eChapters

Key Points

• Dogs exhibit respiratory distress symptoms more frequently than cats.

• Respiratory distress might have overt or covert clinical symptoms.

• The thorax and belly move paradoxically in cases of severe respiratory distress.

• Immediate intubation is the first step in managing a respiratory emergency: opening the airway.

Introduction

The telltale symptoms of "oxygen hunger" include tachypnea, stretched head and neck, abducted elbows, flare of the nares, cyanosis, open-mouth breathing, anxiety, and inability to lie down or relax. It is more usual for dogs than cats to exhibit symptoms of respiratory distress. Tachypnea and conspicuous breathing motions when in a sternal recumbency position are the only indications of respiratory dysfunction in cats, who often mask the severity of their illness. Despite their seeming stability, these patients are often extremely vulnerable and can rapidly decompensate when under stress.

Orthopaedic Radiography
 
Radiography as an aid to diagnosis the orthopaedic cases has become an integral part of every modern hospital. This technique may also be helpful in detecting some previously unrecognized lesions in the area radiographed.

The radiologist must be aware of the radiological anatomy of part being examined, and of its normal variation with age, species and breed. The anatomical features which can be appreciated in a radiograph are:

Key Points

• It is frequently reported that metal, non-metal, and metalloid components cause toxicity in farm animals.

• The type of element causing toxicity affects both the treatment and the clinical indications of toxicity.

• The best course of action for managing toxicity is to treat symptoms f irst, then, if the causal toxin is known, use targeted antidotes.

Introduction

Animal diets contain a variety of environmental components, including metals and non-metals. Certain substances are necessary for the animal and only become poisonous when consumed in excess, while others simply endanger the animal's health. However, a number of variables, including the absorbed dose, the exposure route, the period of exposure (acute versus chronic), and others, affect how toxic the substance is, and these variables must be taken into account when diagnosing, treating, and managing clinical cases. Given the multitude of factors affecting these metals' toxicity. An attempt is made in this chapter to present a streamlined synopsis of the toxicity of metals, non-metals, and metalloid elements that are frequently encountered.

It has been well established that the risk of health problems rises as the amount of radiation exposure increases. All types of radiation produce changes in the living tissues. The resultant cellular injury causes physiological and pathological changes leading to “Radiation sickness”. The radiation effects may be somatic or genetic. Somatic effects are harmful to a person in his lifetime whereas genetic effects affect generations. Radiation may cause changes in complex molecular systems of living cells, primarily in following two ways :- 

Occasionally some diseases can be noticed in male animals, which are responsible for the reduced reproductive performance of the bucks. Sometimes these diseases can damage or obstruct the male reproductive passage and responsible for the infertility and sterility in the bucks. This type of infertility may be associated with pathology of testes, epididymis, vas deferens, accessory sex glands, and urethra or may be associated with abnormal semen production due to congenital or hereditary causes or due to acquired causes.

Eyes Anatomy The eye has following important structures. •     Choroid is the layer containing blood vessels that lines the back of the eye and is located between the retina and the sclera. •     Ciliary body is the structure containing muscle and is located behind the iris (that assist in focusing the lens). •     Cornea is the clear outer layer at the front of the eye that transmits and focuses (i.e., sharpness or clarity) light into the eye. •     Fovea is the depression in the inner retinal surface, the photoreceptor layer of which is entirely cones specialized for maximum visual acuity (sharp vision). •     Iris is the colored part of the eye regulating the amount of light entering the eye. In bright light,

Infertility or reduced fertility in male animals particularly in bulls had considered being a rare occurrence, but now infertility in males is being considered a common and severe problem. Still there is lack of information concerning the male’s infertility.

Miscellaneous causes of male infertility 

1. Failure of proper delivery of semen into the vagina

It may be secondary to lacerations of the ventral caudal portions of the glans penis with a fistulous opening of the urethra ventrally. In such case, at the time of ejaculation, neither semen is deposited in the middle portion of the vagina nor sprayed over the cervix. In addition, it is observed in rams following necrosis of most of the urethral process secondary to urinary calculi or lacerations or injury.

