Fabiano José Ferreira de Sant’aNa

Objective: To evaluate the precorneal tear film (PTF) of clinically healthy sheep using the tear ferning test (TFT) and investigate its association with conjunctival histological parameters. Animals Studied: One hundred and thirty‐four eyes from 67 adult sheep. Procedures: Tear samples were collected and graded by three evaluators using the Rolando and Masmali grading scales. Digital stereological analysis of tear ferning patterns was performed using STEPanizer to quantify crystalline points. Conjunctival histology included assessment of inflammatory cell infiltration and goblet cell (GC) density. Data were analyzed using descriptive statistics, Spearman's correlation, Kendall's coefficient of concordance, and simple linear regression. Results: Rolando and Masmali grading scales showed strong positive correlations between right and left eyes ( r = 0.922 and 0.886, respectively; p < 0.0001), demonstrating high consistency between eyes. STEPanizer crystal point counts were strongly and negatively correlated with TFT grades on both scales ( r = −0.826 to −0.890; p < 0.0001). Linear regression showed that stereological measurements explained 66%–83% of the variation in TFT grades ( R ² = 0.66–0.83). Interobserver agreement was acceptable (Kendall's W = 0.69; p < 0.05). No significant correlations were found between TFT grades and histological parameters. Mild lymphocytic infiltration predominated (83.96%), while only weak negative associations were observed between TFT grades, GC density, and inflammatory infiltrate. Conclusions: In clinically healthy sheep, TFT patterns appear to be influenced primarily by tear film physicochemical characteristics rather than routine conjunctival histological findings. Combining TFT with digital stereological analysis provides an objective and feasible approach for PTF characterization in veterinary ophthalmology.

Canine cognitive dysfunction syndrome (CCDS) shares notable clinical and molecular similarities with Alzheimer's disease (AD), supporting the value of cross-species translational research to enhance diagnostic and therapeutic approaches for both conditions. These disorders are progressive neurological diseases characterized by abnormal accumulation of neurotoxic proteins, primarily amyloid-β and tau. Their pathological aggregation induces neural injury and cerebral dysfunction, culminating in comparable clinical manifestations in dogs and humans. Exosomal microRNAs represent a promising class of molecular biomarkers for early diagnosis and provide insights into disease progression. Current diagnostic strategies include neurological evaluation, advanced imaging techniques, and, in dogs, behavioral assessments based on owner-reported observations. These assessments employ standardized rating scales such as the Canine Cognitive Dysfunction Rating Scale, the Canine Dementia Scale, and the DISHA questionnaire, which evaluate key signs of CCDS, including disorientation, altered interactions, sleep-wake cycle disturbances, house-soiling, and anxiety. This review highlights advances in understanding AD and canine cognitive dysfunction syndrome, linking veterinary and human medicine to foster translational insights benefiting both fields.

Increasing life expectancy has been accompanied by a higher prevalence of age-associated conditions, underscoring the need to better understand biological mechanisms of aging and to identify accessible biomarkers. Extracellular vesicles (EVs) are lipid-bilayer vesicles that mediate intercellular communication by transporting proteins, lipids, and regulatory RNAs, including microRNAs (miRNAs). Here, we investigated whether the abundance, morphology, and molecular cargo of plasma-derived EVs differ between young and senior dogs. Blood samples were obtained from 24 clinically healthy dogs in Gama (Federal District, Brazil), and plasma EVs were isolated by sequential centrifugation, filtration through a 0.22 μm filter, and ultracentrifugation. EVs concentration and size distribution were assessed by nanoparticle tracking analysis (NTA), morphology by transmission electron microscopy (TEM), and cargo by quantification of total protein and sterols using commercial assays. In addition, we quantified miR-19b, miR-29c, miR-7, miR-155, and miR-21 by Real Time Quantitative Polymerase Chain Reaction (RT-qPCR). Senior dogs exhibited a lower plasma EV yield and greater size heterogeneity, with a higher proportion of larger EVs. Total protein and sterol content per starting plasma volume were reduced in the senior group; however, sterol normalized per EV was increased, consistent with compositional remodeling of circulating vesicles with age. Finally, EV-associated miRNA levels were reduced in senior dogs, particularly miR-19b and miR-29c. Collectively, these findings indicate that canine aging is associated with marked changes in plasma EV abundance, morphology, and cargo, indicating that EVs could represent a promising tool for investigating age-related disorders in dogs.

Objective: To report the diagnosis and treatment of an orbital choristoma in a 2‐year‐old male jaguar ( Panthera onca ). Animal Studied: Jaguar ( Panthera onca ). Procedures: The patient presented with unilateral periorbital edema, strabismus, exophthalmia, epiphora, and conjunctivitis. Initial diagnosis was achieved via general physical and ophthalmic exams, ultrasound, computed tomography, and cytology. The cystic structure was surgically excised and submitted for histopathology. Results: Histopathology provided definitive diagnosis of a choristomatous cyst of lacrimal or conjunctival origin. Recovery was successful, without complications or recurrence. Conclusion: This is the first report of an orbital choristoma in wild felids, reinforcing the importance of advanced imaging and a multidisciplinary approach for the management of rare pathologies.

