Bullous pemphigoid is an auto-immune disease, meaning that it is caused by your dog’s own immune system mounting an inappropriate response against a normal body component. With bullous pemphigoid, your dog’s body attacks the protein in the skin. This inappropriate attack causes skin lesions and often mouth lesions. Though a relatively uncommon disease, bullous pemphigoid can be very serious.

Your dog will develop lesions resembling blisters that will usually be painful and itchy. The lesions tend to occur on your dog’s lips, the tissue inside his mouth, on the hairless part of his ear, foot pads and groin. Both male and female dogs can get bullous pemphigoid. It does, however, appear that certain breeds, such as Collies and Doberman Pinschers, are more likely to develop this condition.

It is not known how or why your dog may develop bullous pemphigoid.