Rottweilers are disproportionately affected by torn cruciate ligaments when young, but if an older dog has lameness, the news could be more ominous.

As I (Henri Bianucci) prepared for the morning receiving to begin, I perused the appointments on the desktop. Just the breed, age and presenting problem of the patient is enough information to formulate a likely diagnosis, with accuracy in the 90 percent range.

Doesn’t that sound terribly jaded? It’s like breed profiling, but the fact is, certain breeds of dogs are often disproportionately affected by a given illness. For example a 6-year-old Labrador with a sudden onset of lameness in a hind leg will almost always have a torn cruciate ligament in its knee. Change the breed to a Greyhound, and the likelihood of a cruciate ligament tear drops to nearly zero. If at any age a Boykin Spaniel is vomiting, there is likely a sock or other household item that has been swallowed. There are multitudes of conditions that are more likely in one breed than another.

Sticking with our torn cruciate ligament example, the same could be said of Rottweilers as of Labs, but with an exception with regard to age. It seems that if a young Rottie is suddenly lame in a back leg, the diagnosis will be a cruciate ligament tear. But a similar set of symptoms in an older Rottweiler will often have a more ominous cause: bone cancer.

The appointment schedule had Max, a 10-year-old neutered male Rottweiler. The complaint was limping on a rear leg. There was a notation that the suspicion was of a torn ligament. I was pretty sure this would not be the case, and that my diagnosis would come as an unpleasant surprise. A dull gloom set in with the realization that I would be giving someone some heartbreaking statistics and hard choices.

Max was one of those Rottweilers that seemed to be aware of his breed’s reputation and was determined to prove that it didn’t apply to him. He was a giant goofball: all wagging, licking and rolling. Nothing, not even my orthopedic examination, caused him to bristle. I noticed his owners proudly smiling at his sweet and endearing nature. I knew that they did not know what I was going to say.

I stood up and faced them, and tried to gently approach the news. I explained that the hips, knees, ankles and feet were perfectly normal and stable. This was not a ligament tear or joint problem as their vet had suspected. They briefly expressed relief but read my expression and knew this was not good news.

I pointed to the muscle atrophy as a telltale sign of a longer-term problem. He had recently quit using the leg but had been favoring it long before that. An X-ray confirmed my fears. There was an unmistakable lesion on the bone near the knee. It was most consistent with osteosarcoma, a type of bone cancer.

The basic facts are that this disease is almost uniformly fatal, and amputation is the most effective way to alleviate pain. This, however, does not stop the disease from spreading. With amputation alone, the survival time is approximately six to seven months. If you follow amputation with chemotherapy, the survival average can extend to 14 months, with approximately 30 percent of patients living two years.

This is the same recommendation and prognosis that I have recited for the past 20 years. In that time, there has been virtually no progress in managing this dreadful disease until now. A vaccine is near, for conditional release, against osteosarcoma. The manufacturer will provide the vaccine to certain clinics for safety studies in the field. This is required prior to receiving full licensure. Though still in development, the results have been very exciting.

The first two dogs in the initial pilot study were still alive as of an October report after five years. Other dogs were four-and-a-half years into the study. The overall survival rate was nearly 70 percent after two years, and 50 percent at three years. These dogs were treated with amputation, chemotherapy and then the vaccine.

Some dogs did not respond and died from the spread of the disease, and further study is needed to determine why that is.

In 1796, Edward Jenner observed that milk maids who were exposed to cowpox did not get smallpox, and the idea of a vaccination was born. With little understanding of the immune system, Jenner saw that the body could be primed to protect itself from disease.

I can’t imagine that he could have envisioned using this same concept to fight cancer. But as medical science advances, it is becoming all too clear that the most effective weapons against a myriad of diseases, including cancer, may have been inside of us all along.

Dr. Henri Bianucci and Dr. Perry Jameson are with Veterinary Specialty Care LLC. Send questions to petdocs@postandcourier.com.

 

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