It was only through asking when hay would begin to be fed that I discovered the truth about worm counts. I had commented that the grazing was becoming sparse, and that Brena was a little more interested than usual in food therefore I'd been giving her extra. At that point the vet, who also keeps a horse at the barn, passed on the news. A number of horses were discoved through testing samples of droppings to have really quite high worm counts.
The barn staff, who are paid to remove droppings, have been simply harrowing the fields. Horses come to the barn, are moved between fields, and all the time worm larvae are spread to new hosts. Brena interited a dung-strewn field used to winter a group of New Forest ponies. Now I have an agreement with the manager that, after the next worming, all of the droppings will be removed. I said that I'd clean Brena's field after work. However the impact of lazy pasture management is clear so the job that I pay for monthly will be done properly. Worming and cleaning will take place over the next few days.