Chewing asymmetry in dogs: Exploring the importance of the fossa masseterica and first molar teeth morphology.

Dogs are animals with strong bite force. This strong bite mechanism has led to significant changes in the skeletal system such as fossa masseterica. It can be thought that one side is used more than the other side in chewing and is related to the preference of using the same side's hand, eye and foot. In the study, directional asymmetry and fluctuating asymmetry, which occurs as a result of chewing asymmetry, were examined on the first molar teeth and the fossa masseterica in 85 dog mandibles including a wide diversity of morphotypes. The association of high PC1 values for directional asymmetry with a pronounced cranial index, as evident in breeds like Pekingese, Pomeranian and Bulldog, indicates a potential evolutionary or selective breeding trend favouring brachycephaly. On the contrary, guardian breeds like the German shepherd and Bernese mountain dog, which typically require strong jaws for their roles, showcased reduced PC1 values, which might be related to their functional morphology. Similarly, the PCA results for the first molar teeth shape variations also highlighted the influence of cranial shape, with boxer dogs displaying notably higher PC1 values. The fluctuating asymmetrical distributions provided valuable insights into individualistic variations. Interestingly, no specific breed distribution trend was observed for these asymmetries, indicating a more individual-based variation rather than breed-based. It is essential to note that while these results provide valuable insights, further studies are required to understand the underlying causes better. Factors like genetic variations, developmental processes, dietary habits and external environmental factors could play pivotal roles in these observed morphological differences.

Potential Cytoprotective and Anti-Apoptotic Effect of Metamizole Alone and in Combination with Cytostatic Drugs Observed In Vitro in Canine (D-17) and Human (U-2 OS) Osteosarcoma Cell Lines.

Metamizole (dipyrone) is still a frequently used drug in human and veterinary medicine, especially for pain relief, sometimes also in osteosarcoma treatment. It has a very strong analgesic and antipyretic effect and weaker anti-inflammatory activity. Additionally, it has spasmolytic properties. It is used in many species, including dogs, cats, pigs, cattle, horses, and humans, in Europe, Canada, and South America. The aim of this study was to assess a potential synergism of metamizole as a non-steroidal anti-inflammatory drug with routinely used cytostatics (cisplatin, carboplatin, doxorubicin, and etoposide). In vitro studies were performed on a canine osteosarcoma D-17 cell line and a human U-2 OS cell line. We used the MTT method to assess cell viability, TUNEL staining to assess proapoptotic effects, and propidium iodide to analyse the cell cycle (potential arrest). The obtained results showed that metamizole at 50 µg/mL has potential cytoprotective and anti-apoptotic effects. Metamizole administered simultaneously with cytostatic drugs reduced their cytotoxic effect, which may suggest that such a combination of drugs used in the treatment of osteosarcoma may significantly reduce therapy effectiveness.

Los tipos craneométricos caninos aparecen bien expresados a nivel de conformación del arco cigomático / Craneometric canine types are well expressed at the level of the zygomatic arch conformation

Dentro del espectro de conformación del cráneo, se reconocen generalmente tres amplias categorías que se corresponden con el concepto de biotipo cefálico, determinado por el Índice Cefálico. El Estos tres biotipos cefálicos son: el braquiocefálico, mesaticefálico y dolicocefálico, pero están basados en medidas lineales. A fin de revisar esta clasificación en base a su geometría, se estudiaron 53 cráneos de perros adultos, correspondientes a los tres grupos craneométricos descritos: 16 braquicéfalos, 20 mesaticéfalos y 17 dolicocéfalos. Para ello se obtuvieron fotografías en el plano ventral, en las que posteriormente se ubicaron 17 hitos anatómicos que se analizaron mediante técnicas de morfometría geométrica. De estos hitos, 5 correspondían a la zona neurocraneal y el resto al esplacnocráneo. Los tres grupos craneométricos mostraron diferencias estadísticamente significativas entre ellos tanto por el tamaño como por la forma. Las variables que contribuyeron más a explicar la diferenciación fueron las ubicadas en el margen más lateral de los arcos cigomáticos y en la base de este mismo arco. Las variables esplacnocraneales presentaban una alometría mucho más marcada que las neurocráneos. Puesto que el arco cigomático debe ser considerado como parte del esplacnocráneo, sugerimos que es tan importante el índice cefálico (que tiene en cuenta la máxima anchura de la cabeza) como el facial (que tiene en cuenta la máxima anchura de la cara). La conformación neurocraneal sería mucho más conservativa y por ende el índice craneal, de mucho menor poder discriminatorio entre grupos. El cambio entre tipos se debería a los músculos masetero y temporal, que tienen su inserción en el arco.

Within the wide conformation of skull spectrum, there are generally three recognized broad categories that correspond to the concept of cephalic biotype, determined by the cephalic index. The three cephalic biotypes are: brachiocephalic, mesaticephalic and dolichocephalic, which are based on linear measures. In order to revise this classification based on its geometry, we studied 53 skulls of adult dogs, corresponding to the three craneometric groups previously described: 16 brachycephalic, 20 mesaticephalic and 17 dolichocephalic. Images on ventral plane were obtained and 17 anatomical landmarks were subsequently located and analyzed by means of geometric morphometric techniques. Five of those landmarks corresponded to the neurocraneal area and the rest of the splanchnocranium. The three craneometric groups showed statistically significant differences between them for both size and shape. The variables that contributed to the differentiation between them were located along the edge of the zygomatic arches and on the basis of this arch. Splanchnocranial variables also presented a much more marked allometry than the neurocraneal variables. Since the zygomatic arch should be considered as part of the splanchnocranium, we suggest that the cephalic index (which takes into account the maximum width of the head) is as important as the facial index (which takes into account the maximum width of the face). The neurocraneal index would be much more conservative, and therefore less discriminatory between the groups.

Morphometric Examination of Red Fox (Vulpes vulpes) from the Van-Yoncatepe Necropolis in Eastern Anatolia / Examen Morfométrico del Zorro Rojo (Vulpes vulpes) de la Necrópolis de Van-Yoncatep en Anatolia del Este

In the burial chamber M4 of the Van-Yoncatepe necropolis in eastern Anatolia, dated to the beginning of the first millennium before our time, fox skeletal remains have been discovered together with human skeletal remains. The fox remains consist of two skulls and a large number of skeletal (postcranial) bones. Examination of the material led us to the conclusion that five foxes had been buried in the chamber. Craniometric and osteometric measurements were carried out on the bones, and estimations of shoulder height and body weight have been calculated. Evaluation of all quantitative and qualitative data and comparison with modern fox species led to identification of the remains as red fox (Vulpes vulpes).

En la cripta mortuoria M4 del cementerioVan-Yoncatepe en Anatolia del Este, se encontraron restos de zorro y humanos que datan de mil años aC. Los restos de zorro corresponden a 2 cráneos y variados huesos postcraniales. Los estudios de dicho material nos lleva a concluir que, hubo 5 zorros enterrados en la cripta. Conjuntamente, se realizaron exámenes craniométricos y mediciones osteométricas, estimaciones de altura de hombro y cálculo de peso corporal. Las evaluaciones cuantitativa y cualitativa de la información obtenida y las comparaciones realizadas con especies de zorros modernos, permiten concluir que dichos hallazgos corresponden a zorro rojo (Vulpes vulpes).