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Botulism in the Domesticated Animals
ABSTRACTS.
309
In all the experiments the total amount of vaccine given to the dogs, whatever their size, was 40 c.c. This was divided into two doses of 20 c.c. each, which were given at an interval of 21 to 24 days, and each injection of 20 c.c. was divided and given at two places. Three dogs were tested one month after the second injection and all resisted infection while two controls developed rabies in 15 days. Of eight dogs tested after the lapse of 40 days, three developed the disease in 14,18, and 23 days. Two control dogs became rabid on the 14th and 16th days. Of four dogs tested after two months, one developed the disease on the 12th day. The three controls became rabid on the 11th, 12th, and 13th days. Four dogs tested after three months all failed to become infected. Two controls developed the disease in 19 and 27 days. Four dogs were tested after an interval of six months. One proved infected on the 16th day. The controls developed rabies on the 14th and] 6th day. One dog tested after ten months resisted infection, but a fellow dog which should have been tested had died of gastritis during the 8th month. Two of the dogs from the previous experiment were again tested at 10 months after the second dose of vaccine. One became infected on the 20th day. The three controls became rabid on the 11th, 12th, and 13th days. In view of the severity of the test inoculation, it is held to be a very satisfactory result that 75 per cent. of the vaccinated dogs resisted infectoin, and it is considered that the experiments warrant the view that the method provides a serviceable immunity against natural infection for a year. In the author's opinion the Japanese method, which has had a very wide application in Japan and elsewhere, does not give so strong an immunity. The glycerinised and phenolised vaccines suffer from the disadvantage that they cannot be preserved for more tilan a short time, and this is a matter of considerable importance, particularly in hot countries, where the attenuation of the virus is more rapid. This may perhaps furnish an explanation of some of the variable results obtained. On the other hand, the formolised vaccine, which is dead and freed from soluble toxin by centrifugalisation, is absolutely harmless. Large doses, such as 100 or 150 c.c. can be injected into rabbits at one time without causing any trouble, and among over 100 animals treated before or after infection no single accident which could be attributed to the vaccine has occurred. Experiments have shown that the vaccine retains its immunising power up to four months after preparation. (Receuil de Med. vet., Vol. 103, No. 14, July 30,1927, pp. 288-292.)
BOTULISM IN THE DOMESTICATED ANIMALS. By A. THEILER and E. M. ROBINSON. BOTULISM was originally described as a disease of man which resulted from the ingestion of diseased meat. The cause of the condition was established by van Ermengem, who incriminated the Bacillus botulinus. The principal symptoms in man are those of paralysis, particularly of the cranial nerves. There is generally no gastric or intestinal disturbance, and there is neither fever nor loss of consciousness. There appear to be several types of the Bacillus botulinus. In America three varieites, A, B, and C, have been recognised, but the organism isolated by van Ermengem does not appear to be identical with any of these. In America Type B appears to be the one most frequently encountered. TheA and B Types are only distinguishable by the fact that the
310
ABSTRACTS.
