eChapters

Luxation/Dislocation : It refers to the displacement of opposing articular surfaces of bone. The direction of displacement is described with reference to the distal bone in relation to the proximal bone.

Subluxation : It refers to partial or incomplete dislocation.

Classification
    1.    Acute : Recent occurrence of luxation.
    2.    Chronic : Luxation existing for a long time.
    3.    Recurrent : Reluxation after correction.
    4.    Simple : No open wound is communicating with the joint.
    5.    Compound : Open wound is communicating with the joint.
    6.    Pathological : Dislocation due to any pathological lesion.

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.

  Term anesthesia by Dr Oliver Wendell Holmes (1886).
  Anasthesis (Greece Word) – absence of sensation.

History of Animal Anesthesia
  Paracelsus (1540) produced ether and reported it to have a soporific effect on fowl. 
  Sir Humphrey Davy (1800) suggested that N₂O might have anesthetic property. 
  Chloroform was discovered by Liebig in 1831.
  Dr. Horace Wells (1844) discovered the general anesthetic properties of nitrous oxide. 

Preanesthetic agents are so named because they are usually given to prepare the patient for administration of an anesthetic agent for one or more of the following reasons:

    1.    To reduce the amount of general anesthetic needed and increase the margin of safety.
    2.    To calm the patient so that anesthesia can be administrated without fright or struggling. 
    3.    To reduce secretions of salivary glands (antisialogogue) and mucous glands of the respiratory tract, thus maintaining a free airway. 
    4.    To reduce gastric and intestinal motility and prevent vomiting while the patient is under anesthesia. 
    5.    To block the vagal reflex, thus prevent cardiac slowing or arrest (bradycardia).

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.

Injectable Anesthesia

Injectable anesthetics are the agents which are administered to the patient parentrally. They include drugs which are given intravenously to rapidly induce anesthesia in a patient. Single or combinations of drugs usually administered intramuscularly to patients which are difficult to handle. Injectable agents generally require less equipment and are easier to administer than inhalation anesthetics, but it must be remembered that once they are given to a patient they cannot be removed.

Advantages
    1.    These agents are primarily exhaled through the lungs and recovery is not dependent upon redistribution within the body and detoxification mechanisms. This is helpful in poor risk patient.
 
    2.    Anesthesiologist has good control over the anesthesia.
 
    3.    Early recovery of the patient.

    4.    Closed system available for thoracic surgery.

A sound understanding of general anesthetic emergencies and surgical techniques is vital for all practicing veterinarians. In most of the veterinary practices, after induction of anesthesia, no one is assigned the task of anesthetist to monitor anesthesia and occurrence of complications during surgery which may lead to the development of anesthetic emergencies. Onset of general anesthesia disturbs the physiological equilibrium of patient and increase the threshold of harmful events. The harmful events of anesthesia includes:

Endotracheal intubation is the placement of a tube in the trachea to provide a patent airway.

It is a valuable technique that enables to attach an animal to a breathing circuit or, just as importantly, to secure an airway during an emergency such as respiratory or cardiac arrest.

It is important that time be taken to learn the anatomy of the laryngeal area and the skill of intubation so that intubation may be performed quickly and with little chance of misplacement.

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.
 

These are the drugs that reversibly block the propagation of action potentials along nerve axons. General anesthesia may be advantageous where complete immobilization and relaxation of the patients required. However, local anesthetic techniques are advantageous for providing surgical anesthesia in animals that are considered at risk for inhalant or intravenous anesthesia. These drugs are injected directly at the target site.

Local Anesthetic Techniques of Head Region
The following nerves can be blocked in the head region for performing surgery.
    1.    Cornual nerve block 
    2.    Peterson’s orbital nerve block 
    3.    Auriculopalpebral nerve block 
    4.    Supra orbital nerve block 
    5.    Infra orbital nerve block 
    6.    Retro bulbar nerve block 
    7.    Mental nerve block 
    8.    Maxillary nerve block 
    9.    Mandibulo alveolar nerve block 

Acus means needle. It is an ancient Chinese system of therapy utilizing long fine needles at specific points and their stimulation by various means to induce analgesia and to cure certain diseases. The specific points are known as acupuncture points or acupoints.
 
The procedure is safe. There are no post anaesthetic complications and can be used in poor surgical risk patients. The major disadvantage is poor muscle relaxation. Acupuncture has been used to produce local anaesthesia.
 
