Wildlife lecture notes

WILDLIFE MEDICINE
By: Abebe Abuhay (DVM, MVSc, Assisst prof.)
Email: abebeabuhayy@gmail.com
abuhayabebe@yahoo.com
1

General Objectives
 Students be able to understand and define wild life in
general.
 What and which Animals and Plants will be
categorized as wildlife?
 Knowing different National Parks of the country….
 To understand the general wildlife management
systems.
 To know the reproductive cycles and breeding
seasons.
 To understand the general health status and disease
conditions of wild animals (viral, bacterial...)
 The importance of wild animals in ecotourism and their
roles in the economic development of the country.
2

GENERAL TERMINOLOGY
3
 Wildlife: refers to exclusively to animals that are
not domesticated but inhabit their natural form of
environments.
 Such animals are prefer to live in their natural
habitats where they may co-inhabit with one
another and with other species and with abiotic
component of the ecosystem.
 The management of wildlife concerns on the
manipulation or skillful handling of wildlife
resources.

 Examples of wild animals include: lion, elephant,
python, gorilla, chimpanzee, monkey, duiker,
antelope, eagle, kob etc.
 Examples of plant form of wildlife include many
timber tree of the rainforest and savanna: iroko,
mahogany, obeche, opepe, iron wood, etc.
 Wild: This describes Animal or Plant species that
are not domesticated or cultivated but live or grow
in their natural environments.
 Game: This refers to wild animals, birds and fishes
that are hunted for food, sports and for their
commercial values. 4
Cont…

Definition of Wildlife
 Wildlife: refers to free ranging and captive wild
vertebrates, including amphibians, reptiles, birds,
and mammals (but excluding fish).
 This includes all introduced and indigenous
species, as well as domestic animals that have
become feral.
 The specialty of Wildlife Population Health has an
emphasis on ecosystem health and wildlife
population medicine, including disease
management and prevention, surveillance,
outbreak investigation and epidemiology. 5

 It is not clinically oriented but emphasizes on
ecosystem health and wildlife population medicine,
 Including:
 Disease management and prevention
 Health surveillance
 Outbreak investigation
 Epidemiology (with consideration of population
estimates, habitat use, landscape
 Structure and other ecological factors
 Assessment of causes of wildlife population
decreases including assessing impact of
 Human activities on wildlife populations
6
Cont…

 Wildlife: This refers to collection of undomesticated
animals and their environments,
 Vulnerable: Exposed stable population of a
species to certain factors that could decline its
recruitment.
 Threatened Species: This refers to plant and
animal species that are adversely affected by
human activity and natural hazards or by accidents
 In such extent that continued existence is not
favourably guaranteed, except corrective measures
are put in place to check them.
7
Cont…

• Threatened members are not endangered; except if
threatening condition continue unabated.
• Endangered Species: These are species whose
number have become so few that they could
become extinct in the future.
• Examples: African elephant, leopards and sea cow
or manatee.
• Extinct Species: These are species that have no
living representative anywhere on earth because
they had all died out due to several hazardous
conditions they could not adapt to.
• Examples: Asian elephants, dinosaurs, European
wales and Australian Dodo. 8
Cont…

 Endemic Species: This refers to certain animals or
plants that are found only in a particular locality or
country and never in any other part of the world.
 Reserve: Protected resource e.g. game, forest or
oil that is left unused till future time.
 Natural Resources: Materials or provisions from
nature in a given area or country e.g. oil, wildlife,
water, land etc. which may be renewable or un-
renewable.
9
Cont…

 Renewable Resource: These are natural
resources that are replenished by nature overtime
e.g. air, water, soil, wildlife and forests.
 Non-renewable resources: Are those natural
resources that cannot be replenished by nature or
man after use e.g. fossil fuels and minerals.
 Prevailing habitat (i.e. place where an organism
lives) is destroyed mostly due to human activities
and occasionally by natural hazards or accidents.
 Conservation: This is the preservation of natural
resources from waste, harm or loss by wise usage
in a way that gives man best advantages.
10
Cont…

 Zoological Garden/Zoo: Relatively small place
where living wild animals are kept for the public to
see and where they can be studied and breed.
 Sanctuary: An area where birds and wild animals
are protected and encouraged to breed.
 National Park: A large area of land within a
country whose natural beauty is preserved and set
aside for the protection and conservation of
wildlife and their habitats.
11
Cont…

 National park has been defined by the international
union for the conservation of nature and natural
resources as an area relatively large sized and
containing natural ecosystems of special interest,
 Which are not materially altered by human
exploitation, or occupation, protected and managed
by the highest competent authority of the country
and open to visitors under special condition for
inspiration, educational, cultural and recreational
purposes.
• Field Mark: The most outstanding feature of the
animal that catches the eye or other senses such as
voice, odour.
12
Cont…

• Habitat or Nitche: Specific area the animal lives in
a habitat describes its niche while the habitat as
earlier defined is the place where an organism
normally lives.
• Ex-situ protection: is the maintenance of wildlife
outside their natural habitats such as zoos,
botanical gardens, farms and plantations.
• In-situ protection: Protection and maintenance of
wildlife in National parks, natural reserves and
sanctuaries where they and their habitats are
protected as well.
13
Cont…

INTRODUCTION
 Wildlife species are those animals, both aquatic
and terrestrial, whose genetic and physical
characteristics have not been intentionally
selected over time by humans and
 They can be found living free in nature or under a
variety of management regimes such as captive
collection and extensive ranching system.
 Wildlife species live in diverse ecosystem from the
desert lowland (e.g. Dalol depression) to the
highest Afro alpine environment (e.g. Bale and
Semien mountains). 3/12/2020 14

 Ethiopia has several designated wildlife
conservation areas.
 Ethiopia is endowed with extensive and unique
environmental conditions.
 80% of the land over 3000 m.a.s.l found in Africa
occurs in Ethiopia; high diversity and endemicity is
associated with these highlands.
 These have resulted in the evolution of a plethora
of endemic animals and plant species especially
those confined to the Afroalpine ecosystem.
3/12/2020 15
Cont…

Cont…
 The future of several of these wildlife species is in
question due to continuing and insidious
pressure on the habitat and on the species
themselves.
WHY???
HOW???
16

Cont…
In Ethiopia:
 277 Species of mammals ------- 28 are endemic.
 862 Species of bird life of which ------- 16 are
endemic.
 201 of reptiles of which --------- 9 are endemic
 63 Species of amphibians of which --------- 24
are endemic.
 150 Species of fish of which -------- 4 are
endemic.
17