toxin of the one is not neutralised by the anti-toxin of the other. The foragepoisoning of equines in America is attributed to the toxin of Type B. . Type C was first isolated from Lucilia cregar by Bengtson . The symptoms produced by the toxin are identical with those caused by A and B. The organism itself closely resembles these two morphologically, but its cultures present some points of difference. A and B anti-toxins do not neutralise the toxin of type C. Type C is probably the cause of limberneck in poultry, and of the bulbar paralysis of horses and cattle seen in Australia . Lamsiekte in South Africa, which is caused by the ingestion of putrid bones, is probably a form of botulism. Within the last two years a spinal paralysis of equines in South Mrica has been traced to a bacillus of the C Type. Thus it appears that toxins of organisms belonging to Group C are the most common causes of disease of this kind among domesticated animals. These conditions resemble the corresponding diseases in man in that they are afebrile, and that paralysis, particularly of the cranial nerves, is a pronounced symptom. Cases of the disease sometimes run so acute a course that diagnosis is a matter of great difficulty, but in sub-acute cases the symptoms of paralysis are so typical that recognition is easy. The authors give an extensive review of the literature regarding the occurrence of botulism in horses, ruminants, and poultry, and they summarise their views in connection with each. With regard to the occurrence of botulism in horses their review of the literature leads them to the conclusion that a disease identical with that occurringin man occurs in equines. All the varieties of B. botulinus may be concerned in the causation, but the symptoms produced are more or less the same in all cases. Reviewing the work done in America, Australia, and South Mrica, the authors conclude that Types A and B scarcely ever cause botulism in cattle. Type C, the B. parabotulinus of Seddon, may cause enzootics and epizootics of botulism. Botulism in poultry is of rather infrequent occurrence. Fowls are ordinarily refractory, and there must be certain favouring circumstances in cases in which intoxication occurs. There are two groups of organisms which are responsible for the various forms of botulism. The first comprises Types A and B, while the second, which may be called the parabotulinus group, contains the American Type C, Seddon's bacillus, and both the varieties isolated in South Mrica. In a tabular 'ltatement ihe authors set out the important morphological, staining, and cultural characters of these, and in a second table they give the results of cross tests of toxin and anti-toxin. A third table shows the susceptibility of the various species of domesticated and laboratory animals, and gives information, so far as it is available, regarding the minimum lethal dose of toxin or culture. The authors think that too great importance ought not to be paid to some of the differences recorded by different authors. It has, for example, been shewn by Seddon that toxin derived from a pure culture is less toxic than that from an impure culture. The authors think that, taking all the points into consideration,the differences between the Types A and B on the one hand and Type C and the parabotulinus organisms on the other, are so small and so inconstant that the name parabotulinus should be dropped altogether. While the various toxins are capable of causing death even when small quantities are administered, the bacilli themselves when freed from toxin are quite harmless. The toxin is thermolabile and is destroyed by cooking, but exposure to sunlight and desiccation are without effect.
ABSTRACTS.
311
The authors think that the evidence brought forward by American investigators incriminating silage is not quite satisfactory, because it appears to be a very general rule, if not an absolute one, that the bacilli produce toxin only in media which have been prepared from meat. Theiler and Robinson have encountered a case in which the carcase of a rat was responsible for the con veyance of the toxin, and in the United States the freces of fowls, themselves not susceptible, were found to be toxic. Thus, in cases in which vegetable foodstuffs are suspect, such possible causes as these must not be lost sight of or ignored. Occasionally in South Africa asses die from botulism as the result of eating portions of,or the alimentary contents of,cattle that have died and the carcases of which contain the organism. In enzootic and epizootic botulism of cattle-the so-called para botulismwhich is known in South Africa as lamsiekte, in Australia as bulbar paralysis, and as cattle paralysis in Texas, special circumstances playa part in the mass production of the disease. In these cases the cattle eat the remains of dead animals, a deficiency of phosphorus in the soil causing them to seek it in the bones of carcases left on the feeding grounds. The grass or soil deficient in phosphorus varies in its phosphorus content during the year. In the spring the young grass contains sufficient to supply the animals' needs, so that bone eating is not indulged in, but as winter approaches the phosphorus content of the grass decreases, until it may be only a tenth part of what it was in the spring. This leads to the eating of bones, or osteophagia, as it has been called by Theiler. Osteophagia can be prevented by suitable manuring and by the addition of phosphates to the drinking water. The administration of phsophorus in this way causes the symptoms to disappear. Bone meal is a very suitable addition to the diet. In Australia and Tasmania similar conditions exist, and there dead rabbits are not infrequently the source of toxin. It is noteworthy that in all countries in which botulism of cattle is observed there also occurs under the same conditions another disease. This in Mrica is called Stywesiekte; in· Australia, Cripples; and in Texas, Creepers. This is simply an advanced stage of the Aphosphorosis which has been described as Osteomalacia. Botulism is seldom seen in the sheep and goat, but they are susceptible. Botulism is occasionally seen in the ostrich. It occurs fairly frequently in ducks in South Mrica, and there the carcases of dead sheep or lambs are the source of the toxin. It has not, however, been encountered in fowls. These are very resistant to the parausbotulism bovis toxin, and this is the toxin most frequently encountered. Dogs and pigs, and to some extent rats, are resistant to botulinus toxin, but their carcases may nevertheless be sources of toxin. It must not be supposed that the toxin develops in all putrefying carcases, for it has been shown in many experiments that this is not the case. Although the bacillus has a wide distribution it is not ubiquitous. It is carried by certain genera of flies (Pyknosoma), and it can exist as a saprophyte in the alimentary canals of herbivora; unpublished experiments carried out by Scheuber show that this is particularly the case with cattle suffering from osteophagia. The period of incubation may range from a few hours to a maximum of ten days, but it is seldom so long as the latter period. Peracute, acute, subacute, and chronic forms of the disease may be distinguished, and, apart from mdividual susceptibility, the severity of the symptoms depends upon the quantity of toxin ingested. Recovery occurs in exceptional cases only.
