Portland Press Herald -- Akari's career as a Portland police horse has been cut short just as it started. The 17-year-old German riding horse suffers from arthritis in its back, rendering it unridable. The condition became apparent only when the horse-patrol season started this spring and Akari was being ridden five days a week, six hours a day. "When one of the officers was attempting to mount, (Akari) would either stagger or, on a couple occasions, had somewhat dropped his front portion to the ground," said Lt. Ted Ross. When police first realized something was wrong, they were told the horse probably suffered from narcolepsy, which can cause a person or animal to suddenly fall asleep. The city had Akari taken by trailer to Tufts Veterinary Hospital in Massachusetts, the preeminent diagnostic facility for animals in New England. Doctors concluded that Akari suffers from arthritis. Akari first arrived on Portland's streets last fall, joining its partner, Kookaburra. Akari replaced 16-year veteran Spree, who retired at the age of 28. The horses are popular with shoppers, tourists and children in the Old Port. They also are useful for enforcement when officers need to get through heavy traffic or break up an unruly crowd. The Portland Police Department boards the horses and cares for them, but relies on donations to acquire them. The $ 3,000 cost of acquiring Akari for duty was covered by Alan Labos, owner of Akari Day Spa in Portland. "He's a beautiful horse. My whole staff has become attached to him," Labos said. He said he is willing to help the city obtain another mount. The city has been trying to increase its horse patrol to three mounted units, and this month began trying out another horse. If that horse can handle unruly crowds and adoring children, it will replace Akari. Ross said the city will give the horse an exhaustive physical if it passes the temperament test. The city obtained Akari from a private owner in Monmouth, who said the horse had not been ridden often. "We're in the process of talking to the prior owner," Ross said. "Right now they have voiced they were unaware of this problem." The city tried out Akari last fall and then rode it occasionally and observed it during the winter. After determining that Akari would work well as a police horse, the city had it checked out by a veterinarian. The checkup revealed no problems. The condition became apparent only after extensive riding, Ross said. The city did not have insurance on the horse. Police are trying to find Akari a home. The arthritis is not fatal and is painful only when the horse is being ridden regularly. Doctors say the horse should not be ridden any more, to avoid aggravating the condition. Anyone willing to adopt Akari should contact Ross at the Portland Police Department.