Preface Authors feel a great privileged in bringing out the first edition of course VSR-411 “General Animal Surgery and Anesthesia”. The exercises in this book have been arranged to provide a sequential knowledge of the subject. The course content of this book is totally based as per the guidelines set up by the Veterinary Council of India. This book is prepared by consulting several standard textbooks and journals of related field. A number of illustrations and photographs have been incorporatd at places to make the text more meaningful. Authors are grateful to Dr. D.N. Verma, Ex. Dean and Prof. J.P. Misra, Dean, College of Veterinary Sciences and Animal Husbandary for his resolute guidance, sagacious advice and constructive criticism during the preparation of this book. Authors are hopeful that this book will serve the intended purpose. We will be grateful to the professionals and colleagues if any suggestions are suggested for the betterment of this book. 

Surgery : The branch of medical science which deals with the treatment of injuries, deformities or disease condition by manipulation or operations with the hand. The term surgery is derived from a Greek word – Chirurgia.  Cheir – Hand  Ergon – Work  Veterinary surgery : Veterinary surgery is the surgery which is practiced on animals. 

Surgical Plan i. Pre-operative Course of Action      a.    Client communication.     b.    Clinical laboratory evaluation, radiograph, treatment for fluid or blood volume deficits.  ii. Intra-operative Plan of Action      a.    Surgical approach      b.    Material and equipment needed      c.    Technical and support personnel

Sterilization is a process of killing all microorganisms, including bacteria, fungi and their spores, and viruses from animate or inanimate surfaces with the use of either physical or chemical agents. Joseph Lister first gave antiseptic principle in 1867.

Sutures or surgical threads : means a material used to hold the edges of tissue in close approximation.  Objectives     1.    To facilitate healing.      2.    Haemostatic.     3.    To retain drainage tube and implants.      4.    To reduce the size of natural opening.

There is a delicate balance among electrolyte concentrations, body water and acid base status to maintain body homeostasis. Disturbances in homeostasis results in life threatening abnormalities. The aim of fluid therapy is to replace losses and maintain fluid and electrolyte balance in the body.

Shock is a life threatening condition which is usually manifested by serious pathophysiological abnormalities. In most cases it is due to poor tissue perfusion with impaired cellular metabolism.        It is a clinical state resulting from an inadequate supply of oxygen to the tissues or an ability of the tissues to properly use oxygen.        Shock can also be defined as imbalance between oxygen supply and oxygen consumption. In other words, the delivary of oxygen does not meet the needs of the tissues.        Shock is a state in which the vital functions of the body are depressed because of acute reduction in cardiac output and effective circulating blood volume.

Dissolution in the continuity of bone/cartilage with or without displacement of fractured fragments is known as fracture. Classification 1. On the Basis of Communication of Fractured Site to the Environment     a.    Simple fracture : The fracture site does not communicate with the environment.      b.    Compound fracture : The fracture site communicates with the environment.  This type of fractures is more prone to infection.      c.    Complicated fracture : A closed fracture in which there is considerable injury to important neighboring vessels or nerves or accompanied by the opening of a joint or vascular cavity.

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.

Burn : Tissue changes due to excessive absorption of heat is known as burns. Scald : A scald is a burn caused by moist heat and is usually partial thickness. Etiology        Dry heat        Actinic rays (sunburn)        Irradiation        Moist heat        Electricity        Friction        Dry heat causes desiccation and charring.

A hernia is the protrusion of an organ through a defect in the wall of the abdominal cavity in which it lies. Classification 1. On the Basis of Anatomical Site     Abdominal (umbilical and ventral)     Diaphragmatic

It is defined as the reaction of living tissue to injury which begins following a sub-lethal injury to tissues and ends with complete healing. The purpose of inflammation is to destroy and remove the irritant and to repair the damaged tissue.  Causes     1.    Pathogenic organisms: Bacteria, virus, fungi, protozan and parasites.     2.    Chemical poisons: Acid and alkalies.      3.    Mechanical or thermal injuries.      4.    Immune reaction: Antigen antibody reaction.

Sprain : It is defined as a joint injury in which fibers of supporting ligaments of the joint are ruptured by direct or indirect trauma. Depending upon the degree of ligament rupture, sprain can be classified as follows: 

Inflammation of the joint is known as arthritis. Coxitis : Inflammation of hip joint. Gonitis : Inflammation of stifle joint. Omarthritis : Inflammation of shoulder joint. Carpitis : Inflammation of carpal joint.

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 70ºF 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).

Colour Plates Chapter 8: Wound