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 Hog cholera and anti-hog cholera serum. 
 
 3 1924 000 260 301 
 
 LIBRARY 
 
 NEW YORK STATE VETERINARY COLLEGE 
 
 ITHACA, NEW YORK 
 
 THIS BOOK IS THE GIFT OF 
 
 T'co'\ft.%%0\- d^ TWero^Y CAAign, ^STftnW Aift'|v*a.\g Imifi, 
 
State Veteeixary College. 95 
 
 HOG CHOLERA AND ANTI-HOG CHOLERA SERUM. 
 
 H. J. 'Milks. 
 Department of Materia Medica and Small Animal Clinic. 
 
 The importance of '' Hog Cholera " and the production of anti- 
 hog eholera serum to the live stock interests of the State will be 
 readily seen when one considers that according to the year book 
 of the United States Department of Agriculture for 1910, there 
 were 656,000 hogs in the State with a value of $7,5i4,000. There 
 has always been doubt as to whether the highly infectious disease 
 hog cholera existed in the State or whether the reported outbreaks 
 of cholera were not caused by some dietary condition as, for in- 
 stance, Moore has pointed out in the case of feeding swill which 
 contained large quantities of powdered soap. 
 
 However, after the discovery that a filterable virus is the cause 
 of the|epizootic disease and not the bacillus of hog cholera, it was 
 suggested that some of the outbreaks of apparently infectious 
 diseases of swine from which this latter organism could not be 
 isolated might be due to the filterable virus. With this in view, 
 several inoculations were made with the filtered blood of animals 
 which had died of supposed hog cholera. The result of this work 
 proves , conclusively that hog cholera exists in four counties of 
 the State and there is good evidence that it is present in other 
 localities. 
 
 . Historically it is interesting to note that hog cholera has existed 
 in this country for a long time. It was first reported from Ohio 
 in 1833 and was thought by American authorities to have been 
 imported from Europe. Scientists on that continent, however, 
 denied its existence in Europe until long after its appearance 
 here. The absence of positive diagnosis at that time failed to 
 make clear in which country it originated. It is reasonably cer- 
 tain, however, that Ohio was the first state to be infected. During 
 the next twenty years after its first appearance there were over 
 ninety outbreaks divided among several states and furnishing 
 centers from which the infection has been carried to practically 
 ever state in the Union. 
 
 Dr. Geo. Sutton of Aurora, Ind., made the first report upon 
 the disease in 1853. This was followed by reports by E. M. Snow 
 of Providence, R. I., in 1861, Dr. James Law, Ithaca, N. T., in 
 1875, and Dr. Detmers in 1877. Dr. Law's re^p^rt coiitains, the 
 
96 Annual Eepoet of the 
 
 first fairly accurate and complete description of the disease. The 
 work of these men covered the symptoms of the disease and the 
 post-mortem appearance of the organs of animals that had died of 
 it, in fact all that could be learned from field observation alone. 
 In 1878, Congress made an appropriation for the investigation 
 of swine diseases, ^ine men were appointed for the investiga- 
 tion of ISTS, and these for a period of two months only. Con- 
 sequently little was accomplished. The researches of these men 
 were to be made in the field and various measures applicable to 
 the control of epizootic di eases were tried. The results of these 
 investigations were summed tip as follows in a publication of the 
 Bureau of Animal Industry, 1889, Hog Cholera: 
 
 1. Swine diseases were found destructive in the most widely 
 separated districts of the countrjr. 
 
 2. The symptoms and post-mortem lesions were similar to those 
 described by Sutton, Snow, Law, and others. 
 
 3. Xo evidence was discovered to show that there was more 
 than one disease which prevailed as an epizootic. 
 
 1. It was believed that the outbreaks were due to a contagion 
 and that the disease was communicable. 
 
 5. The remedies tested were either without effect or of doubt- 
 ful value ill the treatment of affected animals or guarding against 
 the contagion. 
 
 Of the nine investigators only Law and Detmers retained their 
 appointment longer than two months. These men did consider- 
 able laboratory work. Law made inoculations into rabbits, rats 
 and sheep and seemed to establish the communicability of the 
 disease he investigated. Detmers, by the aid of the microscope, 
 thought he had discovered the cause of the disease and naiked the 
 organism Bacillus siiis. Both of these conclusiofis were in error 
 but pointed out the need of bacteriological research and careful 
 laboratory work as the only means of determining the cause and 
 prevention of the disease. Law and Detmers continued their in- 
 vestigation for the Department of Agriculture in 1879. In 1880 
 Salmon was added. Law devoted much of his time to the produc- 
 tion of a vaccine by attenuation of the virus or cause of the 
 disease. In this he was unsuccessful. During this time Detmers 
 continued his investigation with the microscope. During the next 
 four years little was done in investigation because it was under- 
 stood that it had been carried about as far as possible under 
 the methods then emplo^'ed and because of a lack of facilities 
 for and clear methods of bacteriological research. 
 