Acupoints : Alphanumeric code system is used to recognize the acupoints universally e.g. BL, LI, SP, GB etc means meridians of the urinary bladder, large intestine, spleen, gall bladder etc. respectively.

Operation theatre (OT) is a place where surgical operations are performed under the principle of aseptic surgery. An ideal operation theatre :
    Should be located near the work and intensive care areas of the hospital.

    Should be independent of general traffic. One way traffic flow is maintained to ensure sterility. 

    If possible, air within the OT should be under mild positive pressure so that when the surgery room opened, air flows out of rather than into the room.
 
    Floors, walls and ceilings should be constructed of impervious material that can easily be cleaned and disinfected.
 
    The lighting of the OT should entirely be dependent on artificial light.
 
    Room temperature should be about 70^ºF with a relative humidity of about 50% provides a better environment for the surgeon and patient.

Surgical pack : It is sterilized bundle containing the conventional surgical instruments and drapes etc. required for routine surgical operation.
 
Common surgical instruments: These instruments are used in routine general surgery and made up of stainless steel. Stainless steel not only has excellent strength but also resistant to corrosion. The general instruments are:

    1.    Towel clamp : It is used to hold the drape in position. It has pointed ends so that drape does not slipped away from the area of operation. Small amount of skin is grasped to secure the drape. It is of two types :

    a.    Backhause towel clamp
 
    b.    Cross action towel clamp

    2.    Bard Parker knife / scalpel (B.P. handle with blade) : Bard Parker knife is available as disposable knife. BP handle is available with changeable blades.

1.    Milking tube : It is used for milking the animal after udder or teat surgery. It can also be used for infusing intramammary medication through teat canal.
 
 2.    Teat plug : It is used to plug the teat in cases of leaky teats or trodden teats or following operation at teat sphincter. It can also be used for retaining medication in the teat canal.
 
 3.    Udder infusion tube : It is used for infusion of medication in the udder/teat.

 4.    Teat slitter with concealed blade : For cutting any growth inside the teat canal without injury to the teat.
 
 5.    Teat tumor extractor : It is used for removal of teat tumour or polyps from the teat canal. 

These specialized instruments are used for operation of skeletal system. Common instruments are as follows :

    1.    Loman bone holding clamp : It is used for holding fractured bony ends with bone plates.
 
    2.    Bone plates : are used for rigid immobilization of fractured fragments. Bone plates are of difference shapes, sizes and with varying number of holes. These are of following types :
 
        a.    Dynamic compression plate.
        b.    Neutralization plate.
        c.    Shcrnab plate etc.
 
    3.    Bone screws : are either used to immobilize fractured fragments or to fix bone plates. They are of different sizes and classified in to cancellous and cortical types.

These instruments are used for surgery and need special care and attention for sterilization and storage.
 
    1.    Strabismus scissors : It is used for treating strabismus i.e. sectioning of affected muscle.
 
    2.    Me Guire corneal scissors : It is used for incising cornea
 
    3.    Graefe’s eye speculum : It is used for retraction of eyelids for examination of eye or for ophthalmic surgery.
 
    4.    Ziegler knife needle : It is used for separation of ocular tissues during ophthalmic surgery.
 
    5.    Iris hook : It is used for handling of Iris drug ophthalmic surgery.
 
    6.    Tenotomy scissors : It is used either for cutting the ocular ligament of eye or for removal of ocular sutures.
 
    7.    Dressing forceps : It is used for manipulation of eyelids, 3rd eye lid and other tissues of the eye.

These instruments are used for different surgical conditions of hoof.
 
    1.    Drawing knife: It is used to remove excess sole and trimming of horny tissue (Fig. 6.1). 
    2.    Hoof plane: it is used to plane the surface of the hoof. 

    1.    Molar tooth cutter :  It is used to cut the extra sharp molar tooth in large animals (Fig. 7.1).

Catheters are hollow tubes made up of rubber, gum elastic, polyethylene or teflon or metal and are indicated.
 
    1.    To evacuate fluid from the body cavity.
 
    2.    To collect fluid sample from the hollow organ.
 
    3.    To administer medication inside a hollow organ.

Restraining means use of strong force or chemical agents to prevent or suppress or to control the action of animal for clinical examination or for prevention of self-injury and for performing surgical interventions.
 
