The prosecution rested and the defense began its case Thursday in the animal cruelty trial of a man whose carriage horse collapsed in Hell's Kitchen nearly three years ago.

Video of a carriage horse named Ryder on the ground at 45th Street and Ninth Avenue on Aug. 10, 2022, went viral.

The horse's handler, 56-year-old Ian McKeever, has pleaded not guilty to overdriving, torturing and injuring animals, and failure to provide proper sustenance, a misdemeanor.

Vet testifies Ryder "was pushed beyond his limit"

The Manhattan district attorney's office alleges Ryder the horse collapsed after working a full day in 84-degree weather and that McKeever repeatedly tried to force the animal to stand, never offering water and ignoring signs he was in distress.

A forensic veterinarian who examined Ryder nearly two months after the fall was called as a witness by the prosecution and testified the horse "never should have been working on that day."

Ryder retired to an upstate farm, but was euthanized in October of that year.

A necropsy was done. The veterinarian said cancer was found in multiple organs and the final diagnosis was T-cell leukemia.

The effects of the leukemia likely were a contributing factor in the animal's collapse, the vet testified, but not the sole cause, adding Ryder not having enough fat and muscle, the heat, and a long day as other contributing factors.

"He was pushed beyond his limit," the vet testified.

Chief shop steward for carriage drivers says Ryder appeared healthy

The defense argues the horse tripped and fell, and was well taken care of.

They called the director of Veterinary Public Health Services for New York City to the stand. She testified before they sign off on horse licenses, a vet has to submit a certificate of health.

Christina Hansen, the chief shop steward for Central Park Carriages TWU Local 100, testified Ryder was in the stall next to her horse. Hansen said she saw Ryder most days, calling him bright and alert.

"[He] never struck me as being an unhealthy horse," she testified.

The defense called the current equine veterinarian for the NYPD as an expert witness. Prosecutors pointed out the doctor, a former horse racing vet, has been repeatedly fined with the state's gaming commission and faced other suspensions.

He examined Ryder after the collapse and says he appeared responsive, but right away thought the horse had neurologic issues and was underweight.

McKeever is expected to take the stand in his own defense before both sides make their closing arguments. If convicted, he faces up to one year behind bars.