State Vetetiinaky College. 97 
 
 In 1885 it was amioiinced that Salmon and Smith had dis- 
 covered the cause of the disease. This was determined as due 
 to a motile rod, to which the name has been given Bacillus cJwlerae 
 ^uis or hog cholera bacillus. These investigators showed that 
 this organism was found in the organs of most of the animals 
 which they had examined that died of cholera. Further, they 
 ■could produce symptoms similar to hog cholera and lesions, in 
 many cases, indistinguishable from those of animals that had con- 
 tracted the disease naturally. They were also able to recover the 
 bacillus from the animals which had died as the result of the 
 inoculation. 
 
 In 1886, Smith described an entirely different infectious dis- 
 ease of swine due to an organism belonging to the present Septi- 
 caemia Plaemorrhagica group. Accordingly, it was considered 
 that there were two distinct infectious diseases: hog cholera in 
 which the lesions were largely in the digestive tract, and swine 
 plague in which the lungs were mostly involved. In many out- 
 breaks they were able to find both diseases present and to recover 
 both organisms from the same animal. 
 
 The results of Salmon and Smith were confirmed by scientists 
 ■of this and other countries and it was generally conceded that 
 there were two contagious diseases of swine, namely hog cholera 
 .and swine plague. 
 
 Since Bacillus cJiolerae suis was announced as being the cause 
 of hog cholera, the work has been largely to find a vaccine or 
 •serum which would serve as a preventive for the disease. Various 
 vaccines and sera were tried but none of the preparations gave 
 satisfactory or practical results. It was not imtil about twenty 
 years later that de Schweinitz was led to the suspicion that 
 B. cholerae suis was not the cause of the epizootic form of the 
 'disease. He noticed that although hog cholera is very contagious 
 and spreads readily to other members of the herd when once it is 
 introduced, yet when an animal was injected with pure cultures 
 ■of B. cholerae suis, in many cases the animal would become sick 
 and die from the effects of the injection, but other animals asso- 
 ciating with it would remain well. He also found that it was 
 difficult to produce hog cholera by subcutaneous injections of 
 •cultures of the hog cholera bacillus, while the injection of some 
 of the blood of a sick animal siibcutaneously into a sound one 
 would produce the disease. Other reasons were that although 
 made immune to pure cultures of the hog cholera bacillus, animals 
 4 
 
OS Anxual EhfO^Tt of thi; 
 
 were by no means immune when exposed to animals sick witb 
 cholera. 
 
 These facts led to further investigation. In 1903- de Schweinitz 
 and Dorset (Circular 41, B. A. I.) reported that B. cholerae suis 
 was not the specific cause of the epizootic disease, but that the 
 cause was a filterable virus or one so small that it could be passed 
 through the finest porcelain filter. It might be' well to add a word 
 relative to the term '' filterable virus." There are? certain diseases, 
 for instance rinderpest and foot-and-mouth disease, that are 
 highly contagious, and which are due to invisible organisms or 
 viruses present in the blood and fluids of the body. These viruses 
 are so small that they can be passed through the finest porcelain 
 filter and are invisible even with our strongest microscopes. 
 
 As a result of experiments published in 1805 (B. A. I. Bul- 
 letin 'Ko. 72i), it was determined that the filterable virus is the 
 real cause of the epizootic disease of swine j that the hog cholera 
 and swine plague bacteria are, so far as the epizootics are con- 
 cerned, secondary invaders. The fact, however, must not be lost 
 sight of that Bacillus cholerae suis and Bacterium septicaemia 
 haemorrJiagica are the cause of certain diseases of swine, and in 
 m^any outbreaks they exert considerable influence as to the mani- 
 festations of the disease. 
 
 Means hy which the infection is spread. Hog cholera may 
 be spread from a single center of infection in many ways. One 
 of the most prevalent is the purchase of a hog from an infected 
 herd and placing it in a sound one. It is also spread to some 
 extent by taking the sows from a sound herd to an infected herd 
 for service. This has occurred once in our experience in which 
 we had a clear history. The infection may also be carried from 
 one farm to another upon the attendant's shoes or upon the wheels 
 of wagons driven through an infected territory. Horses and cattle 
 though not capable of contracting the disease may carry the in- 
 fection from one place to another upon their feet. This also holds 
 good in the case of dogs feeding upon carcasses dead of the dis- 
 ease. Furthermore, it may be carried down a stream of water 
 from pollution higher up. 
 
 Period of incubation. The period of incubation varies from a 
 few days to two or even three weeks. This depends a great deal 
 upon the method of exposure, virulence of the virus, and resist- 
 ance of the animals exposed. Young and pampered animals are 
 usually more susceptible and have the more acute form of the 
 
State Veteeinaey College. 99 
 
 disease. A short period of incubation usually means a virulent 
 type of the disease. As in the case of most infections, the virus 
 •of hog cholera is more virulent in the earlier part of an outbreak 
 ■of the disease and may become so v^eak that the resistant animals 
 may not become affected at all. 
 
