eChapters

Introduction

We come across a variety of chemicals every day in a laboratory. While some of them are relatively safer, others are extremely hazardous. Thus, it is very important to know the potential hazards that can be caused by the chemicals present in the laboratory and the safety measures needed to be followed to avoid the hazards. Additionally, we should also be aware of the steps necessary to be taken on such hazardous situations. According to IUPAC, a hazardous chemical mean the chemical which has the potential to cause damage in various ways. In a laboratory, there are chemicals that might be irritant, carcinogen, respiratory fibrogen, systemic poison, asphyxiant, flammable, etc. which have the potential to cause hazard to the workers or environment. Therefore, it is important to use appropriate procedure to reduce the risk and protect the health/safety of laboratory personnel, the public and the environment.

Types of Hazards Associated with Chemicals

Chemical hazards: The hazards caused by chemicals can be broadly classified into three categories.

1. Health hazard: This is also known as toxic effects of chemical. The risk associated with a chemical in laboratory depends on the extent of exposure and the inherent toxicity of the chemical. Many chemical reactions form the product that might be much more toxic than the reacting chemicals. For example, inadvertent mixing of formaldehyde (a common tissue fixative) and hydrogen chloride results in the generation of bis(chloromethyl) ether, a potent human carcinogen. For most of the chemicals, the route of exposure (through skin, eyes, gastrointestinal tract, or respiratory tract) is more important (Figure 17.1) that must be considered during risk assessment.

Introduction

Proper electrical wiring and earthing are crucial for laboratory safety and functionality. A laboratory houses several installations/equipment that demand stable/continuous power supply. Inappropriate or faulty wiring and earthing may lead to significant risks, including electrical shocks, damage to equipment, and even incidence of fire. Therefore, understanding the requirements of electrical wiring and earthing is essential for designing, construction, and maintenance of laboratory. This chapter aims to provide a basic knowledge of electrical wiring and earthing necessary for a laboratory. Importance of earthing in mitigating electrical hazards and ensuring integrity of electrical installations are also described.

Basics of Electrical Wiring

Basic understanding of electrical wiring is necessary for laboratory safety and efficient electrical functioning. The potential difference between two electrical points (negative and positive) is known as Voltage, which drives the flow of electric current. This is measured as volt (V). The rate of flow of electricity in a circuit is known as Current (I), which is measured as ampere (A). Current can be either direct (DC) or alternating (AC). Opposition/resistance experienced in the flow of current in circuit is known as Resistance (R) and it is measured in ohms (Ω). Higher the resistance means lesser the current flows at a given voltage. The rate at which electrical energy is transferred/utilized in an electric circuit is known as Power (P), which is measured in watt (W). The Power can be calculated as the product of voltage and current (P = V × I).

Fracture in animals occur frequently and is a concern of economic importance to the owner. The practice of keeping them as pets in households rather than in sheds or in confinements have increased the chance of encountering accidents like fall from coat, terrace, limbs being trapped in drains, being hit by vehicles, dog bites etc. leading to fracture. Fracture management in small animals/small ruminants can be successfully achieved owing to their light weight; they tolerate external coaptation relatively well and can ambulate in three limbs well in order to spare the injured limb. Fracture can be repaired successfully with regional anaesthetic techniques which they can tolerate very well. The constraint of cost effectiveness can be balanced by carefully selecting the appropriate technique according to the weight and limb involved. Many economical skeletal fixation technique have been evolved which can well fit into the budget of the owner. Knowledge of simple techniques can enhance healing in cases of bone loss and management of infection.

Fracture site stabilization

Fracture repair is usually elective, hence initial support and care of the fracture is necessary to prevent further trauma and complications like communication of fracture site to the exterior through wound or sinus and chances of infection. Initial support to splint the bone not only limits the movements but also supports the soft tissues from untoward consequences. Limb splinting reduces edema and pain, preserves neurovascular supply to the limb till the day of operation and helps to transport the animal safely. Fracture to limbs caudal to mid radius ulna/ tibia can safely be stabilized by splints or full limb casts. Wood, pliable bamboo or split poly vinyl chloride pipes positioned on the caudal and lateral aspects of the limbs and supported firmly with tapes or bandages can serve the purpose. Fracture proximal to mid radius ulna or tibia should not be stabilized using splits since the fulcrum effect created due to this can augment soft tissue injury. Careful assessment of the viability of the structures caudal to fracture site should be assessed prior to a decision regarding surgery, devitalized tissue hamper healing and is a subject to be considered for amputation.

