A New Epidemic Proves Fatal to 21 Foxhounds
August 25, 2000
By DAVID W. CHEN
MILLBROOK, N.Y., Aug. 22 -- For months, no one could figure out why
the foxhounds here were suddenly dying.
One after another, the fit and feisty hounds of the Millbrook
Hunt became haggard and lethargic. They lost weight and patches of
hair. They developed enlarged joints, crusty skin lesions and
ropelike knots underneath their skin. In all, 21 dogs out of a
group of about 120 died, and another 20 or so became ill.
This spring, researchers at North Carolina State University
identified the culprit: a strain of a parasitic disease called
leishmaniasis, which is normally transmitted by sand flies and
has killed humans in other countries, but had rarely been
diagnosed in the United States.
But that was not the only surprise researchers eventually
Far from being limited to Millbrook, the disease has been
detected in dozens of foxhounds from roughly 40 kennels in 20
states and Canada. And though none of those dogs have died, the
outbreak caused the cancellation of all fox-hunting events around
the country last spring.
As the federal Centers for Disease Control and Prevention
analyzes the situation, the good news is that leishmaniasis has
not been found in other types of dogs or animals, or in humans.
But there are still more questions than answers about how the
disease got to this country, how it is transmitted and what may lie
ahead, offering another reminder of how once-exotic diseases, like
the West Nile virus, are no longer all that unusual as possible
threats to public health.
"Today's world is so much smaller than it used to be," said
Richard Falco, a medical entomologist at the Louis Calder Center
of Fordham University in Armonk, N.Y. "We're at the point where
the urban and rural collide. So when these exotic diseases arrive,
we sort of have everything set up to have a public health problem,
and we really have to be on guard."
M.J. Sharp for The New York Times
Drs. Edward Breitschwerdt and
Amanda Gaskin at North Carolina State University, where a parasitic
disease in foxhounds was identified.
There are several similarities between the West Nile virus and
leishmaniasis (pronounced leash-men-EYE-a-sis). Both only recently
became widespread in this country. Leishmaniasis is typically
found in warmer, coastal areas in places like Brazil, the
Mediterranean, India and the Sudan. If untreated, some strains of
leishmaniasis can be fatal in humans; West Nile has killed seven
people in the New York area in the last year. And sand flies,
found only in the Southern United States, even look like tiny
mosquitoes, albeit with a nastier sting.
But while West Nile has been detected in mosquitoes, birds,
animals and humans across the Northeast, leishmaniasis appears to
have spread no further than the foxhounds.
And in the process, it has unnerved the tight-knit world of
fox-hunting, which reveres its traditions and treats its hounds as
members of an extended family.
This spring, the Masters of the Foxhounds Association, the
sport's national governing body, canceled all fox-hunting events
and urged kennels to quarantine leishmaniasis-positive dogs. Now,
with the fox-hunting season set to begin in only a month or so,
many fox hunters are hoping they can resume their activities.
"We're being super-cautious, because nobody knows all the
answers," said Col. Dennis Foster, the organization's executive
director. "If there's any question, we don't do it, that's our
Here in rural Dutchess County, where hunting is so ingrained that
the Millbrook Vineyards and Winery sells a table wine called Hunt
Country Red, life began to take on an inexplicably cruel cast a
year ago, when the foxhounds began to die.
At first, the hunt and its veterinarians believed that a
tick-borne disease was responsible -- a logical theory, given the
prevalence of Lyme disease in the area. But after months of
frustration, hunt officials sent two of their sickest dogs, Signal
and Nelson, to the North Carolina State University College of
Veterinary Medicine, which has done extensive research on
Signal and Nelson had to be euthanized. But their cases helped
researchers pinpoint leishmaniasis as the unexpected villain.
"This should not be in the U.S.," said Edward B. Breitschwerdt,
professor of medicine and infectious diseases at North Carolina
State. "We're truly dealing with a foreign animal disease that
remains very unclear to all of us still."
As Dr. Breitschwerdt's staff continued to work on molecular tests,
aided by some donations from the hunt, the Centers for Disease
Control stepped in, testing people who had come into contact with
the foxhounds in Millbrook and collecting samples from all 10,000
or so foxhounds around the country.
While 12 percent of the 9,000 hounds tested so far have shown
some blood-test evidence of infection, only 1 percent have been
confirmed as being infected, said Dr. Peter Schantz, a
veterinarian and epidemiologist in the centers' division of
There are two other strains of leishmaniasis: mucocutaneous, a
rare form that affects the mouth and the genitals, and cutaneous,
which affects the skin and has been reported in dogs along the
But the strain humans are most susceptible to is visceral
leishmaniasis, the disease affecting the foxhounds. It can be cured
in humans, but not in dogs; with drug treatments, however, dogs
can live with the malady.
The disease probably arrived in this country when an American
soldier returned from Europe or Northern Africa with an infected
dog. In fact, leishmaniasis was diagnosed in several soldiers in
the Persian Gulf war. (It is named for Sir William Leishman, an
English military surgeon.)
And since hunting groups often travel, many foxhounds, including
the Millbrook group, may have picked up the disease while
participating in hunts in Georgia, Virginia or other warmer
climates with sand fly populations, Dr. Schantz said.
Yet there has been no evidence of any sand flies as carriers --
prompting speculation that the hounds may have passed on the
disease by biting or some other method. Moreover, the disease
may not manifest itself until years later.
"It's a potential public health problem," said Dr. Schantz. "We
are a very mobile universe right now. People come and go with
their pets, and pets are well-known reservoirs of a number of
diseases. So I think we're going to pick up these things
Why the disease has attacked only foxhounds is still a mystery.
But veterinarians suggest a few possible factors: inbreeding,
extensive travel and the dogs' aggressiveness, which causes them
to bite one another. And though unlikely, it is also possible
that a carrier like a mosquito could eventually add leishmaniasis
to its portfolio of infectious diseases.
"At this point in time, this is a dog disease, and it's an
epidemic," Dr. Breitschwerdt said. "But I know what the
potential of this epidemic might be, both for the foxhounds and
for the people, and that's weighed on me tremendously."
There is no evidence that dogs can transmit the disease directly
to humans. But the potential risk has been enough to cause some
animal rights advocates, who have long disliked the sport, to
call for a moratorium on fox-hunting activities.
"It would be selfish on the part of the fox hunters to continue
with their recreational activity when there's even a slim chance
that this might be a threat to humans, domestic pets or
wildlife," said Michael A. Markarian, executive vice president of
the Fund for Animals.
But in the Millbrook area, the reaction has been much more
subdued, with most people interviewed saying that they had
either heard nothing or little about the outbreak, or that it was
low on the ever-expanding list of diseases and hazards.
One businesswoman, Kathie Kessler, who owns Eclectic Designs, an
interior and architectural design store, said that her dog, a
Labrador retriever, had been sickened by a mysterious ailment for
several months; the symptoms included weight loss, vomiting and
And though she counts several hunt members as clients and proudly
displays a charcoal fox-hunting sketch in her showroom, she had
not heard of the disease until a visitor asked about it. "I'll
mention this to my vet," she said earnestly.
The hunt, meanwhile, has worked with local health authorities and
sent letters to local landowners and members assuring them that
the infected dogs, now quarantined, have been improving with drug
treatment and that fox-hunting can resume as scheduled this fall.
Even so, the ordeal has been difficult to handle.
"The lowest point for us was when we didn't know what we had,"
said Farnham F. Collins, joint-master of the Millbrook Hunt.
"Since then, I don't think we're all celebrating, but at least we
know what we're up against."