 Many of these spp. are confined to the Afroalpine
ecosystem. Why???
 36 of the 4,226 species of mammals found
worldwide were extinct during the last four
hundred years.
 Another 120 species are in imminent danger of
extinction. Among the most endangered wild
mammals in Ethiopia are: Ethiopian Wolf, Waliya
Ibex, mountain Nyala
18
Cont…

(a) Alceluphus buselaphus swaynei, (b)Tragelaphus boxtoni
(c) Equus assinus somalensis (d) Capra walie
(e) Panthera leo abyssincum, (f) Canis simensis, (g) Theropithecus
gelada, (h) Loxodonta africana, respectively
19

•
•
Conservation
 Conservation: Is the wise use of natural
resources, without wasting them.
 Preservation: (Saving natural resources, but with
no consumption of them), is another means of
protecting or saving a resource, such as outlawing
hunting of endangered species.
 Both preservation and conservation are necessary
to sustain resources for future generations.
20

Category of Conservation Areas
 National park:- A large area of public land chosen
by a government for its scenic, recreational,
scientific, or historical importance and usually
given special protection.
 Sanctuary:- A place or area of land where wildlife
is protected from predators and from being
destroyed or hunted by human beings.
21

Cont…
 Wildlife Reserve: Wildlife reserve is one of the
wildlife-protected areas designated for the
conservation of wild indigenous flora and fauna
where wild animals used the sites as a refuge
during food and water shortage seasons.
 Control hunting area: is one of the Wildlife
Protected areas where controlled hunting of
huntable wild animals under permit allowed.
22

 In Ethiopia, the protected areas cover roughly
16.4% of the country’s land area.
 Proportion of land under wildlife conservation
6.8%.
 These areas face many challenges due to
growing populations, and recurring drought.
24
Cont…

 Ethiopia has 20 National parks, 18 control hunting
areas, 7 open hunting areas, 11 wildlife reserves and 3
sanctuaries.
 Two of Ethiopia's wildlife conservation sites (among
the 18) the Simien and Bale Mountains National
Parks, where endemic species like walia Ibex, Red
fox, chilada baboon etc.
26
Cont…

Cont…
 Walia Ibex (Capra walie),
 Gelada baboon (Theropithecus gelada),
 Menelik bushbuck (Tragelaphus scriptus
menelikii),
 Mountain Nyala (Tragelaphus buxtoni),
 Ethiopian wolf (Canis simensis),
 Giant mole-rat (Tachyoryctes macrocephalus)
 Most endemic birds are found.
27

 The rest of Ethiopia's wildlife species are either on
the borders or down the length of the Rift Valley:
Yangudi‐Rasa, Awash, Abijata-Shala Lakes,
Nechsar, Omo, and Mago National parks and
Senkele Swayne's Hartebeest Sanctuary and etc.
 In the lowlands are found Babile and Yabello
sanctuaries and Gambella National Park.
 The wild ass lives in the remote desert confined by
the Danakil (Afar) Depression and is conserved in
the Yangudi‐Rasa National Park (Mile sardo
reserve area).
28
Cont…

 In Gambella, one can finds wildlife from neighboring
Sudan, including the white‐eared kob, Omo and
Mago boast an abundance of the usual African
savannah wildlife: the Giraffe, common eland,
Buffalo, Elephant, Ostrich, Greater and Lesser kudu,
and Burchell's zebra.
29
Cont…

Cont…
 Further north, in Nechsar, are found Grant's
gazelle and Guenther's dik‐dik, in addition to
Burchell's zebra and Greater kudu.
 The Awash part of the Rift Valley is inhabited by
Beisaoryx, Greater and Lesser kudu,
Waterbuck, Soemmering's gazelle and
Hamdryas baboon.
 The Afroalpine range is threatened by loss of
habitat to high altitude subsistence agriculture
and livestock over grazing.
30

Cont…
 An example of rare and endangered mammal is
the Ethiopian wolf, one of endemic species to the
Afroalpine habitat of Ethiopia.
 Currently there are less than ~500 adult individuals
surviving distributed in 7 small packs.
 It is currently registered as the most critically
endangered canid in the world.
31

Challenges to wild animal existence
 Some of the endemic species are frequently affected
with disease problems.
 Disease threats often arise through contact of wild
animals with domestic livestock.
 Even though more than 70% of domestic dogs in
core wolf areas within the BMNP have been
vaccinated against rabies;
35

Cont…
 In 2003 rabies caused the loss of 2/3 of Ethiopian
wolf and in 2008 the death of 15 Ethiopian wolf.
 Anthrax outbreak that occurred in Mago and Omo
National park in 1999 and 2009 caused the death of a
number of wild animals as well as human being.
36

Cont…
 At present, 16,119 species of animals and plants are
listed by the World Conservation Union as being
threatened with extinction (IUCN 2006).
 Extinction of species is part of the natural process of
evolution and is irreversible, but is now occurring at a
much higher rate than speciation because of human
activities, such as habitat destruction, over-hunting, or
competition with introduced herbivores.
37

Cont…
 Causes:
 Destruction and/or fragmentation of habitats by urban
sprawl,
 Intentional/unintentional introduction of alien species
into ecosystems,
 Hunting and other exploitation pressures such as
intoxications by pollutants,
 diseases,
 Artificial hybridization,
 global warming, especially for mountain species, and
diminishing resources
38

Cont…
 Survivability in general and reproduction in
particular are affected habitat loss, human
interference, loss of genetic diversity, hybridization,
health problems.
39

Cont…
 Habitat loss (fragmentation and isolation,
deterioration due to overgrazing, encroachment of
protected areas etc):
 The impact of environmental variables upon the
social organization of mammalian species has been
widely discussed in the many literatures.
40

Cont…
 Ecological factors: Both the spatial and temporal
distribution of resources (food, water, shelter, and/or
predators) and mates, which are dependent climate
and topography upon environmental variables, affect
the mating strategy of a species by imposing limits on
sexual selection.
41

Cont…
E.g. African antelope: dispersion and availability of
food plants and anti-predator behavior directly affect
the typical group size, and dispersion of females.
 Female location in turn affects male reproductive
strategy and this interaction determines the social
organization of each antelope species.
42

Cont…
 In the BMNP rodent biomass varies several-fold
between the different habitats, and the abundance of
the rodent prey is closely correlated with that of
wolves.
 The loss of Afroalpine habitats is directly linked to
the expansion of agriculture into the Afroalpine zone.
43

Cont…
 Virtually all area below 3700m have been
converted to barley fields.
 These put pressure on both social organization
and mating strategies limiting survivability
outside of this habitat
44

