Rebeca Castaneda
Biology 1615
Th 10:00am-12:50pm
Antibodies to Canine and Feline Viruses in Spotted Hyenas
Introduction
Spotted hyenas, also known by their scientific name Crocuta crocuta, are very liberal
predators in the Serengeti ecosystem. Being that spotted hyenas interact with other species, they
merge in ways that could boost disease transmission. These other species would include
domestic animals and wild carnivores. Spotted hyenas have a rare hierarchical social system that
could possibly affect their risk of gathering and transmitting viral diseases, which include the
flow of pathogens. Nonetheless, only somewhat little is known about which viruses are the ones
that affect spotted hyenas, and how they affect pathogen transmission in the Serengeti
ecosystem. Spotted hyenas have broad home domains that overlap habitats of endangered
cheetahs, jackals, lions, and endangered African wild dogs. The viruses that have been detected
in other Serengeti predators are: antibodies to canine distemper virus (CDV), feline
immunodeficiency virus (FIV), feline pan leukopenia virus/canine parvovirus (FPLV/CPV),
feline coronavirus/feline infectious peritonitis virus (FECV/FIPV), feline calicivirus (FCV), and
feline herpecvirus 1 (FHV1), indicating that these viruses are present in the ecosystem. If spotted
hyenas were exposed to feline and canine viruses, the differences in hierarchal space usage and
social interactions could impact how infectious the diseases are transmitted within the
ecosystem. To be aware of these viruses if very likely because spotted hyenas have a close
phylogenetic relationship. The reason for this study was to ordain whether or not spotted hyenas
had also been infected with these viruses and to figure out the risk factors for infection.
Materials and Methods
Between 1993 and 2001, blood samples were collected from spotted hyenas in the Talek
clan, which consisted of 119 hyenas. Blood samples were also collected from nine other groups
of spotted hyenas, which consisted of 121, in a combination of behavior and genetic studies in
the Serengeti ecosystem. All of the animals inhabited in the Maasai Mara National Reserve
(MMNR). The blood samples used in this study were collected from the jugular vein and they
were separated into cell components and serum. The serum samples collected were stocked in
liquid nitrogen, shipped in dry ice, and subsequently reserved at -80 degrees Celsius in the lab of
where the study took place. It was kept there until the serum was analyzed. All serologic
evaluations were done at the New York State Animal Health Diagnostic Laboratory. Serumneutralizing antibodies against CDV were measured by a tool called the Onderstepoort strain. If
the titers on the Onderstepoort appeared greater then 1:10, it meant that it was considered
positive for CDV. For the other viruses FECV/FIPV, FCV, and FHV1, sera were tested with a
micro plate serum neutralization technique, comparable to the CDV test that was done, along
with some adjustments.
The spotted hyenas were grouped by certain categories, most of which consisting of age
class: juvenile 5-4 months old (84 hyenas), adult 2-16.5 months old (153 hyenas), and unknown
age (3 hyenas), sex: female (130 hyenas) and male (110 hyenas), and social rank: high ranking
Talek clan female and their juvenile cubs (38 hyenas), medium- and low ranking Talek clan
female and their juvenile cubs (54 hyenas), adult low ranking Talek clan males (24 hyenas), and
unknown ranking of Talek clan members (3 hyenas).
Results
The results from the study done, showed that the antibody prevalence was much greater
in the adult hyenas for FIV and FECV/FIPV than any other ages of the hyenas. A female spotted
hyena of high social rank was indeed to be found as a risk factor for FIV, in contrast to hyenas
near human habitation that apparently appeared to be at lower risk to have CDV, FIV, and
FECV/FIPV antibodies. While FPLV/CPV antibodies where at risk for spotted hyenas near the
human habitation. The canine distemper disease and FECV/FIPV antibody prevalence varied
significantly over time, while FIV, FPLV/CPV, and FCV had a stable temporal pattern. These
results reveal that spotted hyenas could possibly play a role in the ecology of these viruses in the
Serengeti ecosystem.
Conclusion/Discussion
This study indicates that free-ranging spotted hyenas in the Maasai Mara National
Reserve (MMNR) become infected and are exposed to canine and feline viruses. It is suggested
that the results of these viruses should be further researched in order to get a much more
thorough answer. Unfortunately, this evidence of infection demonstrates that whether hyenas are
a reservoir for these viruses, or are exposed by another wildlife species that is not known. The
age issue might be an outcome of exposure during previous epidemics, or it could be because it
is more likely that the viruses will encounter overtime during the hyenas lifetime. From this
study, the results propose that domestic animals associated with the Maasai manyattas are not the
sole source for CDV, FIV, and FECV/FIPV.