eChapters

The drug conventionally used for sedation is xylazine, which is an alpha-2 agonist (Dugdale, 2010; Rankin, 2015). Dexmedetomidine is the latest drug of the same class used for sedation, and is more specific to alpha2 receptors than xylazine (Ishyama et al., 1995). Doses of 1-2 mg per kg body weight of xylazine (Hall and Clarke, 2001) and upto 20 mcg per kg body weight of dexmedetomidine (Ko, 2013) are required for sedation when used alone (Hall and Clarke, 2001; Rankin, 2015). Similar degrees of sedation could still be achieved at lower doses of xylazine (0.2 to 0.4 mg per kg body weight) and dexmedetomidine (2.5 to 5 mcg per kg) if administered in combination with any opioid drug like hydromorphone / oxymorphone / fentanyl / buprenorphine / butorphanol / nalbuphine / tramadol at their usual doses (Hunt et al., 2013). Another drug - acepromazine, which is a phenothiazine tranquiliser, is used at its doses of 0.01 to 0.05 mg/kg combined with an opioid for achieving sedation (Smith et al., 2001; Dugdale, 2020; Ko, 2013). Combination of an opioid with either a phenothiazine tranquiliser or an alpha2 agonist sedative drug provides neurolept anaesthesia/analgesia (Dugdale, 2020; Rankin, 2015). An anticholinergic drug - glycopyrrolate is administered in combination with acepromazine and opioid to prevent bradycardia (Dyson and James-Davies, 1999). Anticholinergics are generally not recommended with sedative cocktails containing dexmedetomidine, but preferred with sedative cocktails containing xylazine (Congdon et al., 2011; Billah et al., 2017). If sedation is to be achieved with acepromazine alone, higher doses need to be administered where there will be an increase in its dose dependent side effects, and hence not preferred (Simon and Steagall, 2020). Benzodiazepines are another class of sedative drugs, which generally doesn’t provide predictable sedation in animals. Paradoxical excitement is caused in healthy adults when these drugs are used alone (Herron et al., 2008). Predictable sedation is achieved when these drugs are administered in combination with any opioids (KuKanich and Wiese, 2015). Also, benzodiazepines can be combined with an alpha2-opioid combination to enhance the overall sedation (Maze et al., 1992). Various balanced sedative cocktails prepared with the drugs available for a veterinary practitioner in India, are presented. The balanced sedative cocktails are prepared with either

Introduction
Enzymatic regulation refers to the mechanisms that control the activity of enzymes, ensuring that they function optimally and in accordance with the needs of the cell or organism. These mechanisms are crucial for maintaining homeostasis and regulating metabolic pathways. Here are the primary methods of enzymatic regulation:
1. Allosteric Regulation: Allosteric regulation involves the binding of regulatory molecules (allosteric effectors) at sites other than the active site (allosteric sites) on the enzyme. This binding can either enhance (activators) or inhibit (inhibitors) enzyme activity. Allosteric enzymes typically exhibit a sigmoidal (S-shaped) kinetics curve.
2. Covalent Modification: Covalent modification involves the addition or removal of specific chemical groups to an enzyme, altering its activity. The most common form is phosphorylation, where a phosphate group is added by kinases and removed by phosphatases. Other modifications include acetylation, methylation, and ubiquitination.
3. Feedback Inhibition: Feedback inhibition occurs when the end product of a metabolic pathway inhibits an enzyme involved earlier in the pathway. This prevents the overproduction of the end product and helps maintain balance within the cell.
4. Proteolytic Activation: Some enzymes are synthesized as inactive precursors (zymogens or proenzymes) that require proteolytic cleavage to become active. This mechanism is common in digestive enzymes and blood clotting factors.
5. Enzyme Induction and Repression: The synthesis of enzymes can be regulated at the genetic level. Induction increases the production of an enzyme in response to a substrate or other signal, while repression decreases enzyme synthesis. This regulation is often mediated by transcription factors and other regulatory proteins.
6. Substrate Availability: The availability of substrate can directly affect enzyme activity. High substrate concentrations can increase the rate of reaction up to a certain point (saturation), beyond which the enzyme operates at its maximum rate (Vmax).
7. pH and Temperature: Enzymes have optimal pH and temperature ranges within which they function most efficiently. Deviations from these optimal conditions can lead to decreased enzyme activity or denaturation.

