Fundamentals of veterinary surgery: classification of operations, instruments and methods of sterilization

Veterinary surgery is divided into operative, general, and special surgery, orthopedics (surgical diseases of the limbs), and ophthalmology (eye diseases).

Veterinary operative surgery with topographic anatomy is a science that studies the rules and methods for performing surgical operations on animals.

General veterinary surgery is a science that studies surgical pathology and methods for its elimination (treatment). It studies all types of traumatism, the causes contributing to its occurrence, considers the species-specific reactivity of animals, their body's response to traumatic factors and infection, principles of etiological and pathogenetic treatment, reflexology, and other issues.

Special surgery deals with the study of surgical diseases of specific regions and organs of the animal's body while considering a particular condition (diseases in the area of the head, nape and neck, abdomen, pelvic area, etc.).

Regardless of the type of surgery, surgical instruments are used when performing various surgical procedures. Surgical instruments are categorized by their purpose into the following groups:

• for general anesthesia and local anesthesia;
• injection needles and syringes;
• for separating animal tissues: scalpels (pointed, bellied, and blunt-ended) and surgical scissors (straight and curved at an angle or flat), forceps, retractors;
• for connecting tissues: surgical needles, needle holders;
• for stopping bleeding: tourniquets, clamps;
• injection devices;
• specialized equipment: ophthalmoscopes, emasculators, hoof knives, farrier tools, etc.

Dressing material: gauze bandages, gauze, cotton wool; these are used to prepare swabs and tampons (gauze, cotton-gauze).

Twisted natural silk threads, catgut, and sometimes soft wire are used as suture material.

Sterilization. Instruments are sterilized by boiling, flaming, and chemical means.

Simple or electric sterilizers are used for boiling; in their absence, enameled cookware with a lid is used. Metal, glass, and rubber items are sterilized by boiling. Before boiling, instruments are disassembled and opened; new ones are cleaned of lubricant; mandrins are removed from injection needles; and glass or sharp parts of instruments are wrapped in 1-2 layers of gauze. Boiling is performed in water (distilled water is better) or in solutions of soda (caustic soda — 0.1-0.25%; bicarbonate or baking soda — 1-2%), etc.

Prepared instruments are placed on a mesh and immersed in the liquid inside the sterilizer, which is then covered with a lid. The liquid is brought to a boil. It is recommended to immerse metal instruments in boiling water (or solution).

After this, the liquid is drained from the sterilizer, the tray is removed (using special hooks), and the instruments are laid out on a sterile cloth. Syringes, however, should remain in the water (solution) until completely cooled after boiling.

Metal instruments can also be processed by flaming — burning them over the flame of a spirit lamp or ignited cotton wool soaked in alcohol. When sterilizing with chemical agents, the instruments are immersed for 30-60 min in disinfectant solutions:

• 3-5% carbolic acid;
• 1-2% lysol;
• Karetnikov's liquid (20.0 — formalin; 3.0 — carbolic acid; 15.0 — sodium carbonate per 1 l of water).

Antiseptic solutions are also used in cases where instruments are damaged by boiling (non-metallic catheters, bougies, etc.).

Rubber items (gloves, tubes) are sterilized both by boiling and in an autoclave:

They can also be processed with chemical agents: by immersion in a 2% chloramine solution for 15 min, a mercury bichloride solution (15:500) for 30 min, or 3% lysol for 10 min. Gloves worn on the hands are wiped with an alcoholic formalin solution (2.5 parts formalin to 500 parts alcohol).

Dressing material, special clothing (gowns, caps), towels, sheets, and medicinal solutions can be sterilized in an autoclave, just like rubber gloves and items.

Suture (ligature) material is disinfected by several methods. For example, according to the Kocher method, silk skeins are first washed in warm soapy water; after drying, they are wound loosely on glass rods and immersed in ether for 12 hours; then the suture material is transferred for 12 hours into 70-80% ethyl alcohol, followed by boiling for 5-10 min in a 0.1% mercury bichloride solution (in porcelain crucibles). Sterile silk is stored in glass jars with ground-glass stoppers in a 0.1% mercury bichloride solution or absolute alcohol, into which it is transferred using sterile forceps. Catgut is immersed for 3 days in a 1-2% formalin solution or iodine-benzine (40.0 crystalline iodine, 400.0 benzine).

