88 SWINE DISEASES Catdrrhal Pneumonia Catarrhal pneumonia is a lobular involvement char- acterized by occlusion of the air cells, with exudate and desquamated epithelium. Etiology. — Catarrhal pneumonia is practically always a sequel of bronchitis and is therefore produced by the same causative factors. Bacillus pyocyaneus may cause catarrhal pneumonia. Catarrhal pneumonia is one of the characteristic lesions of swine plague due to the Bacterium suisepticus. (Description will be found in Chapter VIII.) Bronchopneumonia is occasionally sec- ondary to other diseases, such as hog cholera or septi- cemia. Lesions. — The inflammatory process is confined to a lobule or a group of lobules. As the disease progresses, other adjacent lobules may become involved, the affected areas thus becoming confluent and larger. In the beginning the affected areas are hyperemic. The alveoli soon become filled with inflammatory exudate which is at first fluid but later coagulates and becomes dry, the diseased lobules thus becoming solid. These areas are first red in color, but early become brown, gray, then yellow or yellowish-white, and if the condition persists abscess formation may occur. Bronchitis is usually associated with bronchopneumonia and in such cases the lesions characterizing bronchitis would also be present. Symptoms. — Catarrhal pneumonia in swine is ex- tremely difficult to differentiate from bronchitis because of the inability to efficiently auscultate or percuss the thorax. Catarrhal pneumonia offers the same general symptoms that have been noted in bronchitis, except that pneumonic symptoms are usually more intensive than those of bronchitis. Catarrhal pneumonia has no definite course, the length or duration of the disease depending upon the cause, extent of the disease, and the resistance of the affected animal. The disease is most fatal in young swine. Treatment. — Medicinal treatment other than in- halation of medicated vapors is of little or no value. THE RESPIRATORY SYSTEM 89 Proper sanitary conditions should be provided, and the affected animals should be given easily digested, whole- some food in sufficient quantities to build up the body and maintain strength. If the causative factor is an infection, isolation and proper quarantine regulations should be enforced. Croupous Pneumonia Croupous pneumonia is a disease involving lobes or large lung areas and is characterized by the presence of a hemorrhagic exudate in the air cells. It is not a common primary condition in swine, but is frequently associated with hog cholera. Etiology. — Many predisposing factors enter into the causation of this disease, such as undue exposure or inhalation of irritating gases, but it is probable that the specific active cause is microbian. Lesions. — Croupous pneumonia is characterized by the regularity of the successive changes that occur in the affected portion of the lung. The disease usually involves the dependent part of the lung and is essentially lobar, but more or less than this amount of lung may be involved. The various stages that occur in the lung are as follows: congestion, red hepatization, gray hepatization, and resolution. These stages occur in the order mentioned, and there is no distinct line of demarcation between each succeeding stage. The length of duration of each stage is subject to variation, but on the whole is quite constant. The congestive stage is of about twenty-four hours' duration. During this stage the affected portion of the lung is engorged with blood. In the beginning the air cells contain air but as the disease progresses the alveolar capillaries begin to leak or there is a hemor- rhagic exudate into the alveoli. Red hepatization begins when exudation is evident, and this stage persists for from three to five days; the area affected is red, dense, heavy, and liver-like. Gray hepatization is characterized by a gray or yellow coloration of the affected lung. This stage succeeds red hepatization and is due in part to the 90 SWINE DISEASES substitution of leukocytes for the coagulated hemorrhagic exudate that characterizes red hepatization and in part to chemical change of the hemoglobin of the extravasated red blood cells in the hemorrhagic exudate. The lung tissue affected with gray hepatization is gray in color, dense, heavy, and cuts like liver tissue. Gray hepatiza- tion persists for from three to five days, and when the alveoli are relatively free of exudate and leukocytes the lung is said to be in a stage of resolution, which includes that period of time during which the air cells are freed of all inflammatory products and return to the normal condition. This is a variable period and depends upon the resistance of the affected animals. The lung, during this stage, contains some inflammatory products in the beginning and later small quantities of mucous and debris, but in the final stages the lung is practically normal. Symptoms. — Inappetence, high temperature, and increased respiration and heart action characterize croupous pneumonia. On the second or third day a "prune-juice" nasal discharge may be observed which later becomes mucous or mucopurulent. The affected swine are dull, listless, and^will probably cough more or less when agitated. Treatment. — Sanitary surroundings, good water to drink, and an abundance of fresh air without drafts are prerequisites in the treatment of pneumonia. Laxatives should be given to prevent constipation. Heart stimu- lants may be required, but should not be administered except when necessary, as indicated by a rapid, weak pulse. Purulent Pneumonia Purulent pneumonia is an inflammation of the lung characterized by the formation of pus. This condition is relatively common in young pigs, although it may occur in swine of any age. Etiology. — Purulent pneumonia is of bacterial origin. The pyogenic Micrococci, Bacillus pyocyaneus, and THE RESPIRATORY SYSTEM 91 tubercle bacillus are the most frequent causative factors of this condition. These organisms may be inhaled direct but they are more frequently introduced into the lung from elsewhere as emboli. Purulent pneumonia in old swine is therefore frequently associated with pyemia, abscess formation, or purulent metritis. Several cases have been observed in the carcasses of swine that had previously been hyperimmunized