Cont…
 Small population/Inbreeding:
 In small population the chance for inbreeding is high
thereby making the animals incompetent to fit the
harsh environment.
 In a species with a strict specialization to a given
habitat and with no suitable habitat to act as corridors
for dispersals (e.g. Wolves to Afroalpine highlands)
some genetic differentiation is expected, even between
nearby populations. 45

Cont…
 In wolves and other wild ungulates in Ethiopia, there
is no evidence of inbreeding depression or reduced
fitness at present but the extremely small breeding
sizes raises concerns.
46

Cont…
 Hybridization:
 Is most common in cannids because of possibilities of
cross breeding. Example: in Bale Ethiopian wolf
hybridizes with domestic dogs (4 hybrids were known).
 Male wild yaks could also be seen mingling and mating
with the domestic female yaks around Asia
47

Cont…
 Hybrids threaten the genetic integrity.
 Following hybridization, a population may be affected
by out-breeding depression or reduction in fitness,
although to date this does not seem to have taken place
in wolves.
48

Cont…
 A species is endangered when its survival in the wild
is unlikely if causal factors of extinction continue to
operate.
 Threatened populations may be extinct in the wild if
composed of less than 50 mature individuals raised in
captivity.
 For domestic breeds, populations are considered as
endangered when less than 1000 females or less than
20 fertile males remain 49

Cont…
 Factors that reduce the population size of a small
breeding group of animals are variations in litter
sizes, a skewed sex ratio in offspring, preferential
mating, fluctuations in birth and death rates, and an
overlap of generations
50

Cont…
 The lack of genetic diversity leads to a bad adaptive
capacity and risks of transmission of inherited diseases,
congenital defects and fertility problems.
 The reproduction process may be impaired in captivity
by small space, health and husbandry problems, a non
adapted diet, modified sexual behavior or infertility.
 Therefore, field conservation and captive breeding need
the help of assisted reproductive techniques (ART)
including gamete cryopreservation, AI, ET. 51

2. Reproduction in wild animals
 Different reproductive strategies are used by
eutherian (placental) mammals for the control of
ovulation and pregnancy
52

Cont…
 Spontaneous ovulation (ruminants),
 Ovulation induced by coitus (felids),
 Luteal life span not prolonged by mating (canids),
 Embryonic diapause (dormancy) in (mustelids, roe
deer, bears, seals),
 Extra corpora lutea during pregnancy (equids, deer).
53

Cont…
 Marsupials however, differ from eutherian species in
several aspects of their reproduction.
 Knowledge about reproduction is critical for
predicting the viability of wildlife populations in
nature and for managing breeding programs in
captivity.
54

Cont…
 Monogamy (single bond) Vs polygamy (multiple
bond)
 Reproductive seasonality
 Social organization and dominance
 Grouping pattern
 Biparental (both parents) and Alloparental (other than
parents) care giver of infant
55

Cont…
 The evolution of the two types of social organization
(harem bands vs. solitary individuals) has been
attributed to habitat differences.
 Harem formation and maintenance behavior
(herding and chasing (hunting) to maintain a cohesive
group) could be affected by habitat.
56

57
Search for Partner; and Location of Partner

Cont…
 Among the factors that influence reproductive
success in wild animals is sex-biased maternal
investment.
 This involves differential allocation of resources to
production and rearing of sons or daughters as a
function of their anticipated reproductive output.
58

Cont…
 Maternal investment is regulated by the reproductive
value of offspring at the end of the period of infant
dependency.
 Some reports from studies link investment patterns
with fitness consequences, which is crucial for
evaluating adaptive significance of sex ratio
modification.
59

Reproductive cycle and seasonality
 Reproductive cycle in most wild mammals constitute
the four basic phases: proestrus, estrus, metestrus and
dioestrus.
 Proestrus is a crucial period of preparation and
staging, both physiologically and behaviorally.
 Social interactions increases in comparison to
behavior commonly observed at other times of the
year.
60

Cont…
 In canids (e.g coyote), intra-pair physical contact such
as play-wrestling, allogrooming (taking care),
hippushes, body bumps, and sleeping together will be
frequently seen.
61

Reproduction in Ethiopian wolves:
 Mature in about 2 years and become adult
 Life expectancy ranges between 8 and 9 years
 Mating occur between August and November each
year and it usually occurs outside the pack with males
of all rank or within the pack only between the
dominant male and female
62

Cont…
Dominant female in each pack gives birth to a litter of
2-6 pups
Whelping (giving birth) take place once a year b/n
October and January
Subordinate females may assist the dominant female
in suckling and feeding the pups (alloparenting)
63

Reproductive management
 Application of ultrasound imaging in reproductive
management.
 induction of the sexual cycle and ovulation, super-
ovulation regimes, contraception programs, semen
collection and testicular sperm extraction techniques,
and ovarian transplantation procedures, as well as the
application of AI, embryo collection and transfer.
64

Cont…
 Cryobiology: semen, tissues etc banking
 Application of biotechnology
 Semen Banking (Cryopreservation), one of the first
steps in order to begin a study on AI
65

Cont…
 The whole aim of semen banking is for later use in
reproductive management (in natural or captive units),
with possible re-introduction programs and for different
researches.
 Through this, both the genetic diversity and
reproductive viability can be assured.
66

Cont…
 The challenges of semen banking would be the limited
reproductive window during the year in seasonal
breeders and the labor/cost intensive need for setting a
filed application unit.
 Basic equipment required, field anesthetic setup,
semen handling, evaluation and storage materials.
67

3. Conservation Strategies
 Among the different techniques in the conservation
strategies are the development and use of molecular
markers such as microsatellites, mini satellites,
mitochondrial control region, and cytochrome to
assess the genetic variation in various wild animals
such as African wild dog, different kinds of antelops,
the lion, tiger, leopard and deer.
68

Captive breeding
 Wildlife management measures used by species
recovery programs include captive breeding, (a
combination of ex situ and in situ efforts).
 Ex situ efforts can be defined as occurring outside
the species natural range, whereas in situ
conservation occurs within the species natural
range.
69

Cont…
 Translocation of surplus animals between
populations may be used to re- establish the species
after a local extinction or to supplement small
populations; involves movement of wild-born
individuals or populations from one part of the range
to another.
70

Cont…
 A re-introduction is an attempt to re-establish a
species in an area which was once part of its
historical range, but from which it has
disappeared. (e.g. Release of animals from
captivity into the wild)
 A translocation to an area from which the species has
been extirpated is a reintroduction.
71

Cont…
 Restocking involves the release of either captive-
born or wild-born animals into an already occupied
habitat, to build up population numbers and/or
increasing genetic variations.
72

