Northwest Trek Wildlife Park’s three gray wolves were given a clean bill of health at their triennial exams last week.   “Tala weighs 39.1 kilograms or about 86 pounds,” said head veterinarian, Dr. Allison Case.   On average, gray wolves weigh 75 to 110 pounds. That meant 7-year-old Tala, a gray wolf with a white coat, was already on the right track to a healthy doctor’s appointment.   Dr. Case made sure Tala’s exam was as comfortable as possible. She put down a warm blanket, gave her eye drops and sprayed her tongue with water.   “It’s all about the …