intramuscularly for the production of anti-hog-cholera serum. Lesions. — The principal lesion is suppuration, the centers of which vary in size and number but in the beginning are relatively small and in the earlier stages are not encapsulated but are surrounded by a zone of lung tissue intensely infiltrated with cells. As the condition progresses a circumscribing capsule is formed and the pus becomes thicker, and if the capsule is not destroyed the contained pus becomes caseous and may later become calcified. Should the capsule of a suppurative center become eroded the contained pus may infiltrate the adjacent lung tissue or discharge into a bronchial tube, the original suppurative center thus becoming a cavity. The pleura covering superficial suppurative centers usually shows some involvement. Symptoms. — The evidence of purulent pneumonia varies according to the nature and extent of the lesions. The presence of a single abscess may not cause any noticeable symptoms. General embolic purulent pneu- monia is characterized by intense symptoms consisting of chills, fever, difficult and hurried breathing, uneasiness, and general distress. The discharge of pus within the lung tissue is evidenced by rise of temperature and the associated cardiac and respiratory disturbances. Treatment. — No special line of treatment is of value. The animals should be placed in good quarters and cared for properly. Septic or Gangrenous Pneumonia Septic pneumonia is relatively common in swine. It has occurred enzootically in swine affected primarily 92 SWINE DISEASES with forage poisoning associated with pharyngeal paraly- sis. Sometimes it is a sequel to croupous pneumonia. Etiology. — The usual cause of septic pneumonia is the introduction of foreign substances into the lung. In cases of pharyngeal paralysis food escapes into the air tube. Drenching is another means by which foreign substances are frequently introduced into the lung. Thrombic obstruction of vessels supplying an area affected with croupous pneumonia favors the action of saprophytic bacteria, and hence putrefaction and the production of septic pneumonia. Abscesses sometimes become infected with putrefying organisms and produce septic pneumonia. The Bacillus necrophorous is active in the production of necrosis and putrefaction in the lung. Lesions.- — Necrotic centers are most frequently found in the dependent and anterior part of the lung. The foci vary in size from that of a pea to a baseball, and may be few or many. They appear dirty brown, red, or dirty white in color. When incised they are found to be soft, the content being semifluid in the early stages but later of a cheesy consistency. The surrounding lung tissue will be inflamed. In the beginning, an infiltration circumscribes the lesions, but in the older lesions there may be a distinct capsule. Superficial necrotic foci may be associated with pleurisy. Symptoms. — The first symptom evidencing septic pneumonia is the foul-smelling exhaled air. This symptom does, not occur in all cases, as the escape of putrid odors is dependent upon the erosion and discharge into the bron- chial tubes of necrotic putrid material. Rise of tempera- ture accompanies practically all cases of septic pneumonia. The fever may be irregular and intermittent, the thermal disturbance depending upon absorption of septic products. In those cases of croupous pneumonia in which septic pneumonia is a sequel, the general symptoms will be the same, plus the offensive breath, as those observed in a case of croupous pneumonia A microscopic examination of the nasal discharge will reveal the presence of shreds of disintegrated lung tissue in cases of septic pneumonia, THE RESPIRATORY SYSTEM 93 which fact is of diagnostic value. The course of septic pneumonia is uncertain. The attack may terminate fatally in two or three days after the onset of the disease or, if the septic lesions are limited in extent, they may become encapsulated and the animal recover, the length of time required varying from a few weeks to as many months. Treatment. — Remedial agents are of little, or no value so far as the septic process is concerned. The treatment of symptoms as they develop will be of some value. The animal should, be given good care and sanitary surroundings provided. Interstitial or Chronic Pneumonia Interstitial pneumonia is a chronic condition char- acterized by proliferation of fibrous tissues. This con- dition is usually a sequel to chronic catarrhal bronchitis and chronic bronchopneumonia. It is observed in swine in those sections of the country where it is continuously dusty and in swine kept in quarters where slightly irri- tating gases prevail. Etiology. — Constant inhalation of mild irritants, such as dust or chemical fumes. Lesions. — Fibrous proliferation characterizes this disease. The fibrous tissue forms around the bronchioles, the process gradually extending and involving the alveoli. The bronchioles and alveoli also show evidence of catarrh. The affected lung is dense, and when cut offers more resistance than the normal lung. The degree of fibrous proliferation is quite variable in some instances; there is a limited amount, and in other cases the normal lung tissue is displaced by fibrous tissue. Encapsulated suppurative or necrotic centers may be found. Symptoms. — A persistent cough, associated with a limited but variable nasal discharge of a mucopurulent material, characterizes chronic pneumonia. The animals are Usually unthrifty and emaciated. Treatment. — The cause should be removed and the animals properly housed and fed. Other than this, little can be done. 94 SWINE DISEASES Tumors Various tumors have been encountered in the lungs of swine, but principally in autopsies or at abattoirs. Lung tumors of swine are similar to the same type of tumors of other tissues. Pulmonary neoplasms produce no typical symptoms by which they may be recognized clinically. Parasites The principal pulmonary parasite is the Metastrongy- lus Apri, which has been described under bronchial disorders. Echinococcosis pulmonum is a common disease of swine. This condition is caused by the larval form of Taenia echinococcus. The cysts of pulmonary echinococ- cus are the same as those occurring in the liver. Distomiasis, or invasion of the lung with flukes or Distoma, occurs but is not common in swine. Pulmonary stephanurosis has also been observed, but is rare. Parasitic nodules, the supposed result of invasion of some unknown parasite, are occasionally noted by veterinary, inspectors, but there is little significance in such invasion as the lung is not edible, according to the meat-inspection regulations in the United States. PLEURA Disease conditions of the pleura of swine are rarely recognized clinically, though some cases of pleuro- pneumonia may be determined by a clinical examination. Pathologic conditions of the pleura are occasionally observed by veterinary inspectors in the carcasses of swine that are slaughtered. Hydrothorax Hydrothorax is a condition resulting from the accumu- lation in the thoracic cavity of excessive quantities of serous fluid. It is of rather rare occurrence in swine. THE RESPIRATORY SYSTEM. 