As our diagnostic capabilities continue to improve, so does our knowledge of the viruses and bacteria that are affecting our pigs. One virus we are quickly learning more and more about is porcine sapovirus.
Clinical Picture
Sapovirus causes a gastroenteritis with the main clinical sign being diarrhea, and similar to other diarrhea causing pathogens, it leads to an increase in fallout pigs. The scour ranges in appearance but it is most frequently seen as a pasty yellow to grey stool, very similar to a coccidia scour. Sapovirus appears to only affect young pigs, having been diagnosed in pigs that are a few days old in the farrowing crates all the way up to a few weeks placed in the nursery. Co-infections with rotavirus can be found frequently and unsurprisingly increase the severity of the clinical disease.
Diagnosing the Issue
Finding the virus can be done via PCR on fecal samples or rectal swabs and histological lesions like villus blunting can be seen on tissues. Once the virus is found, it is important to do further characterization with whole genome sequencing or genotyping to see which virus is affecting your herd and to better match a potential vaccine to give you the best protection.
Another important part of determining if the virus is creating an issue in your herd is to rule out or correct other issues that could be creating a similar issue. Ruling out and/or making adjustments for coccidia and rotavirus control will help to not only improve overall pig quality but also help to determine if sapovirus is playing a major role in your scour issue.
Control and Treatment
Unfortunately, since this is a virus we are dealing with, there is no miracle drug to cure it if your pigs are being clinically affected. Like most scour issues, We have found that nutritional support through electrolytes in the water and gruel feeding the pigs can improve the performance of your pigs as they get through the course of the disease.
To help control over the virus, the best option we have found is vaccinating sows prefarrow. Our clinic has several instances of vaccinating a sow herd prefarrow creating a very measurable benefit in pig quality during lactation and post-weaning through decreased PWM, decreased treatments, and increased wean weights. Other types of scour control like feedback to sows prefarrow has proven to be ineffective at controlling the virus.
At this point, we do not know much about the transmission of the virus and how it is being introduced to herds. We have recently diagnosed sapovirus in several herds that have been closed and internally multiplying for upwards of 4 years. This has posed several questions going forward on whether there is potential for zoonotic transmission occurring or if the virus has become more severe in recent years sparking further investigation into it.
