Prevalence of cholelithiasis in lion tamarins (Leontopithecus spp.) kept under human care by using abdominal ultrasound.

BACKGROUND: Cholelithiasis is a digestive system disorder of multifactorial origin that occurs due to stones formed in the gallbladder. This study aimed at investigating by abdominal ultrasound examination the prevalence of cholelithiasis in lion tamarins kept under human care. METHODS: Thirty lion tamarins from five Brazilian zoos, including 17 golden lion tamarins and 13 golden-headed lion tamarins, were evaluated. RESULTS: Considering all lion tamarins, the overall frequency of cholelithiasis was 53.3% (16/30). There were no significant differences between species and sex. Cholelithiasis was predominant (75.0%) in lion tamarins older than 5 years. Septate gallbladder was observed in 86.6% (26/30) of the lion tamarins. Of these, 53.8% (14/26) had gallstones. Biochemical analysis revealed a moderate positive correlation between gamma-glutamyl transferase and the number of gallstones. CONCLUSIONS: Asymptomatic cholelithiasis is frequent in lion tamarins kept under human care. Therefore, systematic monitoring through ultrasound should be part of the preventive care of these animals.

Immunohematological features of free-living Alouatta belzebul (Linnaeus, 1766) red-handed howler monkeys in the Eastern Amazon.

The red-handed howler monkey (Alouatta belzebul) is one of the 35 threatened Brazilian primate species found in two highly endangered Brazilian biomes. Their Amazonian native populations have been declining due to exponential deforestation associated with human activities, especially the construction of dams. The studied population (n = 27) was located in the Belo Monte dam Area of Influence. For the first time, we presented hematological parameters and the basic profile of T (CD3) and B (BSAP PAX5) cells by immunocytochemistry. The results supported the hypothesis that the immuno-hematological profile is influenced by sex, age, and season. Eosinophils were significantly higher in females (p = 0.03), monocytes statistically greater in juveniles (p = 0.04), and total plasma protein increased significantly (p > 0.001) during the dry season. Furthermore, adults showed a statistically higher average absolute number of B lymphocytes than young individuals (p = 0.03), in contrast to T lymphocytes. Even without knowing the full history of antigenic exposure, these results not only contribute to elucidating the boundaries between health and disease but may help lay the groundwork for future research into the effects of anthropogenic stress on immune activation.

Serum biochemistry panel of free-living red-handed howler monkeys (Alouatta belzebul) in the Eastern Amazon.

BACKGROUND: The red-handed howler monkey (Alouatta belzebul) is one of 116 imperiled Brazilian primate species. We aimed to determine the serum biochemical profile of free-ranging red-handed howler monkeys in a highly disturbed area of the eastern Amazon. METHODS: We obtained serum samples from 26 monkeys, in which we analyzed 20 biochemical variables. RESULTS AND CONCLUSIONS: Calcium concentration was significantly lower in adult males (1.82 ± 0.25 mmol/L) than in adult females (2.10 ± 0.50 mmol/L). Both adults (males = 89 ± 85 UI/L, females = 62 ± 23 UI/L) had lower alkaline phosphatase serum activity than juvenile females (178 ± 120 UI/L). Adult male had higher levels of the direct bilirubin (13.9 ± 8.2 µmol/L) and creatinine (74.3 ± 19.4 µmol/L) than juvenile females (5.1 ± 1.4 µmol/L and 38.9 ± 15.0 µmol/L, respectively). This detailed biochemical profile may be useful for the management of red-handed howler monkeys in the wild and to support further studies at ex situ facilities.

Island and Riverine populations of Alouatta belzebul from the Brazilian Amazon parasitized by Pediculus mjobergi.

Mammalian lice are obligate hematophagous ectoparasites that remain on the host throughout the life cycle. This study showed an endangered wild howler species (Alouatta belzebul) parasitized by Pediculus mjobergi. Twenty-seven primates were rescued during wildlife rescue activities in the process of vegetation suppression at the Belo Monte Hydroelectric Power Plant (UHE), located on the lower Xingu River, in the Brazilian Amazon basin. Among the 27 primates examined from two vegetal formations (alluvial rainforest and liana-infested forest) areas, 13 (48.15%) were parasitized by lice with all positive primates being from alluvial rainforest. Optical and scanning electron microscopy allowed the visualization of the structures and the diagnostic characters of the lice species in greater detail expanding the current description. These results highlight the importance of considering ecological and regional features to provide a better understanding of the factors that promote parasitism.