95 Etiology. — Obstructed outflow of blood from the vena cava, with engorgement, is the principal cause of hydrothorax. Chronic disease of the cardiac valves and chronic pneumonia are the most common causes of obstruction of the outflow of venous blood from the vena cava. Tumors, abscesses, and malformed thorax may also be responsible for the causation of pneumo- thorax. Lesions. — Accumulation of varying quantities of a pale yellow fluid in the thorax is the characteristic lesion, and in addition the primary lesions in the heart or lung are usually evident. The accumulated fluid will com- press the lung. Symptoms. — It is not possible in the beginning to detect any particular symptoms. Those produced by the accumulated fluid are frequently so overshadowed by the primary condition that it is not possible to clini- cally diagnose hydrothorax until the advanced stages. There will be difficult respiration, and if the thoracic wall is not too thick a splashing sound may be noted synchronous with the heartbeat. An exploratory punc- ture with a small hypodermic needle will usually result in the discharge of serous fluid. Treatment. — Temporary relief may be obtained by withdrawing the fluid from the cavity, but permanent results cannot be expected until the primary causative factor has been removed or overcome. Hemothorax Hemothorax is a condition of the escape and accumu- lation of blood in the thoracic cavity. It is not a recog- nized clinical entity, particularly in relation to swine, yet it does occur, and is sometimes observed by inspectors of meat-food products. Etiology. — This condition is observed in swine that have been transported to market, and the affected swine at the time of autopsy show evidence of having been injured, probably while in transit. The injury may be a puncture, wound, or a contusion. 96 SWINE DISEASES Lesions. — Accumulation of blood in the thorax characterizes this condition. The blood may be coagu- lated, but it usually remains in the fluid state until the thorax is opened. The quantity of blood will depend upon the nature of the injury and the length of time elapsing after its infliction. If the hemorrhage is of long standing, pigmentation of the pleura may be the only evidence remaining. Symptoms. — The majority of animals affected with hemothorax show no symptoms. There may be paleness of the visible mucous membranes, weakness of the animal, and difficult breathing due to compression of the lung, but these symptoms are evident only in those cases in which the hemorrhage is extensive. Treatment. — Medicinal treatment is of no value. Pneumothorax This is characterized by the accumulation of air in the thoracic cavity, a condition extremely rare in swine. The usual cause of the condition is injury in which the lung tissue is lacerated. The injury most frequently consists of fracture of a rib occasioned by improper hand- ling in transportation. The principal lesion observed consists of the primary injury. The thorax is found to contain air, and the lung is compressed. Pleurisy Pleurisy is inflammation of the pleura and may be serous, fibrinous, hemorrhagic, or purulent; acute or chronic. ' It is not a common condition among swine, at least in so far as the clinical recognition of it is concerned. Acute Pleurisy Etiology. — Acute pleurisy is practically always the result of infection, although there are many predisposing factors that are active in diminishing resistance and thus increasing the possibility of successful infection. The THE RESPIRATORY SYSTEM 97 causative organisms may gain entrance to the pleura from the lungs through puncture wounds, through the blood, and through the lymph. Lesions. — The pleura becomes hyperemic, tumefied, and dry. This stage is succeeded by an outpouring of a serous, fibrinous, or hemorrhagic exudate upon the pleural surface. Should the disease be due to the activity of pyogenic organisms the exudate will soon become purulent, and the future changes depend upon the nature of the exudate. Serous exudate may accumulate in quantities in the pleural cavity, and remain fluid although it may contain flakes of coagula. The fibrinous and hemorrhagic exudates coagulate early and produce greater or less adhesion of the visceral and parietal pleura. The hemorrhagic exudate is characterized "by the presence of quantities of hemoglobin, which gives to it a red or blood color. Chronic Pleurisy Chronic pleurisy is characterized by the formation of varying quantities of fibrous tissue which produce per- manent adhesions of the two layers of the pleura. There may also be considerable quantities of a fluid (serous) exudate in the pleural cavity, and there may be abscess formation, the pus being circumscribed by a definite capsule. Symptoms ■ — Difficult breathing, each effort being accompanied by a grunt, and sensitiveness of the thorax, characterize pleurisy. In the acute cases there is inap- petence, high temperature, and usually constipation. Chronic cases frequently show little evidence of dis- turbance. The acute type has a relatively short course, ter- minating in recovery, or in death within a few days. The chronic form may persist for weeks or even months. Treatment. — Remove the cause of the trouble and establish sanitary conditions. The treatment of symptoms as they arise will be of some value. If an excessive 98 SWINE DISEASES quantity of serous fluid accumulates in the pleural cavity it should be withdrawn. Tumors Pleuritic