Your Old Dog
Of all the dogs that have been part of our family for the last 30 years; our Jenna has been the most difficult for us to treat.
At two years old, we rescued Jenna, a Doberman Pincher from the Doberman rescue in our area. Although it would take years for me to realize that all of her problems were closely related to the dysfunction of one tiny little gland called the thyroid.
After years of incorrect diagnosis', Jenna was finally diagnosed with Hypothyroidism and placed on daily prescription medicine and she has greatly improved.
Sudden Aggression Is A Symptom of A Thyroid Problem
Many dogs diagnosed with thyroid problems are of a certain breed or cross breeds of families susceptible to a variety of immune disorders and allergies (e.g. Golden Retriever, Akita, Rottweiler, Doberman Pinscher, English Springer Spaniel, Shetland Sheepdog, and German Shepherd).
Some clinical signs before they show the sudden onset of behavioral aggression, can include: fearfulness, chronic urinary tract infections, allergies, anal gland problems, sensitivity to cold, skin problems, etc.
These are often early subtle signs of thyroid dysfunction. If your dog is showing any of these signs and nothing seems to help; I recommend reading more about diagnosing Hypothyroidism in dogs.