812
ABSTRACTS.
The peracute form of the disease in the horse lasts as a rule a few hours only, and the animals either lie extended on their sides without moving and comatose or they retain their consciousness and frequently make movements as if galloping. In other cases affected animals make repeated efforts to rise, but eventually they lie fully extended and comatose. Death in all these cases is not long postponed. In the acute form the period of illness generally extends to about two days. Great muscular weakness is a common symptom observed in these cases, and not infrequently symptoms of colic are seen. There is no loss of consciousness. Cases which last from two days to a week are considered as subacute. Muscular weakness is marked, but animals are not infrequently able to rise after they have gone down. The paralysis of the jaws, tongue, and resophagus may be present in the early stages, but usually appear later and may even set in just before death. In the chronic form of the disease animals move with difficulty, and their gait is uncertain. Sudden collapse not infrequently occurs. Affected mules when they rise do so in the manner of cattle. Recovery is more likely to occur in chronic cases than in acute ones, but the period of convalescence is very prolonged. The secretion of saliva may be slight or very profuse. In animals affected with paralysis of the resophagus there is very pronounced thirst. Appetite may be lost or retained, the passage of freces and urine is normal, and the pulse is accelerated, weak, and of a soft character. In cattle the symptoms presented in the peracute, acute, and chronic forms of the disease run parallel with those seen in horses. In the ostrich the acute form has a period of incubation of from one to four days, and affected birds move their weight from one leg to the other and swing the head from side to side. In the chronic form of the disease death usually occurs about three weeks after the onset of symptoms. Rabbits and guinea-pigs are not affected under natural conditions, but they are susceptible to the intoxication and can be used as test animals as to the presence of the toxin. The symptoms are similar to those seen in the larger animals. Recovery leaves no immunity, but by very careful dosage it is possible to hyperimmunise animals against the toxin. Cases have been known in the field in which bovines have had four attacks of the disease. The relapses are generally less severe. There are no typical lesions of botulism, and therefore diagnosis cannot be made by post-mortem examination alone. So far as is known there is no medicinal treatment that is of the least value, and the solution to the problem presented by the disease lies in prevention. The provision of a sufficiency of phosphorus in the food, generally in the form of bone meal, prevents the development of osteophagia, and, since the bones eaten by animals suffering from this condition form the vehicle for the ingestion of the botulinus toxin, the prevemion of osteophagia also prevents botulism. . Some amount of success appears to have been achieved in America with prophylactic sera, but as two types of bacillus, A and B, are concerned in that country, accidents have occurred in some cases. So far as South Mrica is concerned, serum is not a practicable method of dealing with the disease, on the score of expense. (Zeitschr. f. Infektions, Krankh., parasit. Krankh., u. Hyg. d. Haust., Vol. 81, No.3, July 30,1927, pp. 165-220.)