Introduction
Cell Cycle: Growth at the cellular level involves the cell cycle, which includes phases of growth (G1), DNA replication (S), and cell division (M). During these phases, cells prepare for and execute division to increase cell numbers. Mitosis and Meiosis: Mitosis results in two identical daughter cells, crucial for tissue growth and repair. Meiosis, on the other hand, is essential for producing gametes (sperm and eggs) and ensures genetic diversity.
Hormonal Regulation
Growth Hormone (GH): Secreted by the pituitary gland, GH stimulates liver cells toproduce insulin-like growth factor 1 (IGF-1), which promotes cell growth and division throughout the body.
Thyroid Hormones: Thyroxine (T4) and triiodothyronine (T3) from the thyroid gland regulate metabolic rate and are vital for normal growth and development, particularly in the nervous system.
Sex Hormones: Estrogens and androgens influence the growth of secondary sexual characteristics and contribute to the final stages of skeletal growth during puberty.
Nutritional Factors
Proteins: Amino acids from dietary proteins are necessary for the synthesis of new proteins and enzymes, which are crucial for cell growth and repair.
Vitamins: Vitamins such as A, C, and D are essential for various growth processes. For instance, vitamin D is vital for bone growth and calcium absorption.
Minerals: Calcium and phosphorus are key for bone development, while zinc and iron are important for cellular functions and overall growth.
Genetic Factors
Genetic Blueprint: Growth patterns and potential are largely determined by genetic factors. Genes influence growth rates, final height, and the development of various body structures.
Growth Disorders: Genetic mutations or abnormalities can lead to growth disorders such as dwarfism or gigantism, illustrating the role of genetics in growth regulation.

Artificial Insemination is a very important tool that caters to propagation of high-quality germplasm and breed improvement. It is also economical as it aids in breeding without the necessary to maintain the adult bucks cutting the input cost. However, the bucks maintained for production of semen and AI should be free of any diseases and in specifically venereal diseases. Venereal diseases are not so uncommon in livestock, and they cause a variety of symptoms including orchitis, abortions, still birth, vulvovaginitis etc., leading to infertility in breeding animals. Venereal diseases are infectious in nature and they are transmitted mainly through semen, feed-water, AI gun, artificial vagina, fomites etc. Due to venereal diseases, infertility, orchitis, epididymitis, vasculitis etc. occurs in bucks and leads to abortions and still birth in does (Ahmed et al, 2010; Beena et al, 2017), because they are directly linked with the economic output (Sharma et al, 2008; Azawi et al, 2010) and overall health of the animal affecting the productivity significantly (Menzies, 2011). To keep abortions and other venereal diseases at bay, it is important to raise disease free breeding bucks that deliver clean-semen for natural service or AI operation. Abortion rate between 2 to 5% indicates its endemic nature and abortion level exceeding 5% requires aggressive investigation (Menzies, 2011). Infectious agents that include viruses, bacteria, fungi, parasites etc.; as well as noninfectious cause can lead to infertility in goats (Moeller, 2001; Szeredi et al, 2006; Smith and Sherman, 2009). Many infectious causes are known to mankind that leads to trans-venereal diseases in goats including Brucella melitensis, Chlamydiosis, Campylobacter spp., Listeria monocytogenes, Toxoplasmosis, Coxiella burnetii etc. There are numerous viruses such as

Surgical Plan
i. Pre-operative Course of Action 
    a.    Client communication.
    b.    Clinical laboratory evaluation, radiograph, treatment for fluid or blood volume deficits. 

ii. Intra-operative Plan of Action 
    a.    Surgical approach 
    b.    Material and equipment needed 
    c.    Technical and support personnel

A hernia is the protrusion of an organ through a defect in the wall of the abdominal cavity in which it lies.

Classification
1. On the Basis of Anatomical Site
    Abdominal (umbilical and ventral)
    Diaphragmatic

Introduction
Normal reproduction in the female depends on hormones, which specific chemical substances produced by specialized glands are called endocrine glands. These secretions pass into the blood and lymph fluids and are transported to various parts of the body, where they exert several specific effects. Reproductive hormones may originate in the hypothalamus, pituitary, gonads, uterus, or placenta. Hypothalamic hormones are produced
in the hypothalamus, a portion of the brain that is the neural control center for reproductive hormones. The role of hypothalamic hormones is to regulate the release of other hormones from the pituitary gland, and many hypothalamic hormones are therefore called releasing hormones. The primary releasing hormone of reproduction is gonadotropin-releasing hormone (GnRH). GnRH controls the release of follicle-stimulating hormone (FSH)
and luteinizing hormone (LH) from the pituitary gland, located at the base of the brain. These pituitary hormones regulate the production of estrogen and progesterone from the ovary. FSH stimulates the follicle’s growth, development, and function, while LH causes\= the follicle to rupture and the corpus luteum to develop. The female hormone estrogen is produced by the Graafian follicle on the ovary. Another hormone originating from the
ovary is progesterone, which is produced by the corpus luteum. Each has an important role in the female reproductive process.
A relatively new discovery in reproductive physiology is that follicular growth is not continuous in the bovine, but occurs in waves (2 to 4 waves per cycle). Each wave begins when the dominant follicle in the previous wave gains maximal size, at which time numerous small follicles begin a period of rapid growth. From this group of follicles, one follicle is allowed to grow to a much larger size than the others. This large follicle is called the dominant follicle, because it has the ability to regulate and restrict the growth of the smaller follicles. A few days after reaching maximum size, the dominant follicle begins to degenerate and die.

