BACKGROUND: The foramen magnum (FM) is an important landmark of the skull base and a transition zone between spine and skull as well as its close relationship to the brain and the spinal cord. So the FM has gained considerable interest due to its comparative anatomy, ontogeny, clinical, and animal breeding viewpoints. OBJECTIVES: The aim of this study was to determine morphology and morphometry of the occipital area of 20 mature and immature male Khouzestan river buffaloes. METHODS: 7 parameters of the occipital area and the shape of the FM in the skull of 20 mature and immature male Khouzestan river buffaloes were analyzed. RESULTS: The FM had 4 shapes including round, egg, oval, and tetragonal. In the mature and immature groups, the highest frequency of the FM shape belonged to oval. In the mature and immature groups, the tetragonal FM shape and the oval FM shape had the lowest frequency, respectively. The mean of the width, the length of the FM and the index of the FM in mature group was 38.60± 2.70, 35.34± 2.33, and 92.26±26 mm, respectively and 40.67± 1.51, 36.35± 2.33, and 90.23±3.65 mm in immature group, respectively. Amongst of the all parameters, the width and the length of the jugular process only differed significantly between mature and immature groups. CONCLUSIONS: The variations of the FM shape in river buffalo were more than those of reported animals. The  mean of  the length and  the width of  the FM,  the jugular processes width,  the length of the jugular process, the length  and width  of the  occipital condyles of male river buffaloes were greater than those of reported animals. The index of the FM in river buffalo was less than 100, which corresponded with the findings in rabbit, German shepherd and Pekingese dogs.

The size and shape of the foramen magnum were studied in skulls from 75 adult and 5 juvenile Pekingese dogs. After maceration of the skulls, the height, width, and area of each foramen magnum were measured, and various skull indices were determined. The shape of the foramen varied from ovoid to rectangular and had a dorsal notch in aU but 2 skulls. Prolapse of cerebellum or brain stem through the enlarged opening was prevented by a fibrous membrane covering he dorsal notch. Mean +/- SD area of the foramen was 138.1 +/- 26.1 mm(2); its mean total height was 15.0 +/- 2.9 mm, and its mean maximal width was 13.3 +/- 1.1 mm. Statistically, variability in the area of the foramen was mainly correlated with total height of the foramen, including the dorsal notch. Total height of the foramen was not correlated with age or gender. The degree of dysplasia, notch index, and occipital index of each foramen magnum were determined. To allow a more accurate evaluation of the morphology of the foramen, the foramen magnum index, defined as the ratio between the maximal width and the total height of the foramen, was also computed. Mean +/- SD foramen magnum index was 91.8 +/- 17.1 in the adult Pekingese dogs. Foramen magnum index was not significantly correlated with age, but was significantly larger in male than in female dogs. The large variability in the shape and size of the foramen magnum and the absence of any neurologic problems in dogs of this study indicate that the dorsal notch of the foramen magnum in brachycephalic dogs is a normal morphologic variation, rather than a pathologic condition.

Principal Component Analysis (PCA) is a powerful statistical tool used to reduce the complexity of large datasets while preserving significant variations. In this study, PCA was applied to explore the morphological traits of Japanese quails (Coturnix japonica), specifically focusing on skull measurements to identify key components affecting skull weight. A total of 112 quails (64 males and 48 females) were measured for various skull features, which were then analyzed through PCA. The analysis extracted three principal components for both sexes, explaining 52.76% of the variance in males and 56.52% in females. Key features such as Cerebellar Prominentia and Paraoccipital Process were identified as significant contributors to skull morphology. PCA was correspondingly applied to the measurements of male and female Japanese Quails' skulls, in order to identify those components which may explain most of the variation in skull weight. In this respect, simplification of data by PCA may indicate which morphological features supply most to the observed variation in skull weight and, therefore, provide interesting insights into the avian skull morphology. The goal of this research will be helpful in the laying of clear understanding regarding the anatomical features highly influential for skull structure, and of high importance to evolutionary biology, studies of veterinary importance, and poultry breeding programs. These findings highlight the applicability of PCA in anatomical studies and provide a deeper understanding of avian skull morphology.

OBJECTIVE To assess the extent of damage to the skull and brain of cadaveric dairy goat kids caused by a .22-caliber, 16-g pellet fired from a multipump air pistol at various power levels. SAMPLE Cadavers of 8 male and 7 female dairy goat kids ≤ 5 days old. PROCEDURES Each cadaver was positioned in sternal recumbency with the head and neck extended on a straw bale. A multipump air pistol was held with the barrel perpendicular to and 2.5 cm from the head at the intersection of 2 imaginary lines that extended from the lateral canthus of each eye to the middle of the contralateral ear base and fired at half (5 pumps; n = 2), intermediate (7 pumps; 2), or full (10 pumps; 11) power. The head and neck were removed from the carcass for CT imaging and gross sectioning to determine the location of the pellet and extent of damage caused to the skull and brain. RESULTS The pellet successfully penetrated the skull of all 13 heads shot at full or intermediate power and 1 of the 2 heads shot at half power. The pellet did not fragment after entering the skull of any cadaver and penetrated the brainstem (necessary for instantaneous death) in only 7 cadavers. CONCLUSIONS AND CLINICAL RELEVANCE The described technique was insufficient for use as a stand-alone method for euthanizing young dairy goat kids. Modification of the technique warrants further research to determine whether air pistols can be used to effectively euthanize young goat kids.