Preparation of the operating field. The area of skin where the surgery will be performed is cleared of hair (by clipping with flat-curved scissors and shaving). There are several methods for disinfecting the operating field:

• The most common in practical conditions: washing the skin with warm soapy water, then drying, followed by double application of 10% alcoholic tincture of iodine to the area or wiping with swabs soaked in alcohol.
• Spasokukotsky method: processing the skin with a warm 0.5% ammonia solution, and then with 96% ethyl alcohol.

Hand disinfection. Trim nails short, wash hands with soap in warm water, and dry with a clean towel. After this, disinfect hands using one of the following methods: a 5% ammonia solution (approx. 5 min); ethyl alcohol (subungual spaces — with iodine tincture); a 5% alcoholic tannin solution; or a 0.5% chlorhexidine solution.

Prophylaxis of surgical infection. Surgical infection is understood as the introduction of pathogenic microorganisms into the body's tissues, where they multiply and exert a pathogenic effect as a result of their vital activity. The pathogens of surgical infection can be aerobes and anaerobes.

If an infection develops as a result of the introduction of a single species of microorganisms into the tissues of a livestock animal, it is called a single-species infection; an infection caused by the multiplication of various species of bacteria in the tissues is called a mixed infection.

From a practical standpoint, it is important first of all to consider and prevent the possibility of microorganisms, especially pyogenic ones, entering the surgical wound. Exogenous routes of infection source introduction:

• contact (via insufficiently disinfected surgeon's hands, instruments, dressing and suture material);
• droplet (through coughing, sneezing);
• airborne (with dust settling on the wound).

Endogenous infection occurs during the introduction of microorganisms into the wound from surrounding tissues (for example, in furunculosis), as well as through hematogenous and lymphogenous routes. Prophylaxis of wound infection consists of observing the rules of asepsis and antisepsis.

Asepsis is a method of preventing wound infection by pre-destroying microorganisms on all objects that come into contact with the wound surface.

Antisepsis is a complex of methods for fighting microorganisms present in the wound and its surroundings.

Prophylaxis of surgical (wound) infection is carried out in a combined manner — using an aseptic-antiseptic method. Along with disinfection, the use of antimicrobial agents (antibiotics, sulfonamide, and nitrofuran drugs) is of great importance.

The outcome of the operation largely depends on the level of the organism's resistance. To increase it, it is necessary to provide livestock animals with adequate feeding and create proper zoo-hygienic conditions at all times, especially in the postoperative period.

Purulent processes include furuncle, carbuncle, abscess, phlegmon, and surgical sepsis:

• Furuncle — is an acute purulent inflammation of a hair follicle, sebaceous gland, and the surrounding loose connective tissue.
• Carbuncle is an acute purulent-necrotic inflammation of several adjacent hair follicles and sebaceous glands with loose subcutaneous tissue.
• An abscess is understood as a localized purulent inflammation in an organ or tissues with the formation of a purulent cavity and accumulation of pus within it.
• Phlegmon is called an acute diffuse, predominantly purulent inflammation of loose connective tissue.
• Surgical sepsis — is an infectious disease caused by pyogenic pathogens and their toxins circulating in the blood when the body's reactivity is impaired.

Prophylaxis of surgical infections involves early complete wound treatment, timely treatment of primary purulent processes, and prevention of mechanical skin damage.

The use of cold, heat, and massage in surgical pathology. Physical methods of treatment are combined under the general name "physiotherapy". In veterinary practice, cold treatment and thermal procedures are most frequently used for livestock animal diseases.

Cold has local and general effects on the organism. Under its influence, blood vessels constrict and blood flow decreases, which contributes to stopping bleeding; the development of the inflammatory process and the formation of blood plasma effusion slow down; as a result of decreased excitability and conductivity of nervous tissue, pain sensations weaken.

Cold applications are used for bruises, sprains, acute aseptic inflammations, heatstroke and sunstroke, and hemorrhages. However, in cases of septic inflammation (abscesses, phlegmons), congestive edema, pressure sores, and certain infectious diseases (strangles), the use of cold is contraindicated.

Types of cold procedures: douching, compresses, foot baths, the use of rubber containers with ice or snow, and clay application.

For douching, use water at room temperature (15-20°C); sometimes pieces of ice are added to it. Water is poured over the occipital region (for nosebleeds, heatstroke, and sunstroke), the left paralumbar fossa (for rumen tympany in ruminants), the abdomen (for flatulence), and sometimes the back (for reflex action on kidneys, uterus, and urinary bladder).

