USE OF COMPUTED TOMOGRAPHY FOR INVESTIGATION OF RHINITIS AND SINUSITIS IN A GREATER RHEA (RHEA AMERICANA).

Sinusitis is a common finding in avian species; however, it presents unique treatment challenges in ratites. A 6-yr-old male greater rhea ( Rhea americana ) presented acutely with right infraorbital sinus swelling and chemosis. Oral antibiotics were prescribed based on bacterial culture results with incomplete resolution of clinical signs. A computed tomography scan of the skull demonstrated a mixed-density soft tissue mass with extensive destruction of the right nasal bone, hard palate, maxilla, and frontal bone. The affected tissue was surgically resected and histopathology was consistent with inspissated necrotic tissue. Aerobic culture of the mass grew a multidrug-resistant Escherichia coli and was treated with amikacin. Ten months postsurgery, no further clinical signs were observed. Advanced diagnostic imaging with computed tomography and surgical therapy facilitated complete resolution of this resistant bacterial sinusitis in a species that is not typically amenable to frequent handling and restraint.

Distribution and concentration of maternal progesterone in the yolk of Greater Rhea eggs (Rhea americana).

Progesterone is the most concentrated maternal yolk steroid characterized to date in birds; however, no information about it is available in ratite eggs. We collected freshly laid eggs from zoo-housed Greater Rhea females (Rhea americana) bred under similar rearing conditions during two breeding seasons to characterize concentration and distribution of maternal yolk progesterone. After high-performance liquid chromatography analysis, yolk hormone was measured using a commercial electrochemiluminescence immunoassay. Progesterone concentrations were found to vary significantly among the yolk layers, supporting a follicular origin for this steroid in Greater Rhea eggs. Additionally, highly similar mean absolute yolk progesterone concentrations were detected between 2013 and 2015 breeding seasons (1,332.98 ± 82.59 and 1,313.59 ± 85.19 ng/g, respectively). These values are also comparable to those found in some domestic carinate species. Findings suggest that at population level, when rearing conditions are similar, mean absolute yolk maternal progesterone concentrations also appear bounded. Future research on the factors and mechanisms that regulate progesterone deposition in Greater Rhea eggs is needed to better understand whether its levels depend on different rearing conditions.

Aspects of spermatogenesis and microscopic testicular morphology in Greater Rhea, Rhea americana (Linnaeus, 1758) / Aspectos da espermatogênese e morfologia microscópica testicular em Emas, Rhea americana (Linnaeus, 1758)

The purpose of this study was to study the microscopic morphology of the testicular parenchyma of Rhea americana birds. Fifty-four 2.5±0.5 year-old male adults bred in captivity. were used. During commercial slaughter, samples of testis were collected in November/2005, December/2006 and May/2007, in order to compare possible differences. The samples underwent optical microscopy analysis and measurements of seminiferous tubule (ST) total diameters, lumen, epithelium thickness and the relative volume of parenchyma. The ST had circular form in transverse cross sections. November/2005 and December/2006 samples had many types of germinative cells and spermatozoa in lumen, but in May/2007 the samples of epithelium were poor regarding meiotic and mitotic pictures, and it was difficult to find any spermatozoon; in many tubules the lumen was inexistent or diminished. In December/2006 and May/2007 the averages were: tubule diameter 110.3 and 5.3mµ, lumen 52.4 and 4.5mµ, epithelium thickness 57.8 and 0.7mµ respectively. The volumetric proportions were: seminiferous epithelium 75.6 and 75.9, cysts in epithelium 2.1 and 1.0, ST 93.3 and 84.0, interstitium 6.2 and 15.6 respectively. The sperm reserves were: 19.7±2 and 0±0 x109 sperm cells in December 2006 and May 2007 respectively. Microscopic measures of seminiferous tubules, spermatic cells and diameter of the nuclei were presented. These data confirm reproductive seasonality, with breeding season in spring-summer with sperm production. A great variation n parenchyma, when compared breeding was noticeable.(AU)

O objetivo do estudo foi estudar a morfologia microscópica do parênquima testicular de emas (Rhea americana). Foram utilizados 54 machos adultos criados em cativeiro de 2,5±0,5 anos de idade. Durante o abate comercial foram coletadas amostras de testículos em novembro/2005, dezembro/2006 e maio/2007, para efeitos de comparação. As amostras foram processadas e para microscopia ótica de rotina para análise. Foram medidas diâmetro total de túbulos seminíferos (ST), lúmen, espessura do epitélio e a proporção volumétrica dos componentes do parênquima. O ST apresentou forma circular nas seções transversais. Em novembro/2005 e dezembro/2006, se observaram os tipos de células germinativas e espermatozoides no lúmen. Em maio/2007, as amostras de epitélio se observaram escassas meioses e imagens de mitose e era difícil de ver qualquer espermatozoide, em muitos dos túbulos o lúmen era inexistentes ou diminuído de tamanho. Em dezembro/2006 e maio/2007, as médias das características estudadas foram: diâmetro dos túbulos 110,3 e 5,3 mµ, lúmen 52,4 e 4,5mµ, espessura do epitélio 57,8 e 0,7mµ, respectivamente. As proporções volumétricas foram: epitélio seminífero 75,6 e 75,9, cistos no epitélio 2,1 e 1,0, túbulos seminíferos 93,3 e 84,0, interstício 6,2 e 15,6, respectivamente. Foram apresentadas medidas microscópicas de túbulos seminíferos, diâmetro dos núcleos das espermátides. Estes dados confirmam a sazonalidade reprodutiva, com época de reprodução na primavera - verão, com a produção de esperma. Foi perceptível uma grande variação nas medidas do parênquima testicular, quando se comparou a estação reprodutiva.(AU)