Cont…
 Ex-situ captive breeding programs have now lost
much of their appeal. Additional criteria to be
considered have been suggested by the Born Free
Foundation:
 loss of natural immunity;
 psychological effects of captivity;
 unnatural selection process;
 potential weakening of cultural importance.
73

Cont…
 In summary, a distinction should be drawn between
captive breeding in the ex-situ zoo based model and
specialized in-situ captive breeding programmes
which may significantly reverse many of the effects.
 Captive populations of species such as the Asian and
African elephant, white, Sumatran and Indian
rhinoceros and most aquatic species are not self-
sustaining.
74

Cont…
 Meta population management
 A meta population is a population of populations. It
refers to the range of a species composed of
geographically isolated patches, interconnected
through patterns of gene flow, extinction and re-
colonization.
75

Cont…
 Translocation as a means of restocking small
populations and boosting genetic variability remains
an option more likely to be of use for meta population
management of some species (e.g. Ethiopian wolf).
 This method is less expensive than captive breeding
and reintroduction, but will require a high degree of
planning and implementation.
76

Cont…
 Awareness creation and education as a tool for
conservation
 The wolf and other endemic wild species are also
used as the country's symbols (flagship) by the
government, with the Ethiopian wolf illustrating two
post stamp series and numerous posters promoting
Ethiopia’s wildlife.
77

Cont…
 Establishment of clubs or other social organizations
 Public holidays to promote/confer conservation
plans/ideas to the public.
78

Cont…
 The classic tasks of veterinary medicine in established
breeding programs of non-domestic species are as
follows:
 General health monitoring such as disease prevention
and treatment, diet, etc.
 Determination of basic reproductive parameters such
as onset of puberty, cycling pattern, seasonality
79

Cont…
 Assessment of the reproductive soundness
 Treatment of reproductive disorders
 Pregnancy detection and monitoring
 Birth and perinatal management
80

Cont…
 The following problems are lists affecting captive
breeding as a species recovery programs:
 difficulty in establishing self-sufficient captive
populations;
 poor success in reintroductions;
 high costs and maintaining administrative continuity.
 domestication or preemption of other recovery
techniques
 disease outbreaks; 81

Effect of human population growth on agricultural
practices
 By July 2005, the world had an estimated 6.5 billion
human inhabitants.
 By 2050, it is estimated to increase by 2.6 billion.
 In the next 50 years, the challenge will be not only
feeding an expanding human population, but also doing
so in a world of declining resources, including water and
arable land.
82

Cont…
Large-scale agriculture is susceptible to outbreaks
of disease. The 1983-1984 poultry epidemic of
pathogenic avian influenza in U.S. caused
markets to drop by $349 million during the 6-
month period of the disease.
83

Cont…
The 2001 foot-and-mouth disease outbreak in
England and Europe was estimated to have cost
markets almost $30 billion.
Developing-country livestock practices are highly
different.
Often, livestock share space with people in and
around the home.
84

Cont…
 The rearing of ducks in Asia is an efficient system in
which domestic ducks and geese are given access to
recently harvested rice paddies. This allows wild
waterfowl and domestic species to mix, thereby creating
an environment conducive to the cross-species spread
of pathogens
85

Hunting, pets, and globalized trade in wildlife
 The local hunting of wildlife or bush meat is an
ancient practice that forms the fabric of community
culture at the rural wildlife interface
 Although these fundamental practices have always
posed a cross species disease risk to the local
community, they have been mitigated through cultural
practices.
86

Cont…
 Ecologic changes, as created by increased human
population density, forest fragmentation via road
building, and rural development, alter the
relationships of pathogens to hosts
 These changes, along with increased human
movement and the globalized trade in animals for
food and pets, facilitate rapid movement to distant
sites and greater human-pathogen contact.
87

Cont…
 The estimate for trade and local and regional
consumption of bush-meat in central Africa alone is
over 1 billion kg per year and estimates for
consumption in the Amazon basin range from 67 to
164 million kg annually.
88

Cont…
 In central Africa the majority of wild animals
harvested are small mammals (including small
antelope and primates), birds, and reptiles
89

Cont…
 Monkey pox: Monkey pox is a rare, viral, smallpox-like
disease from central and western Africa that was first
diagnosed in laboratory primates in 1958.
 The first human cases were reported in 1970 in Africa.
 An outbreak in the DRC in 1997 was reported to have
infected 88 people, with three deaths, all in children less
than 3 years of age
90

Cont…
 Severe Acute Respiratory Syndrome (SARS): SARS
was first recognized as a newly emerging human disease
in 2002 in Guangdong Province, China. Symptoms
included high fever, respiratory illness progressing to
pneumonia, in some cases diarrhea, and death.
 The disease first spread to Hong Kong and thereafter
across five continents and 25 countries via infected
people
91

Cont…
 In April 2003 a new corona virus was discovered to be
the causative agent.
 In July 2003 the WHO listed the number of probable
SARS cases in humans at 8437, with 813 deaths.
 Evidence of viral infection, often without signs, was
also detected in palm civets (Paguma) farmed in the
region.
92

Cont…
 The initial suggestion of a link between civets and
SARS led to a government directive to cull more than
10,000 masked palm civets in the province despite the
ambiguity of the disease link.
93

Cont…
 Later, viral evidence was also detected in raccoon
dogs (Nyctereutes) and ferret badgers (Melogale) as
well as domestic cats.
 It now appears that the palm civet served as an
artificial market-induced host or amplification host,
along with a number of other possible species
94

Cont…
 Ebola: Ebola hemorrhagic fever (Ebola) is named
after the river in the DRC, where it was first
identified. Chimpanzees and humans share 98% of
their DNA, and gorillas and humans share 97%.
 Therefore, bush-meat in the form of nonhuman
primates poses a particularly high risk of cross-
species infection into humans.
95

Cont…
 The first three known outbreaks of Ebola occurred
between 1976 and 1979 in DRC and Sudan.
 Between 2000 and 2004, five human Ebola outbreaks
were documented in western central Africa.
 Epidemiologic studies indicated that these outbreaks
resulted from multiple introductions of virus from
infected animal sources
96

Cont…
 The index cases were mainly hunters, and all were
infected while handling dead animals, including gorilla
(Gorilla), chimpanzee (Pan troglodytes), and duiker
(Cephalophus).
 Thereafter, outbreaks spread quickly between people,
especially through caregivers, and were documented to
almost wipe out entire villages.
97

Cont…
 In people the symptoms are referable to multiple
organ effects with internal and external
hemorrhaging.
 The Zaire subtype of Ebola virus has been known to
have a case fatality rate of almost 90%, and the Sudan
subtype has a rate of approximately 50%
98