OBJECTIVE To determine the optimal anatomic site and directional aim of a penetrating captive bolt (PCB) for euthanasia of goats. SAMPLE 8 skulls from horned and polled goat cadavers and 10 anesthetized horned and polled goats scheduled to be euthanized at the end of a teaching laboratory. PROCEDURES Sagittal sections of cadaver skulls from 8 horned and polled goats were used to determine the ideal anatomic site and aiming of a PCB to maximize damage to the midbrain region of the brainstem for euthanasia. Anatomic sites for ideal placement and directional aiming were confirmed by use of 10 anesthetized horned and polled goats. RESULTS Clinical observation and postmortem examination of the sagittal sections of skulls from the 10 anesthetized goats that were euthanized confirmed that perpendicular placement and firing of a PCB at the intersection of 2 lines, each drawn from the lateral canthus of 1 eye to the middle of the base of the opposite ear, resulted in consistent disruption of the midbrain and thalamus in all goats. Immediate cessation of breathing, followed by a loss of heartbeat in all 10 of the anesthetized goats, confirmed that use of this site consistently resulted in effective euthanasia. CONCLUSIONS AND CLINICAL RELEVANCE Damage to the brainstem and key adjacent structures may be accomplished by firing a PCB perpendicular to the skull over the anatomic site identified at the intersection of 2 lines, each drawn from the lateral canthus of 1 eye to the middle of the base of the opposite ear.

The maxillary sinus appeared first among the sinuses of the skull at 92 days of prenatal stage. The early formation of frontal sinus was observed at 157 days in the cranial most part of the frontal bone while the early formation of palatine sinus was observed at 170 days. A total of five fontanelles were observed in prenatal skulls of buffalo. The largest and unpaired fontanelle was anterior fontanelle. The mastoid and sphenoidal fontanelle were paired. The ossification of anterior fontanelle was first observed at 164 days. All the fontanelles were ossified completely prenatally.

Objective: To determine MRI characteristics of the skulls and brains of sheep with chronic cerebral coenurosis (CC) caused by naturally acquired Taenia multiceps infection. Animals: 33 sheep with CC and 10 healthy control sheep. Procedures: Sheep underwent MRI of the head. Volumes of the cranial cavity and rostral and caudal fossas of the cranial cavity were determined. For CC-affected sheep, the number, location, and volume of T multiceps cysts were determined and the percentage volumes of cysts in the cranial cavity and rostral and caudal fossas of the cranial cavity were calculated. Focal and diffuse abnormalities of cranial bones in CC-affected sheep were identified. Brain edema and hemorrhage and signs of increased cranial pressure (ICP) in MRI images were determined. Results: Volumes of the cranial cavity and rostral and caudal fossas of the cranial cavity were significantly larger for CC-affected sheep versus healthy control sheep. Total volumes of cysts ranged from 4.40% to 46.93% in cranial cavities of sheep, 4.12% to 51.53% in rostral fossas of cranial cavities of sheep, and 15.24% to 68.30% in caudal fossas of cranial cavities of sheep. Moderate to severe diffuse cranial bone abnormalities and signs of increased ICP in MRI images were detected in 21 and 24 sheep, respectively, and were positively correlated with cyst volumes. Conclusions and Clinical Relevance: Results suggested that cranial cavity volume and morphological abnormalities can be detected in sheep with CC. These changes may reflect abnormalities in ossification of the cranial bones secondary to chronically increased ICP caused by development of T multiceps cysts.

Objective-To evaluate the osseous structures of the external acoustic meatus, tympanic cavity, and tympanic bulla of llamas (Lama glama) by use of computed tomography (CT) and establish measurement values for use in detection of abnormalities associated with the external or middle ear in llamas. Animals-10 adult llama heads without any evidence of ear disease. Procedures-Heads of 10 healthy llamas euthanized by use of a captive bolt striking the dorsal aspect of the skull were collected. Transverse images of the heads were acquired with 1-mm slice thickness, and images were reconstructed in sagittal and dorsal planes. Measurements of the bony structures of the external and middle ear of each head were obtained. Results-The osseous external acoustic meatus curved ventrally as it tracked medially. Its narrowest portion was located at the level of the tympanic annulus. The tympanic bulla conformation differed widely from the bubble-shaped tympanic bulla in dogs and cats. The bulla was divided by the stylohyoid fossa into a larger caudolateral and a smaller caudomedial process; its interior had a honeycombed structure with pneumatized cells similar to the honeycombed appearance of the human mastoid process. Conclusions and Clinical Relevance-Results provided new information regarding the shape and dimensions of the osseous external and middle ear structures in adult llamas without ear disease. Specific landmarks for location of the external acoustic meatus, tympanic cavity, and tympanic bulla in relation to each other were identified. Knowledge of the CT appearance of normal structures will help clinicians to identify changes attributable to middle ear otitis, external ear canal stenosis, or congenital malformations of the ear in this species.