tumors are not common in swine. Fibromas have been encountered on a few occasions. Of the malignant tumors, endothelioma and sarcoma pre- dominate, but are unusual. SECTION III THE URO-GENITAL SYSTEM SWINE are prone to various disease conditions of the organs constituting the uro-genital system. This may be due to the nature of their food stuff, which is often fermented or putrid. KIDNEYS Kidney diseases are especially common in swine. Frequently the pathologic condition of the kidney is not of sufficient intensity to produce recognizable symptoms, but a diseased condition is easily detected by autopsy or on inspection of the carcasses of dressed hogs. Malformations There may be a total absence of one or the other kidney. A horseshoe-shaped kidney is also occasionally observed. Floating kidney has been reported, but from the number of recorded cases the condition is relatively rare. Hydronephrosis Hydronephrosis, or cystic kidney, is of frequent occurrence in swine. It is very commonly encountered by the food inspector. Tucks reported 0.67 per cent of cystic kidneys in oyer six thousand hogs examined, and the writer found this condition in the kidneys of twenty- nine swine in three thousand examined. The condition May affect one or both kidneys. Etiology. — Obstructed outflow of urine is the primary cause of cyst formation in the kidney. The anatomical arrangement of the openings of the ureters into the bladder predisposes to their obstruction and therefore to the accumulation of urine in the kidney pelvis. Renal and pelvic calculi and inflammatory products occasion 100 SWINE DISEASES obstruction of collecting tubules and favor cyst formation. Cicatrization of newly formed fibrous tissue may obstruct the outflow of urine and cause cyst formation. Complete obstruction of the ureters or kidney pelvis will not as a rule result in hydronephrosis, as this condition results in a compensatory activity on the part of the normal kidney. Lesions. — Hydronephrosis may occur as cysts in the renal substance or the kidney may be practically replaced by a variable-sized watery bag. The cysts vary in size from a pinhead to an inch in diameter. There may be myriads of the small cysts scattered throughout the kidney but occurring primarily in the cortical portion.. The larger cysts are usually not numerous and they frequently represent the fusion of small cysts. The cysts have a bluish-white color, are definitely surrounded by a distinct capsule, and the content is thin and watery. The kidney substance between the cysts is atrophied, due to pressure. In extreme cases the kidney capsule may serve as the cystic capsule, the entire mass being much enlarged and the small atrophied kidney floating within. Bichter reported a case of a hydronephrotic kidney weighing over ninety pounds. Hemorrhage Kidney hemorrhage is relatively common in swine, not as a primary condition, but associated with some disease. The extravasated blood may escape into the uriniferous or collecting tubules, producing hematuria, or it may escape into the kidney tissue. Etiology. — Injury of the capillaries, either glomerular or tubular, may result in hemorrhage. The vessels are most frequently damaged by chemical substances that are being eliminated in the urine or by products of bacteria produced in the kidney or elsewhere in the body. Lesions. — Escaped blood into the uriniferous tubules may be detected by examination of the urine, which, by the way, is very infrequently done. The urine will be THE URO-GENITAL SYSTEM 101 discolored with hemaglobin and will contain blood casts. Renal-tissue hemorrhages may be extensive or limited, but rarely is extensive extravasation observed in the kidney. Small-tissue hemorrhages, particularly petechial hemorrhages, are of common occurrence in the kidney of swine affected with hog cholera. Such hemorrhages have been observed in the kidney of otherwise apparently healthy swine in which no other lesions of cholera could be detected, and the blood from these hogs, when injected into healthy, susceptible pigs, failed to produce evidence of hog cholera. These hemorrhages were not numerous; sometimes only a very few could be recognized by a careful examination; their exact relation has not been discovered. The petechial hemorrhage of cholera merely evidences a vascular disturbance. Symptoms. — Hematuria indicates hemorrhage into the urine in the kidney, ureter, bladder, or urethra. Renal hematuria is characterized by bloody urine and the presence of, blood-tube casts. Fatty Changes The occurrence of the so-called large white kidney is a common experience, at least to those engaged in meat inspection. "Large white kidney" is a name applied to two different conditions — fatty kidney and fibrous kidney. The fatty white kidney is less common than the fibrous white kidney. Etiology. — Some renal vascular disturbance resulting in blood disturbance in the kidney or general malnutrition appears to be the causative factor in the production of fatty kidneys. Lesions. — The affected kidney is large and creamy white in color. The capsule is easily stripped, and the kidney substance is soft and feels greasy. Only one kidney is affected in those cases in which the kidney is exceedingly large. Both kidneys may be affected, but to a limited degree. Symptoms. — No primary symptoms characterize this condition. It is detected only in autopsy. 