Introduction

Several hazardous chemicals, microbes, and techniques like recombinant DNA technology are used for research and development work in research Institutes and universities. Therefore, the researchers, technical, helping and supporting staffs as well as the laboratory outputs must be kept free from contaminations. Thus, biosafety is necessary to prevent unintentional exposure/ release of hazardous chemicals, microbes/pathogens, and toxins to the laboratory staff and environment. Following the biosafety guidelines and ethical considerations are essential to maintain safety standards for the researchers as well as the environment. This chapter deals with various biosafety measures and ethical issues to be strictly followed while working in a research laboratory. The required safety level needs to be determined as per the chemical/biological materials are used in the laboratory to keep the researcher/environment safe for sustainable research and developmental activities.

Biosafety

The term biosafety is used to describe the procedure and policies needed to ensure environmental and personal safety. Biosafety refers to the containment principles, technologies and practices that are implemented to prevent unintentional exposure to pathogens, toxins, or their accidental release into the environment. A fundamental objective of any biosafety program is the containment of potentially harmful chemical/biological agents as precautionary safety measures.

Why Biosafety?

With the increasing number of countries adopting molecular biology tools and techniques in life science research and development activities, especially in the areas of agriculture and medicine, the biosafety issues are gaining importance to ensure biological safety for the public and the environment. Conducting research in safe and sustainable manner is not only a personal requirement but essential collective efforts to ensure biological safety for a clean and safe environment. This requires rules, regulations, monitoring bodies, and awareness among the workers as well as the public. Therefore, biosafety per se is an integral part of laboratory research and requires awareness among the researchers so that biological safety can be well taken care from the grassroot level.

The process of fracture healing is unique, in which damaged bone restores its original architecture but it does not form a poorly organized replacement matrix, otherwise known as scar tissue, rather it regenerates the original matrix and retains its mechanical properties. In order to repair bone defects, a combination of cells with osteogenic activity and appropriate scaffolding material can stimulate bone regeneration and its repair. A potential substitute for autologous transplantation should possess 3 elements: osteoprogenitor cells, osteoinductive factors, and an osteoconductive scaffold. Stem cells from adult tissues are attractive materials for cell therapy and tissue engineering. These cells generally have restricted lineage potential when compared to embryonic stem cells, and this may be advantageous in certain therapeutic applications. Bone-marrow-derived mesenchymal stem cells (BMSCs) have proven to be beneficial in bone regeneration. Bone marrow stem cells are pluripotent cells with the capability of differentiating osteoblasts so that they have been used to facilitate bone repair. Several studies have shown that seeding of cultured BMSCs on bioabsorbable implants can induce bone formation in vivo and lead to improved healing of critical-size bone defects.

Mesenchymal stem cells (MSCs) because of their self replication and osteogenic differentiation capabilities are regarded as an excellent source of cells for bone tissue engineering. Autologous stem cells are not always preferable since the quality and quantity of such cells will be affected by metabolic diseases, old age, and osteoporosis. Allogenic BMSCs might be preferable to xenogenic, but they are always not readily available. In addition, allogenic MSCs have the potential for carrying some diseases. The use of non-autologous stem cells isolated from healthy donors offers a major advantage since these stem cells can be thoroughly tested and formulated into off-the-shelf medicine in advance. Major attractive advantage of BMSCs as a source of cell transplantation is their low immunogenecity. It is now well established that BMSCs are immune-privileged cells that do not elicit immune responses due to an absence of their immunologically relevant cell surface markers.

