Five cases of vesicular disease in pigs in England, which initially raised concerns of a possible foot-and-mouth outbreak, have been confirmed as Seneca Valley virus. Last week the United Kingdom Chief Veterinary Officer verified that the suspected cases from June through September 2022 were SVV positive. The confirmation comes following an extensive investigation by the Animal Plant Health Agency.
According to the Swine Health Information Center, pathogenicity in swine remains unclear. Outbreaks of idiopathic vesicular disease have been linked to SVV in the absence of other identified etiologic agents and also during concurrent infection with porcine circovirus and porcine enterovirus. In contrast, the virus has also been identified in healthy pigs, and experimental infection has failed to produce clinical signs thus far.
Swine SVV infection has occurred across the United States and Canada, and idiopathic vesicular disease has been reported globally from Europe to South America to Australia and New Zealand. Clinical signs of SVV are often indistinguishable from those of swine vesicular disease, vesicular stomatitis virus, vesicular exanthema of swine virus and FMD.
In piglets, SVV can cause an acute increase in mortality in litters less than seven days of age, as well as diarrhea, lethargy and fever. The morbidity and mortality estimates are 30‐70% for a short time period and the clinical signs usually resolve around seven to10 days. For breeding /finishing pigs, vesicles (intact or ruptured) can appear on the snout, oral mucosa, on the feet and around the coronary band, and may be the only clinical sign. Acute lameness, lethargy, decreased appetite as well as fevers up to 105 degrees Fahrenheit have also been reported.
Since the clinical signs resemble notifiable vesicular diseases, in particular FMD, the Department for Environment, Food and Rural Affairs is therefore calling on UK pork producers and veterinarians to continue to promptly report any clinical signs of vesicular disease in pigs so that APHA can carry out an official investigation.
Pork producers should continue to implement high biosecurity standards such as
- Conducting regular reviews of their biosecurity measures and address any weaknesses, minimizing movements of vehicles, people or equipment onto pig sites.
- Controlling rodents, flies and as far as possible, wild birds.
- Isolating incoming pigs away from the resident herd for at least one month.
- Sourcing feed or ingredients from reputable feed companies and never feeding kitchen or catering waste or meat to pigs.
- Following the National Pig Association import protocol if importing live pigs.
To minimize the risk of disease introduction, Defra also recommends pork producers inspect their pigs at least once a day, staying vigilant for lameness and vesicular (blister) foot or snout/mouth lesions.
The UK Chief Veterinary Officer also reminds pork producers and the public that it is illegal to feed pigs meat or meat products, and kitchen or catering waste. Doing so endangers the health of the pigs and risks introducing exotic diseases, such as FMD or African swine fever, into the country.