In this month column of the National Hog Farmer, Dr. Albert Rovira from the University of Minnesota is reviewing the cases of intoxication due to ionophores, these antibiotics given through the feed to control bacterial and coccidial infections in swine.Clinical signs are non-specific. Indeed, pigs become weak and stop eating but do not have a fever. In more severe cases, neurological signs can be noted. However, histological lesions are striking with a dramatic change of the muscle structure as is shown in Figure 1 below.
There are three main causes of ionophore intoxication in swine:
Dosage error in the diet: the optimal concentration is very small, between 15 and 30 parts per milliom.
Mixing ionophore and tiamulin: Tiamulin prevents the ionophore from being excreted by the body, leading to toxic blood levels.
Inclusion of ionophores designed for another species. Usually, the levels are incorporated at a concentration higher than the toxic level.
In conclusion although cases of ionophore intoxication are rare in swine, it may become more prevalent starting in 2017, with the approval of the only swine ionophore as a growth promotant.
This past month, a team of swine pathologists including Dr. Albert Rovira from the University of Minnesota identified, thanks to funds from Swine Health Information Center’s Support for Diagnostic Fees program, a new swine virus called porcine sapelovirus.
This virus is thought to induce atypical neurological signs in pigs and has previously been described in Korea. Videos of the clinical presentation can be been here.
Research is still on-going to prove Koch’s postulate and declare causality between the presence of the virus and the clinical presentation but it is a step forward in the identification and understanding of swine pathogens.
One flu, many colors: that is the title of the latest article published in the National Hog Farmer by two faculty members from the University of Minnesota, Drs. Culhane and Rovira. If it is common to talk about one influenza especially in the One Health initiative which reminds us that human and animal health are intricately related, the authors also emphasize that there are “many variants of influenza A viruses [which] paint a complicated picture, sometimes with colors too numerous to grasp with quick glances.”
Because influenza is common to swine, poultry, and human, there are many differences among the strains, enhanced by the variations found between and within geographic locations. This is why our experts recommend to characterize the virus, and go one step further than the one test common to all influenza A.
As they put it themselves, “Influenza A viruses are fascinating, challenging and dynamic” and it is important to determine their colors.
Dr. Peter Davies is finishing up his sabbatical year, spent in the Presidential Advisory Council on Combating Antibiotic-Resistant Bacteria and is talking about European regulations on antimicrobials in the National Hog Farmer.