Dermatomyositis: A Breeder’s Nightmare – Thoughts from a Breeder*

By Robette Johns
This article is to help breeders understand more about Dermatomyositis, (DMS). First, it’s not the end of the world. Second, openness about this disease will help other breeders and the Collie Breed. Lastly, if we can recognize that we are in a remarkable time for identifying genetic markers for diseases and if we work together, we may be able to eradicate this horrible hereditary disease.


In 1990, I was introduced to Dermatomyositis. At that time, very few breeders, veterinarians, and researchers knew much about the disease in dogs (as with many hereditary diseases, DMS also affects humans). I had a litter of two puppies: a dog and a bitch. Both were striking as puppies, and the bitch was something special. When they were 4½ months old, the dog started to develop tiny lesions on his nose. First they were treated with Antibiotics, then anti-fungal drugs, but the lesions kept getting worse. After a lot of research, my Veterinarian made a diagnosis of DMS. By now, the pup’s ear tips were completely involved, and the lesions on his face had grown larger and covered a broader area. Although this dog was severely affected, his biopsy came back inconclusive. He was treated with prednisone and the lesions cleared up, but he was left with black skin scars where the worst lesions had been. He had mild out breaks off and on for the rest of his life. They became fewer after he was neutered, and they were always treated with prednisone.

As I had just moved to the South from California, I contacted as many breeders as I could both local to where I was living and those I knew in California. I found one who not only knew about the disease, but also was instrumental during my “DMS learning curve”. The bitch in the litter finished her championship at 7½ months, and went on to become a number one Collie. In 1991, a second male around 8 months old had a very tiny lesion on the side of his nose. What I had learned made me suspicious enough to biopsy the spot. One tiny lesion that most breeders would never have seen came back positive for DMS. There was nothing to treat on this dog so he was neutered and put in a pet home close by so I could monitor him.

My last personal encounter with my own dogs was with a 10-week-old puppy bitch from a litter of 9 in 1994. Her face was swollen at the time she was going to her new pet home. Again she was placed near by and spayed, and was the only puppy affected.

The End of the World?

Now the hardest question for a breeder is, where do you go from here? This is where openness about DMS becomes the most important factor. DMS is not the end of the world. I had a number 1 Collie who had a brother with DMS. Should I breed her or not? A lot of phone calls and research gave me a sense of where the DMS may have originated, but you can never be sure. After discussing this matter with every stud dog owner I could, I learned quickly not to ask if they had health problems in their line, but to ask them specifically about the diseases you are researching – like DMS. I was able to breed away from DMS. I developed my own rule. Never breed a dog with DMS. If a stud dog produced more than one puppy with DMS – especially one in every litter – that stud dog needed to be taken out of the gene pool. This would be the same for a dam. If a severely affected puppy was produced, whether its skin (Derma) or muscle (Myositis) was affected, think twice about using that sire or dam again. I found with my cases of DMS that the Myositis didn’t express in the affected dogs until later in life. However, personally, I’ve seen young dogs with Myositis. With careful breeding, you will have a chance to clear your family line. The sooner we find a genetic marker, the easier it will be!

Being Open about DMS:

In my opinion, being open is the most important factor in clearing the Collie breed of DMS. Some of us wondered if there might be some kind of environmental factor that seems to trigger additional out breaks. There was a breeder in our extended area (she was in South Carolina) who had a Collie with DMS. The same time that the Collie in South Carolina broke with DMS, my dog broke with DMS about a week later in the Charlotte, NC area. A third Collie broke in northern North Carolina about a week after that. Because we were communicating, we were aware that this was happening. There may be many more triggers, but that knowledge will come when breeders start sharing their stories of DMS.

Pet Collies:

A pet collie puppy in Canada recently had a terrible out break of DMS. The owner spent over $2,000 on treatments but the puppy continued to get worse. The owner contacted me and I finally convinced her to have her veterinarians try prednisone. I even told the owner that I would be happy to speak to the vets about it, if needed. Finally the veterinarians agreed to start the puppy on a prednisone regimen, and she started to improve within days. She is currently free from outbreaks and has been spayed. Do you want to be the breeder that has to deal with that pet person? Do you want to deal with an owner who wants money back, to return the puppy or wants a replacement puppy? In this case, the owner wanted none of these – but she could have! DMS not only affects a breeding
program, but the population of ‘pet’ collies as well.

Working Together:

There is so much to learn; one or two breeders cannot do this alone. There are people (like me) to whom you can reach out and know that we are here to help, and not be concerned that we will tell the Collie world about you. Be honest and ask for help if you need it. Don’t pass on this “breeder’s nightmare”. Remember, DMS is like Lupus and Pemphigus, also autoimmune diseases. Is one less of a problem than the others – not as far as I’m concerned.

Let’s help our breed become healthier. We’re in a time when we can find genetic markers for so many diseases; let’s work together and support the research to find the genetic marker for DMS that will makes a huge difference in your breeding program and your dog’s life. Step up and join the studies!

* The thoughts and opinions expressed in this article are those of the author and not necessarily those of the Collie Health Foundation, Inc. Any questions or comments should be directed to the author, not the Collie Health Foundation.

A picture of a Collie affected by Myositis. Note the lack of muscle below the zygomatic arch.
A picture of a Collie affected by Myositis. Note the lack of muscle below the zygomatic arch.