Table of Contents

Cover

Title Page

Dedication

Preface

Acknowledgement

Chapter 1: The Biochemical Nature of Cells

Metabolism
Water
Proteins
Carbohydrates
Lipids/Fats
Nucleic Acids
Protein Synthesis
The Genetic Code
Enzymes
Summary Points
Q + A

Chapter 2: Cells, Tissues and Organs

Cells – Building Blocks of Life
Tissues and Organs
Summary Points
Q + A

Chapter 3: Equine Support and Movement

Points of the Horse
The Skeletal System
Bone
The Skeleton
The Mechanics of Movement
Muscles
The Importance of Muscle Fibres in Equine Performance
Fatigue
Summary Points
Q + A

Chapter 4: The Lower Limb

Tendons and Ligaments of the Lower Limb
Blood Supply to the Lower Leg
The Hoof
The Balanced Foot
Summary Points
Q + A

Chapter 5: The Digestive System

Foregut
Hindgut
Equine Microbiota
The Gut and the Immune System
Summary Points
Q + A

Chapter 6: The Respiratory System

Anatomy
Physiology of Respiration
Respiratory–Locomotor Coupling
External Respiration or Pulmonary Gas Exchange
Internal Respiration or Systemic Gas Exchange
Cellular Respiration
Summary Points
Q + A

Chapter 7: The Circulatory System

Foetal Circulation
The Heart
Blood Vessels
Heart Evaluation and Examination
Blood
The Lymphatic or Lymph System
The Spleen
Summary Points
Q + A

Chapter 8: The Nervous System

Nerves and Neurons
Neuroglia or Glial Cells
Organisation of the Nervous System
Action Potential
Resting Membrane Potential
Synapses
Neurotransmitters
Endorphins and Enkephalins
Neuromuscular Junctions
The Brain
Spinal Cord
Reflex Actions or Arcs
Summary Points
Q + A

Chapter 9: The Endocrine System

Hypothalamus
Pituitary Gland (Hypophysis)
Thyroid Gland
Parathyroid Glands
Adrenal Glands
Pancreas
Thymus
Ovaries
Testes
Pineal Gland
The Neuroendocrine System
Circadian Rhythms in Horses
Sleep Patterns in Horses
Summary Points
Q + A

Chapter 10: The Skin

Structure of the Skin
Sensation
Melanin
Sudoriferous Glands (Sweat Glands)
Sebaceous Glands
Hair
Thermoregulation
Skin and Coat Colour
Summary Points
Q + A

Chapter 11: The Senses

Transduction
Adaptation
Somatic Receptors
Thermal Sensations
Pain Sensations
Tactile Sensations
Itch Sensation
Proprioceptor Sensation
Special Senses
Summary Points
Q + A

Chapter 12: Reproduction

Reproductive Anatomy of the Mare
The Oestrus Cycle
Reproductive Anatomy of the Stallion
Spermatogenesis
Acrosome Reaction
Endocrine Pathways in the Male
Fertilisation
Pregnancy Diagnosis
Foetal Sexing
Twins
Endocrine Maintenance of Gestation
Equine Chorionic Gonadotropin
Progesterone
Oestrogens
Relaxin
Gestation
Implantation and Placentation
Embryology
The Foetal Endocrine System
Preparation for Parturition (Birth)
Induction
Lactation
Applied Reproductive Technologies
Summary Points
Q + A

Chapter 13: Genetics

The Genetic Code or Genome
Chromosomes
Gene Expression
Mitochondrial DNA
The Y Chromosome
Alleles
Dominance
Sex Cells
Hybrids
Heredity
Sex Determination
Genotype and Phenotype
Polygenic or Multiple Gene Traits
Multiple Alleles
Sex Linkage
Lethal Genes
Congenital Curly Coat Syndrome
Epigenetics
Muscle Disorders
Nuclear Transfer (Cloning)
Parental Similarity of Clones
Mutation
Single Nucleotide Polymorphisms
The Myostatin Gene and Performance
Coat Colour and Genetics
Melanomas in Grey Horses
Exercise-Induced Pulmonary Haemorrhage (EIPH) or Epistaxis
Summary Points
Q+A