309
In all the experiments the total amount of vaccine given to the dogs, whatever their size, was 40 c.c. This was divided into two doses of 20 c.c. each, which were given at an interval of 21 to 24 days, and each injection of 20 c.c. was divided and given at two places. Three dogs were tested one month after the second injection and all resisted infection while two controls developed rabies in 15 days. Of eight dogs tested after the lapse of 40 days, three developed the disease in 14,18, and 23 days. Two control dogs became rabid on the 14th and 16th days. Of four dogs tested after two months, one developed the disease on the 12th day. The three controls became rabid on the 11th, 12th, and 13th days. Four dogs tested after three months all failed to become infected. Two controls developed the disease in 19 and 27 days. Four dogs were tested after an interval of six months. One proved infected on the 16th day. The controls developed rabies on the 14th and] 6th day. One dog tested after ten months resisted infection, but a fellow dog which should have been tested had died of gastritis during the 8th month. Two of the dogs from the previous experiment were again tested at 10 months after the second dose of vaccine. One became infected on the 20th day. The three controls became rabid on the 11th, 12th, and 13th days. In view of the severity of the test inoculation, it is held to be a very satisfactory result that 75 per cent. of the vaccinated dogs resisted infectoin, and it is considered that the experiments warrant the view that the method provides a serviceable immunity against natural infection for a year. In the author's opinion the Japanese method, which has had a very wide application in Japan and elsewhere, does not give so strong an immunity. The glycerinised and phenolised vaccines suffer from the disadvantage that they cannot be preserved for more tilan a short time, and this is a matter of considerable importance, particularly in hot countries, where the attenuation of the virus is more rapid. This may perhaps furnish an explanation of some of the variable results obtained. On the other hand, the formolised vaccine, which is dead and freed from soluble toxin by centrifugalisation, is absolutely harmless. Large doses, such as 100 or 150 c.c. can be injected into rabbits at one time without causing any trouble, and among over 100 animals treated before or after infection no single accident which could be attributed to the vaccine has occurred. Experiments have shown that the vaccine retains its immunising power up to four months after preparation. (Receuil de Med. vet., Vol. 103, No. 14, July 30,1927, pp. 288-292.)
BOTULISM IN THE DOMESTICATED ANIMALS. By A. THEILER and E. M. ROBINSON. BOTULISM was originally described as a disease of man which resulted from the ingestion of diseased meat. The cause of the condition was established by van Ermengem, who incriminated the Bacillus botulinus. The principal symptoms in man are those of paralysis, particularly of the cranial nerves. There is generally no gastric or intestinal disturbance, and there is neither fever nor loss of consciousness. There appear to be several types of the Bacillus botulinus. In America three varieites, A, B, and C, have been recognised, but the organism isolated by van Ermengem does not appear to be identical with any of these. In America Type B appears to be the one most frequently encountered. TheA and B Types are only distinguishable by the fact that the
310
ABSTRACTS.