Restraining can be performed by:
    1.    Psychic persuasion 
    2.    Physical restraint 
    3.    Chemical restraint

General anaesthesia can be induced by parentral anaesthetics or by gaseous or inhalation anaesthetics. 

Apparatuses

    1.    Syringes : Disposable plastic syringes of different capacities e.g. 1ml, 2ml, 5 ml, 10 ml, 20 ml and 50 ml.
 
    2.    Hypodermic needles : They are of different sizes e.g. 16, 18, 20, 22, 24 gauze. They must be sharp with short bevel to reduce risk of transfixing the vein.
 
    3.    Catheters : They are used for constant infusion of drug or for administration of intermittent small doses of drug. 

Preparation of Patient for General Anesthesia
    1.    Check for feeding status of animal : Dogs should be kept off feed and off water 8-12 hours ruminants 24-48 hours, and horses 12-24 hours before surgery.

        Advantages
    a.    To avoid vomition and choking.
    b.    To avoid respiratory distress due to pressure of full stomach on diaphragm. 
    c.    To avoid gastric rupture.
    d.    While restraining, there may abdominal rupture.
    e.    Prevent increase in BMR.
    2.    Complete blood count like PCV, Hb, DLC and blood chemistry should be undertaken. 

The effects of anesthesia need to be monitored to prevent excessive insult to the cardiovascular, respiratory and central nervous system. 

1. Evaluation of Central Nervous System (CNS)
       Observe reflex activity to monitor degree of CNS depression. 

    Eye reflexes
        i.    Palpebral reflex 
        ii.    Corneal reflex 
        iii.    Position of eye ball 
        iv.    Nystagmus
        v.    Lacrimation 
        vi.    Pupillary reflex

Hemorrhage is a discharge of blood from the vascular system. Control of bleeding is of great importance because besides anesthetic problems the only disaster befalling the surgeon in the operating room is the result of hemorrhage.

Hemorrhage is Classified as
1. According to Source
Arterial : Blood is bright red and flows in spurts.
 
Venous : Blood is bluish red and flows freely. Capillary: Blood oozes under low pressure. 

Bandages
       Bandages are used to protect the wound and incisions, as well as support body parts.

       Bandages are also used to immobilize the limbs.

       Bandages are used to promote the wound healing process by :

        i.    Removal of dead and necrosed tissue from the wound (debridement).
        ii.    Application of topical antiseptics.
        iii.    Pressure to reduce the dead space, hemorrhage and edema.
        iv.    Preserving the hemostasis at the wound site.

General Description of An Animal
    1.    Age      
    2.    Sex                          
    3.    Body weight

Many anesthetic drugs are available to immobilize the lab and wild animals. In wild animals, immobilizing agents are usually administered by intramuscular injection.

Common Anesthetic Agents used for Immobilizing Wild Animals

    1.    Ketamine
    2.    Telazol
    3.    Xylazine
    4.    Medetomidine
    5.    Carfentanil
    6.    Etorphine

Application of various methods of restraints is essential to carry out certain surgical procedures on animals. A particular method of restraint suitable for one animal may proves ineffective for another. Consider the temperament, Age, breed and individual characteristic of the animal as well as purpose of the restraint.

    1.    Trocar and canula : It is used to remove the gas from the rumen during bloat. It should be inserted by sliding the skin through the left paralumbar fossa. (Fig. 18.1). Sliding of skin decreases the chances the formation of ruminal fistula after its removal.

    2.    Probang gag : It is made of a wooden piece with a hole in the middle and straps on either ends. Wooden block having the hole is fixed in the mouth and straps are fastened behind the horn at the poll. The probing is passed through the hole in to the stomach (Fig. 18.2).

1.1 Introduction

Agriculture and allied sector contributes nearly 18 percent of gross domestic product in Indian economy and more than 70 percent population is dependent on agriculture and allied sector. In this sector, livestock is an integral part and it provides essential commodities and livelihood to the majority of its population. Livestock sector provides sustainability and stability to the national economy by contributing farm energy and food security. During last decade, the annual growth rate for livestock population maintained and in contrast the crop production remained stagnant or increased marginally. Between 1983 and 1999, the per capita consumption of milk increased by 37 percent and meat, egg and fish by 24 percent.

