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Linda. Munson,2. Dane. Sanderlin,3 and. Max J. G. AppeI4. I Department of Biology, ..... Robson,. 1973). Sera were evaluated for parvovirus antibody. (CPV-2).
Journal

SEROSURVEY

FOR

DEMOGRAPHY Scott

Marusha

WILD

Creel,1

Linda

DISEASES

DOGS

Munson,2

:5:3 4 , 1997. pp. 523-532 Ds’ae Association 1997

Disea.ws, © \Si!dlift’

AND

IN TANZANIA Dane

Sanderlin,3

and

J. G. AppeI4

Department

I

VIRAL

OF AFRICAN Nancy

Creel,1,5

Max

SELECTED

of %‘:1dlzfe

of Biology,

5971 7-0346, 2 Department

Montana

USA of Pathology,

State

School

University,

Bozeman,

of Veterinary

Medicine,

Montana University

of Tennessee,

Tennessee 37901, USA 3 Viral and Rickettsial Zoonoses Branch, Centers for Disease Control, 1600 Atlanta, Georgia 30333, USA 4 James A. Baker Institute for Animal Health, College of Veterinary Medicine, Ithaca, New York 14853, USA 5 Corresponding author

Knoxville,

Clifton

Road,

Cornell

N.E.,

University,

are endangered, with only 3,000-5,000 remaining unusually vulnerable to viral diseases, particularly rabies and canine distemper (CDV). However, canine distemper has been confirmed by laboratory diagnosis in only one free-living wild dog. The 43,000 km2 Selous Game Reserve (SGR; Tanzania) holds approximately 900 adult wild dogs. In a study area of 2,600 km2, the population maintained high density (1 dog/20.5 km2) from 1991 to 1996. The population was stable, varying 18% below and 9% above the mean density over the 6-yr period. Serum samples (n 22) collected over 3 \T showed that most individuals were exposed to CDV (59%: 95% confidence interval 43-76% African

ABSTRACT:

the

in

wild.

seropositive)

and

seropositive no during

the

(mean

survival

inversely

study.

and

SE

to

93,

1996.

stable

data

words:

Key

20

show

n

the

638

SGR

all age

235).

=

wild

that

wild

54-81% CDV

=

for

healthy

African rabies,

in

± 6%,

demographically

parvovirus,

died

populations

adults:

These

and

that

exposure

other

CI

0-17%).

dog

92

and

classes

uals

populations, to

distemper,

in

to

habitat

(Fanshawe

et

Malcolm, and

Heerden

1986;

to

± 8%,

n

=

like

those

of

and

CPV.

conservation,

after

mean 127,

size

low 22

between

canids,

±

1992

can

remain

Lycaon

demography,

was

were

yearlings:

little

other

with

sampling

litter rates

fluctuated

were

age,

seroconverted

mortality

CDV

a!.,

the

dog

and

Creel et

al.,

Alexander

one

Goddard,

cribed

information

a single

National population 1970 and of

disease.

a fatal

illness

pack loss,

eyes,

most

from

pictus,

to canine attributed

in

the

Park (SNP, Tanzania). declined to extinction 1991, with recurrent Schaller among

that

staggering

on wild

population

caused

(1972) the

de-

members

anorexia

mucopurulent

ing. Based on these mortem examination tality in three packs

persecution

diseases

1995;

of weight

competition

(Estes 1979;

scribed

Creel

wild

recently,

came

outbreaks

low

and

limit

interspecific

Gascoyne

et

with

human

infectious

1991). largely

conditions

Creel may

and

is

all

1991;

carnivores

1996),

31 rates

Serengeti The SNP between

individ-

a!.,

combined

factors

1967; den,

a!.

1988), larger

et

under

including

(Childes,

5,000

are

(Ginsberg status

loss

Several

pictus)

Fanshawe

density

numbers,

to wild

precarious

population

with

the

1990;

due

1996).

3,000

with

species’

in

Annual

Until

(Lycaon

dogs

remaining

Macdonald,

none

related

serology.

wild

The

although

positively

Variation

mortality

exposure

canine

days,).

(pups:

dogs endangered,

were

elsewhere.

