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Unexpected Death in Captive Maras

Unexpected Death in Captive Maras. Mexico. Background. 3 captive-born juvenile Maras Unexpected death 1999-2000 Africam Safari (Puebla, Mexico) Intralesional protozoal cysts with myriads of crescent shaped bradyzoites in the cytoplasm of host cells

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Unexpected Death in Captive Maras

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  1. Unexpected Death in Captive Maras Mexico

  2. Background • 3 captive-born juvenile Maras • Unexpected death 1999-2000 • Africam Safari (Puebla, Mexico) • Intralesional protozoal cysts with myriads of crescent shaped bradyzoites in the cytoplasm of host cells • Host cells were hypertrophied, occasionally multinucleate, surrounded by a thick eosinophilic capsule

  3. Suspected Protozoal Disease • Besnoitia sp. (Family Sarcocystidae) • Indirect life cycle • Definitive carnivore host • Intermediate host • Horses, ruminants, opossums, rodents, rabbits, lizards

  4. Case Confirmation • Gross Necropsy Findings • Histological findings • Other testing • Post-mortem urinalysis • Lung culture • Electron microscopy of lung

  5. Diagnosis • Pulmonary besnoitasis (disseminated in Mara #3) • By light microscopy and EM, Besnoitia cysts can be differentiated from other tissue cyst forming coccidia in the family Sarcocystidae • Specifically, bradyzoites are surrounded by a parasitophorous vacuole within the cytoplasm of a hypertrophied and multinucleate fibroblast surrounded by a thick capsule composed of collagen and electrodense capsules

  6. Establishing Endemic Levels • Retrospective review of all Mara necropsy cases at Africam Safari • 54 Animals, 1996-2003 • 10 more cases that had occasional or low numbers of similar cysts in the lungs with minimal or moderate inflammation surrounding them • Severity of these lesions correlated with the presence of lytic and mineralized cysts • One Mara also had cysts in the pancreas and peripancreatic adipose tissue

  7. Is There An outbreak? • There was no evidence of Besnotiasis prior to 1999 • All of the 13 total cases with cysts • Present in the lungs with concurrent interstitial or granulomatous pneumonia

  8. Descriptive Epidemiology • Herd history • Case description • Environmental factors

  9. Environmental Factors • Diet • Water ad libitum • Oranges, carrots, chopped alfalfa and rabbit pellets • Enclosure • 120m2 • Fenced with 1.20m high wire mesh and bamboo on one side • Sandy substrate • Often see squirrels (Spermophilus variegatus), Mice (Mus musculus) and various birds inside the enclosure. • Often see opossum (Didelphis virginiana), ringtail cat (Bassariscus astutus) and stray cats (Felis domesticus) inside the park.

  10. 1996-2003 • 13 positive animals in an 8 year period • 54 total deaths • 24% • 3 animals from current colony of 37 • 8%

  11. Background of Besnotia • Species of besnotia have heterogeneous life cycles • Uses predator-prey relationships to ensure transmission • Intermediate host becomes infected by ingesting sporulated oocysts in feed or water contaminated with feces • Most besnoitia spp. Have a broad range of intermediate hosts • Cats are definitive hosts of B. darlingi and B. wallace • Role of cats and carnivores in the life cycle of other Besnoitia species is unclear

  12. Hypothesis • Wild carnivores in the park? • Definitive hosts by fecal shedding of oocysts • Hematophagous insects? • Transmission by these insects may occur in ungulates • Pre-existing chronic granulomatous inflammation? • Involved in the development of fatal interstitial pneumonia • Concurrent infection with agent causing interstitial pneumonia? • Undetected by available diagnostic techniques

  13. Investigate Hypothesis • Review literature for similar cases • Environmental Investigation

  14. Referencias • Ayroud M, Leighton F, Tessaro S: The morphology and pathology of Besnoitia sp. in reindeer (Rangifer tarandus tarandus). J Wildl Dis 31:319-326, 1995 • Diesing L, Heydorn AO, Matuschka FR, Bauer C, Pipano E, de Waal DT, Potgieter FT: Besnoitia besnoiti: studies on the definitive host and experimental infections in cattle. Parasitol Res 75:114-117, 1998 • Dubey JP, Greene C: Enteric coccidiosis. In: Infectious diseases of the dog and cat, ed. Greene C, pp. 835-846. WB Saunders Company, Philadelphia, PA,USA, 1990 • Foley G, Anderson W, Steinberg H: Besnoitiosis of the reproductive tract of a blue duiker (Cephalophus monticola). Vet Parasitol36:157-163, 1990 • Glover G, Swendrowski M, Cawthorn R: An epizootic of besnoitiosis in captive caribou (Rangifer tarandus caribou), reindeer (Rangifer tarandus tarandus) and mule deer (Odocoileus hemionus hemionus). J Wildl Dis26:186-195, 1990 • Grisard EC, Elsaid MM, Tafuri WL, Lima JD, Pinto CJ, Steindel M, Vitor RW: Besnoitia sp. (Protoza: Toxoplasmatinae) from Akodon montensis (Rodentia: Cricetidae) in Santa Catarina State, Brazil. J Parasitol 83:314-316, 1997 • Jack S, Van Alisten W, Swackhamer J: Besnoitiosis in Indiana opossums. J Vet Diagn Invest1:189-191, 1989 • Mbuthia P, Gathumbi P, Bwangamoi O, Wasike P: Natural besnoitiosis in a rabbit. Vet Parasitol 45:191-198, 1993 • Nganga CJ, Kasigazi S: Caprine besnoitiosis: studies on the experimental intermediate hosts and the role of the domestic cat in transmission. Vet Parasitol 52:207-210, 1994 • Venturini L, Petruccelli M, Piscopo M, Unzaga JM, Venturini MC, Bacigalupe D, Basso W, Dubey JP: Natural Besnoitia sp. infection in domestic rabbits from Argentina. Vet Parasitol 107:273-278, 2002

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