 Symptoms. The symptoms of hog cholera are not very charac- 
 teristic. Fever is usually present and in animals that are coming 
 down -with the disease, which have not as yet shown any symptoms 
 •of siclcness, the temperature may be several degrees above normal, 
 frequently it is subnormal in the last stages of the disease. Soon 
 .after being attacked the animal loses appetite, becomes weak and 
 may have convulsions. In the early part of an outbreak, the 
 yoimg and very fat animals may succumb without showing any 
 symptoms of sickness. Diarrhoea may be present and usually 
 follows constipation, although constipation sometimes persists 
 throughout the disease. 
 
 The symptoms vary somewhat with the virulence of the out- 
 break and the resistance of the animals attacked. If the virulence 
 is high and the resistance low the acute form is seen. In this 
 type of the disease, the animal shows fever, dullness, stiffness, 
 soreness, tremors, weakness, and loss of appetite. It does not 
 move unless made to do so ; in general there is great depression. 
 The eyes are inflamed and the lids gummed with the secretions. 
 Hed patches usually appear upon the skin, especially in the region 
 ■of the ears, lower jaw, abdomen and inside of the legs. Some- 
 times the redness is d^^ffuse, covering the entire regions mentioned. 
 Before death this may turn to a purplish color. Coughing, rapid 
 breathing, and other symptoms of respiratory derangement may 
 be present but usually these symptoms are not pronounced until 
 shortly before death. 
 
 In the chronic type of the disease 'about the same symptoms are 
 •exhibited as in the acute except that the illness may last several 
 weeks or months, during which there is the usual weakness, loss 
 of appetite, inflammation of the eyes, and usually profuse diar- 
 rhoea. If these cases recover they are rarely of any value to the 
 owner. It will be noticed from the above description that there 
 are no symptoms characteristic of the disease. However, if an 
 animal or two have died and then after an interval of a week or 
 ten days others become affected in a similar manner, there is 
 sufficient grounds for suspecting the presence of hog cholera. 
 
100 AxxuAL Eepoet of the 
 
 Post mortem ajypearances. There may be reddi&h or purplish 
 spots upon the skin or the entire region mentioned under symp- 
 toms may be colored. Petechiae may be present upon the surface 
 of the heart and occasionally on the pericardium and lungs. Fre- 
 quently pneumonia is present but is not so characteristic as the 
 small hemorrhages. In acute cases the spleen is usually enlarged, 
 dark colored, soft, filled with blood, and may show hemorrhages 
 beneath its capsule. In chronic- cases this enlargement is not 
 noticed and the color is often lighter than normal. 
 
 The lymph glands in the ingaiinal region are swollen and red 
 or even dark in color in the acute form of the disease. Those in 
 other parts of the body, mesenteric, angles of the jaw, etc., may 
 be affected in a similar manner. These lesions are not often found 
 in chronic cases. The kidneys in the acute disease are usually 
 the seat of small hemorrhages. To observe the condition of the 
 kidneys it is necessary to remove the capsule. If the kidnej's are 
 slit open hemorrhages of a similar nature may be seen on their 
 inner siirfaces. The color of the kidneys is usually darker than 
 normal and the hemorrhages may vary in size from a mere point 
 up to the size of a pin head. 
 
 Sometimes petechiae are foiind on the serous side of the stomach 
 and small intestine. The mucosae of these organs may also show 
 hemorrhages. The large intestine, however, is usually the seat 
 of extensive lesions. In the acute form of the disease hemor- 
 rhages may be present on both stirfaces of this organ. Erosion of 
 the mucous membrane is also common. The mucosa may be blood 
 stained ■ and the contents of the bowel blood stained from the 
 extravasation of blood. In the chronic form of the disease, thc- 
 so-called " button ulcers " may be found. These ulcers are usually 
 found in the caecum upon or near the ileo-caecal valve and are 
 quite characteristic of the disease. They are circular, hard, 
 yellow in color, with a darker greenish yellow center, raised dis- 
 tinctly above the healthy mucous membrane. They vary in size 
 from mere points to an inch in diameter and are so numerous in 
 some cases that large portions of the organ are destroyed. If the 
 ulcers are found diagnosis can be made fairly accurately, al- 
 though there is no other disease in this country in which the 
 petechiae are found in the heart, lungs, kidneys and other organs. 
 
 Any or all of the above described lesions may be found in an 
 animal dead of cholera, but only an occasional animal exhibits 
 all the lesions. For instance, it is practically impossible to find 
 
State Veteeinaey College. 101 
 
 the button-like ulcers in the acute form of the disease and but 
 rarely are the hemorrhages seen in the chronic type. 
 
