eChapters

The presence of a Y or X chromosome influences sexual differentiation and the development of reproductive organs. The reproductive system comprises the gonads, genital ducts, external genitalia, and gonad descent. Development of reproductive system is initiated in gonads which differentiate into ovary or testis. The formation of genital ducts and glands occur later. Differentiation of reproductive system is a complex process which involves a number of different mechanisms operating at several stages of development. It occurs only after the arrival of primordial germ cells. First, the gonads undergo an indifferent stage before differentiating into the testes and ovaries. Thereafter, the sexual differentiation of the genital ducts is determined by the presence or absence of testosterone and Anti-Müllerian hormone, both of which influence the outcome of the mesonephric and paramesonephric ducts. Then sexual distinction of the external genitalia is also determined by hormonal secretions, or lack thereof and finally, the gonads descend primarily due to the shortening of the gubernaculum. Importantly, the development of the reproductive system is directly related to that of the urinary system. Both systems develop from common intermediate mesoderm and their excretory ducts terminate in a common cavity known as cloaca) Two important ducts develop, i.e. wolffian duct (in males) and mullerian duct (in females). Mesonephric duct which is also known as Wolffian duct, originates from pronephric duct. Pronephric duct continues to grow caudally till it opens into the ventral part of the cloaca. Beyond pronephros (primitive kidney), it is called mesonephric duct. In males, this duct persists and forms epididymis, vas deferens and seminal vesicle. In females, this duct undergoes atrophy. Shortly after the formation of Wolffian duct, a 2nd pair of duct develops i.e. Mullerian duct. Each arises on the lateral aspect of the corresponding Wolffian duct as a tubular invagination of the cells lining the abdominal cavity. Mullerian duct opens on cloaca between the orifices of Wolffian ducts. In females, mullerian duct persist and undergo further development. Gonads develops from 3 important sources, namely mesothelium lining posterior abdominal wall, underlying mesenchyme (Embryonic CT) and primordial Germ Cells

Introduction
The development of the respiratory system in animals is a crucial process that begins early during embryogenesis. The respiratory system, responsible for gas exchange, develops from the endoderm of the early embryo, which is one of the three germ layers. Specifically, the respiratory tract develops as an outgrowth from the primitive gut tube (foregut). This process involves complex interactions of molecular signalling, tissue differentiation, and organ morphogenesis.
Key Stages of Respiratory System Development
1. Formation of the Respiratory Primordium
The respiratory system originates from the laryngotracheal groove, which appears on the ventral wall of the primitive foregut. This groove eventually forms the laryngotracheal tube, which serves as the foundation for the respiratory tract.
2. Division of the Foregut
The foregut is divided into two regions: The dorsal portion (oesophagus) for the digestive system. The ventral portion (laryngotracheal tube) for the respiratory system. This separation is achieved by the formation of the tracheoesophageal septum.
3. Development of the Trachea and Lung Buds
The laryngotracheal tube elongates and gives rise to the trachea) At its distal end, two lung buds form, which will develop into the bronchi and lungs. These lung buds expand, branch, and grow into the surrounding mesenchyme, a process called branching morphogenesis.

Introduction
The development of the head and neck in embryos involves the formation of two primary sections at the cephalic (head) end) These include:
1. Neural Portion: This part consists of the brain, eyes, and internal ears, along with their supportive structures. In early embryonic stages, the neural region is larger and more prominent. Even as the face develops, the neural portion retains a dominant role.
2. Facial or Visceral Portion: This section encompasses the upper ends of the alimentary (digestive) and respiratory tracts. As the embryo matures, the nose and jaws undergo differentiation and growth, reducing the initial size difference between the neural and facial portions.
Pharyngeal (Branchial) Arches and Their Role
The formation of the face and neck is closely linked with the development of the pharyngeal (branchial) arches. These arches appear as bar-like ridges with intervening grooves on the sides of the embryonic head around the fourth week of gestation. Though similar to the gill arches in fish, these structures in mammals do not develop respiratory functions. Instead, they transform into various permanent structures of the adult face and neck.
• Formation of Pharyngeal Arches and Grooves: Five pairs of pharyngeal arches typically develop, separated by four ectodermal grooves known as pharyngeal grooves. Underneath these grooves, the pharyngeal endoderm pushes the mesenchyme outward, forming pharyngeal pouches.
• Fuj results in a congenital condition known as branchial fistula)
• Role of Pharyngeal Arches in Facial Formation: The first pharyngeal arch on each side splits into an upper maxillary and lower mandibular process, forming the basis of the face. The second and third arches play essential roles in forming neck structures.

A thorough history with complete physical examination including careful palpation of the mammary glands should be performed. As there are chances that dogs may be suffering from any other systemic ailments during middle to old age. In dogs with multiple tumors, all tumors should be excised and their location and size should be noted. Histopathological examination of the excised tumors should be carried out to classify mammary gland tumors. Mammary tumors are classified based on some of the parameters i.e., tumor size, lymph nodes, metastasis. Therefore, to stage a dog with mammary tumors information of these parameters needs to be collected and recorded. If lymph nodes are palpable and/or clinically enlarged, fine-needle aspiration should be performed for cytological evaluation. The technique is less invasive but with higher accuracy. Thoracic radiographs remain the mainstay for diagnosing the metastatic condition. The mammary tumors most commonly metastasize into lungs in dogs. The staging of CMTs becomes necessary as it is likely to confer some prognostic significance and provide guidance to veterinarians to make treatment decisions.

