FALL RIVER — The owner of Westport Tenant Farm pleaded not guilty Wednesday to a host of animal cruelty charges, as his lawyer expressed confidence he will be cleared of any wrongdoing.

Richard Medeiros, 83, is among more than two dozen people facing criminal charges after an investigation by the state attorney general’s office into what authorities describe as the largest animal cruelty case in New England history.

Medeiros, who owns the secluded 70-acre farm, rented plots to 26 tenants who are accused of mistreating some 1,400 animals, including dogs, goats, horses, and cows. The animals were living in squalid, overcrowded conditions, often without enough food or water, the authorities said. The alleged abuse came to light last summer when two starving Rottweilers broke free from a squalid enclosure and attacked more than a dozen goats on a neighboring plot.

Medeiros has said he was unaware of the abuse, and his lawyer, Karen Augeri Benson, said he “absolutely denies’’ the charges.

Augeri Benson said she is “confident he will be exonerated’’ after Medeiros pleaded not guilty to 21 charges in Bristol County Superior Court. He was released on personal recognizance.

Augeri Benson said Medeiros has not been doing well and that the charges have “been stressful for him.’’ Medeiros, who walked slowly with a cane, declined to comment outside the courthouse.

In court records, prosecutors depict Medeiros as an active participant in widespread abuse at the farm, saying he either voluntarily buried the dead animals or was paid to by tenants.

Medeiros “knowingly participated . . . by closely monitoring, observing, and advising these tenants on their care of animals and disposing of the carcasses of animals that died as a result of their treatment,’’ prosecutors wrote.

Photographs show Medeiros transporting animals for burial, prosecutors said. Additional evidence, which prosecutors did not detail, places him at the property on a daily basis, talking with tenants about the animals and observing their living conditions, the records state.

When authorities were summoned to the farm last summer, they found some animals housed with carcasses and others living in such deep manure that their hooves had rotted off. They also suffered from painful eye, intestinal, and skin ailments.

Many of the animals were euthanized, and others were sent to recovery farms with severe injuries. Rescue groups spent more than $1.4 million to rehabilitate and relocate the animals.

Along with Medeiros, four tenants — Rhonda Gadomski, Antonio Dias, Jose Aguiar, and Jeffrey Brilhante — were arraigned Wednesday on multiple charges of animal cruelty. They pleaded not guilty and were released on personal recognizance.

The farm has a history of abuse allegations. In 2010, several tenants were charged with animal cruelty, and the property owners, including Medeiros, were summonsed to court. Lax oversight allowed the poor conditions to return, the Globe reported last year.

Barbara Pontolio, who volunteered with the American Society for the Prevention of Cruelty to Animals and saw the conditions at the farm firsthand, said she found it difficult to see the tenants in person and hear their “not guilty’’ pleas.

“They treated those animals horribly,’’ she said. “It breaks my heart.’’

When she arrived at the farm, two weeks after the authorities, there was broken glass, trash, and animal corpses, she recalled.

Constance Gee, a resident who attended the arraignment, said the alleged abuse was part of a “culture of cruelty’’ to animals in the community .

“This is sheer evil,’’ said “It’s stomach-churning.’’

Jan Ransom can be reached at jan.ransom@globe.com. Follow her on Twitter at @Jan_Ransom.