Rickettsial Diseases 4 H Veterinary Science Extension Veterinary

Rickettsial Diseases 4 -H Veterinary Science Extension Veterinary Medicine Texas Agri. Life Extension Service College of Veterinary Medicine and Biomedical Sciences Texas A&M System http: //aevm. tamu. edu

Objectives n Discuss arthropod transmission of rickettsiae n Describe a rickettsial disease of cattle n Decribe a rickettsial disease of swine n Describe a rickettsial disease of horses n Describe two rickettsial diseases of dogs

Review n Infectious diseases n Bacterial diseases n Viral diseases n Fungal diseases n Parasitic diseases n Rickettsial diseases

n Infectious -

Rickettsiae n Definition n A genus of small, rod-shaped, round to pleomorphic microorganisms in the order Rickettsiales. They are true bacteria, gramnegative, and cultivable only in living tissues. Transmitted by lice and ticks, they cause disease in humans and domestic animals but are also found in the cytoplasm of tissue cells of lice, fleas, ticks and mites, which may act as reservoirs and vectors

n Symptoms n Fever n Anemia n Edema n Icterus (jaundice) n Hemorrhages of mucous membranes n Enlarged spleen n Death

n Acute n n n Young animals Summer during vector season Chronic n n Older animals Stressful events

n Transmission n Biological n Examples § Ticks § Sucking lice Live inside arthropods for months n Mechanical n Examples n § Biting flies § Instruments § Blood transfusions n Live short time outside of host

Types

n Anaplasmosis (Gall sickness) n Affects ruminants n Transmission n Mechanical § § n n n Horseflies Deerflies Instruments Ticks Non-contagious Treatable Prevention n Vaccinate n Biosecurity

n Eperythrozoonosis (Epe) n Affects swine n Transmission n Mechanical and biological n n n Sucking lice Instruments Prevention is best treatment

n Ehrilichiosis (Tick fever) n Affects n n Dogs Transmission n Brown dog tick Instruments Blood transfusion

n Rocky mountain spotted fever n Affects n n Dogs Transmission n American god tick Instruments Blood transfusion

n Ehrlichiosis n Affects n n Horses Transmission n Unknown

Diagnosis n Blood smears n Anaplasma n Eperythrozoon n Ehrlichia rickettsial n Serological n Rocky mountains spotted fever