Post by Jeff on Oct 21, 2006 9:28:03 GMT -5
As far as anyone knows, the condition is not found in the wild. "However, few studies have been done of wild gorillas' health," said primatologist Dan Wharton of the Bronx Zoo/Wildlife Conservation Society, "so it's hard to compare."
Veterinarian Tom Clarkson of North Carolina's Wake Forest University, who studies gorillas and other primates, suspects a virus: "Viral infection is one of the main causes of cardiomyopathy, but if that's it, what's the virus, and how is it being transmitted?"
Gorillas are also prone to periodontal disease, which is linked to heart problems in humans; bacteria from gum infections can cause inflammation elsewhere in the body, including the heart.
Protecting captive western lowland gorillas is all the more important because they are endangered in the wild and at risk of being driven to extinction by the year 2050 because of hunting, habitat destruction and infectious diseases such as Ebola.
"The captive population of 375 gorillas soon might be all there is," said veterinarian Hayley Murphy of Zoo New England in Boston. She and cardiologist Ilana Kutinsky, of the Michigan Heart Group in Troy, recently started the National Gorilla Cardiac Database to track the cases in hopes of discovering why so many gorillas are stricken.
"One of the biggest challenges," said cardiologist David Liang of Stanford University, a consultant to the Gorilla Foundation in California, "is that you need to do an echocardiogram to see how well the heart is functioning. A gorilla has to be anesthetized for that, which carries a certain amount of risk." Some zoos are training gorillas to cooperate with simple medical procedures such as blood pressure checks and blood tests without anesthesia, but echocardiograms must be done when gorillas are asleep.
Byrd and Kay think it might be possible to use blood tests for B-type natriuretic peptide (BNP) or homocysteine to check gorillas' heart function without anesthetizing the animals, but it will take further research to confirm that.
Another step, Byrd thinks, might be to perform biopsies on affected gorillas to obtain tiny samples of heart muscle, although this, too, would require anesthesia.
Some scientists are searching the African bush for a solution. Primatologists believe that a key is studying what western lowland gorillas die from in the wild.
"Without knowing that," said Joe Erwin of the Foundation for Comparative and Conservation Biology in Needmore, Pa., "the cardiac problem in captive gorillas is even harder to get a handle on."
Wild gorillas' diet is made up almost exclusively of fiber-laden plants -- roots, shoots and leaves -- and some experts consider diet a chief suspect in the captive animals' disease.
Ellen Dierenfeld, a gorilla nutritionist at the St. Louis Zoo, has found that a member of the ginger family, Aframomum melegueta, also known as "grains of paradise," "is a staple food of western lowland gorillas in their natural habitat."
"Aframomum is a potent antibacterial, antiviral, antifungal and anti-inflammatory 'natural drug,' " said primatologist Michael Huffman, of Japan's Kyoto University. "The plants may be as much a source of preventive medicine for gorillas as they are of food."
Zoos try to give gorillas foods as close to their natural diet as possible, Dierenfeld said, "but aframomum and other native African plants are not part of captive gorillas' daily diets."
Until a way is found to prevent the disease, the best hope for gorillas in zoos may be the procedure that Kay, the Birmingham cardiologist, used to save Babec.
On July 1, his team was called from Birmingham to the National Zoo to operate on Kuja, a 23-year-old gorilla whose cardiomyopathy had rapidly progressed to emergency status. "A June echocardiogram of Kuja's heart showed almost no pumping ability," Kay said.
By the time Kay got to Washington, however, it was too late. Kuja's heart -- the heart of a "silverback," the adult male king of gorilla society -- had died.
"By the time we arrived, Kuja's blood pressure was just about gone," Kay said. "We gave it everything we had, but we couldn't save him."
Veterinarian Tom Clarkson of North Carolina's Wake Forest University, who studies gorillas and other primates, suspects a virus: "Viral infection is one of the main causes of cardiomyopathy, but if that's it, what's the virus, and how is it being transmitted?"
Gorillas are also prone to periodontal disease, which is linked to heart problems in humans; bacteria from gum infections can cause inflammation elsewhere in the body, including the heart.
Protecting captive western lowland gorillas is all the more important because they are endangered in the wild and at risk of being driven to extinction by the year 2050 because of hunting, habitat destruction and infectious diseases such as Ebola.
"The captive population of 375 gorillas soon might be all there is," said veterinarian Hayley Murphy of Zoo New England in Boston. She and cardiologist Ilana Kutinsky, of the Michigan Heart Group in Troy, recently started the National Gorilla Cardiac Database to track the cases in hopes of discovering why so many gorillas are stricken.
"One of the biggest challenges," said cardiologist David Liang of Stanford University, a consultant to the Gorilla Foundation in California, "is that you need to do an echocardiogram to see how well the heart is functioning. A gorilla has to be anesthetized for that, which carries a certain amount of risk." Some zoos are training gorillas to cooperate with simple medical procedures such as blood pressure checks and blood tests without anesthesia, but echocardiograms must be done when gorillas are asleep.
Byrd and Kay think it might be possible to use blood tests for B-type natriuretic peptide (BNP) or homocysteine to check gorillas' heart function without anesthetizing the animals, but it will take further research to confirm that.
Another step, Byrd thinks, might be to perform biopsies on affected gorillas to obtain tiny samples of heart muscle, although this, too, would require anesthesia.
Some scientists are searching the African bush for a solution. Primatologists believe that a key is studying what western lowland gorillas die from in the wild.
"Without knowing that," said Joe Erwin of the Foundation for Comparative and Conservation Biology in Needmore, Pa., "the cardiac problem in captive gorillas is even harder to get a handle on."
Wild gorillas' diet is made up almost exclusively of fiber-laden plants -- roots, shoots and leaves -- and some experts consider diet a chief suspect in the captive animals' disease.
Ellen Dierenfeld, a gorilla nutritionist at the St. Louis Zoo, has found that a member of the ginger family, Aframomum melegueta, also known as "grains of paradise," "is a staple food of western lowland gorillas in their natural habitat."
"Aframomum is a potent antibacterial, antiviral, antifungal and anti-inflammatory 'natural drug,' " said primatologist Michael Huffman, of Japan's Kyoto University. "The plants may be as much a source of preventive medicine for gorillas as they are of food."
Zoos try to give gorillas foods as close to their natural diet as possible, Dierenfeld said, "but aframomum and other native African plants are not part of captive gorillas' daily diets."
Until a way is found to prevent the disease, the best hope for gorillas in zoos may be the procedure that Kay, the Birmingham cardiologist, used to save Babec.
On July 1, his team was called from Birmingham to the National Zoo to operate on Kuja, a 23-year-old gorilla whose cardiomyopathy had rapidly progressed to emergency status. "A June echocardiogram of Kuja's heart showed almost no pumping ability," Kay said.
By the time Kay got to Washington, however, it was too late. Kuja's heart -- the heart of a "silverback," the adult male king of gorilla society -- had died.
"By the time we arrived, Kuja's blood pressure was just about gone," Kay said. "We gave it everything we had, but we couldn't save him."