The speed with which changes in the eye can take place is challenging. Ophthalmic problems do not lend themselves to casual examination or ‘trial and error’ therapy. Therefore, to perform safe cataract surgery with good quality outcome, uniform minimum standard of diagnostic and clinical practice needed to be in place.

Although cataract can be diagnosed by routine gross examination ofthe affected dog even then it is mandatary to develop a routine ophthalmic examinations in a consistent and organized manner to make a confirmatory diagnosis and plan the surgical technique for a favourable prognosis. A sequential examination starting right from history up to electroretinography may be performed as under:

History » Gross Examination » Menace response test » Obstacle course test » dazzle or photic blink reflex » Light induced pupillary reflexes (direct/ consensual) » Corneal reflex test »Schirmer’s tear test

• General considerations

 • Tuberculosis

 • Johne’s disease

 • Brucellosis

 • Infectious bovine rhinotracheitis

 • Campylobacteriosis

 • Tichomonosis

Diagnostic techniques are routinely used for diagnosing different surgical conditions. The most frequently used imaging techniques in veterinary practice are radiography and ultrasonography. Radiography and ultrasonography are not suitable for each organ in large animals. In small animals most organs are suited to ultrasound images except bones and gascontaining structures such as lungs etc. Bone and gas reflect ultrasound and do not allow the sound waves to form image therefore radiography gives better diagnostic images for these organs. The liver, spleen, kidneys, prostate, gravid uterus and fluid containing organs like urinary bladder, gall bladder and major blood vessels can be better imaged with ultrasound. In buffaloes in surgical section important clinical conditions relate to urinary and digestive systems, mammary gland and perineal area.

1. Urinary System: In bovine, the cases of obstructive urolithiasis are commonly observed. These types of cases are more common in bullocks and in buffalo calves. In these cases radiography is not so useful. Sonography can be tried to take the image of ruptured urethra in bullock and can be compared with radiography. Due to ruptured urethra there will be accumulation of urine in the s/c tissue of prepuce. Due to fluid density the image will be radioopaque and will appear white and no detail of the organ can be seen. The ultrasonogram (USG) will show images of glans penis and its coverings. Different diameters of urethra and a point of rupture just behind to glans penis can be make out. Due to obstruction, The B.calves either will pass drop wise urine or there will be complete stoppage of the urine. These cases can also be easily diagnosed by ultrasonography.

X-ray Machines
 
There are many factors to consider when choosing X-ray equipment. The need of an individual practice varies depending on the species majority and case work load.
Types of X-ray machines: 
X-ray machines can be grouped into 3 categories:

I. Portable X-ray Machine

    ·    Is one that can be carried to the animal.
    ·    Portable X-ray machines are widely used in veterinary practice.
    ·    The maximum output is 15 to 35 mAs and kV ranges from 70-110 kVp.
    ·    Cost is less and easy to move around and transport. 
    ·    Suitable for X-raying of thin and small parts (limbs below stifle and elbow of large animals and can be used taking 
X-rays of abdomen an skeletal systems of small animals).

Key Points

• Neonatal diarrhea can be lethal without treatment.

• Administer aggressive fluid and electrolyte therapy to address newborn diarrhea.

• Fecal examination and/or culture findings can help control diarrhea.

• Ringer lactate is the preferred fluid.

• There is a high association between animal age and the presence of the causal factor for diarrhea.

Introduction

Diarrhea is one of the symptoms of a variety of medical problems. Diarrhea is characterized by an increased frequency of defecation and stools of varied consistency, which may have an increased concentration of water or a decrease in dry matter content. Increased peristaltic movement causes an increase in caudal flow of ingesta/GIT content, resulting in a decrease in intestinal transit time and thus diarrhea. Diarrhea is lethal in children; therefore, preventing f luid and electrolyte losses prior to diagnosis is critical to saving lives.

1. The plaster-bandage wrap cast :(Negative cast)

The amputee was restrained on lateral recumbency keeping the amputed leg upwards.

A thin, moistened stockinet was pulled over the stump and it was maintained snugly in place by tying with a string at the top.

The moistened cast stockinet was marked with indeliable pencil indicating prominences with a cross and other sensitive areas with a circle (Fig.1).

Plaster bandages were then wrapped as pen requirement unit I the shell has a thickness of approximately 3mm in proximal third.

After plaster hardened, it was removed either by pulling out or longitudinal splitting with a cutter (Fig.2).

Digital dairy farming integrates IoT, artificial intelligence, machine learning, big-data analytics, cloud computing, sensors and automation to improve herd management. This chapter explains how wearable devices and monitoring systems support early disease detection, welfare assessment, milk-yield analysis and precision feeding. Automated milking, feeding and other operations reduce manual labour, improve consistency and lower operating costs. The architecture of smart dairy systems—including sensors, wireless communication and decision algorithms—is examined alongside environmental and economic benefits. Barriers include high initial investment, limited digital skills, poor rural connectivity and cybersecurity risks. Future developments may include AI-enabled autonomous dairy farms and interconnected, sustainable agricultural ecosystems.

