The patient walks in to the medical center — neutered male Bernese Mountain Dog, 8 years old, 10% weight loss over the previous six months, lethargy, enlarged spleen on ultrasound. Only two words possibly come to mind — malignant histiocytosis.
The primary symptoms fit. The onset fits. The breed fits.
The diagnosis — 100% wrong.
The patient is Panda, who did not die from complications due to malignant histiocytosis, but instead due to complications from a congenital heart condition, discovered quite by accident. This is his story.
When we lived in Massachusetts, Panda was a member of a hiking group known as TrailBerners (now TrailPups). One of the dogs in the group was planning on undergoing a bone marrow transplant as a radical approach to fighting malignant histiocytosis, and we took Panda to Tufts to see if he'd be a good match for her. He failed his physical exam when the vet detected a slight heart murmur. A cardiologist examined him and determined that it was a valvular insufficiency, not quite a grade 1 heart murmur, but something we should keep an eye on.
It's hard to say how the problem affected Panda. He was a 5 minute on, 60 minutes off dog from his puppyhood, nearly failing puppy kindergarten because he slept through most classes. But he had a good life, plenty of canine and human friends, and for 5 years, no roommates (until Pockets and then Bison came along).
After moving to Minnesota, I became involved in conformation with Bison, and decided to work Panda in obedience. In his first trial, he qualified with a very nice 188 1/2. He seemed happy and enthusiastic about the obedience ring, so we kept after it. The next three months produced some hilarious non-qualifying attempts, each one different. Just after his seventh birthday, he performed a perfect heeling pattern — with absolutely no sits on halts, broke the sit-stay, and in general, made himself almost reach negative points! It was time for a vacation.
After a fun match in April in which he qualified nicely, he went to a trial in St. Paul. He was doing fine until the heel-free, when he seemed to be slowing down throughout. Then, on the recall, he stopped halfway and seemed lost. He couldn't pick me out from the crowd, and just seemed confused.
Our vet did a series of blood tests to check for any abnormalities. His thyroid checked out normal, and all of his other levels were fine. Further checkups detected no change in his heart problem, and nothing could explain his weight loss and lethargy other than the aging process.
In September, that all changed. On a Saturday evening in September, he vomited slightly and collapsed. His heart was in arrhythmia. But he seemed to settle down, and wanted to rest. He seemed better on Sunday morning, so we waited until our regular vet opened on Monday and got him in immediately. On x-ray, his heart seemed enlarged and his heart was still in arrhythmia.
We were sent to the University of Minnesota, who kept him overnight and did ultrasound, x-rays, and a needle biopsy. The spleen appeared to have a tumor, but the needle biopsy produced no cancerous cells. The oncologist was convinced that it had to be malignant histiocytosis. All of the symptoms seemed to match. He scheduled Panda for a splenectomy the next day. We refused the surgery, looking at his weakened condition, knowing he wouldn't survive the surgery. The diagnosis was 6-8 weeks without the surgery, and perhaps a few months more with it. We were given prednisone to treat him palliatively.
We took him home. Bison and Pockets, who both used to lord over him, made way for him. He suddenly became the leader of the pack. By the next week, Panda seemed stronger and was gaining weight back. We took him to the Sculpture Garden for a photo shoot. At four weeks, we took him back to the U because he was developing a skin infection, a common side effect to prednisone. The oncologist stated that he was 95% confident it was Malignant Histio. Six weeks went by, he seemed better. Eight weeks... who knew Panda was a fighter? A follow-up in December indicated that the splenic tumor was growing slowly and he was still losing weight.
By mid-January, he was starting to slow down again. I wanted one last snowfall with him, but the weather wasn't cooperating until January 21, when we received 5 inches of snow. Panda and I went for a walk in the backyard, but it was clear he wasn't having the best time. So I took him out front and let him lie in the yard while I shoveled the driveway. He looked happy, just hanging out, getting covered by snow and not having to work.
Two weeks later, we knew it was the end. He was unable to control his bowel and bladder functions. Our quality of life indicators were at zero — he no longer squeaked when Amy came home from work, he no longer offered any behaviors for treats, and he no longer could perform the twirl command (although he did try). We scheduled an appointment at the U. He walked into the hospital lobby under his own power from the car (which he jumped out of carefully!) laid down at the front desk, and refused to move any further. From there on he was placed in a cart — an ironic transportation mode for a carting dog. He seemed happy for the attention he was receiving, but he was physically done.
We ordered a necropsy done, for the sake of the breed. We had samples sent to all of the various studies on malignant histio. Even though Panda wasn't breeding stock, he came from prominent lines with some very notable dogs in it (including two BMDCA BISS winners). The attending vet didn't believe the necropsy and ordered it redone.
There was no malignant histiocytosis cells present in his body. All of the weight loss, splenic mass increase, and lethargy was due to blood clots that were forming around a 2mm by 2mm node on his left atrioventricular valve. These clots would break off and get trapped in vein between the spleen and the liver.
Because Panda was an aging Bernese Mountain Dog with an enlarged spleen, the heart issues were overlooked. Every clinical sign except the needle biopsy indicated MH. Had the heart condition been more heavily factored into the discussion as the proximate cause, not an ancillary symptom, perhaps a different course of treatment would have been favored. Treatment with Heparin or LMWH may have reduced the clotting problem, but subjected Panda to several injections a week, and could have caused a host of complications hastening his demise.Panda's case is a strong reminder of several things.
- An OFA cardiac screening after 12 months is not just for breeding stock.
- It is not cancer until you can prove it is cancer.
- Just because it is a Berner, doesn't mean it's MH.
- Know the quality of life signs for your dog
- Necropsies are invaluable to the breed.