102 SWINE DISEASES Calculi Renal calculi occur but are not common in swine. They may occur in the collecting tubules but are more likely to be found in the renal pelvis. Etiology. — The formation of renal calculi is usually associated with an obstructed outflow of urine. Retained urine in the renal pelvis or in the collecting tubules has a tendency to undergo fermentation, with the production of an unbalanced condition of the chemical constituents resulting in precipitation. Retained urine and fermenta- tion also favors catarrhal inflammation. The muco- purulent discharge may serve as a nucleus upon which the precipitate is deposited. Lesions. — Retention of urine and catarrhal inflam- mation are usually evident. The calcular deposits may be very small and difficult to detect or they may be quite large, one having been observed that practically filled the renal pelvis. The calculi may be variable in shape, color, and consistency, depending upon their composition, and are composed of magnesium or calcium phosphates, urates, or carbonates. Symptoms. — Cloudy urine, particularly when the last discharge contains quantities of brownish deposit, will be observed if the calculi are passing out. The animals will have colicky pains, the loins will be sensitive, and the animals will stand with arched back. If the calculi are small and remain in the kidney there may be no evident symptoms. Treatment. — If the patient is in good condition it will be most economical to sell it for slaughter. Very little can be done toward the actual solution of the formed calculi. Congestion Congestion of the kidneys is common in swine fed on putrid or fermented foods. It may occur as a result of undue exposure, to cold experienced in shipping, or it may be due to injury. The condition is associated with erysipelas, hog cholera, and some forms of pneumonia. THE URO-GENITAL SYSTEM 103 Etiology. — Chemical poison obtained in food, by- products of infection, or destructive metabolism cause renal congestion. Exposure and injury may also produce this condition. Symptoms. — Stiffness and a stilty gait due to hypersensitiveness of the loins usually accompany con- gestion. There is also frequent urination in which an excessive quantity of urine is voided. Treatment. — Remove the cause, give good food, and provide sanitary surroundings. Alkaline diuretics may be - of value, and laxatives may also be used to advantage. Nephritis It is not possible with the present available knowledge to classify the inflammatory disturbances of the kidney in a satisfactory manner. The principal knowledge of porcine nephritis has been obtained from investigation by veterinarians in food-inspection service. The con- dition is rarely recognized clinically, or at least the reports of clinical cases of nephritis in swine are very rare. Urinalysis is not practiced systematically by veterinarians, and the analysis of swine urine by prac- titioners is practically an unheard-of procedure. Accord- ing to the findings of the veterinary inspectors, porcine nephritis is very common. In some instances nephritis appears to be the only pathologic condition existing, but it is also an accompanying pathologic factor in such diseases as hog cholera, swine plague, septicemia, and pneumonia. Acute Parenchymatous Nephritis This is an inflammation of the cells of the glomeruli and convoluted tubules and is characterized by a rather rapid onset, tumefaction, and frequently destruction of the affected epithelium. Etiology. — Exposure to cold and injuries of various kinds predispose to this disease. The specific exciting causes are usually chemical substances that are being eliminated through the renal epithelium. Bacterial 104 SWINE DISEASES products, and vegetable and mineral poisons, when present in sufficient quantities, are capable of establishing inflammation. Thus pneumonia, hog cholera, swine plague, and septic infections are usually accompanied by nephritis. Some serum producers have had losses of hyperimmune swine due to contaminated virus. In the swine that died in these cases not only the lesions evi- dencing general septic infection were present but also marked lesions of an acute parenchymatous nephritis. Turpentine, phenol, and the various coal-tar products are capable of producing nephritis. Corrosive sublimate, too, may be obtained in sufficient quantities to produce the disease. Lesions. — The lesions of acute parenchymatous nephritis are practically confined to the epithelium of the glomeruli and convoluted uriniferous tubules. The affected kidney is slightly enlarged and has a parboiled appearance. The capsule is easily removed, the kidney substance is usually soft, and blood escapes freely from a cut surface. Microscopically the affected epithelium is affected with hyperemia and cloudy swelling which may become so intensive that the cells undergo necrosis. The detritis of the dead cells and coagulated exudate, accumu- lated in the lumina of the tubules, may be readily ob- served. The intertubular tissue may be infiltrated with leukocytes. If the inflammation is intense there may be hemorrhage into the kidney substance or into the glom- eruli or tubules. Symptoms. — The animals show evidence of dis- tress. One of the first indications of the disease is arched back and stilty gait. There are frequent attempts at urination, but little urine is voided, and the animals usually have a temperature ranging from 104 to 106 degrees Fahrenheit. In the beginning of the attack they may eat, but inappetence becomes evident soon after the onset. It is possible that the foregoing symptoms are not characteristic of uncomplicated nephritis, but of cases in which nephritis was the most prominent condition. In the cases that have been observed the disease most THE URO-GENITAL SYSTEM 105 frequently terminated fatally in from two to four days after the onset, the few cases that recovered requiring from one to six weeks. Treatment. — The treatment of nephritis in swine is a difficult problem. Resort should be had to the usual hygienic practices. Diaphoresis is not practical in swine, and purgation should not be resorted to as a means of elimination, for such procedure would probably aggravate the condition existing in the kidney. General treatment of symptoms as they arise is probably all that can be accomplished therapeutically until further knowledge is obtained. Acute Interstitial Nephritis An occasional kidney is found in which there is a leukocytic invasion and other evidence of a reaction in the interstitial or supporting tissue, the parenchymatous tissue being unaffected. But this condition is not com- mon, and thus far has not been observed clinically in swine. Purulent Nephritis Purulent nephritis is inflammation of the kidney characterized by the formation of pus, a condition of frequent occurrence in swine. In the study of swine kidneys from abattoirs one-half of one per cent have been found affected. Etiology. — Pyogenic cocci and the colon bacteria are the most common causative agents. Purulent inflam- mation elsewhere in the body predisposes to renal meta- stasis, although purulent inflammation may occur pri- marily in the kidney Constipation is probably a pre- disposing factor of colon-bacillus invasion