 Diag-nosis. Before diagnosing a disease as hog cholera there 
 are a few important factors one should bear in mind. In the 
 first place, is the disease contagious? That is, can it be spread 
 from one animal to another? Then the symptoms and post- 
 mortem lesions should be considered. It is possible to get a fairly 
 good idea relative to the disease from these observations but 
 m order to prove conclusively that the disease is hog cholera, it 
 is necessary to produce the disease in a sound animal by inocu.- 
 lating it with some of the filtered blood of a dead or very sick 
 animal. 
 
 The disease must be distinguished from sickness due to im- 
 proper feeding, especially in case of swill or garbage fed animab, 
 as it has been shown by Moore that powdered soaps used in wash- 
 ing dishes may cause a disease which resembles cholera. Of 
 course disorders due to dietary conditions would not spread as an 
 epizootic, while hog cholera would most likely spread throughout 
 the neighborhood. There are so very few other diseases which 
 might be confused with cholera that time will not be taken to 
 discuss them. 
 
 Treatment and prevention. There is no successful treatment 
 for hogs sick with cholera. Various products have been recom- 
 mended for this purpose but are of no practical value. The only 
 rational method of dealing with an epizootic is to prevent the 
 spread of the infection instead of attempting to cure those animals 
 already sick. Since there can be no cholera without the filterable 
 virus, every precaution shoiild be taken to prevent its being 
 carried to sound herds. After the disease has appeared in a herd, 
 the only known remedy that will prevent its spread is the Dorset- 
 jSTiles anti-hog cholera serum. This preparation will prevent the 
 infection of other members of the herd if used in the early part 
 of an epizootic. Besides administering serum the pens, troughs, 
 and yards should be thoroughly cleaned and disinfected, so that 
 the infection will not be carried to other places. 
 
 Production of the serum. Since the filterable virus could not 
 be grown artificially, it was necessary to resort to the blood of 
 hogs sick with cholera for any protective agent. On this account 
 many attempts were made to produce a vaccine by attenuating 
 the blood of sick animals. The results obtained by such attenua- 
 tion were too uncertain for general use. While endeavoring to 
 
102 Annual Eepoet of the 
 
 produce a vaccine, it was noticed that by injecting an immune 
 animal with large amounts of virulent blood, a serum of high 
 protective powers could be obtained. (E. A. I. Bulletin Xo. 102, 
 Dorset, -McBi-ide, Niles.) 
 
 In order to produce anti-hog cholera serum it is necessary to 
 have an immune animal. Tor this purpose a pig is immunized 
 by inoculation with a few centimeters of virulent blood and an 
 injection of anti-hog cholera serum in opposite sides of the body. 
 Then the immune is hyperimmunized by the injection of large 
 quantities of virulent blood. The large amounts of virulent blood 
 required are obtained as follows : A few centimeters of virulent 
 blood are injected into susceptible pigs. When these animals are 
 in the last stages of the disease, they are bled under antiseptic 
 conditions, the blood deiibrinated by shaking with glass beads, and 
 strained through sterile gauze. To produce potent serum a strong 
 virus is necessary, that is, one that kills quickly. Otherwise the 
 serum produced would be weak in protective properties. We may 
 hyperimmunize in any of the following ways : 
 
 1. <Slow subcutaneous. Inject the immune animal soibcutane- 
 ously with 1 cc. per pound of body weight, In from seven to 
 ten days repeat the injection using 2^2 ce. per pound. Then after 
 the same interval inject 5 cc. per pound. 
 
 2. Quick subcutaneous. Inject 10 cc. per pound of body 
 weight. 
 
 3. Intravenous. Inject intravenously 5 cc. per pound. 
 
 4. Intra-abdominal. Inject intra-abdominally 10 cc. per pound 
 of body weight. 
 
 As soon as the animal has recovered from the effects of the 
 injection or the last injection, if the slow subcutaneous method 
 has been used, it is ready to begin bleeding from the tail. This 
 is usually within ten days. The bleeding is repeated at intervals 
 of a week for three or four bleedings. The animal is then killed 
 and all its blood used, or it may be rehyperimmunized. In re- 
 hyperimmunizing the animal usually receives half the previous 
 dose of virulent blood. Four or iive cubic centimeters of blood 
 per pound of body weight are usually taken at each bleeding. 
 Sometimes an animal will not bleed so much and occasionally it 
 is possible to take more. A two hundred pound hog will, in most 
 cases, give 800 to 1,000 cc. of blood at each bleeding. 
 
 Treatment of the Mood. The blood is drawn from the tail imder 
 as antiseptic precautions as possible. It is then deiibrinated or the 
 
.State Veteeinaey ' College. 103 
 
 •clots broken up by shaking with glass beads, then strained through 
 sterile gauze to remove the clots. One half per cent, of phenol is 
 -added and the serum is ready for use. The blood of each animal 
 is kept separate and that of each bleeding added. The mixed blood 
 of several animals is tested before using. 
 
