In addition, Dr. Fossum and another A&M heart surgeon, Dr. David Nelson, are interested in mitral valve degeneration, an acquired, difficult-to-treat cardiac disease that eventually leads to heart failure. “Our theory is that if we went into it early and did a simple procedure using a ring around the valve, it would prevent the valve from stretching out,” she explained, adding that treatment of the disease at end-stage is a much tougher proposition, since over time, the valves become increasingly deformed and the heart muscle itself becomes impaired. Because drugs are ineffective, Dr. Fossum is currently seeking funding to support the cost of surgery, which would encourage earlier intervention and thus prevent progression of the disease.*
“Open heart surgery is in its infancy,” she said. “Because we see so much cardiovascular disease, the field needs to continue to grow. There are a great many lives that could be saved.” As with all surgeries, there are risks. “With the heart/lung machine, we’re taking all of the blood out of the body, putting it into a pump, reoxygenating and putting it back in [the body]. There is a risk for bleeding and arrhythmia,” Dr. Fossum explained. Surgical candidates are considered by veterinary referral.
Kidney disease is a common condition in dogs, and kidney-related disorders have been identified in 25 to 30 breeds. Dr. George E. Lees, professor of small animal internal medicine, has been studying hereditary nephritis (HN) in dogs (in humans, this is known as Alport Syndrome) since 1992, when he evaluated an English Cocker Spaniel with the disease. In 1993, Dr. Lees and his colleagues diagnosed another genetic form of the same disease, known as “x-linked HN.” As a consequence, in 1997, Dr. Lees began studying a group of dogs at A&M with x-linked HN; the study is known as the Canine Hereditary Nephritis Project. HN, Dr. Lees explained, is a term used “to designate a general category of inherited kidney diseases, [which] include Alport Syndrome as well as some other disorders that seem to have similar features.”
The aim of the project is to benefit both humans and canines, and the studies have been supported by a series of grants from the National Institutes of Health. “We hope to contribute to the growing understanding of why people who have Alport Syndrome develop chronic renal failure (CRF),” he explained. He added that CRF occurs when the kidneys fail to function sufficiently well to maintain overall bodily health, and the patient becomes ill with a condition known as uremia, which can cause vomiting, weakness and other symptoms.
Additionally, Dr. Lees is hopeful that he and his colleagues, Dr. Anne Bahr and Dr. Keith Murphy, professors in the College of Veterinary Medicine and Biomedical Sciences, will make strides within the international nephrology research community toward slowing or halting the advance of chronic progressive renal disease in dogs. Such an achievement could one day result in a delay of the onset of CRF or, possibly, prevent it in its entirety. Dr. Lees believes that methods can be devised to test urine and/or renal biopsy specimens for “molecular markers” that may help indicate the presence of a specific type of chronic progressive injury common in all renal diseases that lead to CRF.
“The techniques that we have truly ‘mastered’ so far are more along the lines of advancing the diagnosis of the disease than its treatment,” he said. “Being able to do this is essential if we are to study treatment of the disease at all.”
Small Animal Rehabilitation Program