ANATOMY OF THE DOG-^ 



retain the spark of life, is perhaps more in- 

 tense in the dog than in any other animal, 

 even the human being. Were it otherwise, 

 dogs could not live to any advanced age, their 

 numbers would dwindle, and they could not 

 progress under modern living conditions, sep- 

 arated as most of them are from their natural 

 wild life of the woods and fields. 



Thanks to the tremendous natural stamina 

 of the dog's body, many remedies and indeed 

 not a few veterinarians have received credit 

 for saving the dog or keeping it alive when in 

 truth Nature and the vital'ty which Nature 

 has instilled during the hundreds of centuries 



the dog has lived his own life, dependent upon 



his own resources, should receive the credit. 



TEN MAIN DIVISIONS OF ANATOMY 



The physical structure or organization of 

 the dog (or man or any other mammal) di- 

 vides itself into the following ten main 

 groups : 



I. Skeletal or bone structure ; II. Muscular 

 system or movement; III. Circulatory or blood 

 system ; IV. Digestive system ; V. Excretory 

 system ; VI. Nervous system ; VII. Lymphatic 

 system ; VIII. Ductless gland system ; IX. Re- 

 productive system ; X. Sensual system or 

 organs of sense. 



/. THE SKELETON OR BONE STRUCTURE 



See pages 4, 5, 7, 16 for photographs and sketches of the dog's bone structure. 



A reference to the illustrations reveals clear- 

 ly the shape, proportion, size and relative 

 positions of the various bones of the skeleton. 

 Construction of Bone 



A bone is composed of two kinds of ma- 

 terial — outer or compact tissue and inner or 

 cancellated tissue. The cancellated tissue has 

 a spongy appearance, is light and porous, and 

 filled with red marrow. 



The outer surface of the bone is covered 

 with a thin membrance called the periosteum. 

 Thru the minute pores of this membrane and 

 thru the very small blood vessels, nourishment 

 passes into the bone. 



Bones have a "Give" 



The strength and condition of the bones 

 are dependent upon the proper mixture of 

 «arthy (mainly calcium and phosphorus) and 

 animal matter. The composition of bones is 

 about thirty parts by weight of the animal 

 matter to seventy of the earthy matter. 



Bones are not solid. Internally they are 

 porous, containing cavities of various sizes, 

 canals for blood vessels, and an abundance of 

 flat cells. In, fact bone is a dense form of 

 connective tissue, a living thing, not the iron- 

 like substance thot of by the popular mind. 



The skeleton or bone structure of the dog 

 is perhaps the most important of the ten di- 

 visions in the study of anatomy. The skele- 

 ton of the dog, not including the teeth, con- 

 sists of 228 to 232 pieces, varying according 

 to the age, being fewer in the old than in the 

 young as some bones closely related unite in 

 later years. 



The skeleton is the sum total of the bone 

 structure consisting of the bones themselves 

 and the framework of cartilage upon which 

 the soft tissues or flesh of the animal are 

 builded. 



General Divisions of the Skeleton 



There are two general divisions of the 

 skeleton. 



1. The axial, which might be termed the 

 up-and-down or vertical division ; it embraces 

 the backbone, the ribs, the skull and breast- 

 bone. 



2. The appendicular, which includes the 

 bones of the limbs, that is, the arms and legs. 



The splanchnic is very minor ; it includes 

 bones within the viscera or internal organs, 

 such as in the case of the dog, the cartilage in 

 the penis. 



Bones not Stiffly Anchored 



The joints or articulations are made possible 

 by ligaments. These fibrous bands determine 

 the freedom of movement according to their 

 thickness, attachment and other qualities. 



In this present study we can do little more 

 than to group the various bones of the skele- 

 ton and to state the names. 



The Parts of the Skull 



We begin with the skull, which in dogs 

 shows a wide variety of shapes, sizes, and 

 planes. The skull fits into the first bone of 

 the spinal column by a ball-and-socket joint, 

 and thereby the head has free movement. 



The cranium is the cavity which houses the 

 brain. 



• Photografs of the bulldog skeleton. Left a side view and excellent as an aid while reading 

 Sec. I. Center, 'head on" view of the head. Right, complete front view. 