Every nutrient has its specific functions to play in the biological system. As we know there are six nutrients i.e., water, carbohydrate, protein, fat, minerals and vitamins and each of these have different functions, it will be discussed separately for each nutrients.

2.1 Water

Water is the ideal dispersing medium because of its solvent and ionizing powers which facilititates cell reaction and due to its high specific heat which helps to absorb the heat of these reactions with a minimum rise of temperature. Lean adult body contains about 70 percent of water, though the amount varies from embryo to mature animals.

Developments of feeding standards

Feeding standards are statements or quantitative descriptions of amounts of one or more nutrients needed by the body. Since the beginning of nineteenth century, scientists worldwide started formulation of standards for feeing the livestock and poultry and as such with the advancement of science the standards were developed from time to time. For convenience all such standards are grouped under major 
3 headings based on principles of standards. These are comparative type, digestible nutrient system and production value type.

4.1 Ration and balanced ration

A ration is the feed allowed for a given animal during a day of 24 hrs. The feed may be given at a time or in portions at intervals. Balanced ration may be defined as the ration that provides all essential nutrients to the animal in such a proportion and amounts that are required for the nourishment of the particular animal for 24 hrs.

The potential value of any feed for supplying a particular nutrient can be determined by chemical analysis but the actual value of the feed to the animal can arrived at only after making allowances for inevitable losses that occur during digestion, absorption and metabolism. The first tax imposed on feed is that represented by the part of it which is not absorbed and excreted in the feces.

This may be defined as the factor present in feeds/ fodders or trees leaves and impair some aspects of animal metabolism, produce adverse biological effect in animal production. These are referred mostly as toxic factors because of the deleterious effects they produce when taken by the animals. The term ‘toxic factor’ however, is misleading because there is an implication that the substances are lethal beyond certain level of intake.

Diseases of metabolic origin are commonly known as metabolic disease viz., bloat, acidosis, milk fever, hypomagnesimia, pregnancy toxaemia etc. However, few common metabolic diseases encountered in herd/ flock management are discussed in the chapter. Among these diseases bloat, acidosis and ketosis are generally occurs due dysfunction in rumen. In the rumen, microbial fermentation occurs due to unique structures and environment. Microbes converts fibrous feeds which are of no use for human beings to important product viz., milk meat, hair and fibre etc. Some bacteria and protozoa have isolated from rumen by the researchers and with their fermented products and pathways. Name of the fermented products with the products is presented in the following Table 24.

Agriculture encounters a complex dynamic system of natural conditions. The meteorological factors among these natural conditions play a pivotal role so far as agriculture is concerned. The rate of growth and development of a bio-system is largely depending upon its ambient temperature and moisture. The plant productivity per unit area, total production, quality of the produce, operational efficiency as well as econometrics are solely governed by the meteorological parameters. Therefore, their through understanding including the computation and the measurement techniques is absolutely essential. It is no less important to have sufficient workable information on weather phenomena as well as climatic resources to determine realizable potential and an appropriate solution for a number of problems faced in agriculture.

Since meteorology and climatology are primarily observational sciences, adequate care has to be taken for getting most representative and accurate observations of weather parameters for their efficient application. This depends on site of observatory, maintenance of observatory, accuracy of instruments, timely measurements of weather parameters, knowledge and responsibility of the observer.

Monitoring of weather conditions, in a country like India, which is climatologically so diverse because of its unique geographical situation is a challenging task. It is done through a large network of observatories of different types. India Meteorological Department (IMD), Pune, is entrusted with the collection and keeping the record of weather data collected from different stations and also to train the man power in this specialized area. Weather stations installed in different parts of the country are of different types.

Rainfall is precipitation (falling of any type of condensed moisture to the ground) in the form of liquid drops larger than 0.5 mm in diameter falling on the earth surface. Ordinary rain drop size varies from 0.5-4.0 mm in diameter. Rainfall is measured in term of depth of rain water (millimeters) on a solid surface provided that rain water is neither allowed to percolate nor runoff or loss in any form.

Snow is precipitation of solid water, mainly in the form of branched hexagonal crystals or stars. It is “precipitation of white opaque grains of ice”. Measurement of snow cover is related to runoff estimation and also important for hilly agriculture.

4.1. Snowfall

It is the amount of fresh snow deposited over a specified period (generally 24 hours). The measurements relate to depth and water content of the snowfall.