One hundred and nine canine ovaries were collected by ovariectomy and analyzed by histopathology. Sixty-three lesions were neoplastic (57.8%), 41 were cystic (37.61%), and five consisted of circulatory changes (4.59%). Follicular cysts (29/109, 26.6%) were the most commonly diagnosed lesion, followed by granulosa cell tumor (27/109, 24.77%), papillary adenocarcinoma (16/109, 13.76%), dysgerminoma (9/109, 8.26%), cystic corpora lutea (9/109, 8.26%), papillary cystadenoma (4/109, 3.67%), different multiple cysts (3/109, 4.92%), hemorrhage (3/109, 2.75%), malignant mesenchymal neoplasm (2/109, 1.83%), luteoma (2/109, 1.83%), vascular hamartoma (2/109, 1.83%), and one case each of the following neoplasms (1/109, 0.92%): leiomyoma, leiomyosarcoma, and teratoma. The cases were predominantly diagnosed in mixed-breed dogs (22/109), Shih-Tzu (15/109), Poodle (9/109) and Yorkshire Terrier (9/109), with ages ranging from 1 to 18 years (mean=9.1 years). Ovariectomy was performed for three main reasons: elective surgery (46/109), ultrasonographic evaluation (23/109) and reproductive clinical signs (24/109). The most common clinical signs included vaginal discharge (12/109) and irregular estrus (5/109). In addition, the affected animals showed the following uterine lesions: pyometra (23/109) and cystic endometrial hyperplasia (12/109). This study demonstrated that neoplasms and cysts are common lesions in canine ovaries obtained via ovariectomy and that these alterations do not necessarily result in reproductive or specific clinical signs.

Diagnostic imaging methods have been used in human medicine to identify and examine cadavers to determine the cause of death. In veterinary medicine, the use of these resources is still scarce and little known, and it is necessary to establish the contribution that methods such as ultrasound could provide to the investigation of the cause of death in domestic and wild animals. Postmortem ultrasonography (PMUS) can help forensic science find injuries that even in conventional necropsy go unnoticed. Thus, knowing the sensitivity and accuracy of the method is important and, therefore, the present study aimed to evaluate the applicability of the technique and describe the abdominal ultrasound findings in carcasses of wild mammals that died of natural causes and in different states of autolysis. Considering that wild animals are often found in adverse situations, such as the time elapsed before they are discovered, the conservation temperature and environmental conditions that may mask the true state of autolysis, and since ultrasound is portable, this tool becomes important for the forensic expert’s decision‐making. Thus, we hypothesise that the application of PMUS is an important alternative for establishing the thanatological state (TS) and the conditions for performing conventional necropsy. The choice of wild mammals was made due to their similarity with domestic mammals, which facilitates the search for literature and standards. Animals received by the Instituto de Criminalística Nacional (National Forensic Institute) of the Federal Police of Brazil were used. Eighteen wild mammal carcasses were examined, in varying autolytic states: three pumas ( Puma concolor ), three jaguars ( Panthera onca ), two South American coatis ( Nasua nasua ), two giant anteaters ( Myrmecophaga tridactyla ), two white opossums ( Didelphis albiventris ), one pampas deer ( Ozotoceros bezoarticus ), one capybara ( Hydrochoerus hydrochaeris ), one maned wolf ( Chrysocyon brachyurus ), one black‐eared opossum ( Didelphis aurita ), one tayra ( Eira barbara ) and one tapeti ( Sylvilagus brasiliensis ). The accuracy and sensitivity of the ultrasound examination were observed in four TSs: zero 0 (intact), I (mild autolysis), II (moderate autolysis) and III (marked autolysis). The ultrasound evaluation was more sensitive for TS 0 and I; however, it was still possible to evaluate the liver, spleen, kidneys, small intestine and urinary bladder in advanced TS (II and III). The greater the degree of autolysis, the fewer structures and details were visualised. It was concluded that intact or discretely autolysed wild mammals are the most suitable for evaluation by postmortem ultrasound and kidneys and gallbladder were the main structures visualised in cases with advanced autolysis (TS II and III). The findings of this study should be considered preliminary, given that the sampling design was heterogeneous and comprised a limited number of individuals per species.