Despite the benefits that minimally invasive surgery and osteosynthesis have brought to fracture management and bone healing, there are still many circumstances where bone healing remains challenging. Large bone defects are serious complications that are most commonly caused by extensive trauma, tumour, infection, or congenital musculoskeletal disorders. In nonunion cases repairing of bone defects with composite biomaterials as defect filler can promote bone regeneration. Currently, the gold standard for bone regeneration is use of autogenous bone graft. In order to avoid morbidity at the donor site or if large amount of autogenous bone is needed, bone substitution materials can be used. Bone substitution materials can be combined with cells such as mesenchymal stem cells (MSCs) to increase bone formation. Bone-marrow derived mesenchymal stem cells (BMSCs) represent an attractive cell population for tissue regeneration. Bone marrow stem cells are pluripotent cells that have been used to facilitate bone repair because of their capability of differentiating into osteoblasts. Several studies on the regeneration of bone have shown that cultured BMSCs, seeded on different bioabsorbable implants are able to induce bone formation in vivo and lead to improved healing of critical-size defects.

Calcium phosphate bone substitutes such as hydroxyapatite (HA) and tricalcium phosphate (TCP) are currently used for bone substitution in many different clinical applications such as repair of bone defects after trauma or tumour and bone augmentation in spinal arthrodesis. Although these bone substitutes are osteoconductive, they often lack the osteogenecity needed to support bone healing in large defects and are slowly degraded in the body. Studies have shown that coating of hydroxyapatite with a calcium silicate layer could encourage cell proliferation and osteogenic differentiation of human bone marrow-derived stromal cells. Silica-calcium phosphate composite in comparison to calcium phosphate-rich biomaterials has a faster resorption rate owing to greater dissolution of Si ions. The use of several growth factors have been studied in bone repair and these factors are known to play a role in differentiation of mesenchymal progenitor cells specific lineages like endothelial cells or osteoblast. Bone morphogenetic protein-2 (BMP-2) has been shown to accelerate bone healing in humans and animal models. BMP-2 acts by osteoinduction and is involved in the differentiation of mesenchymal progenitor cells into osteoblasts. The addition of recombinant human BMP (rhBMP-2) to a self-cross linkable cellulose hydrogels/biphasic calcium phosphate granules construct promotes bone regeneration in a critical-size segmental defect model of non-union in dogs. It is also reported that protein, insulin-like growth factor (IGF-1) stimulates direct migration of human mesenchymal progenitor cells (MPC) and contributes to the recruitment of MPC in bone formation and bone healing.

Introduction
The endocrine system consists of glands and cells that secrete hormones directly into surrounding tissues or into the bloodstream to regulate various physiological processes. These hormones help maintain homeostasis, working closely with the nervous system, especially through the hypothalamo-hypophyseal connection, where the endocrine and nervous systems integrate their functions.
Pituitary Gland (Hypophysis)
The pituitary gland, often considered the “master gland,” is formed from oral and neural ectoderm. It is divided into two main parts: the anterior pituitary (adenohypophysis) and the posterior pituitary (neurohypophysis). Adenohypophysis: This portion develops from the roof of the stomodeum (primitive mouth) and consists of three parts: the pars distalis, pars intermedia, and pars tuberalis. It contains several cell types, including acidophils, basophils, and chromophobes, which secrete various hormones. For instance, acidophils release growth hormone (GH) and prolactin, while basophils produce hormones like adrenocorticotropic hormone (ACTH), thyroid-stimulating hormone (TSH), and gonadotropins (LH and FSH). The secretion of these hormones is regulated by the hypothalamus through releasing and inhibitory factors delivered via the hypophyseal portal system. Neurohypophysis: Originating from the floor of the diencephalon, the neurohypophysis consists of the median eminence, infundibular stalk, and neural lobe. It stores and releases antidiuretic hormone (ADH) and oxytocin, both synthesized in the hypothalamus and transported to the posterior pituitary. ADH regulates water balance, while oxytocin controls uterine contractions and milk ejection during lactation.
Hypothalamo-Hypophyseal System
The hypothalamus and pituitary gland form a unified control system. The hypothalamoadenohypophyseal system is responsible for regulating the anterior pituitary’s hormonal

