BIO1030 Disease Surveillance

Animal Health - Dr. MacDonald

Surveillance

Surveillance

ongoing collection, analysis and interpretation of animal health data and dissemination of information to those who need to Take Action

this is continued and/or repeated process

two types

Monitoring

surveillance without the call to aciton

ACTIVE Surveillance

aka: targeted surveillance

• focused on one or more pathogens in one or more species

• within a defined sample size, sampling times, places, species and types of samples

• observe prevalence, age, sex, and geographic distributions

  • can reflect entire population

proactive, but expensive (risk based)

PASSIVE Surveillance

aka: general/scanning surveillance

• identify the pathogens that exist in the environment

• focuses on detecting disease/pathogen NOT on collecting data

  • obtain info on pathogens and infected animals

• performed on individual animals

  • does not reflect entire population

reactive

Surveillance System

a method that includes one or more components to generate data on the health and/or disease status of animal populations

based on two approaches (active and passive)

Components of Surveillance

1. detection of sick and/or dead animals

2. identify pathogen(s) causing morbidity and/or mortality

3. information management

Detection of Sick and/or Dead Animals

• who finds them?

• who collects them?

• where are they sent or reported?

Identify Pathogen(s) causing Morbidity/Mortality

• history of disease

  • species, season, location

  • diagnostic tests

• diagnostic lab

  • necropsy

  • testing

Information Management

• database

• store long term

• disseminate to relevant people

Surveillance Process

Why Surveillance?

• identify diseases present

• identify disease absent

• describe prevalence

• describe distribution

• assess progress of controls

• identify risks

• monitor virus evolution

• aid decision making

• PEOPLE:

  • discover diseases

  • reduce zoonotic diseases

• AGRICULTURE:

  • domestic animal disease

  • trade restrictions

• ANIMALS:

  • potential threat to endangered species

  • because we care about their health

Iceberg Model

Challenges to Surveillance

• funding

• standardized, accessible databases

• diagnostic tests

• detection of dead wildlife

• quality samples

Diseases and Artificial Wildlife Practices

• Balancing Mechanisms

  • to limit impact of diseases

• Human Activities

  • alter mechanisms, change impacts

    • wildlife management

    • hobbies and recreation

    • rehabilitation

Artificial Wildlife Activities

• supplemental feeding/baiting

• wildlife rehabilitation

• translocation of native wildlife

• captive breeding/release

• high fence operations

• vaccination/treatment

• pets/feral animals

Diseases Associated with Artificial Activities

• NEGATIVE OUTCOMES

  • increase disease or disease spread

  • introduction to new area/host

  • novel disease

Risk Vocabulary

Risk Factors → variables associated with disease or infection being more likely to occur

Risk Assessment → process identifying hazards/threats and what could happen if occurred. (the probability of disease/infection occurring, consequences of said disease, and potential management)

BIRD FEEDER associated DISEASES

• most often occur in winter due to:

  • increase stress on birds

  • congregation of birds

  • increase in direct and indirect contact

• Examples

  • salmonellosis

  • mycoplasmosis

  • aspergillosis

  • trichomoniasis

  • avian pox

different shaped feeders can harbour different diseases

Bird Feeder Sanitation Practices

• disinfect every 1-2 weeks

• remove old food (ground and feeder)

• monitor feeder and remove if needed

Bird Feeding: pros, risks, management

• benefits:

  • enjoyment

  • education

  • economy

  • supplemental nutrition

• costs:

  • disease

  • altering behaviour/biology

• risks:

  • probability of disease?

  • consequences of disease?

• management:

  • general recommendations:

    • clean feeders

    • monitor for disease

    • respond quickly to disease

    • allow extra space (multiple feeders)

    • just don’t feed

Feeding vs. Baiting

Feeding → intentional placement of food in wildlife for use by wildlife

Baiting → food or food products placed to attract game and enhance successful harvest

Why Feed or Bait?