This study provides the first description of the anatomy and histology of the female internal genital organs of Mico marcai. Descriptions were based on samples collected from two free‐ranging specimens. As in other species of Platyrrhini, the ovaries were oval‐shaped. Histological findings suggest both females were at the beginning of the luteal phase, as shown by the presence of luteal tissue in the ovaries and the high incidence of follicular atresia. As described in other primates, branching longitudinal folds and a tunica muscularis were seen in uterine tubes in M. marcai. The tunica muscularis is responsible for the peristaltic action that carries the oocyte towards the uterus. The uterus had a collagen‐rich endometrium with high numbers of simple tubular glands. Different from other primates, in M. marcai the vagina was lined with non‐ keratinized stratified squamous epithelium with PAS‐positive vaginal fluid. Measurement of serum levels of reproductive hormones is warranted to explain histological changes in female internal genital organs of M. marcai in the different phases of the reproductive cycle.

Antimicrobial resistance (AMR) is a major public health concern influenced by antimicrobial use (AMU) in animal production systems. In swine, metaphylactic treatments may contribute to the emergence and dissemination of resistance genes. In this study, we isolated bacteria from the nasal cavities of 50 sows across 10 farms in the Federal District, Brazil. A total of 132 bacterial isolates were obtained and tested for phenotypic resistance to 23 antimicrobials using the disk diffusion method. Resistance was detected against all tested antimicrobials, with an overall resistance rate of 55.6% (1605/2888 tests). The highest resistance rates were observed for bacitracin (92.4%) and penicillin (79.2%), while lower resistance rates were found for aminoglycosides. Most isolates exhibited multidrug resistance to 7–9 classes of antimicrobials, including strains of Staphylococcus, Escherichia coli, and Klebsiella—all of which are relevant in the context of One Health. Actinobacillus suis showed the highest resistance levels among all identified species. AMR was positively correlated with both the duration and the number of antimicrobial agents used in feed, reinforcing the need for prudent AMU practices. The use of autogenous vaccines against Pasteurella multocida was associated with reduced lung lesions, underscoring the value of vaccination in disease control. AMR surveillance programs may benefit from including bacterial colonizers from the microbiota, though further studies are necessary to better understand the resistance dynamics of these commensals.

Zoonotic poxviruses, including monkeypox virus (MPV), the causative agent for Mpox disease, have gained significant media and scientific attention due to recent outbreaks in human populations across the globe. The increase in human cases of poxvirus infection is not unexpected, as routine vaccination against smallpox (a disease caused by the poxvirus variola virus, which cross protects against other orthopoxviruses) was discontinued in the 1980s after its eradication. Large numbers of vertebrate and invertebrate species are susceptible to infection by Poxviridae . Clinical signs and histologic lesions caused by genetically different poxviruses can be strikingly similar with some notable exceptions (eg, poxviral infections in fish). The purpose of this article is to review poxvirus pathology and pathogenesis observed in species of agricultural significance including poultry, cattle, goats, sheep, camels, swine, rabbits, horses, salmon, and carp.

Studies have demonstrated that many reproductive disorders can compromise the binding pattern of glycosidic residues, mainly in cows and sows. In the current study, the binding pattern of lectins was characterised and compared in normal and pathological ovaries of bitches. Fourteen biotinylated lectins (BSA‐1B, Con‐A, DBA, LCA, PHA‐E, PHA‐L, PNA, RCA‐1, SBA, SJA, STA, WGA, s‐WGA, UEA‐1) were used. In ovaries without lesions, the predominant staining for RCA‐1 was observed in the zona pellucida (ZP) of initial follicles, in the oocytes of primordial and primary follicles, and in the artery wall. For WGA, the reaction predominated in the mesothelium, in the ZP of secondary follicles, in the corpus luteum (CL) and in the oocyte of secondary follicles. Reactivity for STA was more pronounced in the mesothelium and ZP of developing follicles. The mesothelial cells and the CL were mainly marked for LCA. PHA‐L was stained in the mesothelium, CL, and connective stroma, while the lectin PHA‐E showed reactivity especially in the stroma, mesothelium, and artery wall. In the cystic ovaries, changes in the reaction of some lectins were noted in various structures adjacent to the cysts. RCA‐1 staining was reduced in the ZP and oocyte of primordial, primary, and secondary follicles, while there was an increase of staining in endothelial cells. With WGA lectin, there was a reduction in CL and an increase in endothelial cells. Reactivity to STA was reduced in the ZP of primary and secondary follicles and increased in endothelial cells. LCA was also reduced in the CL and ZP of primary and secondary follicles. For the PHA‐L lectin, the staining was reduced in the mesothelial cells, CL, and ZP of the primary follicles, while for PHA‐E the reduction occurred in the stroma, oocyte of the primary follicles, and in the GC of the secondary follicles. In all neoplasms analysed (dysgerminoma, granulosa cell tumour, adenocarcinoma), there was also a reduction in reactivity to various lectins, both in the neoplastic cells compared to the cells of origin and in the adjacent non‐neoplastic ovarian tissue. The data from the current study suggest that the changes in ovarian glycosidic residues observed in cysts and neoplasms may contribute to infertility in bitches.