Introduction
Teratology is the branch of veterinary embryology that studies congenital malformations, often referred to as birth defects, which arise during embryonic or fetal development. Understanding teratology is crucial for veterinarians and researchers because these defects can lead to substantial animal morbidity, mortality, and economic losses in the agricultural and livestock industries. In addition, teratological research can offer insights into human congenital disorders, given the similarities between mammalian developmental processes.
Definition and Scope of Teratology
The term “teratology” derives from the Greek word teras, meaning “monster” or “marvel,” reflecting the historical observation of grossly abnormal fetuses or neonates. Teratology focuses on the etiology (causes), pathogenesis (development), and morphological consequences of developmental disorders. These abnormalities can manifest as structural, functional, or biochemical anomalies, and they can affect a wide range of systems, including the cardiovascular, skeletal, nervous, and reproductive systems. In veterinary medicine, the study of teratogens—agents that cause developmental malformations—is critical. Teratogens include drugs, environmental chemicals, infections, radiation, and nutritional deficiencies, among others. These agents can disrupt normal embryonic or fetal development, leading to a variety of abnormalities.
Causes of Teratogenesis
Teratogenic agents can be broadly classified into several categories:
1. Genetic Factors
Genetic mutations, chromosomal abnormalities, and hereditary disorders can predispose animals to developmental defects. Genetic teratogenesis can occur due to spontaneous mutations in the DNA sequence or inheritance of defective genes from one or both parents. Chromosomal anomalies, such as duplications, deletions, or translocations of

Introduction
Physiological disorders or dysfunctions in domestic animals are prevalent and can significantly impact the health and well-being of these animals. Understanding the fundamentals of these disorders is essential for veterinarians, animal scientists, and anyone involved in the care and management of animals. This chapter covers a diverse range of physiological disorders, including cardiovascular, respiratory, gastrointestinal, renal, endocrine, musculoskeletal, neurological, dermatological, reproductive, and ocular disorders. These conditions can manifest differently across species and breeds. This MCQ chapter serves as an introduction to the basics of physiological disorders in domestic animals and aims to test your knowledge on this important subject.

Introduction
Intracellular transport of molecules plays a crucial role in maintaining cellular function and organization. The genetic and biochemical processes that regulate membrane trafficking, such as membrane bending, budding, fusion, and fission, ensure the efficient movement of molecules within cells. Despite substantial advances in understanding the molecular aspects of these processes, the broader, or “supramolecular,” regulation of membrane trafficking, which coordinates the overall balance and response to environmental changes, remains less explored. This involves the transport and exchange of membranes and proteins betweenorganelles in a highly organized manner, critical for maintaining cellular homeostasis.
Membrane Trafficking Pathways
Membrane trafficking consists of well-defined pathways connecting cellular compartments like the endoplasmic reticulum (ER), the Golgi apparatus, and the plasma membrane (PM). Proteins and lipids are transferred from the ER to the Golgi and then directed either to the PM or other intracellular destinations. These pathways must be tightly regulated to maintain cellular balance, as any disruptions in membrane flow can lead to cellular dysfunction. In addition to routine cellular maintenance, these pathways must adapt to signals from the environment, ensuring that cells respond appropriately to external stimuli.

Introduction
Heart failure can develop as a complication of almost all congenital and acquired cardiac diseases in dogs and cats. Cardiac disease is a significant global health concern, impacting both humans and domestic animals, particularly dogs. In the animal kingdom, the cardiovascular system consists of essential components, including the heart, veins, arteries, and capillary beds. Its proper function depends on complex mechanisms, such
as the atrioventricular valves (mitral and tricuspid) and the semilunar valves (aortic and pulmonic), which ensure that blood flows in only one direction through the heart. The activity of the cardiovascular system, including heart contraction rates and strengths, as well as blood vessel diameter adjustments, is regulated by the autonomic nervous system (both sympathetic and parasympathetic branches) and various hormones.
The strength of ventricular contractions is influenced by several factors, primarily enddiastolic volume (preload) and myocardial contractility (inotropy). Preload is the amount of blood in the ventricles just before they contract, while contractility refers to the ability of the heart muscle fibers to contract. Preload is determined by the difference between the end-diastolic pressure in the ventricle and the pressure in the pleural space, adjusted for the
stiffness of the ventricular myocardium. This pressure is influenced by the ratio of blood volume to the heart muscle’s compliance. Low-pressure volume receptors in the heart and large veins primarily regulate preload. When these receptors detect increased blood volume or vein distension, they trigger responses such as increased urine production and vein dilation, which help reduce blood volume and lower venous pressures. Increased enddiastolic volume (preload) stretches the ventricular wall, enhancing contraction strength through the Frank-Starling mechanism, or Starling’s law of the heart. This stretching activates receptors in the atria and ventricles, leading to the release of natriuretic peptides like brain natriuretic peptide (BNP) from the ventricles and atrial natriuretic peptide (ANP) from the atria) These peptides promote natriuresis, relax smooth muscle, and counteract
vasopressin and angiotensin II. In dogs, levels of BNP and NT-proBNP are directly related to cardiac stretch.

