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This article was published in 1948
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Swine Dysentery
TREATMENT WITH NEOKHARSIVAN, SULPHAGUANIDINE, AND THE APPARENT PROTECTIVE VALUE OF VITAMIN A.
J. E. CANTELLO, B.V.Se., Inspector of Stock, Broken Hill.
Neokharsivan, an arsenical preparation manufactured by Burroughs Wellcome for use in treatment of human syphillis, gave remarkable results in trial treatments of pigs of all ages affected with swine dysentery during the period 1946-1948, when outbreaks of this disease were occurring in a piggery establishment at Broken Hill. Of 867 pigs treated, 794 recovered after intravenous or intramuscular administration of a 20 per cent. solution of Neokharsivan. During the outbreaks, which were of an acute nature, trial treatments with Sulpha G. a Nicholas product of Sulphaguanidine, were carried out with equal success. Of 90 pigs treated with Sulpha G. 82 recovered. It was found also that the supplementary feeding of Vitamin A in addition to the usual ration of cooked offal, hotel food waste and crushed wheat, resulted in an apparently high resistance against infection with swine dysentery.
Following is an account of the outbreaks and the treatments carried out with Neokharsivan and Sulpha G, and trial feeding of Vitamin A supplements in the form of green fresh cut lucerne or Vetemul A, a Nicholas product.
An acute outbreak of swine dysentery among 1000 pigs was investigated at a Broken Hill piggery in January, 1946. Seventy-five pigs died during the first two weeks of the outbreak. Post-mortem examination revealed acute gastritis, colitis, typhlitis and varying degrees of enteritis of the small intestine. Symptoms of anorexia, hyperexia and mucoid diarrhoea or dysentery were constant in all cases. Diagnosis of swine dysentery was confirmed by the Glenfield Veterinary Research Station after specimens from the outbreak were examined in the laboratory.
The origin of the outbreak may have been due to the introduction of store pigs during October, 1945. No dysentery was observed in these pigs but there is a strong possibility of a carrier being present, as on another piggery, in Broken Hill, store pigs from the same origin also were introduced with resultant swine dysentery in contact pigs within three weeks.
First pigs to be affected in the outbreak were those from six to twelve weeks old. Within three weeks, pigs of all ages were affected and were dying with acute dysentery. Isolation of infected pigs and strict hygiene apparently had no effect in checking the disease, which rapidly spread through the piggery. The establishment is well conducted, with good housing and feeding methods. Offal and food refuse always is well cooked in large digesters and crushed wheat is given in self-feeders. Wessex Saddleback and Large White pigs are favoured, and all pigs, apart from stud boars and brood sows, are bred on the premises for slaughter.
Neokharsivan Treatment
It was suggested by the Division of Animal Industry (Dept. Agric., Sydney,) that treatment with Neokharsivan (Burroughs Wellcome) be carried out experimentally, as Russian workers claimed that Swine Dysentery is caused by a spirochaete. It was recommended that Neokharsivan 20 per cent, solution be administered intravenously, using the anterior vena cava in small pigs and the auricular vein in large pigs. Intravenous injection was used for one hundred cases, but it was found that this involved considerable time and that the technique was difficult. Intramuscular injections into the ham were adopted as the standard method after it was found that no lameness or damage to the ham resulted. Neokharsivan was used in a 20 per cent. solution in the following dose rate:—
| Suckers | 0.225 gm. |
| Small Weaners | 0.300 gm. |
| Large Weaners | 0.450 gm. |
| Porkers | 0.675 gm. |
| Adult Pigs | 0.900 gm. |
The results of Neokharsivan treatment were most satisfactory and 90 per cent. of all treated cases recovered within twenty-four to forty- eight hours. Ten per cent. of cases required a second injection after seven days. The outbreak ceased in April, 1946, and no further cases of swine dysentery were observed until September, 1947, when pigs from six to fourteen weeks old became affected. Dysentery cases continued mainly in this age group until April, 1948, and suddenly ceased with the advent of cold weather. Records were kept of the treatment of pigs with Neokharsivan during the outbreaks and it was found that 794 cases recovered after treatment.
Sulphaguanidine Treatment
Trials were conducted with Sulpha G. a Nicholas product of Sulphaguanidine, in the treatment of ninety pigs of all ages affected with swine dysentery, and very good results were obtained after three days' treatment.
Eighty-two pigs recovered of the ninety pigs treated.
For best results twice daily drenching is necessary and involves a considerable amount of labour when there are large numbers of affected pigs to be treated. It was found that the slower action of Sulpha G as compared with Neokharsivan is a disadvantage when pigs are acutely affected. Dose rate of Sulpha G used is as follows:—
Initial dose: 7 grammes for the first 100 lbs., plus 5 grammes for each additional 100 lb. weight, followed by 5 grammes for each 100 lbs. in two or three divided doses daily for 4 to 6 days, or until the diarrhoea begins to subside.
