Horses body characteristics & functions

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1 Need to Know Horses body characteristics & functions Things you need to know about a horse. The physical characteristics of horses have evolved over thousands of years. Horses have been domesticated for almost as long. These animals are used primarily for recreation, such as for show or racing. Horses are also still used in agricultural settings, for tasks that include riding, driving and pulling. These uses have resulted in the development of a number of horse breeds and types that display a wide variation in size, body shape and coat colour. Unlike dogs or cats, horses are prey animals. This means that horses: Feed on grains and grasses Tend to herd together for protection Will take flight in response to perceived danger or threats. Poll Forelock Muzzle Throatlatch Neck Crest {The parts Point of shoulder of a horse s Chest anatomy are Forearm also known as the Knee points of the horse. Many body parts have the same name as human body parts but have different functions. Anatomy refers to the form and structure of organisms. In comparison, physiology is the study of the functions of the body and its parts. Physiology looks at body systems, organs, tissues and cells. In Canada, equines are considered livestock, even though they are raised for recreation, work and competition. Horse owners and caregivers have a responsibility to know and understand a horse s anatomy and physiology, no matter why they own or use the horse. A horse s anatomy includes its skeletal system, muscles, the brain and nervous system, all internal organs and the hair and skin. Shoulder Croup Withers Loin Back Barrel Belly Flank Elbow Stifle Gaskin Fetlock Alberta SPCA 2013 albertaspca.org Permission granted to duplicate for classroom use 1 Hip Thigh Dock Hock Cannon Pastern Coronet Hoof

2 KNOW A HORSE S BODY CHARACTERISTICS Traditionally, a horse s size is measured in hands at the withers, which is the highest part of the backbone and is located between the neck and back. One hand equals about 10 cm. For example, riding horses can stand about 14 to 16 hands high and weigh 400 to 500 kg. Horses have hairy coats in a range of colours, which can include black, brown, grey, white and tan, and a long mane and tail. They grow a heavier winter coat in the fall and shed it in the spring. A horse s head is formed by the cranium, which encloses the brain, the bones of the forehead and face, and the muzzle, which consists of the nose, lips and the lower jaw, or mandible. Horses have powerful teeth and jaws and their teeth grow continuously as the surfaces wear down. A horse s head is held up by its long, flexible neck. The horse has unique eyes they are both monocular and binocular. Monocular means that the horse can see objects with one eye. As a result, the brain usually gets two images simultaneously. With binocular vision the horse can focus with both eyes and the brain receives only one signal. People only have binocular vision and see with both eyes at the same time. {The skeleton gives the horse its physical structure. The structure of a horse s skeletal system and the angles at which its bones connect determines the horse s physical capacity and athletic potential. Joints and ligaments allow the horse to move smoothly. The horse s body has a wide chest, which protects internal organs like the lungs and heart, and a muscular back. The tail helps to keep its hindquarters warm and swishes away insects. The tail also demonstrates behaviours. {The specialized structures of the horse s legs make it a fast and efficient runner. 2 Alberta SPCA 2013 albertaspca.org Permission granted to duplicate for classroom use

3 What is commonly perceived as the horse s knee is actually the equivalent of a person s wrist, and the leg from the fetlock down is actually a highly elongated foot. The tip of its toe is protected by the tough hoof and the sole helps absorb the impact of the foot against the ground. Many of the joints in the horse s leg are like hinges that allow forward and backward motion. This type of joint requires fewer muscles than a ball-and socket joint that can rotate in any direction. Therefore, the horse has long, light legs that allow a lengthy stride with a minimal expenditure of energy. A horse has the same requirements for water, energy, protein, vitamins and minerals as do all animals but differs in the type and function of its digestive system. The horse is a non-ruminant. Non-ruminants (humans, pigs and dogs) digest carbohydrates, protein and fat by enzymatic action. Ruminants (cattle, sheep and deer) use bacteria in the fore stomachs to digest fibre by fermentation and use enzymatic digestion in the small intestines. The horse s foregut includes the mouth, esophagus, stomach and small intestine. The hindgut includes the cecum, large colon, small colon and rectum. A horse s stomach can hold only about 8 to 15 litres. The food passes through the stomach into the small intestine and then to the cecum, large intestine and colon, called the hindgut. The process of fermentation, which allows horses to break down cellulose, takes place in the hindgut of the horse. This system allows the horse to digest simple carbohydrate sources such as starch from grain in the foregut. Fibrous sources such as oat hulls, soy hulls, beet pulp, hay and pasture grass are digested in the hindgut. The small intestine is where the nutrients from carbohydrates are absorbed. Nutrients from fibre in the diet are absorbed in the hindgut. LINK Go to Think Like a Horse, at thinklikeahorse.org/index-5.html, to explore many different photographs, illustrations and drawings some of them interactive on horse anatomy. How do these photographs, illustrations and drawings help to expand your understanding of horse anatomy? Find this and other weblinks on the Virtual Apprentice 2070 site at va2070/anatomy.html. Alberta SPCA 2013 albertaspca.org Permission granted to duplicate for classroom use 3