Annual

despite

dog,

±

INTRODUCTION African

seropositive),

titers

1.9 yr. At least five of 13 dogs positive for CDV CDV titers did not survive better in the years

high

those

CPV

95%

CI

than

for

to

(68%:

95%

with

Dogs

comparison n

parvovirus (0%:

younger

±

related

10%,

that

rabies dogs

(Lycaon pictus) wild dogs are

dogs

canine

for

seropositive

in

wild

It is believed

and

discharge

and

from

myoclona!

twitch-

clinical signs and of one carcass, in

1967-1968

distemper. a decline

postmor-

was

as-

Malcolm 197 1-1973

and

Creel,

(1979)

(van

Heer-

to disease, though no serological or postmortem data were collected to identify the pathogen (cf Burrows et a!., 1994). In the late 1980’s and early 1990’s, the last few

1993;

van

et

al.,

1996). 823

in

824

JOURNAL

wild

dogs

bies

OF WILDLIFE

in SNP

disappeared

epizootic.

was

DISEASES,

Rabies

confirmed

33, NO. 4, OCTOBER

during viral

in four

VOL.

a ra-

1994). graphic

encephalitis

cases

by

brain

his-

tology and which was in domestic

by isolation of the rabies virus, typed as a variant similar to that dogs neighboring the park

(Gascoyne

et

1997

18)

Combining data, van

concluded

that

incriminated death” these

serological Heerden “disease

as

an

in KNP. populations

It

could

important

not

be

cause

of

remains possible are vulnerable to

a!., 1993; Kat et a!., 1995). data from SNP have shown diseases can cause substan-

diseases,

tial

and

virus, CDV or parvovirus anthracis, the bacterium has caused several deaths

(CPV). Bacillus causing anthrax, in KNP, SGR,

and in Luangwa, 1991; Creel et

(Turnbull et van Heerden

mortality,

extinction. conviction

This that

sensitive 1991, “a

p.

main

has wild

to

disease”

140),

and

role

butional et a!., known

can

in

led to the widespread dogs are “particularly (Fanshawe that

the

et

disease

numerical

in

SNP

population

other

wild

(Frame eraging

played

and

distri-

,

intense

many

unusual

1979;

riod (data from 1994). Competition and

populations.

density

in

km2

over

a 20

av-

yr pe-

and

that

could

harbor

eared 1993),

foxes, domestic 1994),

me galot (Alexander

Otocyon

dogs

jackals,

Canis

(Alexander

mesornelas

is’

in with virus bat-

and

misleading

to generalize

about

population Despite

the

role

it

of disease

dynamics. close monitoring,

in wild

serve yr

of 22 yr. or in the (SGR, (Reich,

Tanzania) 1981;

the

ever

dog

other

over Maddock

Game a period and

a

Reof 6 Mills,

CPV dogs,

are

exposed

but

a!., 1994). shown to may

(Mech

hinder

and

carcasses impossible

Goyal

of wild dog to collect, it

No data exist to establish is caused by CPV. wild

unvaccinated

to have nor been

antibodies has canine isolated

dog

what

pro-

has

been

to CDV distemper from

(but

this

see virus

species.

Nonetheless, population declines have been attributed to CDV on the basis of behavioral observations (Schaller, 1972; Malcolm 1979) or concurrent outbreaks in

disease-relat-

Selous

that wild

et been

declines,

Because are virtually

No

be

Kruger over

1989; Johnston CPV has not a decline

found results),

from

ed declines were not observed in National Park (KNP, South Africa) period

may

al., et

is plausible that some juvenile mortality is due to undetected CPV, among other factors. Pup mortality can be substantial for wild dogs, with as high as 70% annual mortality in KNP (van Heerden et a!.,

C.

(Roel-

conclusions

to rabies

evidence

in free-living populations

after

1995).

CroHaas

leo

Zambia 1995;

direct

population

portion

Roelke-

Parker et a!., 1996), spotted hyenas, cuta crocuta (Alexander et a!., 1995; et a!., 1996), and lions, Panthera ke-Parker et a!., 1996). Thus,

1993). pups

(Maas, and Ap-

1994,

no

In

screening

et al.,

recovery

and

aureus

et a!.,

is

exposed.

of exposure

a!.,

mortality some

cause

Fitzgibbon,

might have limited wild dog (Creel and Creel, 1996). Finally,

carnivores

causes although

evidence

Krumenaker, For wolves,

sources in Burrows et a!., from larger carnivores

(Fanshawe

1995). There

been

serological

1992), and it is reasonable to hypothesize that CPV is a factor in some pup deaths. CPV can cause substantial mortality in young wolves (Peterson and

low

1979),

no

(Fuller

several

very

transmit viral infections were common the SNP ecosystem. Common species known exposure to canine distemper (CDV) and/or rabies virus included

SNP

a!.,

The

was

Malcolm,

1 dog/200