Vitamin A Supplements to Offal, Hotel Food Waste and Crushed Wheat
Vetemul A, a Nicholas product containing 5,000 international units of Vitamin A per gramme, was administered first to breeding sows in 1946 at the piggery under discussion, because Vitamin A deficiency was considered to be the cause of small and backward litters. An average of eight suckers weaned per sow per year was obtained at the piggery prior to the administration of Vetemul A supplement to the sow's diet. Now the average number of suckers weaned per sow per year is twelve, despite the ravages of swine dysentery during the last two years. It became evident also that the incidence of swine dysentery became very low in suckers after Vetemul A was given. Whether or not the Vetemul A produced this result is debatable.
However, trials were conducted during the latter part of 1947 and the early part of 1948 with the feeding of Vetemul A or green fresh-cut lucerne and it became evident that those pigs which received the supplement were more robust and showed a very high resistance to swine dysentery. Pigs In the 1947-48 outbreak from 6-14 weeks old, which were the most susceptible to the disease, showed this high resistance throughout the outbreak when they received Vetemul A or green lucerne. Details of the pen trials are as follows:—
Pen 1. Four sows with thirty-five suckers farrowed a few days previously were given one cwt. of fresh green lucerne per week for sixteen weeks as a supplement to swill and crushed wheat. All pigs were robust and no cases of dysentery occurred, although this pen adjoined two acutely infected pens where dysentery cases continually were occurring during the period of the trial. No special disinfection precau- tions were taken to prevent possible infection from adjoining pens. The fly-infested feeding house also adjoined Pen No. 1.
Pen 2. Four sows with twenty-three suckers, from birth were given Vetemul A in the drinking water. All pigs were robust and no cases of dysentery occurred, although nearby pens were affected.
Pen 3. Five sows with forty-three suckers two weeks old were given Vetemul A in their drinking water as a supplement to wheat and 10 per cent. meat meal in self feeders. These pigs were placed in a pen which had been used a few weeks previously for cases treated with Neokharsivan. It was expected that in this pen there would be a greater number of dysentery cases, but during the sixteen week trial only three cases of dysentery occurred. All were treated with Neokharsivan, but one died—this pig was a runt and had pneumonic lesions and ascaridiasis.
Pen 4. One hundred and fifty weaners which were healthy and running in this large pen on a rocky slope, were given their swill and wheat ration as usual but no Vitamin A supplement. During February thirty-eight cases of dysentery occurred in this pen and there were eight deaths after Neokharsivan treatment.
Pen 5. Fifty weaners of various ages which had been in contact with other weaners infected with dysentery were given Vetemul A supplement and no further cases of dysentery were experienced. Vetemul A contains 55 per cent. edible fat and 5,000 international units of Vitamin A per gramme.
D.D.T. Control of Flies.
Spraying with Rucide was adopted as a routine control measure in January, 1948, as it was noticed that infection in several pens could have occurred only by fly transmission. Also, in the beginning of each outbreak flies were particularly numerous and the weather was warm. Wherever flies were noticed to be numerous, such as round the boiler house and on the garbage dump, spraying was carried out with great reduction in the fly population.
Aetiology of Swine Dysentery.
At the time of the preparation of this article (30/4/48) no literature has been received as to the proven exact cause of swine dysentery. Some workers claim that it is due to a protozoan parasite (Balantidium coli), whilst others claim that it is due to a spirochaete.
It was noticed in the Broken Hill outbreaks that Vitamin A deficiency played an important part in predisposition to infection by swine dyrentery. Apparently it had a high protective value in pigs in the most susceptible age group, from two to four months old.
It is thought personally that there is too close a similarity between Salmonellosis and Swine Dysentery for the possibility of a Salmonella causative infection to be overlooked. Salmonellosis apparently occurs in the same age group of pigs, has certain similar features in the enteric form, and also is perpetuated, it is thought, by carriers. Swine dysentery well could be an enteric form of Salmonellosis which occurs when resistance is lowered by nutritional deficiency such as avitaminosis A. Virulence is gained by animal passage to form epidemics. Transmission probably is in faecal matter which is carried mechanically by flies,etc., to other pens of pigs which are not in direct contact with infected pigs.
Summary.
Neokharsivan 20 per cent. solution has been found to be a rapidly efficient treatment for Swine Dysentery in pigs of all ages, with an approximately 90 per cent. curative value. Sulphaguanidine in the form of Sulpha G (Nicholas) also has been found to be a very efficient treatment with equal curative value to Neokharsivan, but slower in action; taking usually three days to stop dysentery as against one to two days with Neokharsivan. Vitamin A supplements to swill and wheat feeding were found to have a highly protective value against Swine Dysentery.
It is considered that flies play an important part in the mechanical transmission of the disease, which is thought to bear a remarkably close resemblance to enteric Salmonellosis; due to the fact that the disease occurs in a similar age group of pigs, is transmitted by carriers, and also is reported to respond to treatment with Sulphaguanidine.