This study investigated the anatomy of the nutrient foramen (NF) in German Shepherds by recording the number, site, position, and direction of penetration of the nutrient canal (NC) in the humerus, radius, and ulna of 50 individuals. The site index of the nutrient foramen (SI) was calculated as the ratio of the length to the NF site from the proximal end to the greatest length of the bone. The NF diameter was measured using different sized needles. Most humeri had only one NF on the caudal surface, particularly on the lateral supracondylar crest, or distal cranial surface. All radii had one NF, usually on the caudal surface, while most ulnae had one NF located on either the cranial or lateral surfaces. The SI and NF diameters were 58.0~59.5% and 0.73~0.78 mm in the humerus, 30.4~30.9% and 0.74~0.76 mm in the radius, and 29.3~29.8% and 0.67~0.68 mm in the ulna, respectively. With the exception of the relatively proximal NF of the radius, the direction of penetration followed Berard's rule. This study provides novel information on the location and diameter of the NF and direction of the NC in the long bones of the pectoral limb of German Shepherds.
Extremities* ; Haversian System ; Humerus ; Needles ; Radius ; Ulna

This study investigated the anatomy of the nutrient foramen (NF) in German Shepherds by recording the number, site, position, and direction of penetration of the nutrient canal (NC) in the humerus, radius, and ulna of 50 individuals. The site index of the nutrient foramen (SI) was calculated as the ratio of the length to the NF site from the proximal end to the greatest length of the bone. The NF diameter was measured using different sized needles. Most humeri had only one NF on the caudal surface, particularly on the lateral supracondylar crest, or distal cranial surface. All radii had one NF, usually on the caudal surface, while most ulnae had one NF located on either the cranial or lateral surfaces. The SI and NF diameters were 58.0~59.5% and 0.73~0.78 mm in the humerus, 30.4~30.9% and 0.74~0.76 mm in the radius, and 29.3~29.8% and 0.67~0.68 mm in the ulna, respectively. With the exception of the relatively proximal NF of the radius, the direction of penetration followed Berard's rule. This study provides novel information on the location and diameter of the NF and direction of the NC in the long bones of the pectoral limb of German Shepherds.
Extremities* ; Haversian System ; Humerus ; Needles ; Radius ; Ulna

The brachiocephalic muscle in domestic mammals is formed as a homology of the sternocleidomastoid muscle and the clavicular part of the deltoid muscle since it results from reduction of the clavicle as a clavicular intersection. The cranial insertions of the brachiocephalic muscle vary among species in domestic mammals. In the dog, the brachiocephalic muscle comprises three parts, which arise from the clavicular intersection and insert at the humerus, the dorsal cervical raphe, and the mastoid process of the temporal bone. These three parts are named the cleidobrachial muscle, the cervical part of the cleidocephalic muscle, and the mastoid part of the cleidocephalic muscle, respectively. This complexity could confuse veterinarians and complicate surgical procedures in this area. Information about the normal structure of this muscle, and any variation therein, would help to avoid such situations. During dissections of a male cross-breed dog, we found that the brachiocephalic muscle had two bellies located on the mastoid part of the cleidocephalic muscle that extended from the clavicular intersection to the wing of the atlas and the mastoid process of the temporal bone. They were innervated by the accessory nerve and the ventral branches of the second, third, and fifth cervical nerves, and they were supplied by the ascending branch of the superficial cervical artery. These bellies were considered to be a rare variation of the muscle. This is the second report of a brachiocephalic muscle variation in a dog, in which the mastoid part of the cleidocephalic muscle was made of two bellies inserted independently. Such variations should be considered during anatomical dissections and surgical procedures.
Accessory Nerve ; Animals ; Arteries ; Clavicle ; Deltoid Muscle ; Dogs* ; Humans ; Humerus ; Male ; Mammals ; Mastoid ; Temporal Bone ; Veterinarians

Background: Aortic arch (AA) branching patterns vary among different mammalian species.Most previous studies have focused on dogs, whereas those on raccoon dogs remain unexplored. Objectives: The objective of this study was to describe the AA branching pattern in raccoon dogs and compare their morphological features with those of other carnivores. Methods: We prepared silicone cast specimens from a total of 36 raccoon dog carcasses via retrograde injection through the abdominal aorta. The brachiocephalic trunk (BCT) branching patterns were classified based on the relationship between the left and right common carotid arteries. The subclavian artery (SB) branching pattern was examined based on the order of the four major branches: the vertebral artery (VT), costocervical trunk (CCT), superficial cervical artery (SC), and internal thoracic artery (IT). Results: In most cases (88.6%), the BCT branched off from the left common carotid artery and terminated in the right common carotid and right subclavian arteries. In the remaining cases (11.4%), the BCT formed a bicarotid trunk. The SB exhibited various branching patterns, with 26 observed types. Based on the branching order of the four major branches, we identified the main branching pattern, in which the VT branched first (98.6%), the CCT branched second (81.9%), the SC branched third (62.5%), and the IT branched fourth (52.8%). Conclusions The AA branching pattern in raccoon dogs exhibited various branching patterns with both similarities and differences compared to other carnivores.