Comparison of Serum Thyroid Hormone Levels in Green-winged Macaws (Ara chloropterus) Using Radio and Chemiluminescent Immunoassays

This study compared the use of radioimmunoassay (RIA) and chemiluminescent immunoassay (CLIA) to measure serum thyroid hormone levels in green-winged macaws (Ara chloropterus). The sample group comprised 20 male and 13 female (n = 33) healthy, captive green-winged macaws of reproductive age but outside of breeding season. Mean free triiodothyronine (T3), total T3, and free thyroxine (T4) measured by CLIA and RIA corresponded to 5.11 and 5.08 pmol/L (3.33 and 3.31 pg/mL), 1.59 and 1.56 nmol/L (103.5 and 101.5 ng/dL), and 8.25 and 8.82 pmol/L (0.64 and 0.69 ng/dL), respectively. Mean total T4 by RIA corresponded to 6.29 nmol/L (0.49 µg/dL). Mean free T4 and thyroid-stimulating hormone (TSH) levels differed according to immunoassay method, with higher values measured by RIA compared with CLIA. Sex influence was statistically significant in immunoassay results only on free T3 levels. Free T3 levels measured by RIA were higher than levels measured by CLIA in male birds, but this difference was not found with the female bird samples. Conversely, free T3 levels measured by CLIA were higher in the female macaws compared with male birds. Comparative analysis of thyroid hormone measurements in this study revealed that RIA and CLIA are equivalent methods to measure free T4 and total T3 levels but not TSH levels. These findings support the use of CLIA for free T4 and total T3 level determinations in green-winged macaws. However, the CLIA kit used in this study provided invalid total T4 level results for the macaws sampled. Radioimmunoassay and CLIA were equally ineffective for determining TSH levels in this species.

Fecal sex steroids and reproductive behaviors in harpy eagles (Harpia harpyja)

Aiming to improve our reproductive knowledge of large birds of prey, behavioral data and fecal steroids were assessed in captive pairs of Harpy eagles, a keystone species that is monogamous and resides in the Neotropics year-round. Adult individuals exhibited different reproductive outcomes and a breeding season extending beyond summer solstice (5-9 months) suggests that harpy eagles may not be absolutely photorefractory. Comparisons among breeding stages in males revealed that mean androgen levels in courtship were higher than in copulation and incubation, but no differences were detected in fecal progestagens or estrogens. Females had higher mean estrogen concentrations in courtship and copulation, whereas mean progestagen levels peaked during egg laying. Mean androgen concentrations were not significantly different among breeding stages in females. Assessment of six egg-lay cycles from three females demonstrated that fecal estrogens peaked predominantly between 31 and 18 days before oviposition (-31 to -18 days), and then remained low until 45 days after laying the first egg (+45 days). In contrast, fecal progestagens raised mostly between -20 and +1 day, lowering to baseline concentrations by +3 days. To our knowledge, this is the first study to describe in detail endocrine and behavioral data regarding reproduction in tropical eagles, which may serve in the future as a reference to developing breeding programs.

Doppler ultrasonography of the pectinis oculi artery in harpy eagles (Harpia harpyja)

Twenty harpy eagles (Harpia harpyja) without systemic or ocular diseases were examined to measure blood velocity parameters of the pectinis oculi artery using Doppler ultrasonography. Pectinate artery resistive index (RI) and pulsatility index (PI) were investigated using ocular Doppler ultrasonography. The mean RI and PI values across all eyes were 0.44±0.10 and 0.62±0.20 respectively. Low RI and PI values found in the harpy eagle´s pectinis oculi artery compared with the American pekin ducks one and other tissue suggest indeed a high metabolic activity in pecten oculi and corroborates the hypothesis of a nutritional function and/or intraocular pressure regulation.

Occurrence of hemotropic mycoplasmas in non-human primates (Alouatta caraya, Sapajus nigritus and Callithrix jacchus) of southern Brazil

Hemoplasmas, the erythrocyte-associated mycoplasmas, have been detected in several primates, causing mostly subclinical infection. This study aimed to determine the prevalence of hemoplasma infection in captive and free-ranging monkeys from southern Brazil, as well as factors and hematological abnormalities associated with infection. Blood samples from 40 non-human primates (NHP) were tested for hemoplasmas and coinfections. An overall of 10/40 (25.0%) NHP tested positive for hemoplasmas using PCR-based assays, including 9/14 (64.3%) black howler monkeys (Alouatta caraya) and 1/24 (4.2%) black-horned capuchin (Sapajus nigritus). Infection was not statistically associated with anemia, but wild-born monkeys and male black howler monkeys were more likely to be positive when compared with captive-born animals and female black howler monkeys, respectively. The sequences from the black howler monkey hemoplasma were similar (94% identity) to the squirrel monkey hemoplasma ("Candidatus Mycoplasma kahanei") and were phylogenetically located in a different cluster when compared to the human hemoplasma ("Candidatus Mycoplasma haemohominis").

