The Napier SPCA waded more than a kilometre through floodwaters to evacuate nine horses from a property on the city outskirts, south of Napier.
SPCA staff and the horses' owners, who did not want to be identified, got the animals to safety on Tuesday morning.
Animal welfare inspector Renee Hickey said in some areas the water was thigh-deep.
"Getting to the horses was the most urgent job – and we knew we were forecast to have more rain," she said.
Hickey said because the water was not subsiding quickly enough, their main priority was to get the horses to drier ground.
"During the night, when the water was at its highest, the horses were belly-deep in water out there, with nowhere to go," she added.
Seven of the horses have since been transported to a safe property in Hastings.
"The two most elderly horses, who were unable to travel, have been taken to higher ground," Hickey said.
She said the owners have "lost their house and everything in the flood".
"They couldn't get any access to their floats or anything. They needed help getting those horses out of there as soon as possible."
All the horses were uninjured during the ordeal but the stress was visible, according to the SPCA.
"They had to put a lot of trust in us to get them out of there. Some of them were younger horses as well - they did amazingly well for a very stressful situation," Hickey said.
The SPCA building in Napier also suffered from minor flooding, meaning all dogs were transported to the Hastings branch as a precaution.
An Animal Evac New Zealand spokesman said they are in touch with the Ministry for Primary Industries, which is offering the assistance of trained animal disaster responders, who are also trained in flood safety.
"At this stage, no requests for animal assistance have been received by authorities," he said.
Animal Evac have two inflatable rescue sleds in Wellington on standby, ready to be pre-deployed if requested.