Horse anatomy - skeleton, musculature, organs and their functions
The anatomy of the horse is fascinating and complex. From the skeleton and muscles to the digestive and respiratory organs - each system has a crucial function for health and performance. In this article, you will learn all about the structure of the horse's body, common diseases and how you can provide your horse with optimal support through targeted training, correct feeding and care.
Contents
➡️ Video tip: Horse anatomy from a new perspective with David O'Connor
Olympic championDavid O'Connor explains the fascinating anatomy of the horse and draws fascinating comparisons with the human body. Did you know that horses have no muscles below the knee - similar to our hands? Or that what we perceive as a horse's back is not actually its back? An exciting insight into the anatomy and biomechanics of the horse!
Horse skeleton - structure and function
The horse's skeleton forms the stable foundation of the body and provides stability, protection and mobility. It consists of around 205 bones, which are connected by joints, tendons and ligaments. This structure enables high resilience and flexibility, which is essential for a flight animal.
➡️ Video tip: The anatomy of the horse - a look inside
Dr.Liz Barrett, sports horse veterinarian and surgeon at the Hagyard Equine Medical Institute, explains the most important bones, organs, ligaments and tendons of the horse. Her lecture is accompanied by a digital model that visualizes the individual structures.
How many bones does a horse have?
An adult horse has around 205 bones, although slight variations are possible depending on the breed and individual differences. Particularly important are the supporting bones of the legs, the spine and the joints, which are crucial for the horse's locomotion and balance.
Horse head
The horse's skull protects the brain, supports the sensory organs and enables food intake. Most of the skull bones are firmly fused together, only the lower jaw remains movable and enables chewing.
Spine horse
The horse's spine forms the central axis of the body and consists of around 54 vertebrae. It provides stability, mobility and power transmission between the forehand and hindquarters.
Thorax horse
The rib cage protects the vital internal organs and consists of 18 pairs of ribs and the sternum. It is flexible enough to allow breathing, but also stable enough to support the weight of the upper body.
Forelegs (forehand)
The forelimbs are responsible for shock absorption and carrying the body weight. As horses do not have a collarbone, they are only attached to the trunk by muscles, tendons and ligaments. This ensures a high degree of flexibility and cushioning during movement.
Hind legs (hindquarters)
The hind limbs are responsible for power transmission and forward momentum. They are firmly connected to the spine via the pelvis, which ensures effective power transmission to the entire body.
Hoof horse anatomy
The hoof is the lowest part of the horse's leg and bears the entire body weight.
Equine musculoskeletal system
The horse's musculoskeletal system consists of two main components:
- The passive musculoskeletal system - includes bones, joints, tendons and ligaments.
- The active musculoskeletal system - comprises the muscles that ensure movement and power transmission.
A healthy musculoskeletal system is crucial for a horse's performance and well-being. Incorrect strain, incorrect training or lack of care can lead to problems such as lameness, muscle tension or joint diseases.
Passive musculoskeletal system
The passive musculoskeletal system consists of the horse's bones, joints, ligaments and tendons. It provides structure, stability and flexibility.
Joints of the horse
The joints connect bones together and enable movement. They are equipped with cartilage and synovial fluid to minimize friction.
Important joints of the horse and their function
Tendons and ligaments
Tendons and ligaments play a central role in the movement and stability of the horse's leg. They connect bones and muscles and ensure that the limbs function correctly. Injuries in this area are among the most common orthopaedic problems in sport and leisure horses.
Difference between tendons and ligaments
- Tendons connect muscles to bones and transfer muscle power to the skeleton. They enable movement and absorb loads.
- Ligaments connect bones to each other and stabilize the joints. They limit the mobility of the joints and protect against overstretching.
Tendon damage horse
Tendon damage are often caused by overloading, incorrect loading or incorrect training. The flexor tendons are particularly affected, as they absorb enormous forces with every step. Overloading can lead to inflammation, fiber tears or even complete tendon ruptures.
➡️ Video tipTendon damage in horses - causes, detection & modern therapies!