Semen collection in bulls and buffalo bulls

Semen collection from domestic animals is an art and skilled job to get maximum quantity and quality of an ejaculate. Ejaculation of semen in a male is a complex process and consists of several events sexual arousal, courtship, erection, penile protrusion, mounting, intromission, ejaculation, orgasm like reaction and dismounting. Ejaculation is the result of neuro-muscular stimulation that starts in the vas differentia and accessory sex glands. The semen ejaculation is finally brought about by the rhythmical contractions of penile musculature and urethra. The muscular contractions proceed progressively in waves, forcing the semen out of the external urethral orifice. To get good quality semen, the bulls must undergo all the related events of ejaculation. The semen collectors should have knowledge of inhibitory and stimulatory factors for the act of ejaculation in male domestic animals. The stimulatory factors are:

Microscopic examination 

A phase contract microscope with biotherm (37o C) is necessary for correct evaluation of semen because the refractive index of spermatozoa differs slightly from that of the surrounding medium. The ordinary bright field microscope will not provide sufficient contrast between the spermatozoa and the medium. Under phase contrast microscope, the object will appear dark on a bright background. This is achieved by reducing the light passing through the object by half a wavelength compared to the light passing through the medium. The eyepiece has a magnifying capacity of 10X while the objectives have 10, 40 and 100X. This will provide the microscope the magnifications of 100, 400 and 1000. The lenses and eyepiece should be kept clean by wiping with tissue paper and distilled water. Xylol can also be used to remove greasy material. The microscope has to be kept in one place and covered with Perspex cover when not in use to avoid dust accumulation. Personnel familiar with the operation of a particular microscope alone should be allowed to handle the microscope, since lot of differences exist between different makes of microscopes. 

Good cataract outcome depends on pre-operative selection of patients, the skills and knowledge of the eye surgeon, the surgical technique, the surgical facilities and environment, the post-operative care and the optical correction provided.

Preoperative Procedures

Owners are advised to instill antibiotic eye drop such as Moxifloxacin @ two drops b.i.d. for 7 days and eye drop tropicamide @ two drops b.i.d. for 2 days before the cataract surgery for proper dilation of pupil. Non-steroidal anti-inflammatory eye drops such as Flubriprofenis started t.i.d on the day before surgery. Further, tropicamide (1%) used as mydriatic agent is instilled 30 minutes before operation at the rate of two drops every 5 minutes in the eye to be operated. 0.5% povidone iodine drops are instilled on cornea prior to surgery.

Introduction

To accomplish experimentations in laboratories, sometimes we need microscope to test/validate our ideas/findings. A microscope is needed to examine objects which are very small which cannot be visualised by naked eyes. However, microscopic study requires some expertise in operating the microscope, particularly the sophisticated microscopes, as well as to prepare (peeling, sections, cutting, fixation, staining, dehydration, mounting, etc.) the sample, so that it can be appropriately examined for the anticipated details.

According to the scientific requirements different types of microscopes are used in the laboratories for research purpose. In this chapter, our aim is to acquaint you with the basics of using and handling of microscopes, particularly a compound microscope that is commonly used by the graduate and post graduate students for basic research.

Microscopy is often designated as the scientific investigation that is employed to review and analyse minute structures and objects using a microscope. The term “microscope” has been derived from ancient Greek words “micros” meaning “small” and “skopeîn” meaning “to look at or see,”.

Microscope

A microscope is a laboratory instrument used to examine objects (biological specimens) which are too small to be seen by the naked eye. The microscope must accomplish three tasks:

• Magnification- to provide a magnified image of the specimen.

• Resolution- to separate the details in the image.

• Contrast- to render the details clearly visible to the eyes.

Although we will tnroduce to you the different types of microscopes used for different speciments, our main focus is to discuss about compound microscope, which is commonly used in the laboratories. Compound microscope was developed around the beginning of 17th century.

Introduction
It is a fundamental biological process in which one cell splits into two or more daughter cells. Both unicellular and multicellular organisms rely heavily on it for growth, development, repair, and reproduction. There are two main types of cell division: mitosis and meiosis. Mitosis occurs in somatic cells and produces two genetically identical daughter cells that share the same chromosomal number as the parent cell. This process is necessary for tissue development and repair. Meiosis, on the other hand, happens in germ cells and results in the formation of gametes, which reduces the number of chromosomes by half to ensure genetic diversity in progeny. Proper regulation of cell division is vital for maintaining cellular health, and disruptions in this process can lead to disorders like cancer.
The different stages of cell division is as follows:-
1. Interphase
• Although not a component of mitosis, interphase is essential for preparing the cell for division. It is separated into three sub-phases:
• G1 phase (Gap 1): The cell expands in size while creating proteins and organelles. S phase (Synthesis): DNA replication occurs, guaranteeing that each daughter cell receives an identical copy of the genetic information.
• G2 phase (Gap 2): The cell continues to expand while new organelles are synthesised)
The cell checks for DNA replication mistakes and gets ready for mitosis.
2. Prophase
• In this phase chromatin condenses into visible chromosomes, each made up of two sister chromatids linked at the centromere.
• The nuclear membrane breaks down, allowing the spindle fibres to interact with the chromosomes.