Chapter 14: The Urinary System

Kidneys
Regulation of Water
Regulation of Permeability of the Collecting Ducts by ADH
Aldosterone
Acid–Base Balance
Micturition or Urination
Summary Points
Q + A

Chapter 15: The Immune System

Health Versus Disease
Microbes
Disease Transmission Routes
Infection
Biofilms
Symptoms of Disease
Diagnosis
Pathogenic Organisms
Protection from Disease
Antigens and Antibodies
Summary Points
Q + A

Chapter 16: Exercise Physiology, Functional Anatomy and Conformation

Exercise Physiology
Functional Anatomy
Conformation
Summary Points
Q + A

Chapter 17: Teeth and Ageing

Equine Teeth
Wear and Tear
Ageing
Care of Equine Teeth
Summary Points
Q + A

Chapter 18: Evolution, Classification and Behaviour of the Horse

Evolutionary Time Period
Classification
Evolutionary Development
The Evolutionary Family Tree
Domestic Breeds and Types of Horses
Donkeys
Przewalski's Horse
Mustangs
Behaviour of the Modern Horse
Summary Points
Q + A

Appendix A: Anatomical Terms Based on the Median Plane

Appendix B: Haematology and Plasma Biochemistry Tests

Appendix C: Functions, Sources and Deficiencies of Vitamins and Minerals in Horses

Index

End User License Agreement

List of Illustrations

Chapter 1: The Biochemical Nature of Cells

Figure 1.1 The biochemical nature of cells.
Figure 1.2 Structure of water.
Figure 1.3 Importance of proteins in the horse's body.
Figure 1.4 Structure of an amino acid.
Figure 1.5 R groups give different chemical properties to amino acids.
Figure 1.6 Formation of a dipeptide.
Figure 1.7 Bonding examples in the tertiary structure of proteins.
Figure 1.8 Model of haemoglobin.
Figure 1.9 Structure of collagen.
Figure 1.10 Alpha and beta structure of glucose.
Figure 1.11 Structure of maltose from two alpha glucose molecules.
Figure 1.12 Structure of cellulose.
Figure 1.13 Structure of glycogen.
Figure 1.14 Structure of triglycerides.
Figure 1.15 Phospholipids are the main component of all biological membranes, including cells and their organelles, and are similar to triglycerides but consist of a glycerol molecule with two fatty acid chains instead of three and a phosphate group attached (a). The phosphate group at one end is attracted to water (hydrophilic), whereas the fatty acid tail is repelled by water (hydrophobic). The hydrophobic end therefore turns inward in the phospholipid bilayer (b) and the hydrophilic phosphate end turns outward.
Figure 1.16 Structure of a nucleotide.
Figure 1.17 Symbolic structure of DNA and RNA.
Figure 1.18 Semi-conservative replication of DNA.
Figure 1.19 Transcription.
Figure 1.20 Information in a gene on the coding strand is read in the direction from the 5′ end to the 3′ end.
Figure 1.21 Transfer of the genetic code from DNA to RNA.
Figure 1.22 Translation takes place on the ribosomes.
Figure 1.23 Induced fit model of enzyme action.

Chapter 2: Cells, Tissues and Organs

Figure 2.1 Structure of a cell.
Figure 2.2 Cytoskeleton of the cell.
Figure 2.3 The fluid mosaic model of cell membranes.
Figure 2.4 Phospholipid bilayer arrangement.
Figure 2.5 Three types of endocytosis.
Figure 2.6 Exocytosis.
Figure 2.7 Mitochondrion showing location of different enzymes involved in cellular respiration.
Figure 2.8 Four stages of the cell cycle.
Figure 2.9 (a) A G-banded metaphase and (b) karyotype of a normal female horse (2n = 64XX).
Figure 2.10 Cell division: mitosis and cytokinesis.
Figure 2.11 Diagram following a pair of homologous chromosomes through one mitotic division.
Figure 2.12 Meiosis.
Figure 2.13 Cell signalling pathways.
Figure 2.14 Production of blood cells from stem cells.
Figure 2.15 Classification of epithelium.
Figure 2.16 Columnar epithelium.
Figure 2.17 Types of connective tissue.
Figure 2.18 A fresh equine wound.
Figure 2.19 Inflammatory response to injury.
Figure 2.20 A colony of embryonic stem cells, from the H9 cell line (NIH code: WA09). Viewed at 10× magnification with a Carl Zeiss Axiovert scope. (The cells in the background are mouse fibroblast cells. Only the colony in the centre is human embryonic stem cells.)

