Muroid rodents mostly have a complex stomach: one part is lined with a cornified (nonglandular) epithelium, referred to as a “forestomach”, whereas the rest is lined with glandular epithelium. Numerous functions for the forestomach have been proposed. We collated a catalog of anatomical depictions of the stomach of 174 muroid species from which the respective nonglandular and glandular areas could be digitally measured, yielding a “stomach ratio” (nonglandular:glandular area) as a scale‐independent variable. Stomach ratios ranged from 0.13 to 20.15, and the coefficient of intraspecific variation if more than one picture was available for a species averaged at 29.7% (±21.5). We tested relationships of the ratio with body mass and various anatomical and ecological variables, including diet. There was a consistent phylogenetic signal, suggesting that closely related species share a similar anatomy. Apart from classifying stomachs into hemiglandular and discoglandular, no anatomical or ecological measure showed a consistent relationship to the stomach ratio. In particular, irrespective of statistical method or the source of dietary information, dietary proxies did not significantly correlate with the stomach ratio, except for a trend towards significance for invertivory (insectivory). Yet, even this relationship was not convincing: whereas highly insectivorous species had high but no low stomach ratios, herbivorous species had both low and high stomach ratios. Thus, the statistical effect is not due to a systematic increase in the relative forestomach size with invertivory. The most plausible hypotheses so far associate the muroid forestomach and its microbiome with a generic protective role against microbial or fungal toxins and diseases, without evident correlates of a peculiar need for this function under specific ecological conditions. Yet, this function remains to be confirmed. While providing a catalog of published depictions and hypotheses, this study highlights that the function of the muroid rodent forestomach remains enigmatic to date.

Introduction: Captive tree shrews (Tupaia belangeri) are widely used as experimental models for neurological, visual, and infectious disease studies. Despite evidence suggesting a genetic or physiological predisposition to systemic amyloidosis in this species, its clinicopathological characteristics are still poorly understood. The present study aimed to characterize clinicopathological changes associated with systemic amyloidosis in a captive breeding colony of Tupaia belangeri (T. belangeri) and to explore potential early ante-mortem indicators in blood indices, imaging, or clinical examination of the disease.Materials and methods: Nineteen T. belangeri were included in the present study (seven males, 12 females) with a mean age of 3.3 years from a single institutional breeding colony at the University of Veterinary Medicine Hannover, Germany. Fifteen animals underwent standardized ante-mortem clinical assessment, including physical and ophthalmic examination, serum biochemistry, urinalysis, radiography, and abdominal ultrasonography, followed by necropsy and histopathology. Four animals were included solely on the basis of pathological and histological examination due to long intervals between the prior clinical evaluation and necropsy. Amyloid was identified histologically by Congo red staining and confirmed as AA-type by immunohistochemistry.Results: Systemic AA-amyloidosis was detected in 74% of the examined T. belangeri (14/19), predominantly affecting the kidneys and intestines. A significant association was observed between renal cysts and amyloid deposition. An association with urine specific gravity was observed, while no significant associations were identified between amyloidosis and other biochemical, urinary, radiographic, or ultrasonographic parameters, nor with sex, body weight, or age.Conclusion: Systemic AA-amyloidosis appeared to be common in captive T. belangeri, predominantly affecting the kidneys and intestine, while lacking reliable ante-mortem clinical or laboratory indicators, highlighting the need for improved diagnostic approaches.

Amphibian populations are undergoing dramatic global declines, with infectious diseases recognized as major contributors. While chytridiomycosis, caused by Batrachochytrium dendrobatidis (Bd), and disease caused by ranaviruses are well known, herpesviruses in amphibians remain comparatively neglected. We conducted a passive survey using carcasses collected between 2022 and 2025 in Schleswig-Holstein, northern Germany. Dead amphibians (n = 187) were dissected. Skin, kidney, liver, and brain samples were screened for Bd, ranaviruses, bufonid herpesvirus 1 (BfHV1), and ranid herpesvirus 3 (RaHV3) by PCR. BfHV1 was detected in nearly half of the Bufo bufo (common toads; 48.6%), while RaHV3 was identified in 23.6% of the Rana temporaria (common frogs) examined. Bd was detected in a single B. bufo, while ranaviruses were not detected. BfHV1 was present in skin, liver, kidney, and brain samples, whereas RaHV3 was detected exclusively in skin samples. No macroscopical or histological lesions characteristic of herpesviruses or Bd were found. However, the carcass-based approach frequently limited detailed examination due to compromised sample quality. Our findings confirm the presence of amphibian herpesviruses (BfHV1 and RaHV3) in the region without associated lesions, raising questions about their potential to cause systemic infections. Furthermore, our results highlight the limitations of carcass-based surveillance and underscore the need for complementary diagnostic approaches, such as immunohistochemistry and meta-omics.

Emerging diseases in wildlife pose significant diagnostic challenges, with increasing evidence that not all cases of inflammatory disease can be directly attributed to infectious pathogens. This case series shows the results of clinical examination, magnetic resonance imaging, and necropsy results of two foxes, a silver fox (Vulpes vulpes) and a polar fox (Vulpes lagopus), with non-suppurative meningoencephalomyelitis. Extensive diagnostics, including pathogen screening and next-generation sequencing, failed to identify a definitive causative infectious agent. These cases suggest the possibility of an immunopathologic disease, highlighting the need for immunological assessments in wildlife disease investigations.

Three different digital detector systems were used to study the effect of a defined radiation dose reduction on the image quality of digital radiographs in bearded dragons (Pogona vitticeps). A series of radiographs of seven bearded-dragon cadavers with a body mass ranging from 132 g to 499 g were taken in dorsoventral projection. The digital systems employed included two computed radiography systems (CR) (one system with a needle-based and one with a powdered-based scintillator) and one direct radiography system (DR). Three levels of the detector dose were selected: A standard dose (defined based on the recommended exposure value of the CR_P, D/100%), a half dose (D/50%), and a quarter dose (D/25%). Four image criteria and one overall assessment were defined for each of four anatomic skeletal regions (femur, rib, vertebra, and phalanx) and evaluated blinded by four veterinarians using a predefined scoring system. The results were assessed for differences between reviewers (interobserver variability), radiography systems, and dosage settings (intersystem variability). The comparison of the ratings was based on visual grading characteristic (VGC) analysis. Dose reduction led to significantly lower scores in all criteria by every reviewer, indicating a linear impairment of image quality in different skeletal structures in bearded dragons. Scores did not differ significantly between the different systems used, indicating no advantage in using a computed or direct radiography system to evaluate skeletal structures in bearded dragons. The correlation was significant (p ≤ 0.05) for interobserver variability in 100% of the cases, with correlation coefficients between 0.50 and 0.59. While demonstrating the efficacy of the use of digital radiography in bearded dragons and the similar quality in using different computed or direct radiography systems, this study also highlights the importance of the appropriate level of detector dose and demonstrates the limits of post-processing algorithm to compensate for insufficient radiation doses in bearded dragons.