 Testing the serum. The following methods of standardizing 
 hog cholera virus and testing the potency of the serum were 
 adopted at a conference of the federal and State official^, in 
 December, 19'09 : 
 
 1. The standardization of hog cholera virus which is used for 
 , ihy per immunization. 
 
 a. Inject at least two pigs intramuscularly, giving each 2 cc. 
 ■of the defibrinated diseased blood which is to be tested. The 
 Wood should not be more than 24 hours old and should have been 
 -kept at a temperature not higher than 55° F. 
 
 b. The test pigs should not weigh less than 50 pounds each. 
 After injection they should be placed in a small disinfected pen 
 •with at least one susceptible uninoculated pig of the same weight 
 and preferably of the same litter. 
 
 c. The virus shall not be considered suitable for use unless the 
 inoculated pigs become visibly ill within eight days and die within 
 fifteen days after inoculation. The carcasses of these pigs must 
 nshow undoubted lesions of hog cholera. Furthermore, the com- 
 municability of the disease induced by the blood inoculations must 
 l3e demonstrated by the contraction of the disease by the check 
 pig within 12 days after the appearance of the disease in the 
 inoculated pigs. 
 
 2. Handling the Mood used for hyperi/mmunization. The 
 diseased blood should be collected and manipulated under -.trict 
 antiseptic precautions, stored at a temperature not higher than 
 55° F. and used within 24 hours after drawing. It is recom- 
 mended that defibrination be postponed until immediately before 
 use of the blood. 
 
 3. Testing the potency of the hyperimmune serum. 
 
 a. If the plan of testing the mixed bleedings of each hyper- 
 immune be adopted by the producer, then we recommend that the 
 test be carried out as follows: 
 
 Inoculate three hogs, each weighing from 50 to 100 pounds, 
 vs^ith 2 cc. each of virulent blood. Inject two of these simiil- 
 taneously with 15 cc. each of the serum to be tested. If the hog 
 receiving virulent blood only sickens with hog cholera within 
 
104 Annual Repoet ov the 
 
 eight, clays and is apparently ready to die in fifteen days, while- 
 the two receiving immunizing serum continue in good health, then 
 the serum may be considered suitable for field use in doses of 
 20 cc. for hogs weighing from 50 to 100 pounds. 
 
 b. If the plan of testing the mixed sera of several hyper- 
 immunes be adopted by the producer^ then inject intra-musctilarly 
 nine similar pigs weighing between 50 and 100 pounds each with 
 2- cc. each of virulent blood. Give each of three of these 15 cc. 
 of the immunizing serum to be tested. Give each of three others- 
 20 cc. of the serum to be tested. If all of those receiving im- 
 munizing serum remain in good health and two or more of the 
 checks become ill of cholera within eight days and are apparently 
 going to die in fifteen days, the serum shall be considered suitable 
 for field use in doses of 20 cc. for hogs weighing from 50 to ICO 
 pounds. If one or more of the pigs receiving 15 cc. of serum 
 become obviously sick of cholera and the three pigs receiving 
 20 cc. each of immimizing serum all continue to remain in good 
 health, then the serum may be used in field work, in increased! 
 doses. 
 
 Methods of using the serum. There are two methods of using 
 the serum. By the simultaneous method a dose of serum and a 
 small amount of virulent blood are injected in opposite sides of 
 the body. This method of vaccination is said to produce an 
 immunity that will last for life. It is to be preferred in cases 
 of well herds or in those that will not be exposed to the disease 
 for several months. This involves the use of virulent blood which 
 if handled carelessly may furnish the source of infection to sound 
 herds. 
 
 Serum only is injected in the other method. This serum will 
 produce an immunity that will last for several weeks or months, 
 but if the animals are not exposed to cholera within a few weeks 
 after receiving the serum, the immunity lessens and the animal 
 may again be susceptible to cholera. If, however, the animals are 
 exposed to the infection within a few weeks after receiving the 
 serum, the immunity is believed to be of a lasting duration. In 
 either case the injection is usually made in the inside of the thigh. 
 Serum will be supplied from this college for use in the latter 
 method only, since in most cases it will not be applied for imless 
 cholera exists in a herd. In this ease all the well animals may 
 be treated. ]^atural exposure to the infection takes place in these 
 cases and the virus is not needed. The serum should be ad- 
 
State Veteeixaey College. 105 
 
 ministered by a competent veterinarian under strict antiseptic 
 precautions. 
 
 Dose and cost of serum. Animals weighing from 50 to 100 
 pounds are taken as the standard. The dose for such animals is 
 20 cc. Suckling pigs shoiild receive from 10 to 15 cc. Older 
 and heavier animals may receive as much as 30, 40 or even 60 cc, 
 in case of very large animals. If the herd is badly infected the 
 dose can be increased somewhat. It is a good plan to take the 
 temperatures of the animals treated and give a larger dose to 
 those having fever. 
 
