TACOMA — The case of five emaciated horses found abandoned in a Pierce County forest has prompted the Humane Society of the United States to offer a $2,500 reward for information leading to arrests and convictions.

In a statement, the animal welfare organization says it appears the animals were afraid to leave the area where they had been dropped off, and could have been stranded as long as two weeks.

It said the horses discovered Nov. 12 on a logging road near Elbe were cold, hurt and “horribly malnourished.”

The HSUS says two of the horses are about 15 years old; another is suspected to be pregnant and a fifth was euthanized.

The group’s Washington state director, Dan Paul, says struggling horse owners can turn to rescue groups, online adoption programs or even humane euthanasia.

Abandoning animals in Washington is a misdemeanor punishable by a maximum 90 days in jail and $1,000 fine.

Pierce County Animal Control is investigating.