Long Quarantine Price for Animals’ Zoo Admission
It’s not easy to get into the San Diego Zoo--that is, if you’re an animal.
If the animal is a cud-chewing, hoofed species coming from outside the country, it will find itself spending up to 150 days in various quarantines, starting overseas and running through two or more facilities in the United States.
A primate might find itself in quarantines for 90 days or more. A rhino or hippopotamus or cheetah could be penned for more than 30 days. Even an animal going from one American zoo to another, or from the San Diego Zoo to the Wild Animal Park, probably will find itself in isolation for a month.
While the required time and lengthy testing may seem onerous, the checks are absolutely necessary to protect the health both of the nation’s existing domesticated animals and exotic species in zoological collections--health concerns that translate into tens of billions of dollars of investment and replacement costs.
“It’s based on economics, of course, but that includes the concerns of our animals, and of human beings,” said Werner Heuschele, the head of the zoo’s infectious disease research and its former veterinarian. Heuschele and his colleagues are strong proponents of quarantines, even though they may not always work to the zoo’s immediate advantage.
“That’s why all zoos are working as hard as they can for self-sustaining populations so we don’t have to go into the wild and go through all the hassles, albeit necessary, for importation,” he said.
So, for example, the two Chinese tufted deer given last year to the San Diego Zoo by the People’s Republic of China--the first to be sent to North America--have still not made it to public display.
The deer went first for 60 days to Hamburg, West Germany, one of five overseas quarantine stations approved by the U.S. Department of Agriculture, where veterinarians made the first checks for diseases that cud-chewers (or ruminants) could conceivably spread to the $46-billion American cattle industry if admitted here with illness. The overseas quarantine facilities allow an animal owner to avoid expensive shipping costs to the United States if the animal shows preliminary signs abroad of being sick. And they add an extra margin of safety to American procedures to keep exotic diseases out of the country.
After the deer showed a clean bill of health for hoof-and-mouth virus (commonly known as foot-and-mouth), brucellosis (undulant fever) and glanders, among other contagious animal diseases, they were shipped to the USDA’s own quarantine center on the grounds of Stewart Air Force Base in Newburgh, N.Y.
They remained there another two months for additional tests to rid them of ticks, viruses and parasites that could threaten cattle, hogs or sheep susceptible to the same diseases that plague ruminants. Then, after arriving at the zoo in December, the deer entered the zoo’s own quarantine cages on an isolated hillside away from the main animal collection. Zoo veterinarian Phil Robinson checks for additional parasites and illnesses that, while not a threat to domestic livestock, could nevertheless wreak havoc with the zoo’s own animals.
If the deer had shown signs of any contagious diseases, they would not have been allowed to proceed further along the road to display.
“The quarantines are thorough because even a single introduction of something like foot-and-mouth could be disastrous,” Heuschele said.
In 1914, an outbreak of foot-and-mouth disease at the Chicago stockyards resulted in the destruction of 175,000 head of cattle, the only way to stem the spread of the deadly disease. Other cases throughout the early 20th Century involved African swine fever, hog cholera, cattle plague and so-called Texas cattle fever. Such diseases are still prevalent worldwide and the USDA at present prohibits importation of swine from any country with African swine fever or hog cholera because of the potential, however remote, that a quarantine may not detect it.
Because of the potential for ruination of domestic livestock, ruminants and swine from abroad are subject to the most stringent quarantines. The federal and state requirements for other species depend on the severity of diseases they carry to infect humans or domestic animals. Individual zoos, including all major institutions such as San Diego’s, impose their own quarantines even in the case of hippopotamuses and elephants, which are not subject to federal isolation procedures.
Zoos such as San Diego’s maintain their own research departments that interact with those of the USDA, in particular the one on Plum Island off New York. And in at least two cases recently, the research is changing the way quarantines are handled because of new information about testing and about how viruses can be transmitted by animals not suspected in the past of harboring them.