 The cost of the serum will be $.25 per dose of 20 cc. This 
 amount partially covers the cost of production. 
 
 How to order serum. In ordering serum the foUowinginforma- 
 tion should be given : Number of animals, weight, length of time 
 ■the disease has been in the herd, number of animals that have 
 died, number of those sick at the present time. Before ordering 
 serum, it should be always considered that anti-hog cholera serum 
 is not regarded as a curative agent but as a preventive and if 
 used in the early part of an epizootic it will prevent the infection 
 of the well animals. The serum will be of absolutely no beneiit in 
 any other disease than that caused by the filterable virus. Con- 
 sequently to avoid useless expense and disappointment, it ii neces- 
 sary to have the disease diagnosed by a competent veterinarian. 
 We would much prefer that the name of the veterinarian who 
 diagnosed the disease and who will administer the serum accom- 
 pany the order. 
 
 Outbreaks of hog cholera in the State. The following outbreaks 
 of cholera were studied and will be named simply from the county 
 in which they occurred. 
 
 . No. 1. Broome county. Early in the fall of 1909 attention 
 was called to a disease among hogs in Broome county. This herd 
 had consisted of about 200 animals. Of these, fifty or sixty had 
 died during the first four weeks of the epizootic. It was im- 
 possible to trace the source of the infection, as no animals had 
 been brought into the herd recently nor had any disease been 
 reported in the neighborhood. About fourteen years previously, 
 there had been a similar disease among the animals but no trouble 
 since. This outbreak was finally controlled by proper sanitary 
 measures, including the removal of the well animals to new 
 quarters, disinfection of the old quarters and proper disposal of 
 the dead animals. 
 
 Blood from a pig that had died at this place was filtered and 
 injected into a sound pig. This animal developed hog cholera and 
 
106 Annual Eepoet of the 
 
 •died within a few days. Filtered blood from this animal was 
 injected into another sound one and in like manner caused sick- 
 ness and death. Blood from this animal caused sickness a:id 
 death in a third and in like manner filtered blood from the third 
 caused death of the fourth. All the inoculated animals showed 
 symptoms and lesions of hog cholera. 
 
 Na. 2. Cayuga county. November 28, 1909, a sick hog was 
 Teceived from Cayuga county. It was in a dying condition when 
 received. It was killed and the autopsy showed lesions of hog 
 cholera. Before it was killed, blood was drawn from its tail, 
 filtered .and used to inoculate another animal. The inoculated 
 animal died as a result of the inoculation with lesions of cholera. 
 
 No. 3. Tompkins county. No. 1. October 17, 1910, a sow 
 weighing about 200 pounds was brought to the clinic for examina- 
 tion. She was exhibiting symptoms of cholera (purplish dis- 
 ■colorations of the skin, difiicult breathing, weakness, and chills). 
 This animal grew rapidly worse and died during the morning of 
 the 19th. Autopsy gave lesions typical of cholera. Cultures were 
 made from most of the organs of the body but no growth took 
 place except in those made from the kidneys, liver and lung from 
 which pure cultures of a streptococcus were obtained. Blood 
 from this animal was filtered and injected into two susceptible 
 pigs. Both of these animals died as a result of the inoculation, 
 showing typical symptoms and lesions of hog cholera. 
 
 The history of the outbreak on this particular farm is very 
 ■clear. October 3d, the sow referred to above, together with two 
 others, were taken to a neighboring farm to be bred. One of 
 them was taken home immediately, the other two were left until 
 October 8th, when they were returned and placed with the herd 
 of sixteen animals. October 16th, the sow was first noticed to be 
 ill. Within a day or two, the other animal which had remained 
 the longer time became ill. This herd was treated with serum 
 and the results will be given later. It was learned after the 
 animals became ill that there was a fatal disease among the hogs 
 on the farm where these animals were taken for service. 
 
 No. 4r. Onondaga county. October 29, 1910, two dead pigs 
 were received from Onondaga county. These animals had been 
 killed when in a dying condition. On this account enough blood 
 could not be obtained for inoculation purposes. However, a few 
 cc. of abdominal fluid were obtained. This was diluted, filtered 
 and used to inoculate a pig but it did not produce the disease in 
 this animal. Of the two animals received, one exhibited typical 
 
State 'Yeteeinaey College. 
 
 lOT 
 
 lesions of cholera while the organs of the other did not show any 
 pathological changes. 
 
 No. 5. Tompkins county. No. 2. December 5th, two pigs were- 
 ibrought for diagnosis. One was already dead and the other in 
 had condition. Autopsy of the dead animal gave typical lesions- 
 of cholera. The second pig did not die until December 13th. On 
 autopsy this animal showed a few lesions in the kidneys and 
 mesenteric lymph glands with typical button ulcers in the large 
 intestine. Another pig from this place was presented December 
 11th, and upon autopsy exhibited typical lesions of the disease. 
 jSTo inoculations were made, as the autopsies revealed characteristic- 
 lesions. 
 
