Download Nutritional Diseases - Extension Veterinary Medicine

Parasitic Diseases
4-H Veterinary Science
Extension Veterinary Medicine
Texas AgriLife Extension Service
College of Veterinary Medicine and Biomedical Sciences
Texas A&M System
http://aevm.tamu.edu
Objectives
 Describe diseases caused by arthropods
 Describe diseases caused by nematodes
 Describe diseases caused by tapeworms
 Describe diseases caused by flukes
 Describe diseases caused by protozoa
Overview
 Remember

Five infectious diseases





Bacterial
Viral
Fungal
Parasitic
Rickettsial

Infectious disease

An illness due to a specific infectious agent or its
toxic products that arises through transmission of
that agent or its products from an infected person,
animal or reservoir to a susceptible host, either
directly or indirectly

Parasite


An organism that grows, feeds, and is sheltered
on or in a different organism while contributing
nothing to the survival of its host
Types
 Arthropods
 Worms
 Protozoa

Arthropods

Affect
 Skin
 Digestive system

Examples





Flies
Ticks
Fleas
Lice
Mites

Worms

Affect
 Skin
 Digestive system
 Circulatory system

Types
 Nematodes
 Tapeworms
 Flukes

Protozoa


Single-celled organisms
Affects
 Digestive system
 Reproductive system

Types
 Amoebas
 Ciliates
 Infestation
 To inhabit or overrun in numbers or quantities
large enough to be harmful, threatening, or
obnoxious
 Infection
 Invasion by and multiplication of pathogenic
microorganisms in a bodily part or tissue,
which may produce subsequent tissue injury
and progress to overt disease through a
variety of cellular or toxic mechanisms
 Parasites may be vectors
 Mechanical
 Carries the pathogen, but the pathogen is not altered
while on the vector
 Example
 Arthropods
 Animals (wild or domestic)
 People

Biological
 An organism that is needed for the life cycle of a
pathogen
 Disease agent multiplies or develops within parasite
 Example
 Arthropods
Skin
 Arthropods
 Ectoparasites




External parasites
Cause infestations
Not worms, bacteria, viruses or fungi
Affect health




Tissue damage
Blood loss
Annoyance
Vectors

Flies

Blood-suckers
 Annoyance
 Anemia
 Disease transmission
 Anaplasmosis
 Bluetongue
 Heartworms
 Examples
 Horseflies
 Deerflies
 Stableflies
 Hornflies
 Mosquitoes
 Gnats

Housefly
Non-blood suckers
 Annoyance
 Example
 Houseflies
Mosquito
Heartworms
Flies

Heelflies

Larval stages
 Cattle grubs

Cause
 Migratory damage
 Internal tissue
 Hide
Heelfly
Cattle grub
Development Process of a Heelfly

Ticks

Two groups
 Hard ticks
 Soft ticks

Adults are free-living

Hard ticks


Feed for several days
Vectors
 Anaplasmosis
 Lyme disease

Soft Ticks


Intermittent feeders
Spinose ticks