Introduction
Gametogenesis is the process by which gametes are produced in sexually reproducing organisms. This process involves a series of cellular divisions and differentiations and can be divided into two main types: spermatogenesis (the production of sperm) and oogenesis (the production of ova). Gametogenesis ensures genetic diversity through the processes of crossing over and independent assortment during meiosis. A gamete is a specialized cell involved in sexual reproduction. Gametes are haploid cells; contain only half the number of chromosomes of a diploid cell. Two gametes one from each parent fuses during fertilization to form a zygote, a diploid cell with a full set of chromosomes. The primordial germ cells develop from the wall yolk sac and differentiate into female and male gametes. During and after migration of primordial germ cells, they proliferate by mitoses and male and female primordial germ cells surrounded by somatic cells of their specific gonads and differentiate into oogonia in ovary and spermatogonia in testis. Meiosis is the process of cell division (Meiosis I and Meiosis II) in two specialized germ cells i.e. oogonia and spermatogonia to produce haploid female gametes (ovum) and male gametes (sperm) respectively. Meiosis I allow genetic recombination where exchange of DNA segment occurs between maternal and paternal chromatids.
Spermatogenesis
The development of sperm in the germinal epithelium of seminiferous tubules of the testis is known as spermatogenesis. Spermatogenesis starts, when the male animal attains the puberty. The sequential stages in spermatogenesis are
1. Mitotic/multiplication phase: Primordial germ cells undergo a series of mitotic divisions and localized in solid cords of primitive sustentacular cells (progenitor of Sertoli cells) within the seminiferous tubules (testis). At the age of puberty, the cell cords differentiated into seminiferous tubules of the testis and simultaneously primitive sustentacular cells became Sertoli cells and primordial germ cells produce spermatogonia throughout the life, having the features of stem cells. These spermatogonia remains dormant until the onset of puberty. Sertoli cells are very important for both physical support and paracrine regulation of spermatogenesis, and also form the blood-testis barrier by sealing off the seminiferous tubules with tight junctions. At puberty, they are activated and undergo series of mitotic division and produce clones of cells referred to as type A spermatogonia. Among type a

Introduction
The mammalian embryos are subdivided into two groups namely domestic animals where extraembryonic membranes form by folding process, and primates where blastocyst implants very soon after it enters the uterus and extra embryonic membranes forms after implantations. The major function of fetal membranes is to provide nutrients to developing fetus, protection, synthesis of enzymes and hormones and caring of fetal waste products. It is consisted of yolk sac, amnion, allantoic and trophoblast or chorion. The trophoblast is the single most important tissue of fetal membranes which has potential role in absorbing, transmitting and handling nutritive and waste products.
Yolk sac
It is a primitive structure. Develops early in the embryonic period from the entoderm which disappears after short period of time in ruminants. The uterine milk, secreted by the endometrial glands, is absorbed by the blastocyst along with yolk sac to provide nutrition to early embryo. Before forming other embryonic membranes yolk sac performs limited functions whose role is limited during mid and late gestation.
Amnion
It is an ectodermic vesicle that arises from an out folding of the chorion which is a double walled sac that completely surrounds the fetus except at the umbilical ring. The inner layer of this double-walled sac is the “true amnion” and the outer layer is the “false amnion” amnion chorion. Like yolk sac, the amnion chorion also lasts for shorter period.The amniotic fluid is clear, colorless and mucous in nature. Source of amniotic fluid: In early to mid-gestation, it is probably from the amniotic epithelium and from fetal urine as the fluid is quite watery. As gestation advances, the allantoic fluid increase in volume while the amniotic fluid volume remains fairly static but

Introduction

Test of pollen viability (extent of pollen viability) is important in pollination experiments to ensure fertility/seed setting. It is also important in monitoring state of pollens during storage in ecological/ taxonomic studies as well as during research on pollen biochemistry, genetics, stigma interactions, and incompatibility studies. Pollen viability refers to the ability of pollen to accomplish post-pollination events to achieve fertilization. Pollen viability test has gained importance particularly in plant breeding and hybrid seed production experiments/ practices. In this chapter, you will be acquainted with the basics of pollen viability test. However, for more professional knowledge on the topic readers are suggested to refer specialized books.

Pollen Viability Test

It is important to know the extent of viability of pollens used in pollination experiment, in finding fertility of a plant of interest, to monitor state of pollen on storage, in ecological/taxonomic studies, as well as in research on biochemistry, genetics, stigma interaction, incompatibility assay, etc. of pollen. Several pollen viability tests have been developed time-to-time. It is recommended to initially use different tests for a given pollen type to find out the most appropriate method that provides reliable result on pollen viability. It is important to note that every procedure requires standardization of protocol according to the sample used. Following different tests are used for assessing pollen viability.

