Morphological comparison of the larynx and trachea of Chelonia mydas (Linnaeus, 1758), Caiman yacare (Daudin, 1802) and Caiman latirostris (Daudin, 1802).

The larynx is in the lower respiratory tract and has the function of protecting the airways, controlling, and modulating breathing, assisting the circulatory system, and vocalizing. This study aims to describe the anatomy and histology of the skeleton of the larynx and trachea of the species Chelonia mydas, Caiman yacare and Caiman latirostris. The study was conducted at the Federal University of Espírito Santo (UFES), using nine specimens of Ch. mydas, 20 of Ca. yacare and four of Ca. latirostris. Samples of the larynx and trachea were collected, fixed, and sent for dissection of the structures and subsequent macroscopic analysis. For histology, samples were processed by the routine paraffin embedding method and stained with hematoxylin-eosin and Verhoeff. For the three species, two arytenoid cartilages, a cricoid cartilage, a hyoid apparatus composed of a base and two horns were found. In Ch. mydas, two structures called thyroid wings were observed, not found in crocodilians. The trachea of crocodilians presented incomplete tracheal rings and musculature, while the trachea of Ch. mydas presented complete tracheal rings. Histologically, the entire cartilaginous skeleton of the larynx of the three species, as well as the tracheal rings, are constituted by hyaline cartilage.

Exploring the impact of high-energy diets on cattle: Insights into subacute rumen acidosis, insulin resistance, and hoof health.

Cattle lameness remains a significant concern, causing economic losses and compromising animal welfare. Claw horn lesions have been identified as a major cause of lameness in dairy cows, but their correlation with high-energy diets and ruminal acidosis remains unclear. Hence, the primary objective of this study was to assess the effects of a high-starch diet and a conventional diet on the rumen environment, acute-phase proteins, and metabolic alterations, with a particular focus on insulin resistance and the consequent implications for the histology of the hooves in Holstein steers. A total of 16 animals were divided into the high-starch (HS; 37% starch) and conventional (CON; 16.8% starch) groups. Glucose tolerance tests (GTT), blood analyses, rumen fluid analyses, and histological evaluations of the hoof tissue were conducted over a 102-d experimental period. The HS group showed a lower ruminal pH than the CON group, and with values indicating SARA. The plasma glucose and IGF-1 concentrations were higher in the HS group, suggesting an anabolic state. Both groups exhibited an increase in the insulin area under the curve (AUC) after the GTT on d 102. Histological analysis of the hooves showed a reduction in the length and width of the epidermal lamella in both groups. We found a significant negative correlation between the insulin AUC and the length and width of the epidermal lamella. Because both groups were similarly affected, the hypothesis that histological alterations were caused by the experimental diets still needs confirmation. Additionally, the development of SARA was not essential for the observed histological changes in the hoof. Further studies are warranted to thoroughly investigate the role of insulin and IGF-1 imbalances in claw health.

Clinical, anatomopathological, and immunohistochemical findings of a transitional cell carcinoma from nasal cavity, frontal and ethmoidal sinus with meningoencephalic invasion in a dog.

Background: Primary neoplasms of the nasal cavity and sinuses are uncommon in domestic animals, most of which are of epithelial origin, being adenocarcinoma the most common tumor diagnosed in this region. Some malignant nasal cavity neoplasms may invade the brain causing clinical neurological signs, as well as purulent nasal secretion and epistaxis. Case Description: A case of neoplasm is reported in a 14-year-old pincher presenting dyspnea, epistaxis, and neurological alterations. Necropsy revealed the presence of a mass in the oral cavity vestibule, and another in the whole nasal cavity with invasion of the cribiform plate, meninges and brain. Squamous cells carcinoma was diagnosed in the oral cavity and transitional carcinoma in the nasal cavity. The immunohistochemistry confirmed that the brain infiltration was of the same origin as the nasal cavity neoplasm. Conclusion: The present report describes a rare case of transitional carcinoma of the nasal cavity as well as the frontal and ethmoidal sinuses with brain invasion, confirmed by immunohistochemistry. It is extremely important for veterinarians to include neoplasms in their differential diagnoses, when these animals show chronic respiratory signs and neurological alterations that do not improve with appropriate treatment, always associating with complementary exams, for correct diagnosis establishment and prognosis formulation.