For compresses, take a piece of cloth or gauze, fold it into several layers, soak it in ice water, and apply it to the affected area of the body; change the compress (or pour cold water over it) every 3-4 minutes.

When using ice containers, it is recommended to place folded gauze between the animal's skin and the rubber bag (bladder). It should be removed for 30 minutes every 2-3 hours (to avoid hypothermia).

Clay treatment is based on the cooling, compression, and chemical action of clay. It is diluted in cold water to the consistency of dough and applied in a layer of 0.5-1 cm to the affected area (if there is no skin damage). It is recommended to add a small amount of acetic acid to the mixture beforehand. Every 1.5-2 hours, the clay application is moistened with cold water. It is kept on for 24-48 hours and then washed off.

Hydrotherapy and thermal procedures in veterinary surgery

In veterinary practice, foot baths are actively used for inflammatory processes in the hoof corium and tendons. Canvas buckets with cold water are used for the procedure, into which the animal's affected limb is submerged, having been securely restrained beforehand. The application of cold is effective in the first 1-2 days of inflammation to localize the process.

Thermal procedures have the opposite effect: under the influence of heat, peripheral blood vessels dilate, blood supply improves, local temperature rises, and edema is reabsorbed. In the chromatic phase of inflammation, heat reduces pain syndrome. It is prescribed as an anti-inflammatory and resolving agent, using both dry heat (heating pads, electric lamps, wrapping) and moist heat (warming compresses, poultices, baths), as well as paraffin, ozokerite, mud, peat, and clay.

• Duration of cold application — first 1-2 days
• Compress exposure time — 5-6 hours
• Course of compress treatment — 4-10 procedures
• Infrared heating mode — 1-1.5 hours of operation and 0.5 hours of break
• Thickness of the paraffin layer — 1.5-2 cm
• Melting point of ozokerite — 52-68 °C

To apply a warming compress, four functional layers are applied in sequence:

1. Gauze or canvas in several layers, moistened with water or an alcohol solution, placed directly onto the inflamed area.
2. Waterproof material (medical oilcloth, cellophane, waterproof paper) extending 2-3 cm beyond the edges of the first layer.
3. An insulating layer of cotton wool or cloth.
4. A fixing bandage or wrapping.

Infrared rays affect vasodilator nerves, causing reflex local hyperemia, which enhances blood and lymph circulation and activates enzymatic and redox processes. For prophylactic purposes, infrared irradiation is used for round-the-clock heating of young livestock in the first weeks of life.

In paraffin therapy, heated paraffin is quickly applied to the skin with a brush until a thin layer sets, after which the thickness of the application is built up to 1.5-2 cm, covered with oilcloth, cotton wool, and bandaged (a suspensory is applied to the udder). Ozokerite ("earth wax") with a melting point of 52-68 °C is applied in a similar manner.

Use of passive and active massage for pathologies

Massage is indicated for bruises, atrophy, paresis, muscle paralysis, myositis, synovitis, tendovaginitis, and congestive edema. Furthermore, massage manipulations are a mandatory element of the technological preparation of a cow's udder for milking. A distinction is made between passive massage, performed by an operator, and active massage, based on the dosed movement of the animal itself.

Passive massage includes five main techniques, the performance of which is strictly regulated:

• Effleurage (stroking): sliding the palm over the skin with gradually increasing pressure towards the nearest lymph node; the procedure is always started and finished with this technique;
• Friction (rubbing): moving the skin and deep tissues in longitudinal, transverse, spiral, or circular directions without sliding the hand;
• Petrissage (kneading): grasping and lifting tissues followed by intermittent pressure on them with displacement;
• Tapotement (percussion): abrupt, gentle strikes with fingers, palm, or fist;
• Vibration: rapidly repeated oscillatory movements of the fingers with pressure on the tissues.

When conducting functional therapy, a gradual increase in load is observed according to the following scheme:

1. Performance of massage and passive movements of the affected body part.
2. Dosed active walking of the animal on soft, level soil.
3. Concluding rubbing, stroking, and warm wrapping.

At the same time, active movements are strictly contraindicated in cases of wound infection, purulent-necrotic processes, thrombophlebitis, fresh injuries to muscles, tendons, ligaments, and hoof diseases.