Seventeen desert tortoises, Xerobates agassizii, with upper respiratory tract disease were examined; thirteen were euthanatized for necropsy. Four normal control desert tortoises from a clinically healthy population were similarly evaluated. Hemoglobin and phosphorus values were significantly (P less than or equal to 0.05) lower and serum sodium, urea, SGOT, and cholesterol values were significantly higher in ill tortoises compared to controls. No significant differences in concentrations of serum or liver vitamins A and E were found between the two groups. While no significant differences were found for concentrations of lead, copper, cadmium, and selenium, the livers of ill tortoises had higher concentrations of mercury and iron. Lesions were found consistently in the upper respiratory tract (URT) of ill tortoises. In all ill tortoises dense infiltrates of lymphocytes and histiocytes obscured the mucosal epithelium and underlying glands. The mucosal epithelium was variably dysplastic, hyperplastic, and occasionally ulcerated. Electron microscopic studies revealed small (350 to 900 nm), pleomorphic organisms resembling Mycoplasma sp., in close association with the surface epithelium of the URT of ill tortoises. Pasteurella testudinis was cultured from the nasal cavity of all ill tortoises and one of four control tortoises. A Mycoplasma sp. was cultured from the nasal passageways of four ill tortoises and was ultrastructurally similar to the pleomorphic organism present on the mucosa in tissue section.

Balamuthia mandrillaris is a newly described free-living amoeba capable of causing fatal meningoencephalitis in humans and animals. Because the number of human cases is rapidly increasing, this infection is now considered an important emerging disease by the medical community. A retrospective review of the pathology database for the Zoological Society of San Diego (the San Diego Zoo and San Diego Wild Animal Park) for the period July 1965 through December 1994 revealed five cases of amoebic meningoencephalitis, all in Old World primates. The infected animals were a 3-year, 10-month-old female mandrill (Papio sphinx), from which the original isolation of B. mandrillaris was made, a 5-year-old male white-cheeked gibbon (Hylobates concolor leucogenys), a 1-year-old female western lowland gorilla (Gorilla gorilla gorilla), a 13-year, 5-month-old male western lowland gorilla, and a 6-year-old female Kikuyu colobus monkey (Colobus guereza kikuyuensis). Two different disease patterns were identified: the gibbon, mandrill, and 1-year-old gorilla had an acute to subacute necrotizing amoebic meningoencephalitis with a short clinical course, and the adult gorilla and colobus monkey had a granulomatous amoebic meningoencephalitis with extraneural fibrogranulomatous inflammatory lesions and a long clinical course. Indirect immunofluorescent staining of amoebas in brain sections with a Balamuthia-specific polyclonal antibody was positive in all five animals. Indirect immunofluorescent staining for several species of Acanthamoeba, Naegleria fowleri, and Hartmanella vermiformis was negative. Direct examination of water and soil samples from the gorilla and former mandrill enclosures revealed unidentified amoebas in 11/27 samples, but intraperitoneal inoculations in mice failed to induce disease. Attempts to isolate amoebas from frozen tissues from the adult male gorilla were unsuccessful.

Abstract. Chelonian intranuclear coccidiosis has been reported once, in two radiated tortoises (Geochelone radiata), and is apparently rare. We describe intranuclear coccidiosis diagnosed histologically in two radiated tortoises, three Travancore tortoises (Indotestudo forstenii), two leopard tortoises (Geochelone pardalis), one bowsprit tortoise (Chersina angulata), and one impressed tortoise (Manouria impressa). Infection was systemic and involved alimentary, urogenital, respiratory, lymphoid, endocrine, and integumentary systems. Trophozoites, meronts, merozoites, macrogametocytes, microgametocytes, and nonsporulated oocysts were seen histologically or by electron microscopy. Intracytoplasmic and extracellular stages of parasite development also were identified histologically. Sequencing of a coccidial 18S rRNA consensus polymerase chain reaction (PCR) product revealed a novel sequence that provided phylogenetic information and may be useful for further diagnostic test design. Intranuclear coccidiosis was associated with variable degrees of inflammation in all cases, was considered the cause of death in six tortoises, and was a substantial contributing factor to the cause of death in two tortoises.