1. In-vitro Pollen Germination Test

It is a simple, speedy, and quantitative test for assessing pollen viability. In this method, a collection/sample of pollen is germinated in vitro and observed under microscope. The percentage of germinating pollens (producing pollen tube) after appropriate treatment and a given period of time is determined. The percentage provides an index of viability of the pollen sample.

In 1965, Urist demonstrates that the implantation of demineralized bone at extra skeletal sites induced de novo formation of cartilage and bone and proposed that the decalcified bone matrix possess high osteoinductive property and the inductor is a unique chemical that differentiates mesenchymal type cells (pericytes) into new bone. Urist and Starates (1971) reported that the inductor is a protein and termed it bone morphogenetic protein (BMP) . BMP is the bone induction principle.

Sources: Bone morphogenetic protein isolate from bovine as well as human bone and designated as bBMP and hBMP respectively. The molecular cloning of the bone morphogenetic proteins and their subsequent expression in recombinant system, resulted recombinant bone morphogenetic protein designated as rhBMP. BMP has been extracted from dentin and bone matrix, as well as from bone tumours, by enzymatic and nonenzymatic methods. The sources of BMP, thus far explored are rabbit dentin, rat, rabbit and bovine bone, human bone, mouse or human osteosarcoma and human placenta.

BMP circulates in the blood and it can be detected by BMP-radioimmunoassay. BMP levels higher in growing children (20-72 ng/ml) and patients with Paget’s disease (over 259 ng//ml) than in normal adults (14-18ng/ml). Crude and partially purified BMP has been extracted with the aid of collagenase, ethylene glycol, calcium chloride urea and Guanidine hydrochloride (GuHCL) solution. Wang et al (1988) purified BMP factor that induces bone formation> 300,000 fold from Guanidine chloride extracts of demineralized bone. As littlie as 50ng of this factor can induce the formation of cartilage and bone in an in vivo assay, though only 40µg could be obtained from 400kg of bovine bone powder.

Introduction
• Overview of the development of the musculoskeletal system, including bones, cartilage, joints, and muscle types within skeletal and cardiac systems.
Development of the Musculoskeletal System
Mesoderm Contributions
• Mesodermal Derivatives
• Gives rise to skeletal muscle, skin dermis, endochondral bones, and joints.
• Notochord and Somite Formation
• The notochord induces the paraxial mesoderm to form somites, with somitomeres developing rostrally to the notochord in the head)
• Somite Differentiation
• Each somite differentiates into three regions:
• Sclerotome (medial): Forms most of the axial skeleton (vertebrae, ribs, base of the skull).
• Dermatome (lateral): Migrates to form the dermis of the skin.
• Myotome (middle): Migrates to form skeletal muscles. Individual adult muscles arise from the merger of adjacent myotomes.
Muscle Development
• Origins of Muscle Tissue:
• All skeletal muscle derives from paraxial mesoderm forming somites and somitomeres, with the exception of iris musculature (derived from optic cup ectoderm).
• Cardiac and smooth muscles originate from splanchnic mesoderm.

• Artificial Insemination (AI) is the technique of deposition of semen (Fresh, Diluted or frozen thawed) in the female genital tract by artificial means for the purpose of conception. • It is first generation biotechnology technique. It is the most economical and best technique which has been widely accepted for genetic improvement and production (calf crop and milk production) in farm animals. • All the aspects like selection of bull, semen collection, semen evaluation, processing of semen, freezing, cryopreservation, thawing and insemination are equally important for making AI successful.History Related To AI • In the fourteenth century an Arabian placed a cotton ball in the mare's vagina and collect it after mating (soaked in semen) with a high-grade stallion; then by inserting this cotton ball into the vagina of desired mare and got it conceived. • Anton Van Leeuwenhoek (Dutch scientist, 1678) and his assistant, Hamm, discovered sperm cell and called it as “Animalcule”.

4.1. Classification

The class Aves, also known as birds, is a group of warm-blooded vertebrates characterized by feathers, toothless beaked jaws, laying hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweight skeleton. Birds are found worldwide and come in a variety of sizes, from the tiny humming bird to the massive ostrich.

The classification of Aves can be broken down into two major subgroups: Palaeognathae and Neognathae.

4.1.1. Palaeognathae: Also known as ratites, these are flightless birds with f lat sterna (breastbones) that lack keels, which are important for flight muscle attachment. Examples of palaeognathae include ostriches, emus, rheas, and kiwis.