of the kidney. Lesions. — Suppuration may be circumscribed, thus forming an abscess or multiple abscesses, or it may be diffuse. Metastatic purulent nephritis usually involves both kidneys, and small suppurative centers occur as gray or yellow areas which are surrounded by a hyperemic zone. The larger foci may be quite definitely circum- scribed and frequently have small bands of fibrous 106 SWINE DISEASES tissue extending from the capsule into the purulent center. Microscopically the small centers are found in the beginning to be collections of leukocytes and later of pus. The surrounding parenchymatous tissue will be affected with cloudy swelling, as in acute parenchymatous nephritis. Symptoms. — Practically the same symptoms are observed in purulent nephritis as in acute parenchymatous nephritis, except that in those cases in which there is absorption of quantities of pus, when there is evidence of pyemia. Treatment. — Symptomatic treatment may be of value. The cause should be removed, and the patient given sparingly of easily digested food. Chronic Nephritis Chronic nephritis is a common condition in swine. It is not an important disease from the viewpoint of the practitioner, but it is of some economic importance to the packer as many kidneys are found to be affected. Chronic nephritis represents a group of pathologic con- ditions — at least, there is a variety of different types of lesions observed. One type of chronic nephritis has been studied and named "chronic non-indurative nephritis," but from the general lesions in these kidneys it seems probable that the condition is confined to the parenchyma and should be called "chronic parenchymatous neph- ritis." Chronic Interstitial Nephritis Typical chronic interstitial nephritis is characterized by the proliferation of fibrous tissue which may or may not cicatrize. This condition includes white-spotted kidneys, some large white kidneys, granular kidneys, sclerotic atrophied kidneys, and all variations of the foregoing. Etiology. — Chronic nephritis, especially the type involving only the supporting framework, is caused primarily by relatively mild irritants acting over a long period of time. These cases have not been recognized THE URO-GENITAL SYSTEM 107 clinically, but by tracing the swine that show the lesions when slaughtered it is usually found that the feed of the animals has been at fault. In some cases parasites #nd calculi are responsible for the condition. Lesions. — Chronic parenchymatous nephritic kidneys are enlarged. The capsule is not easily removed, and when pealed off small fragments of kidney tissue remain attached to it. The kidney is mottled, due to hemorrhages and infarction, and there is no definite line of demarca- tion between the medulla and cortex. Microscopically the parenchymatous cells are found enlarged and cloudy, but tube casts are rarely observed. Chronic interstitial nephritis is characterized by fibrous proliferation. The newly formed fibrous tissue may or may not cicatrize. The gross appearance of the kidney varies according to the amount and disposition of fibrous tissue. If the condition is localized according to the distribution of small arteries the fibrous tissue will occur in foci, and spotted kidney is the result, the white spots being masses of fibrous tissue. If this fibrous tissue is uniformly deposited throughout the kidney and does not cicatrize, the kidney is enlarged, dense, and hard — one of the types of the large white kidney. Granular kidneys are the result of the proliferation, and later cicatrization, of fibrous tissue in and around the glomeruli or tubules. Granular kidneys have rough, small pro- jections thickly studded over the surface; such kidneys are usually of a red color. The extensive proliferation and cicatrization of fibrous tissue in all the cortical substance, when associated with a thickening of the capsule, produces the small, hard, or sclerotic kidney. Microscopically excessive quantities of fibrous tissue are found, and the parenchymatous tissue is diminished, due to pressure atrophy. Sometimes there may be large areas of fibrous tissue in which no parenchymatous tissue appears or only remnants of tubules or glomeruli. ' Symptoms. — Records of the clinical evidence of chronic interstitial nephritis in swine are wanting. Swine 108 SWINE DISEASES with extensive kidney lesions are usually in fair condition when they are observed at the time of slaughter. Treatment. — The application of therapeutic agents . for the relief of chronic interstitial nephritis in swine has not been practiced. Should such a case be diagnosed, the removal of the cause and the provision of good quarters and wholesome food would probably be suf- ficient until the animal was in condition for slaughter. Pyelonephritis Pyelonephritis is an inflammation of the pelvis of the kidney, a condition that has been observed in swine but is rare. Etiology. — Calculi and parasites are frequently pre- disposing factors in this disease. Primarily, the disease is the result of infection. Pyogenic bacteria may cause the condition, but more frequently it is caused by a pleomorphic organism that has been named corynebacillus renalis. Lesions. — The pelvis of the kidney is dilated with a thick, brownish, purulent fluid and tissue shreds. The mucosa of the renal pelvis is thick and contains hemor- rhagic spots. The kidney may contain purulent centers or it may be converted into a purulent mass. Symptoms. — Frequent urination is a symptom- of this disease, the urine voided being cloudy. Loin sensi- tiveness and inappetence are also observed in these cases. Treatment. — Thus far no treatment has been found that is of any value. Albuminuria Albuminuria is a condition in which there is elimination of albumin in the urine. Urinalysis is now in its infancy in veterinary medicine. Considerable time and energy have been devoted to the study of urine from some animals, particularly the horse, but little attention has been given to systematic urinalysis of swine. THE URO-GENITAL SYSTEM 109 Urine has been collected from the bladder of the carcasses of swine that have been slaughtered, and analyzed. It is possible that there may be some modi- fication of the urine of slaughtered animals, but it is doubtful if the changes are of much significance. Albuminuria