toxin of the one is not neutralised by the anti-toxin of the other. The foragepoisoning of equines in America is attributed to the toxin of Type B. . Type C was first isolated from Lucilia cregar by Bengtson . The symptoms produced by the toxin are identical with those caused by A and B. The organism itself closely resembles these two morphologically, but its cultures present some points of difference. A and B anti-toxins do not neutralise the toxin of type C. Type C is probably the cause of limberneck in poultry, and of the bulbar paralysis of horses and cattle seen in Australia . Lamsiekte in South Africa, which is caused by the ingestion of putrid bones, is probably a form of botulism. Within the last two years a spinal paralysis of equines in South Mrica has been traced to a bacillus of the C Type. Thus it appears that toxins of organisms belonging to Group C are the most common causes of disease of this kind among domesticated animals. These conditions resemble the corresponding diseases in man in that they are afebrile, and that paralysis, particularly of the cranial nerves, is a pronounced symptom. Cases of the disease sometimes run so acute a course that diagnosis is a matter of great difficulty, but in sub-acute cases the symptoms of paralysis are so typical that recognition is easy. The authors give an extensive review of the literature regarding the occurrence of botulism in horses, ruminants, and poultry, and they summarise their views in connection with each. With regard to the occurrence of botulism in horses their review of the literature leads them to the conclusion that a disease identical with that occurringin man occurs in equines. All the varieties of B. botulinus may be concerned in the causation, but the symptoms produced are more or less the same in all cases. Reviewing the work done in America, Australia, and South Mrica, the authors conclude that Types A and B scarcely ever cause botulism in cattle. Type C, the B. parabotulinus of Seddon, may cause enzootics and epizootics of botulism. Botulism in poultry is of rather infrequent occurrence. Fowls are ordinarily refractory, and there must be certain favouring circumstances in cases in which intoxication occurs. There are two groups of organisms which are responsible for the various forms of botulism. The first comprises Types A and B, while the second, which may be called the parabotulinus group, contains the American Type C, Seddon's bacillus, and both the varieties isolated in South Mrica. In a tabular 'ltatement ihe authors set out the important morphological, staining, and cultural characters of these, and in a second table they give the results of cross tests of toxin and anti-toxin. A third table shows the susceptibility of the various species of domesticated and laboratory animals, and gives information, so far as it is available, regarding the minimum lethal dose of toxin or culture. The authors think that too great importance ought not to be paid to some of the differences recorded by different authors. It has, for example, been shewn by Seddon that toxin derived from a pure culture is less toxic than that from an impure culture. The authors think that, taking all the points into consideration,the differences between the Types A and B on the one hand and Type C and the parabotulinus organisms on the other, are so small and so inconstant that the name parabotulinus should be dropped altogether. While the various toxins are capable of causing death even when small quantities are administered, the bacilli themselves when freed from toxin are quite harmless. The toxin is thermolabile and is destroyed by cooking, but exposure to sunlight and desiccation are without effect.
ABSTRACTS.
311
The authors think that the evidence brought forward by American investigators incriminating silage is not quite satisfactory, because it appears to be a very general rule, if not an absolute one, that the bacilli produce toxin only in media which have been prepared from meat. Theiler and Robinson have encountered a case in which the carcase of a rat was responsible for the con veyance of the toxin, and in the United States the freces of fowls, themselves not susceptible, were found to be toxic. Thus, in cases in which vegetable foodstuffs are suspect, such possible causes as these must not be lost sight of or ignored. Occasionally in South Africa asses die from botulism as the result of eating portions of,or the alimentary contents of,cattle that have died and the carcases of which contain the organism. In enzootic and epizootic botulism of cattle-the so-called para botulismwhich is known in South Africa as lamsiekte, in Australia as bulbar paralysis, and as cattle paralysis in Texas, special circumstances playa part in the mass production of the disease. In these cases the cattle eat the remains of dead animals, a deficiency of phosphorus in the soil causing them to seek it in the bones of carcases left on the feeding grounds. The grass or soil deficient in phosphorus varies in its phosphorus content during the year. In the spring the young grass contains sufficient to supply the animals' needs, so that bone eating is not indulged in, but as winter approaches the phosphorus content of the grass decreases, until it may be only a tenth part of what it was in the spring. This leads to the eating of bones, or osteophagia, as it has been called by Theiler. Osteophagia can be prevented by suitable manuring and by the addition of phosphates to the drinking water. The administration of phsophorus in this way causes the symptoms to disappear. Bone meal is a very suitable addition to the diet. In Australia and Tasmania similar conditions exist, and there dead rabbits are not infrequently the source of toxin. It is noteworthy that in all countries in which botulism of cattle is observed there also occurs under the same conditions another disease. This in Mrica is called Stywesiekte; in· Australia, Cripples; and in Texas, Creepers. This is simply an advanced stage of the Aphosphorosis which has been described as Osteomalacia. Botulism is seldom seen in the sheep and goat, but they are susceptible. Botulism is occasionally seen in the ostrich. It occurs fairly frequently in ducks in South Mrica, and there the carcases of dead sheep or lambs are the source of the toxin. It has not, however, been encountered in fowls. These are very resistant to the parausbotulism bovis toxin, and this is the toxin most frequently encountered. Dogs and pigs, and to some extent rats, are resistant to botulinus toxin, but their carcases may nevertheless be sources of toxin. It must not be supposed that the toxin develops in all putrefying carcases, for it has been shown in many experiments that this is not the case. Although the bacillus has a wide distribution it is not ubiquitous. It is carried by certain genera of flies (Pyknosoma), and it can exist as a saprophyte in the alimentary canals of herbivora; unpublished experiments carried out by Scheuber show that this is particularly the case with cattle suffering from osteophagia. The period of incubation may range from a few hours to a maximum of ten days, but it is seldom so long as the latter period. Peracute, acute, subacute, and chronic forms of the disease may be distinguished, and, apart from mdividual susceptibility, the severity of the symptoms depends upon the quantity of toxin ingested. Recovery occurs in exceptional cases only.
