14 horses found dead, another 34 seized from Oregon property covered in unsanitary mud The mud went chest-high on the horses in some places, according to reports.

Authorities have found 14 dead horses on a property in Oregon and seized another 34 after spending months trying to work with the owners to improve conditions for the animals.

On Wednesday, the Linn County Sheriff's Office seized the horses after serving a search warrant at the home of Carol Davidson, 69, and Edward Davidson, 66, on Berlin Road just outside Lebanon, Oregon, according to a press release.

The Linn County Sheriff’s Office Animal Control was first alerted to the property in December after it received complaints of horses standing in muddy conditions, and has been trying to work with the property owners ever since, authorities said. At that time, the state of the horses' well being was not a concern, Linn County Sheriff's Lt. Michelle Duncan told ABC Portland affiliate KATU.

"Some animal owners, either they’re not capable or they get overwhelmed with what they’re taking care of, so we always try to work with the owners," Duncan said.

But, those efforts were unsuccessful. In January, Linn County Sheriff's Deputy Corey Putney observed several horses still standing in muddy conditions as well as a dead horses that had not been disposed of properly when he drove by the property, authorities said. Putney also noticed that the horses were starting to show signs of poor health and had lost an unhealthy amount of weight since he saw them the month before, according to the release.

At that time, Putney cited Carol Davidson for placing an offensive substance near a waterway, highway or property, and failure to license dogs, but continued to work with the property owner to improve the conditions the horses were kept in, authorities said. Carol Davidson was "cooperative" and "made some changes to address the conditions," but those changes were "minimal and not sustained," according to the release.

Putney checked on the horses periodically in the months that followed, but the sheriff's office continued to receive several calls regarding the property, and earlier this month, authorities received another report of dead horses on the property, authorities said.

When deputies responded, they found some of the living horses standing in "septic" mud and water full of urine and feces, authorities said. The mud was up to the horses chests in some places, and another 13 horses were found dead, KATU reported.

Putney also found that the health of the still-living horses was deteriorating, and took action to seize them, authorities said. They were "skinny," with their ribs and hip bones showing, and did not have access to clean drinking water or food, according to the release.

Sheep and several dogs that were found on the property appeared to be in "adequate health" and were not seized, authorities said. The sheep were kept in a separate area from the horses, according to the release.

Carol Davidson suffered a medical emergency while deputies were serving the search warrant and had to be transported to the hospital, authorities said. Criminal animal neglect charges are pending for both Carol Davidson and Edward Davidson, according to the release. Because of the number of horses, the charges qualify for a Class C felony, Duncan said.

ABC News could not immediately reach the Davidsons for comment. It is unclear if they have retained an attorney.

The horses were transported to the facility for Sound Equine Options, a nonprofit that rescues horses, to be evaluated and receive veterinary care, authorities said. They will then be fostered out to other locations.