Temperature influences most plant processes, including photosynthesis, transpiration, respiration, germination, flowering, adaptation and distribution of crops. As temperature increases (up to a point), photosynthesis, transpiration, and respiration increase. When combined with day-length, temperature also affects the change from vegetative (leafy) to reproductive (flowering) growth. Depending on the situation and the specific plant, the effect of temperature can either speed up or slow down this transition.

Temperature is the measure of mean kinetic energy per molecule of the molecules in an object, while the heat is the measure of total kinetic energy of all the molecules of that object. A large object may  have a much lower temperature than a small object and may still have greater heat content by virtue of larger number of molecules in it. Thus heat and temperature are not the same.

The surface of the earth gets heated up during the day and gets cooled during the night causing diurnal changes in the top layers of the soil. Soil temperature is an important part of micro-environment, where plant roots grow and capture the water and nutrients and thus, it affects the plant growth and yield. During crop germination also soil temperatures play vital role. Since the heat regimes of these layers are governed by the soil temperature, the measurement of soil temperature becomes extremely important.

It is the actual minimum temperature experienced by the plants near ground surface. The grass minimum temperature is lower than the air temperature at 4 ft level. It is the temperature recorded in open air ground on short turf, with the bulb of the thermometer just in contact with the tips of the blades of grass. It is also described as the temperature at 5.0 cm (2 inches) above ground. It is used during October to March period only when frost occurrence is expected. The readings of the grass minimum thermometer indicate the possibility of ground frosts, which is important information for farmers, gardeners and growers.

The presence of moisture in atmosphere is termed as humidity and plays an important role in formation of weather system and plant as well as insect-pest growth and development. An abundance of moisture results in a rich natural flora and makes possible a wide choice of crops. Deficiency of moisture, on the other hand, permits only narrow range of crops. Humidity also affects the water requirement and the rate of transpiration. Reduction in transpiration reduces the translocation of food material and uptake of nutrients. High humidity with high temperature favours the outbreak of pest and disease. Moisture stress condition reduces the cell size and shape and ultimately plant growth and yield is reduced. High soil moisture and humidity condition cause failure in establishing stand of legumes and pulses. Excess of soil moisture in earlier growing season may result in more vegetative growth and delayed flowering.

Wind influences the plant life both physiologically and mechanically. Wind affects plant directly by increasing the transpiration and intake of CO₂. Thus raising the supply of CO₂ to the plants and thereby increase in photosynthesis. However, the increase in photosynthesis is again upto a certain wind speed beyond which its rate become constant. The warm and dry winds increase evaporative loss and cause moisture stress. Lodging is one of severe injury caused by strong winds which causes great yield loss depending upon the stage of crop. This injury is common in paddy, maize, wheat, sorghum and sugarcane. Strong winds damage fruit trees extensively by breaking leaves and twigs and causing fruit drops.

Sunshine means incoming solar radiation, which consists of a bundle of rays of different wavelengths. At the top of the atmosphere, the amount of radiant energy received is found to be constant (1.94 cal/cm2/min). The receipt of the radiant energy, which is received on the earth and on crop surface, is influence by the cloudy and sunny or clear sky conditions. The brightness hours of the sunshine are an important parameter, which not only influence microclimate of a place but also the photosynthesis of the crop. The radiant energy of intensity of 0.17 cal/cm²/min or 120 W/m² and above is known to specify the bright sunshine.

Cloud is a visible aggregate of minute water droplets and/or ice particles, or both in the air usually above the general ground level. Clouds are the most important form of suspended water droplets caused by condensation. There is no precipitation without clouds.

11.1. Measuring Instrument

The cloudy hours are measured with the help of eye or sensory parts of the body. No particular instrument is required for cloud amount or cloud cover measurement in the sky.

The solar energy is the main source of energy for the processes occurring at the earth surface and in its atmosphere. Crop production, is in fact an exploitation of solar radiation and plants are the converters of solar energy into a useful form of energy which is biomass and sustain life providing food, fodder, fiber, fuel, fruits etc. Sun energy fulfills two essential needs of the plants i.e.  (i) light for photosynthesis including many other photo processes and functions of the plants, (ii) thermal conditions required for the normal physiological functions of the plant. Thus, the crop production and agriculture is basically dependent on quality and quantity of radiation.