 Hog cholera has also been reported from Oneida county. 
 Serum has been sent to this place and the reports of the results 
 obtained tend to confirm the correctness of the report. 
 
 In all eight animals were inoculated with the filtered blood 
 from suspected outbreaks of the disease. Seven autopsies were 
 made of animals from infected herds. From the investigation of 
 the disease of swine, hog cholera has been positively identified in 
 six herds distributed in five counties : Broome, Cayuga, Oneida, 
 Onondaga, Tompkins (2). 
 
 The following table gives the result of the inoculations of 
 filtered blood from suspected outbreaks of the disease: 
 
 
 
 Table ISTo. 1.— 
 
 Table of Inoculations. 
 
 
 No. 
 
 Date. 
 
 Dose. 
 
 Source of 
 infection. 
 
 Results. 
 
 Lesions. 
 
 Remarks. 
 
 1 
 
 19G9. 
 Sept. 28 
 
 lOcc. 
 
 Broome county.. 
 
 Died Nov. 3 . . . . 
 
 Lungs, mesenteric 
 lymph glands, 
 kidneys, bladder. 
 
 Abscess at 
 point of in- 
 oculation. 
 
 2 
 
 Nov. 3. 
 
 3cc. . 
 
 Pig No. 1 
 
 Died Nov. 12 . . . 
 
 Lungs, mesenteric 
 lymph glands, 
 kidneys. 
 
 
 3 
 
 Nov. 12 
 
 3cc. . 
 
 Pig No. 2 
 
 Killed in dyinp 
 condition. Nov. 27 
 
 Kidneys, mesenteric 
 lymph glands. 
 
 ' 
 
 4 
 
 Nov. 30 
 
 5oc.. 
 
 Pig No. 3 
 
 Died Dec. 7 . . . . 
 
 Kidnes'S, lungs, me- 
 senteric lymph 
 glands. 
 
 
 5 
 
 Nov. 30 
 
 5cc.. 
 
 Cayuga county. . 
 
 Died Dec. 15... . 
 
 Skin, pleura, lungs, 
 heart, kidneys, 
 lymph glands. 
 
 
 6 
 
 1910. 
 Oct. 22 
 
 3cc. . 
 
 Tompkins No. 1. 
 
 Died Nov. 10-. . . 
 
 Kidneys, bladder, 
 sra.all intestine. 
 
 
 7 
 
 Oct. 22 
 
 3cc. . 
 
 Tompkins No. 1 . 
 
 Died Nov. IS. . . 
 
 Kidneys, bladder, 
 spleen, mesen- 
 teric glands. 
 
 
 .8 
 
 Oct. 31 
 
 3cc. . 
 
 Onondaga county 
 
 
 
 
 
 
 dominal 
 fluid used. 
 
108 AiS'xuAL Eepoet 'of the 
 
 Table ISTo. 2 shows the lesions found in animals sent in for 
 Table jSTo. 2. — Lesions. 
 
 diagnosis. 
 
 No. 
 
 Date 
 received. 
 
 Source. 
 
 Organs showing lesions. 
 
 Remarks. 
 
 1 
 
 Nov. 28, 1909 
 
 Cayuga Co . . . 
 
 Kidneys, lungs, mesenteric Ijinph 
 glands. 
 
 
 2 
 
 Oct. 17, 1910 
 
 Tompkins Co. 
 No. 1. 
 
 Kidneys, lungs, heart, skin, lymph 
 glands. 
 
 
 3 
 
 Oct. 29, 1910 
 
 Onondaga Co. 
 
 No lesions found. 
 
 
 4 
 
 O.t. 29, 1910 
 
 Onondaga Co . 
 
 Kidneys, lymph glands, bladder, lungs 
 
 
 5 
 
 Dec. 5, 1910 
 
 Tompkins Co. 
 
 No. 2. 
 
 Kidneys, skin, heart, lungs, lymph 
 glands, intestines, bladder. 
 
 
 G 
 
 Dec. 5, 1910 
 
 Tompkins Co. 
 No. 2. 
 
 Lungs, mesenteric glands, intestines. . 
 
 Ulcers in large 
 intestine. 
 
 y 
 
 Dec. 11, 1910 
 
 Tompkins Co. 
 No. 2. 
 
 
 
 
 
 in large intest. 
 