The 'Alala (Corvus hawaiiensis) is the most endangered corvid in the world, and intensive efforts are being made to reintroduce it to its former native range in Hawaii. We diagnosed Toxoplasma gondii infection in five free-ranging 'Alala. One 'Alala, recaptured from the wild because it was underweight and depressed, was treated with diclazuril (10 mg/kg) orally for 10 days. Antibodies were measured before and after treatment by the modified agglutination test (MAT) using whole T. gondii tachyzoites fixed in formalin and mercaptoethanol. The MAT titer decreased four-fold from an initial titer of 1:1,600 with remarkable improvement in physical condition. Lesions of toxoplasmosis also were seen in two partially scavenged carcasses and in a third fresh intact carcass. Toxoplasma gondii was confirmed immunohistochemically by using anti-T. gondii specific serum. The organism was also cultured by bioassay in mice from tissues of one of these birds and the brain of a fifth 'Alala that did not exhibit lesions. The life cycle of the parasite was experimentally completed in cats. This is the first record of toxoplasmosis in 'Alala, and the parasite appears to pose a significant threat and management challenge to reintroduction programs for 'Alala in Hawaii.

Key Words: Hal icephalo bus; ho rses; Micron ern a; posth iti s.Halicephalobus in fectio n a pparen tly is a worldwi de ph enomeno n; it has been rep orted o n five co ntinents in seven diffe re nt co untries : the Un ited Sta tes , th e United Kingd om , Jap an , Egypt, Switzer land , Th e Neth er lands: and Co lo mbia.' Inflam mation o f the ce ntra l nervo us system is a co nsistent fea ture of Halicephaiobus infecti on in h uman bei ngs' an d is a lm ost a lwa ys in vol ved in eq uine in fecti on s." In a review of reported Halicephalobus infecti on in horses, the bra in was th e m ost co m monly in vo lved tissue, follow ed in descend ing order by th e kidne ys, o ra l a nd nasal ca vities, lym ph nod es, lu ngs, spina l co rd, a nd adrena l gla nd, with single rep orts o f hea rt , liver, sto mac h, ganglion, a nd bon e involvcm cnt. !" G ran ulom a tou s os teoa rt hr itis indu ced by II. deletrix has a lso been rep orted ."In Ja nu ar y 1990, a 5-year-o ld ma le Ara bia n showho rsc was exa mi ned by an Albuq uerq ue vete rinaria n becau se o f mu lti ple nod ules on th e exte rna l lam ina of th e prep uce. T he a nima l was nat ive to New Mexico. O ther horses in th e stable we re un affected . Antecedent tra uma had not bee n o bse rved by the ow ner. No d ule di a me ters were 0.5-1 cm , an d th e ski n was ulcera ted over the surfaces. No ot he r cli nica l signs were ev iden t. A bio psy was perfo rm ed , and th e spec ime n was exa mi ned by a patho logist with the New Mexico Depa rtment of Agricult ure . After a prelimina ry d iagnosis of cuta neo us hali cephalo biasis, th e ho rse was treated with ivermect in an d di eth ylcarbamazine. Th e rem a in ing nodules subse q ue ntly regressed. T he biop sy spec ime n was subm itte d to the Ar me d Fo rces In stitute of Pat hology for co nfir ma tio n of the d iagnosis.Hi st o logically, the dermi s was marked ly thi ckened by a d i ffuse gra n ulo ma to us in filt ra te th at di srupted dermal co llagen a nd exte nde d to the ulcerat ed surface. T he in filtra te co ns isted of a b unda nt mu lti n uclea ted gia nt cells, ma crophages, cos ino phils, nc utrop hi ls, and nodula r aggregates of lym ph ocytes a nd plasm a cells (F ig. I ). T hro ugh o ut the section , there were numerou s ad ults , la rvae, and developing eggs ofa nem at od e par asite. Ad ult fem a les, 20 Jlm at th eir grea tes t d iam et er, were ob ser ved . No ma les were seen. The parasite had a smoot h, th in cuticle ; a plat yrn yar ia n-rnerorn yar ian muscul at ure; a psc ud ococ lum ; a rh abditifo rm esophag us co mposed of a corpus , isthm us, a nd bul b (Fig . 2); a nd a n in testina l tract co m posed of single n uclea ted lo w cuboi da l ce lls. There was a single geni ta l tube con ta ini ng o nly one mat ure egg. T he ovary was do rso flcxcd, a nd the uterus was ve ntroflexed a t th e v ulva (Fig. 3). La rvae were up to 10 Jlm in d ia me ter and also had rha bd itifo rm eso phagi. Adults an d Fig. I. Prepuce; horse. A pleocellu lar gra n ulo ma to us reaction surro und...