Chapter 3: Equine Support and Movement

Figure 3.1 Points of the horse.
Figure 3.2 Haversian system or osteon structure.
Figure 3.3 Gross structure of a long bone.
Figure 3.4 Cross-section through a long bone.
Figure 3.5 A splint.
Figure 3.6 Different types of bone cell.
Figure 3.7 Growth and development of a long bone. (a) How cartilage is turned into bone. (b) How the bone enlarges in length and width as the young horse grows.
Figure 3.8 Weanling with physitis of the forelimb fetlock.
Figure 3.9 The equine skeleton.
Figure 3.10 Vertebrae of the horse.
Figure 3.11 The spine is a series of curves.
Figure 3.12 Dipped spine in a mare.
Figure 3.13 Forelimb and knee.
Figure 3.14 Hindlimb and hock.
Figure 3.15 The pelvis.
Figure 3.16 Basic structure of a joint.
Figure 3.17 Cardiac muscle.
Figure 3.18 Smooth muscle.
Figure 3.19 A skeletal muscle fibre.
Figure 3.20 (a) Contractile units in a myofibril in human muscle.
Figure 3.21 Superficial muscles.
Figure 3.22 Deep muscles.

Chapter 4: The Lower Limb

Figure 4.1 The modern horse stands on the equivalent of the human middle finger.
Figure 4.2 Tendons and ligaments of the lower limb.
Figure 4.3 Tendon structure.
Figure 4.4 Arterial supply to the lower limb. a, Artery; v, vein; n, nerve.
Figure 4.5 Medial (a) and lateral (b) aspects of the distal metacarpus, fetlock and digit, showing distribution of major nerves of the lower limb. a, Artery; v, vein; n, nerve.
Figure 4.6 Internal hoof structures.
Figure 4.7 Anticoncussive structures of the hoof.
Figure 4.8 External structures of the hoof. (a) Front view; (b) lateral view.
Figure 4.9 (a) Part removal of hoof wall, showing epidermal laminae underneath. (b) Hoof following complete removal of hoof wall, showing the corium. (c) Photomicrograph cross-section of the equine hoof.
Figure 4.10 Structures of the underside of the external hoof.
Figure 4.11 Internal surface of the sole and frog.
Figure 4.12 This Pacinian corpuscle has a connective tissue receptor surrounding the terminus of the primary afferent neuron.
Figure 4.13 A vertical line drawn through the centre of the cannon bone and down through the hoof should bisect the hoof equally.
Figure 4.14 A line running along the top of the coronary band should be horizontal, that is, the same distance from the ground on both sides of the hoof.
Figure 4.15 Foot balance (solar view).
Figure 4.16 The hoof pastern axis (HPA) should always be aligned.
Figure 4.17 An unbalanced foot trimmed to remove flare and shod to support the underrun side.

