Monitoring the concentration of glucocorticoid metabolites (GCMs) in faecal samples is a non-invasive tool for physiological stress evaluation, particularly useful when studying wild species. However, both negative and positive stimuli (distress and eustress, respectively) can lead to a rise in glucocorticoids. Thus, besides validating whether GCM concentration in faeces reflects endogenous adrenal activity, we also need to identify behavioural indicators of distress to avoid misinterpretation. Therefore, we submitted four adult male spotted pacas (Cuniculus paca) to an exogenous adrenocorticotropic hormone (ACTH) challenge-test in a Latin square design (4 × 4) to monitor changes in the GCM concentration in faeces. We also aimed to describe behaviours potentially indicative of distress. We collected excreted faeces and video-recorded the animals’ behaviours for five consecutive days, one day before and four days after application of the following four treatments: 1st control (no-handling); 2nd control (intra-muscular [IM] injection of saline solution); low-dose ACTH (IM injection of 0.18 ml ACTH); and high-dose ACTH (IM injection of 0.37 ml ACTH). There was a peak in the concentration of GCM in faeces collected 24 h after the injection of the high-dose ACTH treatment. Additionally, independent of the treatments, spotted pacas spent less time on exploration and feeding states, while spending more time in the inactive but awake (IBA) state following the treatment application (challenge day). The use of GCM concentration in faecal samples together with the behavioural changes (less exploration and feeding, and more IBA) showed to be efficient as a non-invasive tool for welfare assessment of farmed spotted paca.

This study evaluated the short-term hormonal and behavioural responses to capture and radio-collar fitting in free-ranging pampas deer (Ozotoceros bezoarticus). Twenty adult deer (eleven females and nine males) were captured in the South Pantanal wetland (Brazil) and equipped with VHF radio-collars (marked deer). Untreated adult deer of the same sex were randomly chosen as the control group (nine females and nine males). On the day following capture, an observer followed all deer for faecal collection and behaviour evaluation. Faecal samples were immediately refrigerated and frozen at-20°C within a maximum of 12 h. Faecal glucocorticoid metabolites (FGM) were measured using an 11-oxoaetiocholanolone enzyme immunoassay. A qualitative behaviour assessment and the consequences of capture were evaluated using pre-defined terminologies and scores. Flight distance was recorded using a range finder. FGM increased from 19-22 h after capture onwards and peak concentrations were five times (median) higher as the respective baseline values. FGM values of marked deer were significantly higher at 22-25 and 25-28 h compared with controls. Marked male but not female deer had significantly higher FGM values at 22-25 and 25-28 h compared with their baseline values. Marked deer were significantly more fearful, less sociable and defensive than controls. The absences of significant increases of FGM in the captured female deer may indicate that females are less prone to capture stress. The significantly more fearful, and less sociable and defensive patterns observed in marked deer may be relevant during capture of lactating females or in areas with high predator pressure.

The performance of 4 serological tests for the diagnosis of Chagas disease was evaluated in Santander, Colombia, a region still presenting active transmission. Serum samples from 638 individuals were submitted to an enzyme immunoassay test (EIA), using total lysate of a local Trypanosoma cruzi strain and 52·5% were positive (335/638). A subset of this group (94 positive individuals and 90 seronegatives) was randomly selected for further serological confirmation. Three additional tests were used – indirect immunofluorescence (IIF) and 2 distinct enzyme-linked immunosorbent assays using total lysate of the Y strain (EIA BM) and a mixture of 2 recombinant antigens (EIA RA). Seventy-nine patients were seropositive in all tests (84·0% – 79/94). The number of positive sera with the IIF, EIA RA and EIA BM was 84/94 (89·4%), 80/94 (85·1%) and 79/94 (84·0%), respectively. In 15 out of the 94 EIA seropositive patients (16·0%), 10 individuals were negative in all 3 tests (10·6% – 10/94). One was negative in the EIA BM and positive in the other two tests (1·1% – 1/94) and 4 patients were positive, solely, in the IIF assay (4·3% – 4/94). Relative to the 90 EIA negative individuals, 89 were confirmed in all other tests (98·9% – 89/90). One individual, although seronegative in the IIF, was positive in both confirmatory EIA tests (1·1% – 1/90). In addition, 120 blood specimens were submitted to PCR amplification. This group consisted of 79 confirmed seropositive cases, 16 individuals with discordant serological results and 25 validated seronegative individuals. The PCR was able to detect the presence of parasite DNA in 67 out of the 79 seropositive patients (84·8%), in 8 individuals with discordant serology (50·0%) and in only one seronegative individual (4·0%). The results pointed to the necessity for performing more than one serological test, preferentially with antigens from autochthonous strains, to achieve a reliable diagnosis of Chagas disease in Colombia.