1. 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

2. 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

3. Overview Remember Five infectious diseases Bacterial Viral Fungal Parasitic Rickettsial

4. 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

5. 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

6. Arthropods Affect  Skin  Digestive system Examples  Flies  Ticks  Fleas  Lice  Mites

7. Worms Affect  Skin  Digestive system  Circulatory system Types  Nematodes  Tapeworms  Flukes

8. Protozoa Single-celled organisms Affects  Digestive system  Reproductive system Types  Amoebas  Ciliates

9. 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

10. 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

11. Skin Arthropods Ectoparasites External parasites Cause infestations Not worms, bacteria, viruses or fungi Affect health Tissue damage Blood loss Annoyance Vectors

12. Flies Blood-suckers  Annoyance  Anemia  Disease transmission  Anaplasmosis  Bluetongue  Heartworms  Examples  Horseflies  Deerflies  Stableflies  Hornflies  Mosquitoes  Gnats Non-blood suckers  Annoyance  Example  Houseflies Housefly Mosquito

13. Heartworms

19. Flies

21. Heelflies Larval stages  Cattle grubs Cause  Migratory damage  Internal tissue  Hide Heelfly Cattle grub

23. Development Process of a Heelfly

28. Ticks Two groups  Hard ticks  Soft ticks Adults are free-living

29. Hard ticks Feed for several days Vectors  Anaplasmosis  Lyme disease Soft Ticks Intermittent feeders Spinose ticks