Chapter 5: The Digestive System

Figure 5.1 Digestive system of the horse compared to ruminants.
Figure 5.2 Structure of the equine digestive system.
Figure 5.3 Structure of the equine digestive system as seen from beneath.
Figure 5.4 Horses can graze pastures closely using their incisors.
Figure 5.5 Position of the three pairs of salivary glands.
Figure 5.6 Structure of the equine stomach.
Figure 5.7 Gastric pit showing origins of stomach secretions.
Figure 5.8 Post-mortem image of a spontaneous gastric rupture secondary to gastric impaction in an 18-year-old Quarter-horse mare. The site of rupture is along the greater curvature, with marked reddening and haemorrhage evident from the site of perforation.
Figure 5.9 Internal anatomy of the jejunum.
Figure 5.10 Post-mortem image of a small intestinal volvulus from a 2-month-old colt. Note the extensive jejunal dilation and poor viability resulting from this strangulating obstruction.
Figure 5.11 Section of pancreatic tissue.
Figure 5.12 A liver lobule.
Figure 5.13 (a) Schematic illustration identifying portions of the gastrointestinal tract accessible from the ventral midline incision. DF, diaphragmatic flexure; LDC, left dorsal colon; LVC, left ventral colon; MES, mesentery of the jejunum with arcuate vessels; PF, pelvic flexure; RVC, right ventral colon. (b) Photograph of exteriorised intestine. The surgeon is standing on the left side of the intestine.
Figure 5.14 (a) Schematic illustration depicting caecal orientation. Lighter-colored parts of the intestine are able to be exteriorised. CCL, Caecocolic ligament; CCO, caecocolic orifice; ICF, ileocaecal fold; ICO, Ileocaecal orifice. (b) Photograph of exteriorised caecum showing the apex, body and caecal bands. Note that the caecum has been reflected backwards towards the caudal aspect of the horse and the ventral caecal band is not visible.

Chapter 6: The Respiratory System

Figure 6.1 Airways of the head.
Figure 6.2 Function of the pharynx. (a) Swallowing and (b) breathing.
Figure 6.3 Relationship between the stomach, diaphragm and lungs.
Figure 6.4 Structure of the lungs.
Figure 6.5 Lung air volumes and capacities.
Figure 6.6 Position of the lungs externally.
Figure 6.7 Synchronisation of stride and breathing.
Figure 6.8 Composition of gases in inhaled and exhaled air.
Figure 6.9 Summary of erythrocyte chemistry related to carriage of respiratory gases.
Figure 6.10 Oxygen dissociation curve.
Figure 6.11 Structure of ATP.
Figure 6.12 Hydrolysis of ATP.
Figure 6.13 Summary of aerobic respiration of glucose.
Figure 6.14 The ten steps of glycolysis.
Figure 6.15 The link reaction.
Figure 6.16 The Krebs, TCA or citric acid cycle.
Figure 6.17 Summary of ATP production during cellular respiration.
Figure 6.18 Aerobic respiration using lipids, glycogen and protein.

Chapter 7: The Circulatory System

Figure 7.1 The heart and circulation of the horse.
Figure 7.2 External structure of the heart.
Figure 7.3 Toxic mucous membranes as demonstrated by hyperaemia, with increased discolouration noted at the gum line.
Figure 7.4 Vertical section through the equine heart, showing the flow of blood through it. LA, Left atrium; LV, left ventricle; RA, right atrium; RV, right ventricle.
Figure 7.5 Movement of blood through the circulatory system.
Figure 7.6 The natural pacemaker of the heart.
Figure 7.7 The cardiac cycle.
Figure 7.8 Cross-section of a human artery.
Figure 7.9 Photomicrograph showing red blood cells squeezing through a blood capillary.
Figure 7.10 Capillary network and direction of blood through it.
Figure 7.11 Photomicrograph of a venule with a vein valve in cross-section.
Figure 7.12 Relationship of pressure in the ventricles to the ECG during the cardiac cycle.
Figure 7.13 (a) Summary of blood constituents. (b) Origin of blood cells.
Figure 7.14 Red blood cells. Source: Blaus, https://commons.wikimedia.org/wiki/File:Blausen_0761_RedBloodCells.png. CC BY 3.0.
Figure 7.15 Summary of the transport of oxygen and carbon dioxide.
Figure 7.16 White blood cells. Source: Blaus, https://commons.wikimedia.org/wiki/File:Blausen_0425_Formed_Elements.png. CC BY 3.0.
Figure 7.17 Blood clot formation.
Figure 7.18 Simplified drawing of a lymph node.
Figure 7.19 Pony with strangles, viewed from the side before abscesses burst.