Tendon damage is a common injury that can be caused by overloading. Dr. Clemens Hayessen uses real cases to explain how to recognize tendon problems early on, what treatment options are available and how you can support your horse in the best possible way.
Pastern damage horse
The fetlock joint is one of the most important ligaments in the horse's leg, as it supports the fetlock joint and protects it from overloading. If it is overstressed or injured, this can lead to fetlock strap damage.
📖 Reading tip: Fetlock strap damage in horses - causes, diagnosis & treatment
Fetlock strap damage is a serious injury that requires long healing times. Find out how to recognize the first signs, what diagnosis and treatment options are available and how you can best support your horse during the healing process - Read now!
Active musculoskeletal system - The horse's musculature
The horse's musculature enables movement, power transmission and posture. Horses have around 700 muscles, which are divided into three main groups:
- Muscles of the forehand (shoulder, neck and chest muscles)
- Back and trunk muscles (supports the rider's weight, ensures upright posture)
- Muscles of the hindquarters (power transmission and forward impulse)
Flexor vs. extensor - what does that mean?
- Flexors → Tighten the limbs, help with collection and posture
- Extensors (extensors) → Ensure erection, forward movement and thrust
➡️ Video tip: Gymnastic training on the lunge - build strong back and abdominal muscles!
Targetedlunge training is a valuable tool for gymnastic training that is often underestimated. Without the weight of the rider, the horse can move more freely, build up specific muscles and improve its balance. Find out which exercises are particularly effective and how you can integrate them into your training - take a look now!
Building muscle in horses - the right way to do it
How do you train your horse's muscles properly?
Targeted training promotes muscle development your horse and improves its performance. A combination of gymnasticsvaried work and sufficient recovery phases is crucial.
- Slow increase: gradually increase the load
- Versatile training: combination of ground work, dressage, jumping gymnastics
- Regular exercise: Daily activity for muscle strength and joint health
- Warming up and cooling down: Prevention of injuries
➡️ Video tip: Muscle building in horses - the right combination of training and feeding!
Musclegrowth requires more than just exercise - the right nutrition also plays a crucial role. Dr. Patricia Sitzenstock explains which nutrients are essential and how you can specifically support your horse in building muscle. Take a look now!
Training plan for a healthy musculoskeletal system
Good training keeps the musculoskeletal system healthy and prevents injuries. Variety, targeted muscle building and sufficient recovery time should be taken into account.
Horse organs
The horse's internal organs are essential for health, performance and well-being. They control vital processes such as digestion , respirationcirculation and metabolism.
A good understanding of the horse's anatomy helps to recognize possible diseases at an early stage and to adapt the correct feeding and training methods.
Digestive system - How does a horse process food?
The horse's digestive system is specially designed to continuously absorb small amounts of raw fiber-rich food. As horses cannot eat in large quantities, a consistent feed intake throughout the day is crucial.
Which organs are on the left side of the horse?
- Stomach - relatively small, cannot stretch much
- Spleen - stores and regulates red blood cells
- Large intestine & cecum - digest raw fiber through bacteria
Special features of horse digestion
- Horses cannot vomit as the stomach entrance is secured by a strong sphincter muscle. This increases the risk of colic if intolerable or fermented feed is ingested.
- The stomach is not designed as a storage organ. Therefore, a continuous feed intake with many small meals is optimal.
- The large intestine is the most important digestive section, as horses obtain most of their energy from the microbial digestion of crude fiber.
Problems in the horse's digestive system
The horse's digestive system is sensitive and can quickly become unbalanced due to incorrect feeding or husbandry. Common complaints are colic, stomach ulcers, diarrhea or constipation.
Colic - the greatest danger
Colic are one of the most common and most dangerous digestive disorders in horses. Causes can be sudden changes in feed, too little roughage, lack of water or stress. The first signs are restlessness, pawing, rolling and loss of appetite. To prevent colic , horses should be given roughage regularly, drink enough and slowly become accustomed to new feed.
