By Dr Tom Spencer on behalf of the Pig Veterinary Society
Acute deaths in growers of 35 to 95kg live mass, but usually towards the heavier side, do occur and are very costly to the farmer. The farmers usually term these deaths “haemorrhagic bowel syndrome” due to the large quantities of clotted and fresh blood in the ileum.One of the forms of Lawsonia intracellulare (proliferative haemorrhagic enteropathy) is presumed to be the cause. Other pathogens can be involved such as Ecoli, clostrdium spp and Brachyspira spp, physical problems of torsion or injuries have been known to cause similar looking intestines.
Often preventative treatment for the remaining pigs offers varying degrees of success. Thus the question remains whether L intracellular is the only or main causative organism. What other organisms are playing a role and how?
June is seen as the month to commence collecting samples for a survey on all possible farms with respect to “bloody scours”, PIA, “haemorrhagic bowel syndrome” and Lawsonia acute deaths. The PVS discussed this at our last meeting and said that it was a problem on farms and control is variable. The complex has been discussed, articled and photographed in Porcus previously, so I will not discuss the pathogenesis. In fact, the development of the disease is very complex and I do not believe it is totally understood.
What makes a perfectly healthy pig suddenly have a massive haemorrhage into the ileum? This sudden loss of blood is so acute, so extensive, that the blood pressure probably drops to critical levels and death ensues. For the lucky pig that survives, it takes a massive drop in growth rate, the pig becomes a poor doer and loses the farmer money. (Not that there is much profit at present.)
The trial wishes to investigate the pathogens found in the ileum in cases of acute haemorrhagic grower deaths. The treatment instituted by the consulting veterinarian will be monitored and the morbidity, mortality and response to treatment will be determined.
The investigation should also result in the development of an objective answer to the pathogens involved in the syndrome in South Africa.
L intracellulare is not the only cause in acute haemorrhagic grower death syndrome. Other pathogens or causes may be involved and therefor the treatment needs to be more tailor-made to the pathogens involved.
This article in Porcus serves to inform the pig farming community about the work that is envisaged and what we wish to attain through the effort. The consultant veterinarians visiting piggeries will inform clients of the trial in more detail.
The farmers will be asked to co-operate so a more specific diagnosis can be made on their farms as well as allowing the grouped data to be used to try and answer some of the questions posed by this complex. Ultimately the results and findings will be combined and published.
At the time of an outbreak the veterinarian will either go to the farm or arrange to receive the necessary samples needed and forward them to the appropriate personnel at the Veterinary Faculty, Onderstepoort.
The samples required are:
- Three pieces of intestine: 1 cms ring of intestine, from the recently died pig, one 30 cms intestine proximal to the ileo-caecal valve, one mid small intestine and the other 30 cms distal to the stomach. These are to be placed in three separate 10% buffered formalin bottles and appropriately marked.
- A 6 cm long piece of ileum, next to the histological sample, tied off at both ends, placed in a plastic packet, marked and chilled on ice.
- If there are other lesions appropriate samples should be collected and submitted.
The veterinarian will complete the form at the time of the sample taking, including treatment suggested. The farm shall be re-visited one month later to assess the response.
The collection of samples will take place as from June 2003 and be completed once 50 samples have been successfully processed. The incidence of the syndrome is usually more prevalent in Spring so there may be a couple of months of samples being processed.
The results of the trial are to be recorded and collated by Dr Spencer. Initial results specific to each farm will be returned to the consulting veterinarian as soon as they are available.
The farmer must agree to offer his herd as a trial sample and must pay all laboratory costs involved. The bacteriology costs will be R80 plus VAT = R91.20 per sample. The PVS will cover any incidental costs that may arise. The extra traveling to the farm for sample collection purposes will be carried by the consulting veterinarians as part of their financial contribution to the survey.
The samples from distant locations will need to be couriered to Onderstepoort, these costs will be borne by PVS.
Thus, if there are acute bloody scour deaths among your pigs, please contact your consulting veterinarian and together we may find out what the cause is. It may be similar to many other farms, yet it may be unique to you. I am not sure whether to wish you and your pigs good health (in which case we have no samples), or that there may be sufficient problems so we can resolve the problem.