Chapter 8: The Nervous System

Figure 8.1 Cranial nerves of the horse.
Figure 8.2 Major nerves of the horse.
Figure 8.3 Summary of actions of the nervous system.
Figure 8.4 (a) Structure of a motor neuron. (b) Structure of a sensory neuron.
Figure 8.5 Types of neuron.
Figure 8.6 Transverse section through the spinal cord.
Figure 8.7 Organisation of the nervous system.
Figure 8.8 The sodium–potassium pump.
Figure 8.9 Propagation of an action potential along a myelinated nerve fibre.
Figure 8.10 Basic structure of a synapse.
Figure 8.11 Structure of the equine brain.
Figure 8.12 Reflex arc.

Chapter 9: The Endocrine System

Figure 9.1 The endocrine glands.
Figure 9.2 The anterior and posterior pituitary gland. Source: Southwood 2013. Reproduced with permission of John Wiley & Sons.
Figure 9.3 Delayed/partial shedding of winter coat is a symptom of PPID (Cushing's syndrome).
Figure 9.4 Section through the thyroid glad.
Figure 9.5 Thyroid follicle cells.
Figure 9.6 Diagrammatic section through the adrenal gland.
Figure 9.7 Section through the medulla of an adrenal gland (human). The pointer is indicating the medulla. Source: Jpogi, https://commons.wikimedia.org/wiki/File:Adrenal_gland_(medulla).JPG.
Figure 9.8 Effects of negative feedback on the hypothalamus and pituitary gland.
Figure 9.9 Negative feedback of glucose production by glucagon.
Figure 9.10 Flehmen response shown by an Andalusian stallion.
Figure 9.11 The Equilume™ Light Mask is an innovative method of providing light to horses. The automated mask provides the optimum level of blue light to a single eye.
Figure 9.12 Foals in (a) lateral recumbency, (b) sternal recumbency and (c) paradoxical sleep. Source: Courtesy of Harthill Stud.

Chapter 10: The Skin

Figure 10.1 Structure of the skin.
Figure 10.2 Layers of the epidermis – photomicrograph of a portion of skin.
Figure 10.3 Horse sweating freely.
Figure 10.4 A donkey shedding its winter coat, revealing the shorter summer coat underneath.
Figure 10.5 Heat exchange between horses and their environment.
Figure 10.6 The hypothalamus controls thermoregulation (homeostasis).

Chapter 11: The Senses

Figure 11.1 The horse's tongue contains a high number of chemoreceptors.
Figure 11.2 Sensory hairs on the muzzle.
Figure 11.3 Pacinian corpuscle.
Figure 11.4 The horse's field of vision.
Figure 11.5 The eye of the horse.
Figure 11.6 Longitudinal section through the human eye.
Figure 11.7 Structure of rods and cones.
Figure 11.8 Retina under high magnification.
Figure 11.9 Structure of the retina.
Figure 11.10 Horse listening to distant sounds.
Figure 11.11 Anatomy of the horse's ear.
Figure 11.12 (a) Inner ear and (b) cochlea straightened out.
Figure 11.13 Structure of a taste bud.
Figure 11.14 The olfactory system. The view is of the equine head in sagittal section. Inset shows a microscopic view of the olfactory epithelium, which covers the ethmoid bone within the caudodorsal nasal cavity. a, Nasal cavity; b, palate; c, oral cavity; d, larynx; e, pharynx; f, vomeronasal organ; g, olfactory bulb of the brain.