Introduction
In cattle, the digestive system consists of four primary compartments: the rumen, reticulum, omasum, and abomasum, followed by the small and large intestines. The rumen plays a crucial role as a fermentation chamber, maintaining anaerobic conditions and ensuring thorough mixing, as well as regulating temperature and pH levels. Food, which is frequently re-chewed, enters the rumen through the esophagus, where fermentation occurs.
The byproducts of fermentation are either absorbed within the rumen or moved on for further digestion and absorption in other parts of the digestive system. Simple indigestion in ruminants is a temporary disruption in gastrointestinal function, usually caused by a sudden change in the quality or quantity of their diet. Consuming large amounts of indigestible feed can impair rumen function for 24 to 48 hours after ingestion, as the accumulation of this feed can physically disrupt ruminal activity. Additionally, the breakdown of proteins in the rumen can produce toxic substances such as amides and amines, including histamine. This condition can lead to a significant drop in milk production due to a marked reduction in the production of volatile fatty acids in a hypotonic reticulorumen. Ruminal impaction is a condition seen in ruminants like cows, sheep,and goats, where the  rumen’s contents become compacted, obstructing their movement through the digestive tract. This condition can arise from various causes, including the ingestion of plastic waste, grazing habits, mineral deficiencies, negative energy balance, urbanization, inadequate water intake, low-fiber or high-grain diets, changes in feed or grazing patterns, and stress. The accumulation of foreign material can block fermentation, interfere with the mixing of rumen contents, and disrupt the rumen’s microflora, leading to indigestion. Acute ruminal acidosis is often caused by the sudden intake of large amounts of carbohydrate-rich feed, particularly grains. Subacute ruminal acidosis (SARA) occurs in dairy cattle and is characterized by disrupted ruminal fermentation. It typically results from feeding large amounts of concentrates with insufficient fiber, a practice often used to boost milk production during early lactation. This imbalance in diet can disturb rumen pH and microbial populations, leading to various metabolic and digestive problems. Chronic ruminal acidosis can lead to complications such as rumenitis, which is inflammation of the rumen, and laminitis, a painful condition affecting the hooves. Alkaline indigestion, also known as ruminal alkalosis, occurs when the pH of ruminal fluid rises above 7.5.
 

A wound is defined as a breach or disruption in the normal continuity of tissue in any body part. The wounds are mainly caused by physical, chemical or biological insult.

General anesthesia : reversible complete loss of consciousness along with analgesia. 
  Unconsciousness occurs due to depressant action or functional disruption by stimulation in brain by anesthetic agents.
  Analgesia is probably due to blockade of synaptic transmission in the dorsal horn of the spinal cord.