• improving condition of animals

• provide resources to enhance survival

• reduce agricultural damage

• enhance recreational sports

Causes of Disease or Harm in Elk/Deer

• Direct Causes:

  • rumen acidosis

  • clostridial diseases

  • aflatoxicosis

• Indirect Causes:

  • aggressive behaviour

  • habitat degradation

  • density-dependant diseases

    • chronic wasting disease

    • tuberculosis

    • brucellosis

Effect of Increased Density on Animals

• increased contact between animals

• increased stress

• increased risk of environmental contamination

basically increase rate of disease

RUMEN ACIDOSIS

direct

• the change in rumen stomach flora

  • increases acid

  • rumen stasis

  • dehydration

  • acid damage

  • acid leakage

  • bacterial leakage

• symptoms:

  • recumbent

  • quiet

  • staggering

  • diarrhea

• caused by abrupt diet change

  • usually an introduction of low fibre-high carb food by hunters or trappers

    • natural diet is high fibre

• severity varies based on:

  • grain type

  • nutritional state of animal

  • previous exposures

• not transmissible

NO TREATMENT (can be fatal in 1-3 days)

BOVINE TUBERCULOSIS

Bacterial → mycobacterium bovis

Transmission → respiratory secretions, closes contact, contaminated feed, ingestion of infected carcasses

strong relationship between TB in deer and artificial feeding

CAN INFECT MOST MAMMALS

Translocation of Wildlife

• contributes to:

  • raccoon rabies strain

  • rabbits tularemia

  • southeast cost meningeal worms

  • exotic ticks

‘when we move animals, we also move their diseases’

CAPTIVE CERVIDS: high fenced enclosures

• Used For:

  • artificial breeding to produce meat, larger animals and antlers

  • canned shoots

• Potential Risk Factors:

  • lack of population control

  • translocation of animals

  • mixing species

  • artificial feeding

  • use of vaccines and other treatment

• Potential Negative Impacts:'

  • disease - TB, CWD

  • public perception (fair chase)

  • privatization of wildlife

• Transmission:

  • escapes

  • wildlife entries

  • through the fence

Wild Animal

phenotype not affected by human selection, lives independent of direct human control

Captive Wild Animal

phenotype not significantly affected by human selection

captive of lives under human control

Feral Animal

domesticated species that now lives without direct human control

Exotic Species

any species not native to a habitat

Native Species

species historically occurring in a particular habitat

evolve n an ecosystem with checks and balances limiting the growth of any one species

Invasive Species

exotic species introduced to an ecosystem (not native) and cause harm

a species that does not have checks and balances limiting its growth, allowing populations to increase dramatically

usually spread by human activity

Exotic =/= Invasive

Invasive Species: TRAITS

• rapid growth

• high reproductive potential

• high dispersal

• human associations

• few predators

• tolerant of environmental conditions

• adaptable

allow them to outcompete native species

Invasive Species: IMPACTS

• Direct:

  • prey upon native species

  • competition

  • source of disease

  • negative effect on reproduction

• Indirect:

  • change food web

  • decrease biodiversity

  • alter ecosystem

• Negative:

  • resources

  • environment

  • wildlife

  • economy

  • human health

Invasive Species: EXAMPLES

• decline of Hawaiian honeycreepers

  • free-roaming domestic cats

  • feral swine

Hawaiian Honeycreepers

over half are now extinct, threatened or endangered, due to loss of habitat, invasive predators, or vector-borne disease

live in high-altitude, cool, dry forests

Types of Domestic Cats

Indoor → always indoors

Outdoor → spend time outdoors, socialized, have home, shelter, food

Feral → not socialized, no human control

Stray → once pets, abandoned or lost

Free-Roaming → non-confined to a house

Free-Roaming Domestic Cats

almost worldwide invasive species as non-native in all natural environments

• non-native

• widespread

• high reproductive potential

• predatory behaviour

• high hunting success rate

  • high prey mortality

• contribution to extinctions

• disease carriers

Free-Roaming Cats: DISEASES

• rabies

• toxoplasmosis

• hookworm

• toxocariasis

• bartonellosis

• typhoid

• plague

• tularemia

infect - humans, domestic and wild animals

Free-Roaming Cats: MANAGEMENT

• indoor cat sanctuaries

• supplemental feeding

• trap-neuuter-release programs

  • issues:

    • fail to achieve objectives

    • fail to significantly decrease populations

    • fail to protect wildlife

    • does not change behaviour

    • testing and vaccination not uniformly implemented

• wildlife conversations:

  • open dialogue

  • owner accountibility

  • human control

  • encourage leashes, sanctuaries, indoor cats

Free-Roaming Cats: CONTROVERSY

• science vs emotion vs humane action

• lack of understanding

• advocacy groups

• few policies and laws

• no easy answers

Invasive Pigs

• highly adaptable

• high reproductive potential & fecundity

• rapid range expansion

• difficult to manage

• favourable conditions

• cause damage & harm

brought over during colonization of north america

Invasive Pigs: DIET

prey → sheep, goats, nests/birds

vegetation → plants, fruits, nuts, roots, tubers

exhibit Gorging Behaviour which impacts sensitive populations

Invasive Pigs: REPRODUCTION

~6 fetuses/pregnancy

• litter size is increasing

  • larger/healthier females >6

• continuous reproduction

• high survivability

• high recruitment

• low predation

Invasive Pigs: BEHAVIOUR

• sounder groups

• behavioural plasticity

• dietary generalists

• landscape generalists

• intelligent

• move extensively

Invasive Pigs: POPULATIONS EXPANDING

• introductions, reintroductions

• escapes or intentional release

• abundant agriculture

• high reproductive rates

• lack of predators

• absence of management and control

Invasive Pigs: IMPACTS

• most damaging invasive species in U.S.

• impacts:

  • environment/ecosystems

    • rooting

    • depredation - native flora

    • predation - native fauna

    • competition

    • water quality

  • agriculture

    • livestock competition

    • agricultural depredation

    • forestry depredation

    • livestock

  • native wildlife

  • disease rates

    • carry >30 diseases

    • carry >36 parasites

  • economy

    • crop damage and control~$1.5B/year

    • pig-vehicle damage~$36M/year

    • fighter jet~$16M

    • disease and border closure=billions

Invasive Pigs: MANAGEMENT

• multidisciplinary response

• prevention

• education

• direct control

  • capture

  • sharpshooting

  • hunting

  • toxicants

  • judas pigs

Livestock

domesticated animals raised for agricultural purposes to provide labour or product

Livestock Disease Spread

1. introduction of diseased animals

2. introduction of recovered animal capable of transmitting disease (carriers)

3. contact with contaminated object (fomites)

4. contact with animal carcasses improperly disposed of

5. rodents and free-flying birds

6. mosquitoes/insects

7. shoes and clothing of persons moving between farms

8. contaminated feed, feed bags, water, soil, old litter, or bedding

9. short range airborne organisms (high population)

POULTRY

any domesticated bird kept for producing eggs or meat

• LAYING → leghorn, rhode island red, plymouth rock

• MEAT → cornish cross, big red, jersey giant, orphington

• DUAL PURPOSE → rhode island red, wyandotle, jersey giant

FREE-RANGE

farm animals allowed to roam free outside, not in cages

CATTLE

a group of domesticated bovine animals, including: cows, buffalos, bison, kept for their mild, meat or hides

BOVINE

of, or pertaining to the subfamily Bovinae

HERD

a large group of animals, especially hoofed mammals, that live, feed or migrate together or kept together as livestock

Cattle: DISEASES

• bluetongue

• bovine brucellosis

• johne’s disease

SWINE

a pig, especially a domesticated pig

FERAL PIG

wild pigs, live freely (aka: wild boar)

HOG

any age, regardless of status or gender of pig

BOAR

sexually mature male

SOW

female that has reproduced

Swine: DISEASES

• pseudorabies

• swine influenza

• swine brucellosis

AQUACULTURE

the breeding, raising and harvesting of fish, shellfish, and aquatic plants under controlled conditions

FISHERY

place where fish are reared commercially, usually and area or fishing grounds where fish are caught

the occupation or industry of catching/rearing fish

INSECT

any small air-breathing arthropod invertebrates of the class Insecta typically having:

• segmented body

  • 6 legs

  • 2 pairs of wings (usually)

  • 3 major Parts:

    • Head

    • Thorax

    • Abdomen

• external chitinous covering

• “mini-livestock”/ “micro-stock”

Insect Farming

the practice of breeding, rearing and harvesting insects for a purpose (animal feed, human consumption, biological pest control, crop pollination and products/silk/dyes, pharmaceuticals and cosmetics)

Insect as Livestock: HEALTH ISSUES

• water related deaths

• cannibalism

• starvation

• parasites

• bacteria

• viruses

Occulusion Body

a crystalline protein matrix which occludes the nucleocapsid in some viruses

HONEYBEES

• Queen Bee → single reproductive female in a hive/colony of honeybees

• Worker Bee → female bees, not capable of reproduction that collect food and do all of the work for the hive

• Drone Bee → male bees whose sole purpose is to mate with queen

• Brood → the eggs, larvae and pupae of honeybees

Bee Colony

the organization of a single family, consisting of one queen, drones and thousands of workers

Hive

the structural unit that houses a colony

Bee Comb

a mass of hexagonal wax cells built by honeybees in their nest to contain their brood and stores of honey

Comb Cells

Brood Cell → a cell in bee comb used for the rearing of a larva

Honey Cell → a cell in comb used to store honey

Cap

layer of wax that seals a cell

Issues of Bees

1. parasites, pests, and predators

2. pathogens

3. poor nutrition

4. pesticides

1 - Parasites, Pests & Predators

Tracheal Mite → internal blood sucking parasite that can cause moderate to serious concerns to hive - managed by chemical treatments, or tolerant bee stock

Varroa Mite → a very serious external blood sucking parasite that is highly virulent (unchecked can kill colony) - managed by chemical treatments and cultural practices

ants, mice, skunks, bears (Predators)

2 - Pathogens

Brood and Adult specific diseases

3 - Nutrition

• bees feed on honey and fermented pollen

  • variation in pollen sources and quality

• protein is sourced from royal jelly

• have increased nutritional needs in spring/fall

• SIGNS of POOR NUTRITION:

  • less royal jelly

  • higher larval mortality

  • smaller adults

  • higher rates of infection/disease

management = supplementary food

4 - Pesticides

a product that claims to kill, prevent, reduce, destroy or repel a pest

herb/insect/fungi/rodent

HERBICIDE

an agent, usually chemical, for killing or inhibiting the growth of unwanted plants, such as residential or agricultural weeds and invasive species

INSECTICIDE

chemical agents used to control insects by killing them or preventing them from engaging in undesirable or destructive behaviours

FUNGICIDE

chemical agents that kill or prevent the growth of fungi and their spores, often used to control fungi that damage plants

Pesticides: ROUTES OF EXPOSURE

• dermal intake

  • absorbed through integument

• oral intake

  • alimentary canal via feeding or cleaning

• respiratory intake

  • absorbed via spiracles

Pesticides: EFFECTS

• direct contact and contamination transfer

• external signs

• behavioural changes

• physical symptoms

• colony impacts

• long term effects

Pesticides: PREVENTION

• apply pesticides in the evening

• choose the appropriate formulation

• use less toxic, rapidly degradable pesticides

• alter application method

• establish apiaries in safe locations

Pesticides: RECOVERY

• clean hives

• supplementary food

• supplementary bees

• protection

Risks to Silkworm Livestock

• viral:

  • grasserie

  • cytoplasmic polyhedrosis

• fungal:

  • asergillosis

  • muscardine (white and green)

• bacterial:

  • bacterial toxicosis

  • digestive infections

    • strep

    • staph

• parasites:

  • pebrine

  • uzi fly

  • wasps

Ladybugs and the Parasitoid Wasp

1. wasp controls ladybug

2. lays one egg in abdomen

3. larva feed on host ladybug tissue

4. larva emerges, spins a cocoon

5. ladybug becomes bodyguard

6. partially paralyzed

7. twitches to ward off predators

8. adult wasp emerges

9. ladybug recovers or dies