Two last horses are recovering at Five Brooks Ranch from an outbreak of equine distemper, a bacterial infection often called “strangles” because it can swell lymph nodes in the throat to the point of suffocation. Over the past month, the ranch, located on parkland in the Olema Valley, fielded over 50 phone calls from concerned horse riders and owners. The highly contagious mumps-like disease affected six of owner Andrew Loose’s 35 horses. “It looks ugly, but it’s not a broken leg,” he said. A Morgan named Dixie first came down ill in early May. Mr. Loose heard it coughing and noticed gummy mucus coming from the horse’s nostrils. “That’s when the red light when on,” he said. He quarantined Dixie, along with five others that began showing similar symptoms, in single-stall stables where they would have access to their own water supply and attract fewer flies, which often spread the disease. Mr. Loose opted to give the animals a “natural healing process” in a comfortable, clean environment. A few horses suffered from burst lymph nodes caused by swollen glands and were treated with antiseptics; four recovered after a few weeks of isolation and monitoring, and two are in the final stages of recovery. Mr. Loose, whose operation serves over 5,500 riders a year, said now that the strangles outbreak is contained, he’s focused on vaccinating for the West Nile virus.