4. Behavioral training for medical procedures
 Training animals to cooperate voluntarily in
veterinary procedures (operant conditioning) is an
important cornerstone of a zoo’s animal care program.
 Preventive medicine tasks, measurement of baseline
physiologic parameters, physical examinations,
diagnostic procedures, therapy, and reproductive
evaluations may be done more efficiently with less
stress to the animals and without the inherent risks of
anesthesia.
99

Cont…
 Animal introductions may occur with less stress and
fewer injuries.
 The hours of training also provide for the animal
positive psychologic stimulation and behavioral
enrichment.
100

Husbandry-related behaviors
 Operant conditioning for efficient and timely movement
of animals between holding areas and exhibit spaces is
important for cleaning and sanitation, distribution of
enrichment items such as food treats, and isolation of
ill or injured animals.
 The ability to isolate an animal from the group is
required for visual and physical examination, weight
monitoring, food restriction, immobilization, and
administration of medications.
101

Behavioral clues for detection of illness
 Models in camelids and elephants
 As often noted, wild animals may be in an advanced
state of disease before clinical signs are evident.
 Wild animals are not immune to pain or discomfort, but
they do attempt to mask overt signs that would reveal
their physical condition.
 Several disciplines use behavior as a basis for study,
including psychology, ethology, sociobiology, and
animal behavior.
102

Cont…
 Zoo and wildlife veterinarians may deal with
hundreds of species of animals, each with their own
behavioral characteristics.
103

Cont…
There are basic behavioral patterns that are shared by
most mammals. Acquiring observational skills is
important for the following reasons:
1. To be able to detect incipient illness.
2. To detect stress in the lives of wild animals.
3. To assist in the welfare and well-being of wild
animals.
4. To be able to advise wisely in the construction of new
enclosures.
5. To help train keepers to identify altered behavior
104

Cont…
 A veterinarian must first understand normal behavior to
be able to detect abnormal behavior.
 Behaviors to be included are methods of offense and
defense; communication (vocalization, body language,
facial expression), social behavior, interaction with
other animals, hierarchic status, locomotion, food
intake, defecation/ urination, scent marking,
recumbency, getting up and down, reproductive
behavior (courting, copulation), and stress
105

Cont…
 Elephant: No one except a trained, qualified elephant
handler should approach, come in contact with, or
command an elephant. Elephants generally will not
listen to or follow the commands of a stranger.
 Elephants use several methods for offense and
defense, including biting, slapping with the trunk, and
grasping with the trunk and pulling, pushing, or
throwing.
107

Cont…
 As an offensive or defensive weapon, the trunk is
without equal in the animal world.
 Elephants may purposely step on a person’s foot.
 Extreme aggression may be exhibited by the elephant
kneeling and head pressing on what they perceive as a
threat, an inconvenience, or a toy
108

Cont…
Behaviors in elephant to be aware of include the
following:
 Alert: The elephant stands facing a person with the
head raised, ears spread, tail raised, and a “sniff” trunk
 Wariness: The elephant is in heightened alertness, and
with eyes wide open, glances at other elephants.
 Sniff: The trunk is extended down and forward in a J
shape, with the tip out to sniff another elephant or a
person. 109

Cont…
 Mock charge: The elephant faces with ears extended,
head held high, trunk extended with trumpeting
 Real charge: The trunk is tucked under the head, and the
head is up and attempts to contact the target.; usually
there is no trumpeting.
 Slap: An elephant strikes another elephant with the
trunk.
 Kick: An elephant may strike forward with a forelimb or
toward the side or rearward with a hind limb. 110

Behavioral Changes Associated with Illness
The general statements about abnormal behavior
in camelids are also applicable to elephants
 Listlessness, decreased movement, and
depression, Inappetence is common.
111

Cont…
 Deviations from normal behavior;
 Slowed ear and tail movement;
Relaxed trunk and head;
Abdominal pain may be evidenced by peculiar
body positions, kicking at the abdomen, and
straining during defecation or urination;
A change in the gait may indicate weakness, a
central nervous system disorder, or lameness
112

Infrared thermography in zoo and wild animals
Infrared (IR) thermography is a noninvasive diagnostic
screening tool that does not require handling of an animal.
Physiologic or pathologic processes involving changes in
surface temperature may be evaluated using this technique.
This modern method provides real-time, instantaneous
visual images with measurements of surface temperatures
over a greater distance.
113

Cont…
 IRT has been used for skin temperature measurement
in medicine and for the early detection of diseases.
 Infrared thermography makes use of the physical
characteristic of bodies or materials to emit
electromagnetic waves, and with the aid of a special
detector, these rays are visible.
 Therefore, surface temperatures are measured over a
greater distance.
114

Cont…
The advantages of IR thermography over other imaging
techniques (e.g., ultrasonography, radiography, MRI) are:
1. Is completely noninvasive because no contact with the
animal is necessary, and therefore no animal training,
immobilization, or sedation is required.
2. Offers an ideal, instantaneous first screening method to
help the veterinarian in decision making, monitoring, and
determining whether other measures need to be taken.
115

Cont…
3. Yields real-time visual imaging in gray or false color coding.
4. Provides surface temperature imaging of a whole animal, or
parts of the animal, as well as easy comparison with herd
mates at the same time.
5. Permits examination of motion and direction (e.g.,
inflammation, reproductive evaluation).
6. Allows easy monitoring of a condition over time (e.g.,
lameness, inflammation, pregnancy).
116

Cont…
7. Facilitates documentation and preservation of
primary data.
8. Is portable and uses battery packs and thus is
conducive to zoo and wildlife field conditions.
117

Cont…
 Vets must be familiar with the thermoregulatory
patterns of different species: color patterns; hair
length; thickness of the dermis; size of ears, horns, or
antlers; location of potential thermal windows (areas
of increased heat emission) on the body itself; and the
anatomy of the legs.
118

Cont…
 Indicators of altered thermoregulation can be
physiologic or pathologic, as follows:
1. Exposure to strong sun
2. High ambient temperatures with simultaneous high
humidity and no water access
3. Physical activity or Stress (psychologic)
5. Pregnancy
6. Abrasions or Inflammation
119

Remote biopsy techniques
 The technique allows for the collection of biologic
materials without the need for, and the risks
associated with, the capture and handling of animals.
 Biopsy darts have been used in a wide range of
vertebrate species, including carnivores, primates,
ungulates, and birds.
120

Cont…
 The most common delivery mechanism for the biopsy
instrument uses a dart projector (e.g., pistol, rifle), a
crossbow, or a mounting on the end of an extension
pole.
121

