The following treatment will help:
If there is no response, then your vet will have to run tests such as skin scrapings and cultures to determine the cause and then they will treat according to these results. In most cases, this is enough to calm down the odor and secondary pyoderma.
Does that make sense to you?
Please let me know if you have ANY other questions. My goal is to give you 100% satisfaction and if you are not yet satisfied, please Reply so I can clarify for you
Sincerely, Dr. Loretta
Thank you for your excellent advice it was for my sisters Westie she has faithfully written down all the advice you have given. Appreciative