Discharge from the penis could be caused by a urinary
, preputial infection
, prostatitis, or prostate cancer. Inflamed gums are signs of Stomach Heat (Chinese lingo), gingivitis, or gum infection. These symptoms are probably just coincidental.
If possible, your holistic vet could try to control the allergies using another formula, Western medicine, immunotherapy, or acupuncture to try to enable your dog to tolerate the Chinese herbs.