5. Categories of diseases of wild animals
 Afro-endemic disease that are clinically “silent” in
their traditional host
 Multi-species disease that are inherently pathogenic in
most of their host.
 Foreign animal (alien) disease
 Emerging or re-emerging disease/zoonoses
 Disease associated with environmental health
122

Cont…
 Example of afro-endemic disease and their natural
host
 Buffalo : FMD, Theleriosis
 Wildebeast : MCF
 Wild suids : ASF
 Zebra: AHS
 Buffalo, Wilde suids and Elephants : Nagana
 Bushbuck: Bovine petichial fever
123

Cont…
 Multi-Species Diseases???
 These disease are not only confined to the African
continent.
 They are frequently zoonotic.
 They are great concern to the international community
and the OIE and may affect trade in animal and their
products. Example:- Anthrax, Rabies etc.
Alien/exotic or foreign animal disease Are great
concern to agriculturalists and conservationists alike
124

Cont…
 Not indigenous and their impact on animal health are
unpredictable.
 May have potential to affect animal species at the
population level
 Most of them are listed by OIE; Example:- RP, BTB
Environmental health issue
 Generally related to ecological disturbances and
environmental pollution 125

Cont…
 Example:
 Cyanobacterial blooms
 Floppy Trunk disease in elephant
126

Cont…
International Emerging Zoonoses
 Appears to be related to intensification of the human
/wildlife interface
 Increased utilization of wildlife product
 Human encroachment in to wildlife refugees
 Anthropogenic disturbance of habitat
 Example: HIV, H5N1 avian and H1N1 influenza pandemic,
SARS, RVF
127

Cont…
 Over 230 viruses in six genera are classified in the
family Picornaviridae, making it one of the largest
virus families; each genus contains viruses causing
disease in domestic and wild animals.
128

Foot and Mouth Disease (FMD)
 FMD is an acute highly contagious viral disease
affecting all cloven footed animals characterized by
fever and the formation of vesicles on epithelial
surfaces.
 Foot-and-mouth disease (FMD) is a List A disease of
major importance internationally.
131

Cont…
 Isolates of foot-and-mouth disease virus (FMDV)
are grouped in seven serotypes, recognized as
separate species, with differing geographical
distributions.
 Elephant and Hippopotamus are reservoir of
infection for SAT types
132

Reoviridae
 The family reoviridae is one of the most complex in
all virology, comprising nine genera that contain virus
of the mammal, birds, reptiles, amphibians, fish,
invertebrate, and plants.
Members of the genera includes
 Orthoreovirus
 Rotavirus
 Orbivirus. 133

Cont…
 Disease caused by member of the family reoviridae
Rhabdoviridae.
 The family comprises several important animal pathogen
including rabies virus, vesicular stomatitis virus,
bovine ephemeral fever virus and several rhabdo
viruses of fish.
 Rabies is a vector born viral infection which affects the
central nervous system of most mammals including man,
and in nearly all instance the infection end in death. 134

Cont…
 Pathogenesis
 Emerging diseases at the interface of people,
domestic animals, and wildlife.
 Increasingly, diseases are moving among people,
domestic animals, and wildlife, creating concerns
about food safety, public health, and wildlife
conservations.
135

Cont…
 Some of these diseases have existed for millennia,
whereas others are emerging or reemerging, gaining
the ability to jump between species and overloading
traditional methods of disease surveillance and
prevention.
136

Cont…
 Out of 1407 human pathogens, 58% are zoonotic; 177
are emerging or re-emerging, and zoonotic pathogens
are twice as likely to be in this category as non-zoonotic
pathogens.
 Outbreaks of BSE, FMD, avian influenza, RP and other
diseases have prompted governments to impose trade
embargoes and to mandate animal culling with
increasing frequency
137

Transmissible spongiform encephalopathies
 The transmissible spongiform encephalopathies include
chronic wasting disease of cervids, scrapie of sheep,
bovine spongiform encephalopathy (BSE) of cattle, and
Creutzfeldt-Jakob disease (CJD) of people.
 They are caused by pathogenic prions, which are
transmissible particles devoid of a nucleic acid genome
and composed of a modified iso form of normal prion
protein.
138

Cont…
 These prion proteins are extremely resistant to
inactivation by ultraviolet light, ionizing radiation,
steam sterilization, and almost all forms of traditional
disinfection.
139

Cont…
 It was likely through the ingestion of prion infected
meat from cattle that a new emerging disease of
people was discovered in 1996, variant Creutzfeldt-
Jakob disease (vCJD)
 As confirmed, 13 species of zoo animals, including
bovidae and felidae, have died as a result of infection
with the BSE agent.
140

Avian Influenza
 Avian influenza is an infectious disease of birds
caused by type A strains of the influenza virus.
 Wild birds, predominantly ducks, geese, and
shorebirds, are the reservoir species for the low
pathogenic strains of avian influenza A virus (LPAI)
in nature. it does not usually cause illness.
141

Cont…
 The virus is subtyped on the basis of the antigenic
properties of hemagglutinin (HA, or H) and
neuraminidase (NA, or N) glycoproteins; 16 HA and
9 NA subtypes have been demonstrated.
 Viruses containing subtypes H5 and H7 have been
observed to become highly pathogenic avian
influenza (HPAI) in poultry
142

Cont…
 The H5N1 influenza A viruses have been detected in
birds, pigs, cats, leopards, tigers and people in Asia.
 Live-bird markets that sell a wide variety of domestic
and wild birds to the public provide the perfect
conditions for genetic mixing and spread of flu viruses.
143

Cont…
 Traditional poultry livestock practices that bring
people into close contact with domestic fowl and
promote the mixing of wild and domestic waterfowl
also provide opportunities for domestic wildlife viral
exchange and spread into humans
144

Cont…
 Such an occurrence may have been the cause of the
avian flu (H5N1) outbreak in Hong Kong in 1997 and
2003-2004 in Asia.
 Once established in poultry in Asia, a combination of
intensive production, high-volume poultry movement,
and poor sanitation allowed the disease to spread.
145

Cont…
 Most countries have banned vaccination of poultry
because of interference with eradication policies and
international trade agreements, but they will allow
regulated vaccination in emergencies.
146

Cont…
 Eradication measures during an outbreak in domestic
poultry include (long-term) confinement, stamping out
of all poultry on the infected farm, preemptive culling
of animals on neighboring farms, and emergency
vaccinations (European Union [EU] Directive
92/40/EEC).
 The threat posed by avian influenza goes beyond the
food supply to becoming a lethal virus that is easily
spread between people, a global pandemic.
147

Cont…
 As of December 2005 the WHO confirmed 142
human cases, with 74 resulting in death.
 The fear is that the H5N1 viruses will gain the ability
to spread efficiently among people, causing a global
pandemic
148