812
ABSTRACTS.
The peracute form of the disease in the horse lasts as a rule a few hours only, and the animals either lie extended on their sides without moving and comatose or they retain their consciousness and frequently make movements as if galloping. In other cases affected animals make repeated efforts to rise, but eventually they lie fully extended and comatose. Death in all these cases is not long postponed. In the acute form the period of illness generally extends to about two days. Great muscular weakness is a common symptom observed in these cases, and not infrequently symptoms of colic are seen. There is no loss of consciousness. Cases which last from two days to a week are considered as subacute. Muscular weakness is marked, but animals are not infrequently able to rise after they have gone down. The paralysis of the jaws, tongue, and resophagus may be present in the early stages, but usually appear later and may even set in just before death. In the chronic form of the disease animals move with difficulty, and their gait is uncertain. Sudden collapse not infrequently occurs. Affected mules when they rise do so in the manner of cattle. Recovery is more likely to occur in chronic cases than in acute ones, but the period of convalescence is very prolonged. The secretion of saliva may be slight or very profuse. In animals affected with paralysis of the resophagus there is very pronounced thirst. Appetite may be lost or retained, the passage of freces and urine is normal, and the pulse is accelerated, weak, and of a soft character. In cattle the symptoms presented in the peracute, acute, and chronic forms of the disease run parallel with those seen in horses. In the ostrich the acute form has a period of incubation of from one to four days, and affected birds move their weight from one leg to the other and swing the head from side to side. In the chronic form of the disease death usually occurs about three weeks after the onset of symptoms. Rabbits and guinea-pigs are not affected under natural conditions, but they are susceptible to the intoxication and can be used as test animals as to the presence of the toxin. The symptoms are similar to those seen in the larger animals. Recovery leaves no immunity, but by very careful dosage it is possible to hyperimmunise animals against the toxin. Cases have been known in the field in which bovines have had four attacks of the disease. The relapses are generally less severe. There are no typical lesions of botulism, and therefore diagnosis cannot be made by post-mortem examination alone. So far as is known there is no medicinal treatment that is of the least value, and the solution to the problem presented by the disease lies in prevention. The provision of a sufficiency of phosphorus in the food, generally in the form of bone meal, prevents the development of osteophagia, and, since the bones eaten by animals suffering from this condition form the vehicle for the ingestion of the botulinus toxin, the prevemion of osteophagia also prevents botulism. . Some amount of success appears to have been achieved in America with prophylactic sera, but as two types of bacillus, A and B, are concerned in that country, accidents have occurred in some cases. So far as South Mrica is concerned, serum is not a practicable method of dealing with the disease, on the score of expense. (Zeitschr. f. Infektions, Krankh., parasit. Krankh., u. Hyg. d. Haust., Vol. 81, No.3, July 30,1927, pp. 165-220.)