has been found to exist in swine showing a high temperature, particularly cases that have been affected with cholera. The urine has also been found to contain varying quantities of albumin in which there was an acute nephritis. Pneumonic cases also evidenced albumin in the urine. The exact cause of albuminuria is still being debated. The condition in swine, as well as in other animals, occurs in those cases where the renal epithelium is dam- aged either by degeneration or inflammation, although it may occur in the absence of damaged epithelium. Some veterinarians are maintaining that albuminuria is caused by acid intoxication. At this time, with our present knowledge, albuminuria, at least in swine, must be thought of as secondary to some other conditions. Albuminuria in swine has not been studied clinically, therefore, symptoms of the condition cannot be recorded. It is an important condition because albuminous substances that should be conserved are eliminated from the body in the urine. Disturbances of nutrition follow, and the primary and associated con- ditions produce emaciation and marasmus. Albuminuria usually terminates fatally. Uremia Uremia is a condition characterized by the presence in the blood of a greater or less amount of the solid constituents of urine. This condition has not been identified clinically in swine, but the nature of the lesions observed" in some kidneys by veterinary inspectors is sufficient evidence that the disease exists in swine. Etiology. — The primary cause of uremia is obstructed outflow of urine, which may be the result of disturbance in the kidneys, ureter bladder, or urethra. Severing or 110 SWINE DISEASES puncturing the ureters during operations, as in cesarean section, may result in uremia. Lesions. — No particular gross tissue changes are attributed to uremia. The lesions found are those incidental to the obstruction of, the outflow of urine, as calculi, tumors, and so on. Symptoms. — Stupor, vertigo, emesis, inappetence, diarrhea, clonic muscular spasms, and convulsions are the principal symptoms of uremia. The disease, at least in the acute form, is usually fatal. Chronic uremia is associated with digestive derangements. Treatment. — Removal of the cause is practically always successful unless the case is too far advanced. Therapeutic treatment is of no value. Parasites The cystic form of the Taenia solium of man has been observed in the kidney of swine, but is not of common occurrence in that location. - The cystic forms of the tsenic echinococcus also occur in this organ. The Stephanurus dentatum is sometimes found in the kidney structure, although it more commonly occurs in the perirenal fat. Tumors The kidney of swine is affected with adenosarcoma. In the living swine the presence of these tumors is not suspected. They appear as irregular, incapsulated masses, usually involving only one kidney, and in size vary from five to fifteen pounds. Although they have not been recognized clinically, their structure and appear- ance evidence rapid growth. They have their origin in the kidney substance near the pelvis, and the tumor tissue produces pressure atrophy of the renal parenchyma. The outline of the tumor is irregular and frequently lobulated. On being sectioned, fibrous bands are found extending in various directions and dividing the tumor mass into lobes. The neoplastic tissue is of a white or dirty-white color, but is often mottled, due to hemor- THE ITRO-GENTTAL SYSTEM 111 rhage; there may also be grayish-yellow centers of necrosis. Microscopically these tumors are composed of embryonic epithelium and connective tissue, the epithelium disposed as irregular tubules or remnants of tubules, while the connective tissue occurs around and between the epi- thelia tumor cells. Sometimes larger areas of embryonic P1 S . 4.-ADENO-SARCOMA OF THE KIDNEY. A. Normal kidney tissue. B. hemorrhaKic areas. C. pelvis. D. sar- comatus tissue. (This kidney was seven or eigrht times as large as a normal kidney.) connective tissue cells are found independent, of epi- thelium, and again the epithelium may occur in nests in the sarcomatous tissue. The time for growth of these tumors has not been determined, but they are most frequently found in swine less than two years of age. 112 SWINE DISEASES Sarcomas have also been encountered by veterinary inspectors in the kidney of swine. They are usually metastatic, although one case of a primary, large-spindle celled sarcoma has been recorded. URETERS Malformations. Malformations of the ureters are not uncommon, but the malformations that are observed are not of such a nature that the function of the organs is interfered with and therefore are of no practical importance. Renal pelvic calculi may become lodged in the ureters and establish inflammatory disturbances, and also obstruct the lumen. The ureters are subject to injuries in spaying and other abdominal operations. BLADDER Malformations Malformations of the bladder are not common. A few cases of double bladder have been recorded, or the bladder may be very small, such animals urinating frequently. Vestiges of the urachus may be retained, and these may become cystic. Hematuria Hemorrhages into the bladder sometimes occur in swine. They are, caused by injuries which may be inflicted by calculi and from diseases of the mucosa. They may also be caused by drugs, such as cantharides and turpentine, obtained accidentally in large quantities. This condition is frequently associated with such diseases as hog cholera. , Lesions. — The primary lesions observed depend upon the cause of hematuria. There may be cystic calculi, injuries of various kinds, infection, and lesions elsewhere in the body. The extravasted blood will be THE URO-GENITAL SYSTEM 113 accumulated in the bladder and may or may not be coagulated, and the entire bladder content will be colored red with hemaglobin liberated from the disintegrated red blood cells. Symptoms. — Hematuria is evidenced by bloody urine in which the entire urine is uniformly red. It is distinguished from renal hemorrhage by the absence of tube casts, and from urethral hemorrhages by the fact that in urethral hemorrhage only the first urine voided is red. Treatment. — The exact cause should be identified and removed. Urinary sedatives may also be of value. Dilatation