Chapter 12: Reproduction

Figure 12.1 The artificial breeding season of TB mares.
Figure 12.2 The reproductive system of the mare.
Figure 12.3 External genitalia of the mare.
Figure 12.4 Anatomy of the equine uterus. Source: Frandson 2009. Reproduced with permission of john Wiley & Sons.
Figure 12.5 Section through an ovary.
Figure 12.6 The oestrus cycle of the mare.
Figure 12.7 Diagrammatic representation of the oestrus cycle.
Figure 12.8 Gametogenesis – spermatogenesis and oogenesis.
Figure 12.9 Mare in season.
Figure 12.10 Teasing the mare.
Figure 12.11 The Equilume™ Light Mask is an innovative method of providing light to horses to encourage the early onset of oestrus, following the winter anoestrus period.
Figure 12.12 Stallion genitalia. This Figure was produced with kind permission of the copyright holder Wiley-Blackwell from Angus O. McKinnon, Edwards L. Squires, Wendy E. Vaala and Dickson D. Varner (2011) Equine Reproduction, Vols 1 & 2, 2nd edn. Oxford: Wiley-Blackwell.
Figure 12.13 Cross-section through a testis.
Figure 12.14 (a) Section through a seminiferous tubule. (b) Light microscopic view of a cross-section of an equine seminiferous tubule, showing the nuclei of some spermatogonia.
Figure 12.15 A spermatozoon.
Figure 12.16 Events immediately following fertilisation.
Figure 12.17 Day 14 sonogram of an equine embryo.
Figure 12.18 A 27.5-day-old embryo.
Figure 12.19 A 34-day-old equine foetus – forelimb and hindlimb buds protruding.
Figure 12.20 Mare giving birth: presentation of the forefeet. In a normal presentation the first visible sign is a transparent bluish-white amnion which surrounds the foal, then come the forefeet with one slightly extended in front of the other for easier passage of the shoulders.
Figure 12.21 Lactation curve.
Figure 12.22 The stallion is encouraged to mount a phantom or dummy mare.

Chapter 13: Genetics

Figure 13.1 Thoroughbred mare ‘Twilight’ – the DNA donor for the sequencing project.
Figure 13.2 A karyotype of a mare with 63XO (Turners Syndrome) resulting in infertility.
Figure 13.3 Terms used to describe genes and chromosomes.
Figure 13.4 Grévy's zebra.
Figure 13.5 A typical ‘curly coated’ yearling.
Figure 13.6 The four basic types of chromosome mutation.
Figure 13.7 (a) Grey mare with ‘bay’ foal with grey around the eyes (b).
Figure 13.8 Deaf American Paint Horse with frame splashed with white overo phenotype.
Figure 13.9 Palomino foal with deep pink skin.
Figure 13.10 Buckskin Quarter-horse.

Chapter 14: The Urinary System

Figure 14.1 Excretory products of the horse.
Figure 14.2 Position of the urinary organs.
Figure 14.3 Dorsal view of the urinary system.
Figure 14.4 Section through a kidney.
Figure 14.5 Renal papillae fused into the renal crest.
Figure 14.6 Structure of a nephron.
Figure 14.7 Malpighian corpuscle showing blood passing from glomerular capillaries to the tubules.
Figure 14.8 Glomerulum of mouse kidney under a scanning electron microscope, magnification 1000×.
Figure 14.9 Control of water balance.
Figure 14.10 The loop of Henle countercurrent multiplier system.

Chapter 15: The Immune System

Figure 15.1 A generalised bacteria cell.
Figure 15.2 Bacterial cell division. Colourised electron micrograph of a Salmonella bacterium dividing.
Figure 15.3 West Nile virus transmission cycle.
Figure 15.4 Structure of a simple virus.
Figure 15.5 Viral replication within the host cell.
Figure 15.6 Summary of the equine immune system.
Figure 15.7 Summary of physical and chemical barriers against harmful organisms.
Figure 15.8 Comparison of innate and acquired immune responses.
Figure 15.9 Summary of inflammation.
Figure 15.10 Interferon interferes with replication of viruses.
Figure 15.11 A 1975 transmission electron micrograph (TEM) revealing the presence of a number of eastern equine encephalitis (EEE) virus virions in a specimen of central nervous system tissue.
Figure 15.12 Training of T cells in the thymus.

