An Overview of Hygromas in Dogs

The German Shepherd was only nine months old when his owner died. The foster family caring for him for the local rescue group was shocked when the dog still had no permanent home six months later. The individuals who had been interested in adopting him, it turned out, were put off by the sight of the hygroma the young dog had developed. When the rescue asked if we'd adopt him, I had to tell them that our townhouse was too small for him and was filled to the brim with cats.

What is a Hygroma?

The best thing that can be said about a canine hygroma is that it's usually painless. This unsightly bump that develops under a dog's skin is actually a swelling filled with fluid. It's enveloped by a thick capsule that's very fibrous and that develops under the dog's skin, according to PetEducation.com.

The most common spot where the bump appears is on the outside of a dog's elbow. The Pet Lovers Companion states that hygromas can also develop on the hip and the hock. To someone such as a prospective new owner who is unfamiliar with the bump, this false bursa might look like a tumor.

Some hygromas grow to two inches in diameter. Others become very hard. However, most are small and soft and are largely cosmetic concerns.

Causes

A hygroma forms after repeated trauma to an area that lies over a bony part of the dog's body. The most common way this happens is the simple action of the dog lying on a hard surface, such as hardwood floors or cement, for prolonged or repeated periods.

Hygromas are most common in larger breeds, particularly in dogs who lead a sedentary lifestyle due to certain medical conditions that restrict their activity. Some occur while a dog is recovering from surgery. They tend to develop most often in dogs who are adolescents, according to VeterinaryPartner.com.

Prevention and Treatment

Owners whose dogs are at an elevated risk can take several steps to help ward off this type of growth. The ideal bed for the dog should be soft. Those made of orthopedic foam are ideal. Owners should make sure to turn a dog recovering from surgery from side to side several times each day, according to specific instructions from the veterinarian.

The type of treatment appropriate depends on whether the pet has a simple or a complicated hygroma. For those with the simple type, changing the bedding often is a solution. As the dog continues to lie on softer material, often the growth will disappear over a period of several weeks. Sometimes a vet will recommend special bandages or pads to protect the dog's elbows. Most avoid draining a simple hygroma due to a risk of infection.

A complicated hygroma develops when a simple hygroma becomes infected. Because it becomes tender and causes the pet discomfort, vets typically drain it surgically. The area is drained and flushed with rubber drains, assuming the surface of the wound hasn't become ulcerated. The hygroma will continue to drain into bandages that need to be replaced every day. In many cases, it will disappear after about two weeks and a callus will form to protect the site in the future. Owners will also need to make sure the dog has a softer place to sleep.

When the surface of the hygroma consists of an ulcerated or large area or if the wound drains continually, more serious surgery is necessary. In some cases, the dog will need skin flaps or grafts to cover the area. Recovery often requires use of a splint to immobilize the affected area. The healing process can take a month or even longer.

Owners should gain a basic knowledge of hygromas in dogs order to be able to recognize them before they progress to a complicated stage requiring surgery. Whenever a dog's joint looks abnormal, it's important to have a vet perform an exam to determine the cause.

Sources:

http://www.peteducation.com/article.cfm?c=2+1592&aid=2861

Holly Nash, DVM, "Hygroma!," Pet Lovers Companion, 11^th annual edition (Northern Virginia), Jan-Dec 2011, p. 40.

http://www.veterinarypartner.com/Content.plx?P=A&A=2491&S=1&SourceID=42

Personal experience as an animal rescuer