Cystic dilatation is sometimes occasioned by urethral obstruction or spasms of the muscles in the neck of the bladder. The urine continues to be produced in the kidney and accumulates in the bladder until its capacity may be far in excess of the normal. Lesions. — The characteristic lesion of dilatation con- sists of distention of the bladder and attenuation of its walls. In fatal cases the bladder ruptures and urine and uriniferous odor are detected when the abdomen is opened, and the rent in the bladder wall will also be evident. Symptoms. — Distress, anuria, frequent attempts at urination, and possibly some enlargement of the abdomen characterize distended bladder. In distention succeeded by rupture the foregoing symptoms would be succeeded by stupor, vertigo, emesis, inappetence, diarrhea, clonic muscular spasms, convulsions, and death. Treatment. — Treatment is available only during distention, and effort should be directed principally to removing the cause. If it is a urethral obstruction in the male and the obstruction is below the ischiatic arch an artificial opening may be made into the urethra where it passes over the ischiatic arch, giving temporary relief, and if the obstruction cannot then be removed the tem- porary opening in the urethra may be made permanent. In valuable animals obstructive calculi may be removed 114 SWINE DISEASES from the bladder by surgical procedure and the condition thus corrected. Tumors and abscesses that affect urethral obstruction may be removed and permit of the ready outflow of urine through the urethra. Calculi Cystic calculi are of common occurrence in swine. There may be a single calculus or there may be myriads of them. In size they vary from mere grains of sand to masses as large as English walnuts. In shape they may be spherical, ovoid, or all kinds of irregular surfaces and outlines may be presented. Some have been observed that were practically the shape of jack straws. When several occur together they may be faceted. As a rule they are of a dirty-white color, though they may be of any color. They are usually composed of magnesium and calcium phosphates and catbonates. Etiology. — Retention and fermentation of urine in the bladder favor calculous formation. Retention and urine fermentation also favor catarrhal inflammation, which is associated with epithelial desquamation, and this serves as a nucleus for the calculous deposits. Lesions. — The presence of calculi is the principal thing to be sought for, and they are not difficult to identify. There is also more or less evidence of catarrhal cystitis, and there may be retention of urine. Symptoms. — Evidence of catarrhal cystitis — that is, frequent voiding of relatively small quantities of urine — characterizes most cases of cystic calculi. The urine in these cases is frequently acrid and may produce dis- turbances in and around the prepuce of the male and in the perineal region of the female. Should the calculi produce obstruction to the outflow of urine there will be symptoms of cystic distention. Treatment. — Solvents for cystic calculi are not wholly successful. If the calculi are causing such dis- turbance that marked symptoms are evident, operative procedure is indicated, providing the value of the animal is sufficient to justify it. THE URO-GENITAL SYSTEM 115 Cystitis Inflammation of the bladder may be catarrhal or purulent. Neither type has been extensively investi- gated by the clinician, therefore the present knowledge concerning them has been obtained by veterinarians at abattoirs. Catarrhal Cystitis Catarrhal cystitis is not uncommon. In many instances the condition is associated with cystic calculi, but it may also be caused by infection. Occasionally several cases of catarrhal cystitis may occur simultaneously or successively in the same herd, and on obtaining the history it is found that the affected swine have been fed food stuff containing some urinary irritant or they have obtained quantities of turpentine or cantharides. Reten- tion and fermentation of the urine predisposes to inflam- mation of the cystic mucosa because of the liberation of ammonia. Lesions. — Catarrhal cystitis is characterized by the following sequential lesions of the mucosa: hyperemia, tumefaction, and coating of the surface with tenacious mucus, desquamated epithelia, and pus cells. Later there is desquamation of the surface epithelium, leaving a denuded granulating surface. Symptoms.— Frequent attempts at urination in which small quantities of a turbid urine is eliminated are symptoms of catarrhal cystitis. There may be a straddling gait. Treatment. — Remove the cause. The bladder in females may be cleansed by a weak solution of corrosive sublimate or creolin, and urinary sedatives should be administered. Internal treatment is practically all that can be given in male animals affected with cystitis. Purulent Cystitis Purulent cystitis is an inflammation of the urinary bladder accompanied by the formation of pus. This condition is not so common in swine as catarrhal cystitis. 116 SWINE DISEASES Predisposing causes mentioned in catarrhal cystitis are also operative in purulent cystitis. The exciting cause is most frequently the Bacillus coli communis, although any of the pyogenic cocci may produce it, or even the Bacillus pyocyaneus being responsible for an occasional case of cystitis. Lesions. — Hyperemia, tumefaction of the mucosa, accumulation of tenacious mucus upon the mucosa, and the production of pus in quantities characterize purulent cystitis. The surface mucosa is eroded and becomes a granulating surface. Symptoms. — Frequent urination and the voiding of small quantities of urine admixed with pus typifies purulent cystitis. Treatment. — Remove the cause, and cleanse the bladder of females with weak antiseptics. The males should be treated by internal medication, with urinary antiseptics and sedatives. Tumors Very few cases of the occurrence of tumors have been observed in the bladder of swine. Papillomata have been reported in a few cases. URETHRA The urethra may be imperforate, particularly in the male. Such cases are rarely observed, and those affected die soon after birth. The condition is easily remedied, providing the imperforation is near the outlet, by making a crucial incision or by puncture with a small trocar. 