Chapter 16: Exercise Physiology, Functional Anatomy and Conformation

Figure 16.1 Racehorse at full gallop.
Figure 16.2 The ATP/CP system. (The energy continuum.)
Figure 16.3 Use of glucose in a working muscle cell.
Figure 16.4 Fate of lactate build-up in working muscles.
Figure 16.5 Training causes increased capillarisation of muscle fibres. PPAR, Peroxisome proliferator-activated receptor gamma; NRF-1, nuclear respiratory factor 1.
Figure 16.6 Horses involved in endurance competitions need extensive training.
Figure 16.7 Training the racehorse.
Figure 16.8 The horse's centre of gravity.
Figure 16.9 The horse's body is slung in a cradle of muscle known as the serratus ventralis.
Figure 16.10 The stay apparatus.
Figure 16.11 Reciprocal apparatus or mechanism of the hindlimb.
Figure 16.12 There should be room at the poll and jaw for flexion.
Figure 16.13 Conformation of the neck.
Figure 16.14 Angulation of the scapula and humerus.
Figure 16.15 Forelimbs viewed from the front (above) and side (below).
Figure 16.16 Poor conformation/farriery can cause horses to be unsound and more prone to injuries such as broken knees and bowed tendons.
Figure 16.17 Using the head as a standard measurement.
Figure 16.18 Hindquarters and leg viewed from behind (above) and side (below).

Chapter 17: Teeth and Ageing

Figure 17.1 Dentition of the horse.
Figure 17.2 Incisors or biting teeth of a Mediterranean Miniature donkey.
Figure 17.3 Hypsodont teeth.
Figure 17.4 Vertical section through a molar tooth.
Figure 17.5 Incisor with part of the cementum removed.
Figure 17.6 Sections through an incisor tooth. As the tooth wears down, the pattern on the tooth table changes.
Figure 17.7 Implantation and continual eruption of the teeth.
Figure 17.8 (a) Upper and (b) lower jaws, showing the wearing surface of molars.
Figure 17.9 Incisor teeth sloping in an older horse.
Figure 17.10 Ageing the horse.
Figure 17.11 The upper jaw is slightly wider than the lower jaw and sharp edges may result.
Figure 17.12 Rasping the teeth with manual instruments.

Chapter 18: Evolution, Classification and Behaviour of the Horse

Figure 18.1 Przewalski's wild horse from Colwyn Bay Zoo.
Figure 18.2 Herd of Przewalski's horses reintroduced into the wild in Mongolia. Source: Karamollaoglu, https://www.flickr.com/photos/okaramollaoglu/8367788369/. CC BY 2.0.
Figure 18.4 Grevy's zebra.
Figure 18.5 Evolutionary pathway of the horse.
Figure 18.6 Equine evolution. Composed from skeletons of Staatliches Museum für Naturkunde Karlsruhe, Germany. From left to right: size development, biometrical changes in the cranium, reduction of toes (left forefoot). Highest point of the withers: Equus 1.5 m; Pliohippus 1.2 m; Merychippus 0.8 m; Mesohippus 0.5 m.
Figure 18.7 Changes to the forelimb through evolution.
Figure 18.8 Mediterranean Miniature donkey.
Figure 18.9 Poitou donkeys in the nature reserve of Olfen, Nordrhein Westfalen, Germany. Dreadlocks are a characteristic of this breed.
Figure 18.10 Youngstock turned out in groups are happier than on their own.

List of Tables

Chapter 1: The Biochemical Nature of Cells

Table 1.1 Examples of organic and inorganic compounds in the horse's body
Table 1.2 Essential and non-essential amino acids
Table 1.3 Structural classification of proteins
Table 1.4 Common carbohydrates – disaccharides, monosaccharides and polysaccharides
Table 1.5 Some common fatty acids
Table 1.6 Comparison of RNA and DNA
Table 1.7 The genetic code – mRNA/amino acids (64 codons)
Table 1.8 Amino acids and their codons

Chapter 2: Cells, Tissues and Organs

Table 2.1 Summary of the similarities and differences between eukaryotic and prokaryotic cells
Table 2.2 Classification of lining epithelia
Table 2.3 Functions of connective tissue

