Case # A Janildo Reis, Alvin C. Camus, Elizabeth W. Howerth and Cecil Jennings. University of Georgia Department of Pathology Presented at SEVPAC 2008 – Permission granted for use on SEVPAC website only

Signalment & History Adult robust redhorse sucker (Moxostoma robustum). Found dead in tank with no reported clinical signs. Picture from American Fisheries Society Presented at SEVPAC 2008 – Permission granted for use on SEVPAC website only

Necropsy findings Multiple white pinpoint nodules throughout the skin of the head. Catfish with similar lesions. Presented at SEVPAC 2008 – Permission granted for use on SEVPAC website only

Microscopic findings Fresh gill clipping: Note typical horseshoe nucleus (trophozoites) Presented at SEVPAC 2008 – Permission granted for use on SEVPAC website only

Microscopic findings Nodular hyperplasia and dysplasia of the epidermis replacing accessory structures. Normal skin - accessory structures are present. Presented at SEVPAC 2008 – Permission granted for use on SEVPAC website only

Microscopic findings Epidermal hyperplasia and dysplasia associated with a parasitic structure. Presented at SEVPAC 2008 – Permission granted for use on SEVPAC website only

Microscopic findings Skin: H&EGill: H&E - 60 to 150 um, round to oval, single cell ciliated protozoan (trophozoite) um thick hyaline wall, abundant granular and vacuolated basophilic cytoplasm - 20 to 50um deeply basophilic nucleus, in some sections of gills present horseshoe shaped nucleus. Presented at SEVPAC 2008 – Permission granted for use on SEVPAC website only

Microscopic findings Secondary findings Gills –Hyphae consistent with Saprolegnia spp. –Mixed bacterial colonies. Skin –Trematode metacercaria encysted in the dermis. Presented at SEVPAC 2008 – Permission granted for use on SEVPAC website only

Morphologic diagnosis Skin, head: Severe, nodular, lymphoplasmacytic and hyperplastic dermatitis, with intralesional protozoans, consistent with Ichthyophthirius multifiliis. Presented at SEVPAC 2008 – Permission granted for use on SEVPAC website only

Background information Disease names: White Spot Disease or ichthyophthiriosis (“Ich”) Etiology - Ichthyophthirius multifiliis –Obligate parasite –Large ciliated protozoan with characteristic horseshoe shaped nucleus –One of the most common freshwater parasite –Mortalities may reach 100% Clinical signs and lesions: –Pinpoint white nodules widely distributed Body surface and gills –Signs of hypoxia Increased respiratory rate, lethargy and “flashing” Life cycle is temperature dependent - important to treatment Presented at SEVPAC 2008 – Permission granted for use on SEVPAC website only

Life cycle Trophozoite Tomont Tomites Theronts Presented at SEVPAC 2008 – Permission granted for use on SEVPAC website only

Questions? Rio de Janeiro Presented at SEVPAC 2008 – Permission granted for use on SEVPAC website only

Red & Black Rocks!! Bulldogs Flamengo Thank you! Presented at SEVPAC 2008 – Permission granted for use on SEVPAC website only