The choice of hormones and drugs acting on reproductive system are important as therapeutic agents during reproductive disorders like anoestrus, metritis, pyometra, repeat breeder, retention of fetal membranes, delayed puberty, ovarian disorders etc.  The administration of specific chemotherapeutic agent is of paramount importance in treating reproductive disorders in dairy animals.  The dosage, route, frequency and indications of chemotherapeutic agents acting on reproductive system are mentioned in tabular form as below.

Introduction
The testicle is a unique and important reproductive organ that serves two main purposes. The primary purpose is the development of mature spermatozoa that are able to fertilise the egg.The production of hormones, which plays a role in ensuring that mature spermatozoa are delivered to mature eggs where fertilisation may take place, must be considered a supplemental function to the development of germ cells. The induction of behavioristic
reactions—also referred to as sex drive or mating instincts—and the provision of a means of transportation for spermatozoa, as well as the regulation of ejaculate—either its release into the aquatic medium surrounding the egg in the case of lower vertebrates or its introduction into female passages through an organ of intromission—are the two concrete necessities involved. The animal loses its ability to reproduce as long as either the production of germ cells or the propensity to mate is impaired, even though the two processes undoubtedly work in tandem to achieve the end result.

Historical Aspect
    Curare was the first known muscle relaxant which was used by South American Indians to immobilize wild animals. Hence the term curariform has been applied to the action of this group of drugs. 
    In year 1958, a plant alkaloid alcuronium was introduced but there were difficulties in reversing the action of this drug.
    Succinylcholine was first used in 1906. However, its paralyzing property was discovered in year 1949.
    Pancuronium was introduced in 1964.
 

Introduction
The renal system is primarily responsible for the filtration of waste products from blood plasma through urine production. The kidneys, along with the ureters, bladder, and urethra, are part of the urinary system responsible for removing waste products from blood and eliminating them in urine. They filter around 120 ml of blood plasma per minute and perform homeostatic roles such as regulating blood volume and pressure, pH and electrolyte
composition, stimulating erythropoiesis, and supporting vitamin D biosynthesis. Nephrons, with around 1-1.3 million per adult kidney, are primarily cortical, with 80-85% of them located in the renal cortex. The remaining 15-20% are called juxtamedullary nephrons. The kidneys remove nitrogenous compounds like urea, uric acid, and creatinine, as well as metabolic waste products, toxins, excess hormones, water, and electrolytes. Urine formation involves three main stages: glomerular filtration, tubular reabsorption, and secretion. The kidneys produce renal filtrate, which contains blood components that can be filtered out, and the body recovers 99% of the water and electrolytes from the filtrate. The renal corpuscle, comprising the Bowman’s capsule and glomerular capillaries, is responsible for filtration of blood plasma and producing renal filtrate. Its structural elements allow
for efficient filtration, with glomerular capillaries having a 100-fold greater permeability to water, small ions, and solutes. The glomerular capillaries also have increased pressure due to the smaller diameter of the efferent arteriole. The filtration membrane consists of endothelium, basement membrane, and podocytes. The proximal convoluted tubule in the kidneys plays a crucial role in reabsorption of water and electrolytes, including sodium,
chloride, potassium, calcium, and bicarbonate. It reabsorbs approximately 80% of filtered bicarbonate, with further reabsorption from the loop of Henle and distal convoluted tubule. This reabsorption regulates the body’s acid-base balance, contributing to the acidic nature of urine. The proximal convoluted tubule is the only region able to reabsorb glucose. The loop of Henle is a crucial region in the kidney, responsible for concentrating urine and facilitating water and electrolyte reabsorption. It regulates fluid volume, blood pressure, and acid-base balance through bicarbonate reabsorption. The loop consists of two main regions: the descending limb and the ascending limb.