Chapter 3: Equine Support and Movement

Table 3.1 Muscles of the neck and shoulder.
Table 3.2 Muscles of the trunk
Table 3.3 Muscles of the upper hindlimb
Table 3.4 Slow twitch versus fast twitch muscle
Table 3.5 Slow twitch fibres in different breeds

Chapter 5: The Digestive System

Table 5.1 Digestive enzymes: origins, substrates and end products.
Table 5.2 Distribution of bacteria and protozoa in the horse's gut
Table 5.3 Microbiota – examples of functions of some hindgut bacteria

Chapter 6: The Respiratory System

Table 6.1 Respiratory rate or respiratory frequency (fR) (breaths per minute) of various domestic animals and man
Table 6.2 Some factors affecting the lung volumes of equines
Table 6.3 Total ATP produced from oxidative phosphorylation in aerobic respiration

Chapter 7: The Circulatory System

Table 7.1 Components of plasma

Chapter 8: The Nervous System

Table 8.1 Examples of parasympathetic and sympathetic functions

Chapter 9: The Endocrine System

Table 9.1 Classification of major hormones
Table 9.2 Summary of major hormones in the horse's body, their sites of production and effects.

Chapter 10: The Skin

Table 10.1 Composition of sweat
Table 10.2 Heat loss ability at different effective temperatures

Chapter 12: Reproduction

Table 12.1 Main derivatives of embryonic germ layers
Table 12.2 Composition (%) of milk from various species

Chapter 13: Genetics

Table 13.1 Genetic disease and allelic variants identified by DNA testing
Table 13.2 Common coat colours and dilutions with their genetic formulae

Chapter 15: The Immune System

Table 15.1 Species of bacteria found in the horse's normal flora
Table 15.2 Some equine bacterial infectious diseases
Table 15.3 Bacterial species that may be found in equine wounds
Table 15.4 Common virus families and examples of diseases they cause
Table 15.5 Influenza virus A – equine influenza
Table 15.6 Common mycotoxins in equine feeds
Table 15.7 Summary of adaptive/acquired immunity in horses
Table 15.8 Class I and II MHC glycoproteins have different properties

Chapter 16: Exercise Physiology, Functional Anatomy and Conformation

Table 16.1 Energy production systems available for horses and their timings
Table 16.2 Description of conformation

Chapter 17: Teeth and Ageing

Table 17.1 Eruption of the horse's teeth

Chapter 18: Evolution, Classification and Behaviour of the Horse

Table 18.1 Timeline of the appearance of different life forms

Equine Science

Zoe Davies

Third Edition

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Description: Third edition. | Hoboken, NJ : John Wiley & Sons, 2017. | Includes index. |

Identifiers: LCCN 2017020437 (print) | LCCN 2017035568 (ebook) | ISBN 9781118741177 (pdf) | ISBN 9781118741160 (epub) | ISBN 9781118741184 (pbk.)

Classification: LCC SF285.3 (ebook) | LCC SF285.3 .P54 2017 (print) | DDC 636.1-dc23

This book is dedicated to my lovely family, Ian, Sophie and Katie, and to all the horses I have owned or helped as part of my work that have inspired me to write it.

Preface

Horses are integral to our culture, and they continue to be used for work, leisure and competition throughout the world. Knowledge of this magnificent animal is continually improving as science delves deeper, uncovering new information that helps us to understand how the horse functions.

This edition of Equine Science has been rewritten and expanded to provide more detailed and up-to-date information for those studying equine courses at higher academic levels or more knowledgeable horse owners keen to understand the inner workings of horses in their care. The systems of the horse are covered extensively with new and expanded information, with full colour artwork and photographs to assist the reader in understanding its scientific content.

Knowledge of equine science for all involved with horses results in higher standards of management and welfare, particularly for those working or competing, no matter what the discipline.

Zoe Davies, MSc., R.Nutr.

Acknowledgement

I would like to thank Sarah Pilliner for her important contributions to some chapters of this new edition and Julie Musk for her editing skills and support during the production process. I would also like to thank Harthill Stud and all the other contributors for supplying many of the photographs.