WESTFIELD, Mass. — Nine show dogs have died at a private kennel in Westfield, and their owner says she believes a faulty air conditioner is to blame.

The Massachusetts Society for the Prevention of Cruelty to Animals says it is investigating.

Brenda Coggin says her Australian shepherds were fine when she left them last Thursday morning. When she found them dead that afternoon, the air conditioner had tripped a reset button and was giving off mist and a chemical odor.

Coggin said she doesn’t know if the dogs were poisoned by leaking coolant or became overheated. She said buried the dogs that night without calling authorities.

She told WWLP-TV she was “devastated” and it’s still “pretty traumatic” to deal with the loss.

Coggin also keeps about 30 horses at her Coggin Creek Stables.