Stomach ulcers due to incorrect feeding
Inadequate feeding with long breaks between meals and too much concentrated feed can damage the stomach lining. Typical symptoms are weight loss, frequent yawning and fatigue. To stomach ulcers the horse should have continuous access to roughage and concentrate feed should be fed in small quantities.
➡️ Video tip: Gastric ulcers in horses - causes, symptoms & diagnosis!
Stress, incorrect husbandry or feeding - the causes of gastric ulcers are varied and often difficult to recognize. Find out how to recognize them, why a gastroscopy is essential for diagnosis and how you can help your horse. Take a look now!
Diarrhea and indigestion
Diarrhea can be caused by poor quality food, stress or changing food too quickly. Parasites or dental problems can also play a role. A balanced diet, slow changes and regular veterinary checks help to prevent digestive disorders.
Blockages and incorrect fermentation
Too little exercise, a lack of water or the wrong feed, such as too much straw, can lead to constipation. The horse then defecates less frequently or very hard. Incorrect fermentation in the large intestine, for example due to too much starch or fresh grass, can also cause digestive problems. Slow feeding and an adapted diet reduce the risk.
Feeding - The basis for healthy digestion
The horse's digestive system is designed to continuously absorb feed rich in crude fiber. High-quality roughage should be the basis of the horse's diet, as it:
- Stimulates chewing activity and ensures sufficient saliva production
- Protects the stomach and stabilizes the intestinal flora
- The slow passage through the digestive tract supports
📖 Reading tip: Horse feeding - everything you need to know!
From roughage to concentrates and supplements - the right feed is essential for your horse's health and performance. Find out what types of feed there are, what you should look out for and how to give your horse the best possible care - Read now!
Equine respiratory system - structure and function
The horse's respiratory system is designed for high oxygen uptake. The surface area of the lungs is equivalent to about ten tennis courts and is one of the largest in the animal kingdom. Despite this capacity, the lungs are a sensitive organ that reacts strongly to environmental factors such as dust or ammonia.
Facts and figures
- A 500 kg horse has a lung volume of 40-55 liters.
- Around 90,000 liters of air flow through the lungs every day.
- At rest, a horse breathes 8-16 times per minute, moving 6-8 liters of air per breath.
- Under stress, the breathing rate increases to 120-150 breaths per minute.
Structure of the respiratory system
The respiratory system of the horse is divided into upper airways (nostrils, nasal cavity, larynx) and lower airways (trachea, bronchi, lungs). The upper respiratory tract filters, warms and humidifies the air, while the lower respiratory tract is responsible for gas exchange.
➡️ Video tipThe horse's lungs - breathing is life!
Find out why the lungs are a unique performance organ, which diseases can affect them and how you can optimally support your horse's respiratory health - watch now!
Special features of equine respiration
- Horses breathe exclusively through their nostrils. Breathing through the mouth is not possible.
- Cilia in the airways transport mucus and foreign substances to the outside.
- Horses have a very sensitive respiratory system that quickly reacts to dust, allergens and poor air quality with illnesses.
Performance and illnesses
A healthy respiratory system is essential for performance. Oxygen is required for all metabolic processes. If the lungs are diseased, this manifests itself in the form of:
- Loweroxygen uptake → The horse tires more quickly.
- Shortness of breath or difficult breathing → Resilience decreases.
- Chronic diseases such as COB (chronic obstructive bronchitis) or RAO (Equine Asthma).
➡️ Video tip: Healthy airways for optimal performance!
Learn how to protect your horse's lungs from dust, dirt and allergens to improve oxygen supply and optimize performance - for a healthy and happy horse!
Cardiovascular system
The cardiovascular system supplies the body with oxygen, nutrients and hormones and removes metabolic products. It plays a central role in physical performance and thermoregulation.
Facts about the cardiovascular system
- A horse's heart weighs around 3.5-4.5 kg, but can reach up to 10 kg in high-performance horses.
- The heart rate at rest is 28-44 beats per minute, but can rise to up to 250 beats per minute under heavy exertion.
- The blood volume of a horse corresponds to about 7 % of its body weight - for a 500 kg horse this is about 35 liters of blood.