 After it was determined without doubt that hog cholera existed 
 in the State and after a favorable expression from many promi- 
 nent swine breeders of the State, the production of the anti-hog 
 cholera serum was undertaken. The serum has been produced 
 upon a limited basis only, since it was impossible to ascertain any 
 idea of the extent of the disease or demand for the serum. Ten 
 hundred and ninety^five doses, or 21,'90O cc, of serum have been 
 produced. At times the demand has been so great that it could 
 not be supplied promptly. Four hundred doses, or 8,100 cc, have 
 been sent out, leaving 695 doses, or 13,800 cc, on hand. It seems 
 reasonable to suppose that the demand will be much greater when 
 it is widely known that serum can be obtained at the college. It 
 is impossible to ascertain from our work an approximate cost of 
 serum. Simply calculating the number of pigs required to pro- 
 duce a certain amount of serum, for instance sufficient to 
 immunize 150 pigs, will require by the quick subcutaneous, slow 
 subcutaneous, or intra-abdominal method, one 100-pound pig and_ 
 two 50-pound pigs; by the intravenous method, one 100-pound 
 pig and one 50-pound pig. This does not make allowance for 
 unavoidable loss of -pigs by death in the process of preparing the 
 serrmi. A fair estimate would seem to be that to produce enoughi 
 serum to immunize 150 pigs would require four animals of the 
 above size. 
 
 Results of the use of the serum. The first herd treated was the 
 one described as Tompkins county Xo. 1. The eighteen animals 
 
State Veteeixaey College. 109 
 
 of this herd were treated October 19, three days after appearance 
 of disease among the animals and eleven days after the exposed 
 animals had been brought home. On the day of treatment the sow 
 that had remained iipon the infected farm for five days was sick. 
 She had a temperature of 104° F. and was very stupid. Serum 
 was administered in the following doses: Tor the small pigs, 
 15 cc. ; for the shoats weighing about 150 pounds, 30 cc. ; for the 
 old sows weighing about 200 pounds, 50 cc. 
 
 The sow that was so well advanced with the disease died after 
 ii few days. jSI^one of the other animals have shown any symptoms 
 of cholera since the imnumizijig treatment. 
 
 Onondaga county. The Origin of this outbreak cannot be 
 traced, although the troixble started soon after the purchase of 
 .several rough looking animals and adding them to the herd. The 
 lierd consisted of 280 hogs when the disease first appeared. The 
 first deaths were in xVugust Avhen eight died. A number of 
 Teterinarians were called but they were unable to control the 
 •disease. The animals continued to die and were still dying up to 
 November 14, when the remaining animals were treated with 
 serum. At this time there were eighty of the original herd left. 
 Two pigs died the night previous to the treatment. 
 
 iSerum was administered in the following doses: Four pigs, 
 two weeks old, received 8 cc. each; eighteen pigs, two to four 
 weeks old, received 8 to 12 cc. each; twenty pigs, weight about 
 sixty pounds, received 15 to 18 cc. ; thirteen hogs, weight 200 to 
 400 pounds, received 40 to 60 cc. 
 
 Several of the animals described as weighing 100 pounds did 
 not appear to be well at the time of the treatment. One of these is 
 reported to have died later. One of the pigs, weighing about 
 thirty-five pounds, was reported sick at the time of treatment, but 
 recovered. Although two animals died the night previous to the 
 ■treatment only one died after the serum was administered. 
 
 Oneida county. In this herd twenty animals had died before 
 the serum was administered. Thirty-five doses were sent to this 
 J)lace on November 10. In a letter dated December 3, the owner 
 of the animals reported that the pigs' showing symptoms of cholera 
 at the time of treatment died. Xone of the others have, as yet, 
 taken the disease. 
 
 TompKns county outhreaJc No. 2. Serum was given as fol- 
 lows: Five pigs, weight about 35 pounds, 20 cc. ; one shoat, 
 
110 
 
 Annual Eepoet of the 
 
 weight aboiit 125 pounds, ''■'40 cc. Two animals died shortly after 
 the treatment. One of them was very sick at the time and the 
 other exhibited lesions of the chronic type of the disease on post- 
 mortem. 
 
 Table Giving the Eesults of the Treatment witbc, Seeum. 
 
 No. of 
 herd. 
 
 No. 
 treated. 
 
 No. of 
 
 animals 
 
 that died 
 
 before 
 
 treatment. 
 
 Interval 
 between 
 
 first 
 death and 
 treatment. 
 
 No. of 
 deaths after 
 treatment. 
 
 RemarljB. 
 
 1 
 
 IS 
 
 1 
 
 2 days 
 
 1 
 
 The animal that died after 
 treatment was" sick* whenv 
 treated. 
 
 2 
 
 80 
 
 200 
 
 3 months 
 
 1 
 
 
 3 
 
 100 
 
 20 
 
 Several weeks 
 
 Report not clear. All well anirrnds-at time- 
 of treatment remained well. 
 
 4 
 
 6 
 
 3 
 
 2 to 3 weeks 
 
 2 
 
 Of the animals:^ that died 
 after treatment, one was 
 very sick at time of treat- 
 ment, the other showed 
 lesions of chronic type of 
 the disease. 
 
 * This animal was in a very unthrifty condition. The large amount of serum was administered 
 on this account. 
 

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