Animal anatomy, histology, pathological anatomy

Autopsy of pigs
Pigs belong to the class of mammals, the superorder of ungulates, the order of artiodactyls, the suborder of tuberculate teeth, and the family of pigs. This family is represented by a large number of species and subspecies.


OPTION TECHNIQUE
The procedure and sequence of autopsy of a pig are similar to those of cattle and horses.
External inspection.Among the identifying characteristics, it should be noted: species (pig); gender (sow, boar, hog, piglets - gilt, gilt, hog); breed; color (white, black, motley); mass.
Agedetermined by the following characteristics: the remainder of the umbilical cord is black and dry; milky fangs and edges are evident - newborn piglets; the umbilical cord has fallen off - at least 48 hours (the umbilical wound is covered with a crust); premolars – 2 above and 2 below – 4–14 days; hooks + 3 premolars above and 1 below – 2–5 weeks; margins at the top + 1 premolar – 5–12 weeks; margins below + 1 premolar – 8–16 weeks; full set of primary teeth: incisors 3/3, canines 1/1, premolars 3/3 (28) – 3–7 months; 1 premolar (wolf tooth) + 1 molar – 4–6 months; incisors Z (edges) replaced – 7–10 months; incisors Z (edges) replaced + 2 molars – 8–12 months; incisors Z (edges) replaced + canines – 8 1/2–10 months; incisors 1 (hooks) replaced – 11–14 months; premolar 1 and premolar 2 replaced – 12–15 months; 3rd premolar – 13–16 months; incisors (middle) below have changed - 16–18 months; 2 incisors (middle) at the top were replaced; complete dental apparatus: incisors 3/3, canines 1/3, premolars 4/4, molars 3/3 (44 in total) – 16–20 months.
Body type:proportional, disproportionate – curvature of the spine, limbs, sagging back, stylized butt, etc.
Fatness:skinny, below average, satisfactory, above average, fat.
Corpse changes.When opening fat, well-fed pigs, especially in the hot season, decomposition processes occur very quickly in the internal organs (kidneys, liver, spleen).
When examining visible mucous membranes, pay attention to the conjunctiva: for example, with plague, catarrhal or purulent-catarrhal conjunctivitis is often observed.
In many infectious-toxic diseases, one can see acute congestive hyperemia of the mucous membranes of the eyes, mouth and anus, sometimes hemorrhages, necrotic foci.
LeatherIn pigs, with the exception of some breeds, the unpigmented and poor growth of bristles makes it possible to detect in it various pathological processes associated with infectious diseases. Necrosis: with plague, chronic erysipelas, necrobacteriosis. Circulatory disorders: hemorrhages in plague, erythema in acute erysipelas, congestive hyperemia in erysipelas endocarditis. The formation of vesicles in foot and mouth disease, blisters in subacute erysipelas (urticaria), the development of exanthema in smallpox, etc. Edema in infectious diseases of pigs can be detected only in the pharynx and neck (in acute pasteurellosis, anthrax and edematous disease in piglets).
Superficial lymph nodes in pigs are presented in the form of packets consisting of several small nodules.
Submandibular lymph nodes in the amount of 1–2 are localized in the submandibular space, in front of the submandibular salivary gland, covered by the oral end of the parotid salivary gland, form a package up to bcm long and 3cm wide. Some animals have accessory submandibular lymph nodes (2–4).
Superficial cervical lymph nodes are located in two groups - dorsal and ventral. The dorsal group (1–3 nodes) lies in front of the shoulder joint, under the brachioatlas and trapezius muscles, reaching 4–5 cm in length. The ventral group (3–8 nodes) is located in the region of the jugular groove, from the shoulder joint to the parotid salivary gland. In addition, 1–3 nodes lie on the scalene muscle.
The patellar lymph nodes (1–2) lie in the knee fold in the form of a package up to 5.5 cm long.
The mammary glands of pigs, unlike large animals, are not separated from the corpse, but are examined on the spot, making incisions that penetrate deep into the parenchyma.
Inflammatory processes often occur in bones and joints: with brucellosis - purulent spondylitis and arthritis, with tuberculosis - arthritis and osteomyelitis, with chronic erysipelas - serous arthritis and osteomyelitis, with chronic erysipelas - serous arthritis.
After an external examination, before removing and examining the lymph nodes, the skin of adult animals is removed.