CLINICOPATHOLOGICAL FEATURES OF TOXOPLASMOSIS IN FOUR RED PANDAS (AILURUS FULGENS)

Morphological examination of the visual system and orbital region in the red panda (Ailurus fulgens fulgens)

OBJECTIVES

The red panda is currently the only surviving member of the Ailuridae family in the Caniformia suborder. In this study, we provide data on anatomical, morphometric, histological and histochemical examination of the orbital region, eyelids, orbital gland, and eye tunics in two adult males Ailurus fulgens fulgens from the Wroclaw Zoological Garden, Poland.

METHODS

The study involved morphometric analysis of the eyeball and selected accessory organs of the eye, along with analysis of the bony orbit, including its morphometry, macroscopic, and microscopic evaluation. Microscopic evaluation encompassed histological and histochemical staining, with the former involving hematoxylin & eosin (H&E), Movat pentachrome, picro-Mallory trichrome, Fontana-Masson, and the latter including PAS, AB pH 1.0, AB pH 2.5; AB pH 2.5/PAS, and HDI.

RESULTS

The upper (UE) and lower (LE) eyelids presented well-developed tarsal glands, sebaceous glands, and a characteristic simple alveolar gland (producing a mucous secretion). The palpebral part of the lacrimal gland was present. A single lymphoid follicle was observed only in the upper eyelids. The superficial gland of the third eyelid (SGTE) was a multilobar acinar complex that produces mucous secretion and is contained within the interlobular ducts of numerous aggregates of lymph nodes. The third eyelid (TE) was T-shaped and composed of hyaline tissue, containing CALT. The lacrimal gland (LG) also revealed a multilobar acinar complex that produced mucous secretion, with a single lymphoid follicle. The cornea consisted of 4 layers, as Bowman's membrane was absent. The Vogt palisades composed of 7-10 layers of epithelial cells were demonstrated. The pupil was horizontally ovoid at rest (post-mortem). The sphincter pupil and the dilator pupil were well developed. Macroscopically, the tapetum lucidum appeared as a milky, non-opalescent crescent. Histologically, the choroidal tapetum lucidum cellulosum consisted of 5 to 9 layers of loosely packed oval cells. The retina showed a composition similar to that of terrestrial nocturnal carnivores.

CONCLUSIONS

The results of our research indicate that the anatomical features of the eye and orbital region in the red panda share similarities with those described in the Musteloidea clade, as well as the Canidae and Ursidae families.

Seroprevalence and risk factor analysis of Toxoplasma gondii infection in Siberian tigers (Panthera tigris altaica) and giant pandas (Ailuropoda melanoleuca) in China

Toxoplasmosis, caused by Toxoplasma gondii, is a worldwide zoonosis. The aim of the present study was to detect the seroprevalence of T. gondii infection and associated risk factors among Siberian tigers (Panthera tigris altaica) and giant pandas (Ailuropoda melanoleuca) in China. Blood samples from 112 Siberian tigers and 22 giant pandas were tested for immunoglobulin G (IgG) against T. gondii by enzyme-linked immunosorbent assay (ELISA). The seroprevalence of T. gondii infection was 7.14% among Siberian tigers and 9.09% among giant pandas. No risk factors were found to be significantly associated with seroprevalence (P > 0.05). This is the first study to evaluate T. gondii infection in Siberian tigers on a large scale in China, and it also updates the information regarding the positivity rate of T. gondii infection among giant pandas in China.

Reaching over the gap: A review of trends in and status of red panda research over 193 years (1827-2020)

The red panda is a unique species taxonomically known for its peculiar biological and ecological characteristics, and extreme attractiveness. Despite being highly significant from conservation, scientific and economic perspectives, this species has experienced a declining population in the wild. Thus, to direct further research priorities and conservation actions and assess gaps in the current research trend of this species, a systematic literature review was conducted covering 175 journal articles published in English over 193 years (1827-2020). This review revealed that (1) the biological aspect was highly studied compared to other thematic areas of red panda (2) captive-based studies are relatively higher than the studies based in wild populations (3) China is leading the red panda studies amongst all red panda range (4) The universities were found contributing more to red panda studies than other institutions. Surprisingly, we found that the researchers from the non-range country were leading red panda study than those from range countries. Our review highlighted the need of prioritising studies in underrepresented locations and understudied thematic areas focusing on the assessment of climate change impact, bamboo distribution status, ecosystem services of red panda habitat, behavior and movement ecology, population estimation, and metapopulation dynamics. We urge landscape-level studies and long-term population monitoring. Besides, we also suggest the documentation and evaluation of the effectiveness of ongoing red panda-focused conservation programs. We also stress the need for strengthening the capacity of institutions and people from range countries.