Clinical signs
 LPAI usually produce no clinical signs wild birds. In
poultry, LPAI is characterized by mild to severe
respiratory signs, excessive lacrimation, decreased
egg production, and generalized malaise.
 HPAI may vary depending on species, age, strain of
virus, and environmental factors.
149

Cont…
 Infections of poultry by HPAI viruses are
characterized by a drop in egg production,
inappetence, depression, respiratory signs, sinusitis,
watery diarrhea, excessive lacrimation, edema of
comb and wattles with cyanosis and hemorrhages,
neurologic signs, and high mortality.
150

Cont…
 In mammals it is predominantly an URT infection
with some lung involvement.
 Signs include sneezing, nasal discharge, malaise, and
pyrexia.
 HPAI H5N1 in wild felids have additionally shown
RD, protrusion of the third eyelid, conjunctivitis,
neurologic signs, and death
151

Cont…
 Postmortem Lesions
 Gross lesions are variable, depending on host species,
pathogenicity of the virus, and presence of secondary
pathogens.
 Lesions caused by LPAI in poultry are mostly found in
the respiratory tract (sinuses) and coelomic cavity (egg-
yolk peritonitis), Lesions caused by HPAI are more
diverse.
 If death is peracute, no gross lesions may be observed.
152

Cont…
 In poultry, s/c edema of the head, neck, and feet
accompanied by hemorrhages and cyanosis (wattles and
combs).
 Hemorrhages of visceral organs (epicardium, pectoral
muscles, and the mucosa of the proventriculus and
ventriculus).
 Necrotic foci in pancreas, spleen, and heart. Interstitial
pneumonia with edematic and congested or hemorrhagic
lungs
153

Control
 Hygienic practices are the first line of defense during
epidemics.
 AIV remains viable for long periods in feces (32 days)
and water (4 days at 22° C, more than 30 days at 0° C).
 Simple cleaning with water without a detergent may
result in spreading of virus through footwear, clothing,
cages, equipment, and other fomites.
 It is essential to thoroughly disinfect items that have
been in contact with bird feces or other secretions. 154

Cont…
AIV is easier to inactivate than many viruses.
Orthomyxoviridae contain an outer lipid layer
that enables the virus to enter animal cells.
This layer is very sensitive to detergents, and
therefore soap and detergents are effective for
disinfecting most items.
155

Arthropod Vector-Borne Diseases
Vector organisms, such as mosquitoes and ticks,
transport pathogens from an infected individual
or its wastes to susceptible individuals, their food,
or immediate surroundings
 Major arthropod vector–borne zoonotic
pathogens includes both parasitic and viral
diseases.
156

Cont…
 Parasitic organisms spread by vectors include malaria
(Plasmodium), Chagas’ disease (Trypanosoma cruzi),
Lyme disease (Borrelia burgdorferi), and
leishmaniasis (Leishmania).
157

Cont…
 Vector spread arboviruses include those in family
Flaviviridae (encephalitis, dengue fever, yellow fever,
West Nile virus), Bunyaviridae and Togaviridae
(eastern, western, and Venezuelan equine
encephalitis)
158

Tuberculosis in zoo animals
 TB is a cause of significant morbidity and mortality in
both domestic and wild animals worldwide.
“tuberculosis” refers to infection with specific
organisms: M. tuberculosis complex.
 The TB complex includes M. tuberculosis, M. bovis, M.
africanum, M. microti, and M. pinnipedii.
 M. tuberculosis is the major cause of TB in humans and
elephants, whereas M. bovisis the major cause of TB in
domestic and wild mammals.
159

Cont…
 No antemortem test is 100% reliable for detecting TB
in zoo animals.
 The approach to routine screening and clinical
examination of suspected cases requires application
of multiple testing modalities).
160

Cont…
Tuberculosis in zoo animals: clinical findings
 Tuberculosis should be on the differential list for any
mammal that exhibits signs of chronic weight
loss/emaciation, weakness, dyspnea, cough, and enlarged
LN.
 Unfortunately, many infected animals are asymptomatic
until disease is advanced.
 Therefore, a proactive quarantine and routine screening
program should be developed for each zoo housing
susceptible species.
 What measures should be taken to prevent
introduction TB to zoo through addition of new
animal? 161

Cont…
 OIE recommends that all imported primates be tested at
least 2-3 times at 2-4-week intervals during quarantine
(OIE Terrestrial Animal Health Code, 2005).
 Primates require 1-10,000 more tuberculin than humans
to elicit a delayed hypersensitivity response.
 The site for injection is the upper eyelid, examined at
24, 48, and 72 hrs for degree of swelling and erythema.
Other injection sites include arm, thorax, or abdomen.
162

Cont…
 Occupational exposure to zoonotic simian
retroviruses: health and safety implications for
persons working with nonhuman primates.
 Simian viruses present risks to both captive NHP
populations and persons exposed to NHPs.
 A growing body of ongoing research has documented
retroviral disease risks to captive and wild
163

Cont…
 NHP populations, as well as risks of retrovirus
transmission to zookeepers, research workers, and
other human populations exposed to NHPs by
hunting, by keeping primate pets, or after direct
contact during visits to Old World countries where
NHPs are endemic
164

Cont…
 Simian retroviruses, including simian
immunodeficiency virus, simian type D retrovirus,
simian
 T-lymphotropic virus, and gibbon ape leukemia virus,
have been shown to cause clinical disease in NHPs
 Occupational exposure to zoonotic simian
retroviruses: health and safety implications for
persons working with nonhuman primates
165

Cont…
 SR have received renewed public health interest since it
was discovered that HIV-1 and HIV-2 originated
zoonotically from cross-species transmission of SIV from
infected chimpanzees (Pan troglodytes) and sooty
mangabeys (Cercocebusatys) in central and western
Africa, respectively.
 Institutions employing persons who work with primates
should provide comprehensive occupational health and
safety plans (OHSPs) for working with NHPs, as well as
appropriate safety equipment and training to these
workers to prevent occupational zoonosis.
166

Cont…
 Thus, first-aid kits for the treatment of bite wounds
and other cutaneous exposures should be easily
accessible and readily available to all personnel
working with NHPs
167

Cyanobacteria (Blue-Green Bacteria)
 Cyanobacteria, also known as blue-green algae, grow
in any type of water and are photosynthetic.
 Cyanobacteria live in terrestrial, fresh, brackish, or
marine water. Human poisonings are rare; however,
kills of livestock, other mammals, birds, fish, and
aquatic invertebrates are common.
168