Definition

Digital tender include superficial digital flexor, DDF & suspensory ligament which is situated in volar & plantar upset of metacarpus and metatarsus. These tendons are generally transected during ploughing or intensional approach (Fig.1).

Sign

After cutting of these tendon the foot became flat and animal bears weight on fetlock is can’t able to walk freely.

Arterial diseases are important because of their serious effect on vital organs like brain, heart and kidney. Thrombosis is the most common complication of arterial diseases but hemorrhage and aneurysm formation may occur.

Etiology

 Acral lick dermatitis is usually observed on extremities of dogs and the probable etiology is persistent licking. It is also caused due to self-trauma or mutilation.

A laboratory is essential for research work in science and development. Most of the research institutes have dedicated laboratories for researchers and students to conduct experiments, perform research work, as well as to provide hands-on learning/training to students. There are certain rules and regulations laid down by the laboratory in-charge which need to be followed strictly for safety purposes. Some of the laboratories keep ‘safety manual’ for researchers to read before entering into the laboratory to conduct experiments. Whenever safety is compromised in a laboratory, there is increase in risk of unwanted incidents in the laboratory. Storing food/beverages in the same refrigerator where laboratory chemicals are kept may lead to disastrous effects on health. This chapter aims to provide instructions in brief on the things to be performed (Do’s) before and after entering onto a laboratory as well as the things never to be done (Don’ts) in a laboratory for the safety reasons.

Good Laboratory Practices (Do’s)

• P Wear apron/labcoat while working in the laboratory.
• P Use gloves/respiratory mask/fumehood while handling toxic/volatile/inflammable chemicals/reagents.
• P Use pippet or pippetor for safety in transfer of solutions.
• P Protect eyes, face and naked parts of the body from UV radiations. Use safety goggles or face mask/apron.
• P Keep your eyes away from Liquid Nitrogen and use cryogloves while handling it.
• P Arrange all the necessary materials/solutions before starting the experiment.
• P Periodically fumigate/ozonize culture and inoculation rooms.
• P Autoclave all contaminated materials before discarding.
• P Pre-treat gel or solution containing Ethidium Bromide (EtBr) before discarding into laboratory waste-disposal bin, and use gloves while handling them.
• P Burn all the transgenic plant materials in an incinerator after taking necessary observations.
• P Make entry in the designated log-book and clean the instrument after using it properly.
• P Switch-off the instrument after use or when not in use.
• P Wash hands with soap and remove the labcoat before leaving/going out of the laboratory7.
• P Ensure that switches for fans/lights, and water taps are off while leaving the laboratory.
• P Follow the biosafety guidelines suggested for handling and disposal of the hazardous chemical.

Indication

Bilateral digital cancerous growth cauliflower like(fig-1),cancerous growth with continuous bleeding and myasis.

Aim

To remove the cancerous growth from healthy side by surgery. (Fig. 1-2)

Material Required

Amputation saw, thick padded with bandage roll ,a mixture of powder containing resin and naphthalene ball powder, bicycle tube protection sleeper(Fig-3),local anesthesia.

Key Points

• Drowning is a common cause of accidental death in animals.

• Submersion in water or other fluids prevents atmospheric air from reaching the lungs.

• To diagnose drowning, trustworthy witnesses and a history of drowning at the accident location are required.

Introduction

Drowning or immersion is a type of asphyxial death caused by a body being submerged in water or another fluid medium and preventing atmospheric air from reaching the lungs. Drowning isn't always fatal. When a drowning causes death, it is known as a fatal drowning. Complete submersion is not required for lethal drowning; simply submerging the nose and mouth is sufficient. Drowning is a difficult process. It comprises liquid aspiration, struggle, involuntary movements, dyspnea, and cardiovascular responses. Drowning ultimately leads to hypoxia and death.

Introduction

While experimenting with chemicals, sometimes we need to dry the chemical/ solution (solid, liquid or gas) using a process like evaporation or distillation, mainly to remove water or different solvents. Drying is the process of evaporation or distillation to remove water/solvent from a solution, solid or even from gas. Generally, a drying agent (usually an anhydrous inorganic salt) is used for this process, which reacts with the water (present in the chemical/ solvent to be dried) to form a hydrate. For example, anhydrous MgSO4 is one of the drying agents. The drying agents are recognized by their capacity (the rate at which they absorb water) and their intensity (the amount of water left behind in the solvent at equilibrium). No chemical reaction or change in phase occurs during the drying process.

Type of Solvents

Apart from water (a universal solvent), there are three families of organic solvents used in laboratories.

1) Oxygenated solvents: Alcohols, Ketones, Glycol ethers, Glycol esters, etc.

2) Hydrocarbon solvents: Aliphatic and Aromatic hydrocarbons.

3) Halogenated solvents: Chlorinated hydrocarbons.