Haematological values for captive harpy eagle (Harpia harpyja)

Decreasing of harpy eagle (Harpia harpyja) populations in natural environments, mainly in non-preserved areas, makes captive population management an important contribution to genetic diversity conservation. The aim of this study is to evaluate hematological parameters for captive harpy eagles maintained at the wild animals breeding center of Itaipu Binacional, Paraná State, Brazil. Fourteen blood samples from nine harpy eagles were collected from animals of both sexes, of different ages and with no clinical signs of disease. Significant variations were found in haematological values of hematocrit, hemoglobin, mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), leukocyte, a relative number of heterophils, absolute and relative number of lymphocytes, monocytes, eosinophils, basophils and plasma protein between groups of young (less than six months old) and adult birds. Comparing males and females there was variation in the values of erythrocytes, hemoglobin, mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH) on heterophils, absolute and relative number of lymphocytes, eosinophils and basophils. There was also variation in the values of red blood cells, hematocrit, hemoglobin, mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), leukocyte count, absolute number of lymphocytes, eosinophils and basophils among birds that study compared to another reference birds. Due to the limited information available on harpy eagle hematology, this study will be useful to the clinical assessment of birds maintained in captivity.

Anti-Rickettsia spp. antibodies in free-ranging and captive capybaras from southern Brazil

Capybaras (Hydrochaeris hydrochaeris) are among the main hosts of Amblyomma spp. ticks, which is able to transmit Rickettsia species to human beings and animals. Since they are often infested with potential vector ticks, capybaras may be used as sentinels for rickettsiosis, such as the Brazilian Spotted Fever. The aim of the present study was to determine the prevalence of antibodies against Rickettsia spp. using the indirect immunofluorescence assay (IFA) in 21 free-ranging and 10 captive animals from the Zoological Park of the 'Bela Vista Biological Sanctuary' (BVBS), Itaipu Binational, Foz do Iguaçu, Southern Brazil. Antigens of six rickettsial species already identified in Brazil (Rickettsia rickettsii, R. parkeri, R. bellii, R. rhipicephali, R. amblyommii and R. felis) were used for IFA. Ticks from each capybara were collected for posterior taxonomic identification. A total of 19 (61.3%) samples reacted to at least one of tested species. Seropositivity was found in 14 (45.2%), 12 (38.7%), 5 (16.1%), 4 (12.9%), 3 (9.7%) and 3 (9.7%) animals for R. rickettsii, R. bellii, R. parkeri, R. amblyommii, R. felis and R. rhipicephali, respectively. Two captive capybaras presented suggestive titers of R. rickettsii infection and one sample showed homologous reaction to R. parkeri. Only one free-ranging capybara presented evidence R. bellii infection. Ticks collected on capybaras were identified as Amblyomma dubitatum e Amblyomma sp. Results evidenced the rickettsial circulation in the area, suggesting a potential role of capybaras on bacterial life cycle.

A quantitative TaqMan PCR assay for the detection of Mycoplasma suis

AIM

To develop a TaqMan probe-based, highly sensitive and specific quantitative PCR (qPCR) assay for the detection and quantification of Mycoplasma suis in the blood of pigs.

METHODS AND RESULTS

Primers and probes specific to Myc. suis 16S rRNA gene were designed. The qPCR assay's specificity, detection limit, intra- and inter-assay variability were evaluated and its performance was compared with a Myc. suis conventional PCR assay (cPCR). Blood of two experimentally infected pigs, 40 Indiana pigs, 40 Brazilian sows and 28 peccaries were tested. The assay detected as few as ten copies of Myc. suis plasmids and was 100-fold more sensitive than the cPCR. No cross-reactivity with nontarget pig mycoplasmas was observed. An average of 1·62 × 10(11) and 2·75 × 10(8) target copies ml(-1) of blood were detected in the acutely and chronically infected pigs, respectively. Three (7·5%) pigs and 32 (80·0%) sows were positive while all peccaries were negative for Myc. suis.

CONCLUSION

The developed qPCR assay is highly sensitive and specific for Myc. suis detection and quantification.

SIGNIFICANCE AND IMPACT OF THE STUDY

TaqMan qPCR is an accurate and quick test for detection of Myc. suis infected pigs, which can be used on varied instrumentation platforms.

Special challenges of maintaining wild animals in captivity in South America

The author summarises the occurrence of major diseases in wild animals maintained in captivity in South America. The epidemiology, impact and significance of the diseases are discussed, together with appropriate husbandry practices to control and prevent transmissible diseases. The following animal groups and pathologies are considered in this review: poxvirus dermatitis, gastroenteritis, pneumonia, amoebosis and coccidiosis in reptiles, management practices and diseases (including botulism, bacterial enteritis, psittacosis, aspergillosis and parasitic diseases in birds), enterocolitis, pneumonias and internal parasites in non-human primates, canine distemper, parvoviruses, babesiosis, internal and external parasites in carnivores, tuberculosis and enteritis in tapirs, haemorrhagic disease in cervids.