- The spleen stores red blood cells and can release them quickly into the blood during physical exertion in order to increase the oxygen supply.
Excretory organs - detoxification and metabolism
The excretory organs of the horse are responsible for detoxifying the body and regulating the water balance. The most important organs are the kidneys, liver and bladder.
Facts about the elimination system
- A horse's kidneys filter around 50 liters of blood every day to excrete toxins and metabolic products.
- Horses have a particularly efficient water regulation system to conserve fluid for digestion and cooling.
- A horse's urine contains high amounts of calcium, which can lead to a cloudy color - this is normal.
Special features of excretion
- Horses sweat more than many other animals to get rid of excess heat and metabolic waste.
- Insufficient water intake can lead to bladder stones or kidney problems.
Horse bit
The horse's teeth are specially adapted to the intake and grinding of feed rich in crude fiber. The teeth grow for a lifetime and wear down continuously through chewing.
How many teeth does a horse have?
- Stallions and geldings: 40-44 teeth
- Mares: 36-40 teeth
- Teeth grow for life and need to be checked regularly.
➡️ Video tipDental care for horses - prevention is the be-all and end-all!
Horse teeth are constantly growing - so regular check-ups are essential. Find out from Dr. Carsten Vogt how dental treatment works, what makes horse teeth so special and why dental care is essential for your horse's health - watch now!
➡️ Video tip: Healthy teeth through correct feeding!
Feedinghas a direct influence on your horse's dental health. Dr. Sitzenstock explains how the wrong diet can promote dental problems, why the right wear and tear is crucial and how you can ensure healthy horse teeth with targeted feeding and care. Watch it now!
Nervous system horse
The horse's nervous system controls all vital functions, movements and sensory impressions. It enables quick reactions to environmental stimuli and plays a central role in the horse's behavior and ability to learn.
Structure of the nervous system
The nervous system is divided into two main areas:
- Central nervous system (CNS): Consists of the brain and spinal cord, controls vital processes and movements.
- Peripheral nervous system (PNS): Includes all nerves outside the CNS, transmits stimuli between the body and the brain.
Important functions of the nervous system
A horse's brain is relatively small compared to its body size. Nevertheless, a horse can learn very quickly, remember and react to the smallest of signals.
Horse sensory organs
Horses are flight animals and have highly developed sensory organs to perceive their surroundings at an early stage.
Special features of sensory perception
- Eyes: Horses have an almost all-round field of vision of 340°, but cannot see directly in front of or behind them.
- Ears: Horses can rotate their ears independently by up to 180° in order to perceive sounds from different directions.
- Tactile hairs: They are used for orientation and food control, especially on the lips and mouth.
- Sense of smell: Horses recognize conspecifics, food and even emotions by smell.
The combination of these highly developed senses enables horses to react quickly to danger, perceive their surroundings precisely and communicate with conspecifics and humans.
Conclusion
The horse is an efficient, adaptable and sensitive animal. Its anatomy is designed to move efficiently, utilize food optimally and perceive environmental stimuli at an early stage.
Important findings from the anatomy of the horse:
- Skeleton and musculoskeletal system: The horse's skeleton is optimized for stability and movement, while muscles, tendons and ligaments ensure power transmission and joint stability.
- Digestive system: Horses need a continuous feed intake as their digestion is designed for food rich in crude fiber. Incorrect feeding can lead to colic or stomach ulcers.
- Breathing and circulation: The lungs are highly efficient but sensitive. A well-functioning cardiovascular system ensures endurance and performance.
- Nervous system and sensory organs: Horses perceive their environment differently to humans - their sense of sight is designed for long distances, while their sense of hearing and smell warn them of danger.
A good understanding of anatomy helps to optimally adapt training, husbandry and feeding to the natural needs of the horse and to prevent injuries or illnesses.
Frequently asked questions (FAQs) about the anatomy of the horse
Which organs are on the left side of the horse?
Parts of the stomach, the small intestine, the left lung and a large part of the large intestine, especially the appendix, are located on the left side of the horse.
What promotes muscle development in horses?