Cont…
 They usually are too small to be seen, but sometimes
can form visible colonies, called an algal bloom.
 Cyanobacterial poisonings is caused by a variety of
biotoxins and cytotoxins produced by several species
of cyanobacteria.
169

Clinical symptoms
Affected animals are commonly found dead, Clinical
signs may become apparent within 15 minutes after
exposure.
 In acute cases
 Muscle tremor
 Increased salivation
 Recumbency
 Hyperesthesia to touch
 Abdominal pain
 Diarrhea and dyspnea
170

Cont…
 Necropsy lesions are usually absent in animals that die
suddenly of the neurotoxic syndrome.
 In cases of the hepatoxic syndrome, lesions may
include.
 Massive hepatic necrosis,
 Plasma transudates in body cavities
 Congestion of most viscera
 Severe gastroenteritis with intestinal hemorrhage and
severe bloody diarrhea have also been observed in
some outbreaks
171

6. Disease control strategies in wild animals
 'Control' is the reduction of the morbidity and
mortality from disease, and is a general term embracing
all measures intended to interfere with the unrestrained
occurrence of disease, whatever its cause.
 It is an ongoing process.
 Control can be achieved by treating diseased animals,
which therefore reduces disease prevalence, and by
preventing disease, which therefore reduces both
incidence and prevalence.
172

Cont…
 However, prevention is an increasingly important part
of disease control, being better than cure on
humanitarian and, frequently, economic grounds.
 The term 'eradication' was first applied in the 19th
century to the regional elimination of infectious
diseases of animals.
173

Strategies of control and eradication
 Quarantine
 Slaughter
 Vaccination
 Movement of hosts
 Restriction of movement of hosts
 Control of biological and mechanical vectors
 Biosecurity
 Surveillance and monitoring
174

Cont…
A. Quarantine:
 Quarantine is the isolation of animals that are
either infected or suspected of being so, or of
non-infected animals that are at risk.
 Quarantine is an old method of disease control
that is still very valuable.
175

Cont…
 It is used to isolate animals when they are imported
from countries where exotic diseases are endemic;
for example, the compulsory quarantine of wild dogs,
cats and zoo animals when they are imported to some
countries to prevent the introduction of rabies.
 It is also used to isolate animals suspected of being
infected, until infection is either confirmed or
discounted by clinical examination or laboratory
testing 176

Cont…
 Similarly, when an infectious agent is not spreading
within a herd or flock, quarantine may be adopted as
part of a control campaign.
 Ultimately, eradication can be achieved by the gradual
removal of affected animals
 The period of quarantine depends on the incubation
period of the agent, the time taken for the infection to
be confirmed, and the time taken for an infected animal
to become non-infectious (either with or without
treatment)
177

Cont…
B. Slaughter
 If a disease is infectious, affected animals can be a
source of infection to others.
 In such circumstances it may be economically and
technically expedient to slaughter the affected
animals.
 In eradication campaigns, infected animals may be
slaughtered to remove sources of infection.
178

Cont…
Thus, in some countries, all cloven-hoofed
animals in infected herds are slaughtered during
foot-and-mouth disease epidemics.
Eradication of specific diseases from herds often
involves a 'test-and-removal' strategy, in which
all animals are tested, and only those testing
positive are removed and slaughtered.
Example: bovine tuberculosis
179

Cont…
C. Vaccination
Vaccines can confer immunity not only to many
bacteria and viruses, but also to some helminths.
They are used routinely to prevent disease.
 Strategic vaccination: Vaccination may be
deployed strategically to prevent incursion of
disease from endemic areas, and the spread of
disease when epidemics occur; this is emergency
vaccination
180

Cont…
 There are several strategies, dictated by different
circumstances.
First, animals in an area surrounding an infected
region are vaccinated to provide a circumjacent barrier
against spread of infection; this is ring vaccination.
 For instance, in the 1950s and 1960s, rinderpest was
endemic in the Karamoja region of north-eastern
Uganda but was absent from other parts of the country.
 A 20-mile-deep ring of cattle around the region was
vaccinated to prevent transmission to disease-free
areas.
181

Cont…
 Secondly, a barrier, not completely circumscribing an
infected region, may be created (barrier vaccination).
 Thus, animals in parts of Bulgaria and Greece bordering
Turkey have been vaccinated to prevent entry of foot-
and-mouth disease from Asia.
 Thirdly, vaccination can be practiced both within and
around a region where an outbreak occurs; this
strategy (which includes ring vaccination) is
suppressive or dampening-down vaccination
182

Cont…
 Emergency vaccines are generally manufactured to a
higher potency than routine vaccines.
WHY ???
HOW ???
183

Cont…
D. Movement of hosts:
 Animals can be removed from 'high risk' areas
where infections are endemic.
 This control strategy is implemented in tropical
countries where hosts are seasonally migrated
from areas in which biological vectors are active.
184

Cont…
E. Restriction of movement of hosts:
 The movement of animals is often restricted
during epidemics and eradication campaigns to
reduce the risk of disease transmission.
 Restriction of international animal movements is
important in ensuring that countries remain free
from exotic diseases
185

Cont…
F. Control of biological vectors: ????
 Infectious diseases transmitted by biological vectors
can be controlled by removing the vectors.
 Insect vectors can be killed with insecticides. The
habitat of the vectors can be destroyed
 Some infections of definitive hosts may be prevented
by the elimination of infective material found at post-
mortem meat inspection of intermediate hosts
186

Cont…
G. Control of mechanical vectors: ????
 Living organisms that mechanically transmit
infectious agents can be controlled by
destruction and disinfection.
 Biting fleas that transmit bacteria, for
example, can be destroyed by insecticides.
187

Cont…
H. Surveillance:
Surveillance was originally applied to individuals;
primarily to contacts of serious communicable diseases
(e.g., pneumonic plague), who were closely watched for
the development of the first signs of illness.
Surveillance of disease: is the continued watchfulness
over the distribution and trends of incidence through
the systematic collection, consolidation and evaluation
of morbidity and mortality reports and other relevant
data. 188

Cont…
 Surveillance has three distinct elements:
1. Gathering, recording and analysis of data;
2. Dissemination of information to interested
parties,
3. Action can be taken to control disease.
189

Cont…
Goals of surveillance
 Rapid detection of disease outbreaks;
 Early identification of disease problems (endemic
and non-endemic
Assessment of the health status of a defined
population;
 Definition of priorities for disease control and
prevention; 190

Cont…
 Identification of new and emerging diseases;
 Evaluation of disease control programmes;
 Provision of information to plan and conduct
research;
 Confirmation of absence of a specific disease.
191

192
Effects of good land use plan spills over beyond target areas; River
Tarangire has its source in Kondoa but pouring its waters in Lake
Burunge

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