Introduction
The genetic code and protein synthesis are fundamental processes that underlie the
expression of genetic information within all living organisms. These processes are integral
to understanding how DNA, the hereditary material, dictates the production of proteins,
which are essential molecules that carry out various functions in the body, from structural
support to catalyzing biochemical reactions.
Genetic Code
The genetic code consists of rules that guide the translation of information stored in
DNA or RNA sequences into proteins within living cells. It is nearly universal across
all organisms, underscoring the shared evolutionary origins of life. The genetic code is
composed of codons, which are sequences of three nucleotides in mRNA (messenger
RNA) that correspond to specific amino acids or stop signals during protein synthesis.
Each of the 20 amino acids used in protein synthesis is encoded by one or more codons.
For instance, the codon AUG not only codes for the amino acid methionine but also serves
as the start signal for translation, marking the beginning of a protein-coding sequence. The
redundancy of the genetic code, where multiple codons can specify the same amino acid,
provides a protective mechanism against mutations, as some changes in the nucleotide
sequence do not alter the resulting protein.
Protein Synthesis
Protein synthesis is the process by which cells construct proteins based on the instructions
encoded in mRNA. This process takes place in two primary stages: transcription and
translation.
Transcription: Transcription is the first step of gene expression, where a particular segment
of DNA is copied into RNA by the enzyme RNA polymerase. During transcription, one
of the two DNA strands serves as a template for the formation of a complementary RNA
strand, This newly synthesized RNA strand, known as pre-mRNA, undergoes further
processing, including splicing, capping, and addition of a poly-A tail, to become mature
mRNA, which is then exported from the nucleus to the cytoplasm in eukaryotic cells. In
contrast, in prokaryotes, both transcription and translation occur within the cytoplasm.

Site of incision: Make a midventral incision on the neck from larynx up to thoracic inlet then make ventrodorsal incision from both ends of this incision up to mid dorsal aspect of neck region.

Accurate early diagnosis of pregnancy is essential for successful breeding programme.

Ability is required for successful practice.

Skill is to be developed to indicate the duration within weeks in early and months in late pregnancy.

Introduction Ultrasonography is well-established technique in human sciences, particularly for diagnosis of pre-natal defects of fetus. In veterinary sciences, this technique is emerging an important tool. This tool is being employed in the small animal practices, particularly bitches for diagnosis of various reproductive disorders and estimation of gestational status. In the past, veterinarians had limited assistance for assessing reproductive status of this animal. Pregnancy diagnosis in a bitch was possible either with the use of X-rays or transabdominal palpation, but that too at an advanced stage of gestation. These methods could provide information either about presence of pups in vitro, or their number, but assessment of fetal viability was not accurately predicted with these traditional methods. With the use of X-rays, there was always risk of harmful effects on the health of mother and fetus. As far as reproductive disorders are concerned, most of them remained either undiagnosed due to the lack of proper access to the internal organs or were diagnosed with a guess. Diagnostic ultrasound is a valuable alternative imaging system that can provide more accurate information about the canine pregnancy and reproductive disorders in comparison to traditional methods.

The Liver

The liver is a large and an irregular organ of the body, which extends from the sixth to the eleventh intercostal space. It extends much more caudally on the right side as compared to the left side. Its most caudal part is the caudate lobe whose small portion is visualized encircling the right kidney dorsally at the eleventh intercostal space. The liver of a dog is divided into various lobes namely the left lateral, left medial, quadrate, right medial, right lateral and the caudate lobes which are not identifiable ultrasonographically, except when f luid is present in the abdomen. Otherwise, the position of the different liver lobes can only be approximated. The gallbladder is located to the right of the midline between the quadrate and the right medial lobes of the liver.

Proper preparation of the animal is important to obtain images of abdominal orgnas including that of liver. It is better to keep animal off fed for at east six hours prior to ultrasound scanning. This will avoid interference of gases and solid contents of the gastrointestinal tract. If stomach is taken as landmark of scanning then enough fluid should be given prior to scanning to get good images of stomach. The liver can be easily visualized on one side of stomach. One should be liberal in applying good amount of gel over transducer and body for better image of liver.

Ultrasonography of the GI tract presents problems and challenges for the sonographer. Sonography of the GI viscera was once throught to be impossible because of artifacts created by gas within the lumen but with the technical advancement in the ultrasonography now the problem has been solved. If the animal is kept of feed and adlib water is given to the dog with I/v fluid than ultrasonography becomes helpful in the diagnosis of gastrointestinal tract disorders. Other conditions such as esophageal carcinomas can also been diagnosed by ultrasonographic endoscopy. in human beings.

The normal ultrasonography of the liver, kidney, stomach & spleen in dogs has been standardized and its use in evaluation of pathological lesions has been reported but ultrasonographic evaluation of oesophagus & intestine, both in normal animals and diseased conditions is yet to be established. Therefore normal ultrasonography of the oesophagus & small intestine in dogs and the importance of diagnostic capability of ultrasonography in diagnosis of pathology of these organs have been compiled.

• General considerations

 • Indications

 • Limitations

 • Techniques of bone marrow examination

 • Cell types

 • Cellular composition of bone marrow

 • Morphology of the cells

 • Interpretation of bone marrow examination

• General considerations

 • Collection

 • Preservation

 • Examination

 • Physical examination

 • Chemical examination

 • Microscopic examination

 • Organized sediment

 • Unorganized sediment

 • Cultural examination