Targeted training, a protein-rich diet with high-quality amino acids and sufficient recovery phases are essential for building muscle.
What are PSSM2 horse symptoms?
Horses with PSSM2 often show muscle weakness, stiffness, rapid fatigue and sometimes muscle tremors or atrophy, especially after exercise.
How do you build up muscles in an old horse?
Muscle loss can be reduced or reversed through joint-friendly training, targeted gymnastics, uphill training and an adapted high-protein diet.
What is the fastest way to build muscle in horses?
A combination of regular, varied training (e.g. ground work, pole work, uphill training) and a balanced, protein-rich diet effectively promotes muscle development.
What helps with a PSSM2 horse?
A diet low in starch and sugar with additional amino acids and an adapted exercise program help to alleviate symptoms and strengthen the muscles.
How long does it take to build muscle in a horse?
The first visible progress can be seen after about 6-8 weeks, but sustainable muscle building takes several months to a year.
Can a thin horse build muscle?
Yes, but first the horse must reach its ideal weight through a sufficient and balanced nutrient intake. After that, targeted training can strengthen the muscles.
What is the best way to build muscle in horses?
Muscle growth can be optimally promoted through varied training with targeted exercises, a balanced diet with high-quality protein and essential regeneration phases.
How often should a horse be moved when building muscle?
Three to five training sessions per week with targeted exercises and sufficient breaks for regeneration are ideal.
Why is my horse not building muscle?
Possible causes include an unbalanced diet, too little or incorrect training, health problems such as PSSM or stomach ulcers and too little recovery time.
How do I train the horse's trapezius muscle?
Riding forwards and downwards, pole work, lateral movements and targeted stretching exercises promote the development of the trapezius muscle.
How many muscles does a horse have?
A horse has around 700 different muscles that are responsible for movement, stability and bodily functions.
Which substances are suitable for building muscle in horses?
High-quality proteins, essential amino acids such as lysine and omega-3 fatty acids effectively support muscle building.
How does my horse get more muscle?
Targeted strength and gymnastics training as well as an adapted diet with sufficient energy and protein can promote muscle building. You can find out more about muscle building in our article on the topic of muscle building read.
Which amino acids are important for building muscle in horses?
Lysine, methionine and threonine are essential for muscle buildingas they support the protein metabolism.
What do I feed my horse to build muscle?
A balanced mixture of roughage, high-quality protein (e.g. alfalfa, linseed) and, if necessary, supplements with amino acids promotes muscle growth.
How can I build up my horse's abdominal muscles?
The abdominal muscles can be strengthened through targeted gymnastic exercises such as back stretches, uphill training, lateral movements and ground work.
How long does it take to build muscle in horses?
Muscle building is a long-term process and usually takes several months, but the first successes can be seen after about 6-8 weeks.
Can a horse build muscle at a walk?
Yes, targeted stride training with uphill work, pole exercises and stretching can effectively strengthen the muscles.
How do I recognize a well-muscled horse?
A well-muscled horse shows a harmonious muscle distribution, a well-developed back, a round croup and an even development of the topline.
What strengthens the horse's bones?
A balanced diet with calcium, phosphorus and vitamin D as well as regular exercise and sunlight strengthen the bone substance.
How many bones does a horse have?
A horse has around 205 bones, although the exact number can vary slightly.
How many teeth does a horse have?
Stallions and geldings have 40-44 teeth, mares usually have 36-40 teeth, as their canines are often not developed.
What calms the horse's stomach?
Continuous feeding of feed rich in crude fiber such as hay, supplemented with substances that protect the gastric mucosa such as lecithin or pectins, helps to regulate stomach acidity.
How do you treat a horse's stomach?
Acid-reducing medication such as omeprazole can help with stomach ulcers, in combination with an adapted diet with lots of small meals and little starch.
What does the spleen do in horses?
The spleen stores red blood cells and releases them during physical exertion to improve the oxygen supply.
How do you treat a swollen hock in a horse?
Cooling, immobilization and anti-inflammatory measures such as bandages or medication are the first treatment. A veterinary examination is necessary if the swelling persists.