An emergency vaccination clinic for horses is set to open as more cases of eastern equine encephalitis turn up in Massachusetts.
The Massachusetts Society for the Protection of Cruelty to Animals is setting up the clinic at Nevins Farm in Methuen, with vaccinations scheduled to begin on Tuesday for any horses in the Merrimack Valley region whose owners request them.
State officials say four humans and seven horses have tested positive for EEE so far this year.
The MSPCA says the vaccine is highly effective. Horses that have been vaccinated in the past but more than six months ago can receive a booster shot.
The farm is home to horses that are awaiting adoption. Those horses are vaccinated upon intake.
EEE is rare and can cause brain infections.