The Rural Voice, 1990-06, Page 28OCCUPATIONAL
HAZARD:
RABIES
by Cathy Laird
Rabies has always been feared, and rightly so, as any
warm-blooded animal can get or transmit the disease —
and it is usually fatal. Ages ago, treatment of human
cases of rabies prompted such dramatic measures as
repeatedly submerging the victim in cold water, apply-
ing dog ashes to the wound, and drinking concoctions
of wormwood or seahorse ashes.
Preventive measures included docking the tails of
puppies and worming dogs by removing the membrane
under their tongue. These measures of treatment and
prevention were practised until the late 1800s, when
Louis Pasteur was preparing to test an experimental
vaccine for rabies on himself. A young boy was brought
to him for treatment of rabies. Pasteur immunized the
boy and saved his life.
Dorothy Moore, DVM, who
works at the Owen Sound Veterinary
Clinic, recently spoke to the Grey -
Bruce Humane Society on the subject
of rabies. "Grey County has the
highest number of rabies cases in all
of Ontario — in fact in all of Canada,"
she told the society. "New Zealand,
Australia, Hawaii, and Antarctica have
never had a case of rabies. These
countries are islands and the migration
patterns of animals are restricted."
Dr. Moore notes that there are two
cycles of rabies: wildlife and domes-
tic. The two cycles form a vicious
circle because domestic animals usu-
ally get the disease from wild animals.
"Domestic animals are rarely the
source of the disease," Dr. Moore
says. "Rabies is generally spread by
the wild animal population."
The original influx of rabies into
southern Ontario came from the north
in the mid-1950s, compliments of the
Arctic fox. The number of cases
peaked in 1986, when more than 3,000
rabid animals were reported in Ontario
and 4,212 people were treated for
exposure to the virus.
The last fatal human rabies case in
Rabies cases by county
0
G
Duflerin
WESTERN ONTARIOS
Huron 1. 102
79
43 Waterloo f.o9
Perth 52
112 Oxford
Lampton Middlele. ` 39
111 SOUTHERN ONTARIO Norlolt
Elgin it
ONTAR
33
Halton
Hamilton- 45
$ Wentworth
Niagara
Metro Toronto
Brant
Haldimand.
5O M.
21
April 1, 1987 to March 31, 1988
Ontario was in 1967. A young girl,
bitten by a rabid cat, died near Ottawa.
The rabies virus is passed primarily
through bites, but also through skin
abrasions and through the mouth,
nose, and eyes.
In Ontario, the red fox is the major
transmitter of the disease. Foxes are
100 times more likely than skunks and
1,000 times more likely than raccoons
to show symptoms of rabies. As many
as 50 per cent of foxes can die of rab-
ies in an area overpopulated by the
animals.
The average number of pups in a
litter of foxes is five (a world-wide
statistic). In Ontario, vixens often
have eight pups in a litter. But it is
rare to find a fox over the age of four
in Ontario.
The incubation period, or the
length of time it takes for rabies to
develop in an animal, varies from
species to species. The incubation
period for foxes is 12 to 153 days.
The migration of young males takes
place in the fall when the foxes travel
to establish new territories, and the
ground they cover can vary from 2
miles to 200 miles.
Foxes can be tracked by radio
transmitters attached to collars. Be-
cause there appears to be a waxing and
waning pattern to rabies outbreaks,
scientists are trying to find a link
between the life cycle of the red fox
and how rabies is transmitted. They
have noted that 95 per cent of foxes
found with porcupine quills in their
skin are diagnosed as rabid.
The striped skunk is the second
major wildlife culprit — an estimated
15 to 20 per cent of rabies cases are
attributed to it. Foxes and skunks
share habitats, and while skunks don't
travel as far as foxes, they can carry
the rabies virus for 6 months or longer
without showing signs of the disease.
The incubation period for skunks
ranges from 25 to 177 days, and
skunks can excrete the virus in saliva
for up to 18 days before they die.
Generally, skunks with rabies are
aggressive. They often attack, which
spreads the disease further.
The animal most responsible for
the spread of rabies to domestic pets
is the raccoon. Adaptable and easily
domesticated, raccoons tend to be
found near humans, as the animals
24 THE RURAL VOICE