4 {The relationship between the structure and function of a horse s body can help you better understand, care for and responsibly manage a horse. The cards that follow provide a description of major body parts and their function. The poll is the highest point on a horse s head and is found between the ears. The crest is the top line of the neck. Withers are the prominent bony ridge near the base of the mane where the neck meets the back. A horse s height is measured at its withers. The point of the hip is the bony point that lies just forward and below the croup. The back stretches from the withers to the loin and includes part of the horse s spinal column. The loin is a short, muscled area that joins the back to the croup. The croup is the area at the top of the rump and in front of the tail. It extends from the highest part of the hip to the tail. The horse s tail helps provide the horse with balance. The tailhead is the base of the horse s tail. The tail has many small vertebrae in it, called the dock. The gaskin is a muscled are of the hind leg. It is above the hock and below the stifle. The thigh is a large muscled area below the croup. It is in front of the buttock and behind the stifle joint. The flank is the area between the belly and the hindquarters. The stifle is a joint, similar to a person s knee joint, at the front of the thigh in the flank area. It is the point where the horse s hind leg meets the body. It is the largest joint in the horse s body and stabilizes the leg when the horse is moving. 4 Alberta SPCA 2013 albertaspca.org Permission granted to duplicate for classroom use

5 The hock is the joint of the hind leg and is similar to a person s ankle joint. It is below the gaskin and above the cannon bone. Strong ligaments in the hock joint stabilize the leg and allow movement. The hoof is the hard outer covering that starts below the coronet band. It protects the sensitive part of the horse s hoof, known as the frog. The forearm is the upper part of the foreleg, from the elbow to the knee. It is muscular, so it can hold the heavy weight of the horse. The fetlock is the joint near the bottom of the horse s leg, between the long pastern bone and the cannon bone. The cannon is a long bone, on both the front and back legs, between the hock and the fetlock joint on the hind leg. The shoulder stretches from the withers to the point of shoulder. The shoulder is very muscular and provides a horse with a great deal of strength. It should slope gradually and be rounded. The shorter the shoulder muscle, the shorter the horse s stride will be. The knee is the joint of the front leg. It is located below the forearm and above the cannon bone. The throatlatch is the area behind the jaw where the head attaches to the neck. The pastern is the area above the coronet band and below the fetlock joint. The point of shoulder is the most forward part of the shoulder. Its connection with the horse s arm creates an angle that helps determine the length of the animal s stride. The abdomen or belly is the broad area underneath the horse between the elbow and the flank. The neck is the muscled area from the poll to the withers. The coronet is the area at the bottom of the pastern where the horse s hair stops and hoof growth begins. The elbow is the joint at the top of the forearm. The chest is the muscled area at the front of the horse. It is located from the neck down to the front legs. The width, depth and muscling of the chest influences how well the horse can move. A chest that is too wide produces a labouring, waddling stride and a chest that is too narrow may interfere with the horse s travelling. The muzzle refers to the area that includes the nostrils, chin and mouth. Adapted with permission from Parts of the Horse. 4-H Horse Reference Manual: Alberta Agriculture and Rural Development. www1.agric.gov. ab.ca/$department/deptdocs.nsf/all/4h7933/$file/g_partsofhorse.pdf Alberta SPCA 2013 albertaspca.org Permission granted to duplicate for classroom use 5