Each dog breed has its unique characteristics.... Pugs have their unique noses, Ridgebacks have their ridges, Dalmatians have their spots, and Shar Peis have their wrinkly skin. Sometimes, as humans have bred for certain characteristics in breeds over time, they also inadvertently select for problems. For example, Pugs may have a harder time breathing with their shorter noses, and Ridgebacks occasionally will form cysts under their ridges. Shar Peis have been known to have more than their fair share of skin problems, due to the wrinkly and thick nature of their skin.

Riley is a 13 year old Shar Pei who has been coming to Southpointe for many years. In October of 2008 Riley's owner noticed that his left front forearm started looking bigger than the right. On palpation of his forearm it was soft and moveable. We did a fine-needle aspirate to determine why his arm was getting larger, and when we did this we got a thick slimy-substance out of his arm. Under the microscope, there was a lot of proteinaceous background with occasionally round cells that were all uniform in appearance. The swelling appeared benign (non-cancerous) but it was so unique that we did not know what it was.

Riley
(select to enlarge)

Over the next two years, the swelling gradually got larger and larger, and we affectionately referred to Riley's left forearm as his 'Popeye arm'. Eventually Riley's owners decided to have his arm biopsied while he had a dental done, so we admitted him into surgery to attempt to remove the swelling. When we opened up his arm to remove the mass, we found that it did not look like a mass at all, but a large amount of "slime" that was non-encapsulated (not within a capsule, or no outer shell). In order to remove this, we made an incision through his skin and 'milked' out the slime that lay just below the surface.

After removing the tissue/slime, we sent some of it to a pathologist to figure out what it was. Riley's biopsy came back as Myxedema, also called cutaneous mucinosis. This condition is unique to the Shar Pei dog, but can occur in other dogs with medical issues such as hypothyroidism or lupus. Mucin in a normal component of skin, but Shar Peis have more mucin than do other breeds. It is believed that distorted lymphatics (assists in drainage as well as fighting infections in skin and other tissues) and massive accumulations of hylauronic acid (present in joint fluid and other tissues) play a large component in this disorder in Shar Peis.

Surgery
(select to enlarge)

Riley's arm has gone down after the draining, but we do expect it to recur over time. In most cases, the excessive mucin under their skin is a cosmetic problem only. Riley is currently doing very well 6 months after his surgery.