The case of Sonette, a French donkey, brought about a change in federal testing procedures for exotic equines such as donkeys, mules and zebras.
Equines, including horses, donkeys and other members of the species, must be quarantined in the country of origin for 60 days if that country has African horse sickness about. Otherwise, the animal must be kept for 60 days at one of several USDA receiving centers, including one in Los Angeles. (Ruminants must be kept at the Newburgh, N.Y., facility only.)
But, Heuschele explained, initial blood tests for four deadly equine-borne diseases can be done before an animal is shipped, again to save the owner unneeded expenses if the tests show positive. In the case of Sonette, however, the donkey was airfreighted to Los Angeles by Sonette’s private owners before the test results were completed.
And when tested in Los Angeles, Sonette showed positive and was judged by the USDA as unfit to remain in the United States. When Sonette’s owners in Olivenhain appealed to San Diego Zoo researchers for help, the researchers found that exotic equines such as donkeys have a substance in their blood that makes the blood-testing register false results. Heuschele was able to get the USDA to alter its regulations so the blood can be treated first to eliminate the substance before undergoing testing.
Soon after Sonette was saved from deportation, the zoo discovered it had the same problem with a kiang, a rare Chinese exotic equine being held for two years in Hamburg because it continued to fail the blood tests. With the change proposed by San Diego Zoo researchers, the kiang subsequently tested negative and became eligible for importation.
“We’ve been lucky that we haven’t run into more cases with this blood problem,” Heuschele said.
While quarantine procedures are designed conservatively to err on the side of caution, Heuschele is working on one case where a disease apparently was brought in by an animal not suspected of being a carrier and therefore not tested for it during quarantine.
The white-tailed gnu (or wildebeest) is among the world’s highly endangered animals and among the animals the zoo has bred successfully at the Wild Animal Park. However, it was discovered at both the San Diego and Oklahoma zoos several years ago that the African antelope is a carrier of a highly deadly virus for antelope, cattle and sheep, called malignant catarrhal fever, or MCF.
The disease apparently is spread during the birth of the gnu, being shed during nasal secretions that can contaminate grasses shared by cattle in the wild or can be blown downwind toward cattle in an aerosol form, which would be possible in the grazing areas around the Wild Animal Park.
“This puts us on the horns of a dilemma,” Heuschele said. “The animal is endangered but a lot of them have tested positive for this virus. The only time the virus is spread is during the time we have babies but potentially this could be a time bomb for cattle, especially in areas like Texas where wild game ranches are in close proximity to major cattle areas.”
The zoo has temporarily separated its male and female gnus to prevent breeding while it wrestles with the issue and makes recommendations to the USDA. The Wild Animal Park lost many Pere David deer to the disease in 1980 that might have resulted from the wildebeest being carriers. The disease also has occurred in the United States independent of exotic animals such as gnus, with domestic sheep being the suspected virus carrier, although the precise method of transmission is not yet clear.
“We’ve recommended to the USDA that it should put restrictions on wildebeests unless they show negative blood tests,” Heuschele said. Already, the zoo has cancelled a shipment of one male and two females wanted by the Miami Zoo because they have tested positive for the disease.
“Sometimes knowledge comes after the fact (of importing),” Heuschele said.
Rhinoceros were previously not subject to any federal quarantines until a rhino died at a breeding ranch in Texas from a tick that USDA authorities said could transmit a serious disease in cattle called heartwater. As a consequence, all rhinos arriving in the United States now are dipped in insecticide to kill the parasite.
Although not every zoo can afford as extensive an individual quarantine facility as the one maintained in San Diego, zoo veterinarian Robinson said that some type of isolation is necessary to check for diseases that could harm members of the same species. In receiving primates, for example, Robinson looks for internal parasites that the USDA or state public health officials pass over because they do not constitute a human or domestic animal threat.
“We do a complete physical, tag (tattoo) the animals for future identification, etc.,” Robinson said. “And we do this whether the animal is arriving or leaving (to another zoo). We don’t want any surprises.”