Introduction
Respiratory diseases are a common clinical issue in dogs, particularly in those housed in environments like pet shops, shelters, breeding and boarding kennels. Puppies and senior dogs are at a higher risk of developing respiratory infections compared to adult dogs. The respiratory system is one of the body’s four major systems, comprising the upper airways (pharynx, larynx, and trachea and the lower airways (bronchi, bronchioles, and
alveoli). The pharynx, which serves as a common passageway for both the respiratory and gastrointestinal systems, explains the relatively high incidence of aspiration pneumonia. The luminal diameter of the pharynx is the widest, followed by the larynx and trachea.
The ratio of tracheal diameter to thoracic inlet height (TD:TI) remains relatively constant, regardless of the animal’s size or respiratory phase. The respiratory tract is typically protected from harmful pathogens by physical, chemical, and immunologicbarriers, including mucus, mucociliary clearance, innate antimicrobial factors, alveolar macrophages, and the pulmonary immune response. The entire respiratory tree is lined with ciliated epithelial cells, except for the bronchioles, which are lined by non-ciliated granular secretory cells known as club cells. The respiratory system’s primary function is achieved through four major processes: pulmonary ventilation; diffusion of oxygen and carbon dioxide between the alveoli and the blood; transport of these gases in the blood and body fluids to and from the body’s tissue cells; and regulation of ventilation and other respiratory factors. The pulmonary alveoli, the main sites for gas exchange between air and blood, are highly vulnerable to injury if the body’s defense mechanisms are compromised, underscoring the importance of prompt emergency treatment for respiratory diseases

Laparoscopy is an operative procedure designed for the visual inspection of peritoneal cavity and biopsy of organs. Laparoscopy is a valuable diagnostic and therapeutic tool in clinical medicine. In the field of cholecystectomy, appendicectomy, vagotomy, hernia repair and adhesion release laparoscopy surgery offers significant advantages over open surgery in humans. For gynecological problems like ovarian cyst or in the case of oophorectomies and hysterectomies, laparoscopic surgery (‘scarless surgery’) is now considered a better alternative in addition to laparoscopic sterilization. Only in the last 15 years laparoscopy is widely used in different animal species for research and clinical diagnostic and therapeutic purposes. The first canine laparoscopy procedures were performed in the early 1900’s (Kelling, 1902). Anderson (1937) used dogs to perfect his skills prior to human clinical trials. The first clinical application of laparoscopy in dog’s involved ovarian function studies in the early 1960’s and Lettow reported the first laparoscopic liver biopsy procedure in a dog in 1972.

Laparoscopy is not only used in the examination of the abdominal cavity organs, surgical treatment but also in the diagnosis of the different disease conditioned by biopsy examination (removal of a sample of tissue from the living body for histopathological examination). Biopsy is indicated to ascertain a correct diagnosis, specific therapy and accurate prognosis. Laparoscopy is becoming an alternative method of monitoring biopsies of internal organs. It permits precise localization and accurate site on the various abdominal organs surface such as kidney, liver, spleen etc. Since, it is relatively noninvasive so it ranks highest amongst biopsy techniques. The technique allows visual control over the biopsy procedure, which considerably limits post biopsy complications and increases the likelihood of obtaining diagnostically useful biopsy specimens.

This paper primarily considers the general principles of ultrasound and instrumentation and its application in camel reproduction.

Ultrasound waves are mechanical pressure waves similar to audible sound waves and must have a medium in which to audible sound waves and must have a medium in which to propagate. The “frequency” (f) is the number of high- or low- pressure regions crossing each area of tissue each second. The frequencies of the sound waves used in medical ultrasound are much higher than the human audible range (20 to 16000 Hz); hence the waves are called ultrasound. Ultrasound instrumentation

The gray scale imaging equipment uses only time delay and echo amplitude information in creating the image. Most equipment contains the same basic building- block circuits; transmitter, receiver, display and scan converter.

Transmitter

The first circuit building block, the transmitter circuit produces either a high- amplitude, short- duration voltage shock pulse or a driving voltage waveform. Then an output control attenuates the amplitude of the shock pulse or the driving voltage wave form before it is applied to the transducer.

• General considerations

 • Collection of blood

 • Storage

 • Examination of blood

 • Coagulation time

 • Bleeding time

 • Determination of movement of parasites under wet film

• Total erythrocyte count

 • Total leucocyte count

 • Differential leucocyte count

 • Hemoglobin

 • Erythrocyte sedimentation rate

• Hematocrit value

 • Mean corpuscular volume

 • Mean corpuscular hemoglobin

 • Mean corpuscular hemoglobin concentration

 • Erythrocyte fragility test