Lisa Keefe, of the Meadows in Nottingham, did not realise her Bengal crossbreed Bobby had climbed inside the appliance for a nap.
She raced to get him out after hearing "a loud thudding noise" from inside the appliance.
A vet at the clinic who treated him said: "In my 15 years as a vet, I've never seen a case like this."
Nine-month-old Bobby was taken to Nottingham Pet Hospital on the verge of collapse and needed IV fluids to treat shock.
His brush with death has seen him nominated for a PDSA (People's Dispensary for Sick Animals) Pet Survivor award.
Ms Keefe, 47, said Bobby was known to climb in the machine and she had put him outside before putting in a new load.
But she said the curious puss must have snuck back in and hidden under a duvet before she switched on the appliance.
"As soon as I heard the noise I rushed to the machine and could see the colour of his fur mixed in with the quilt. I was petrified and raced to get him out," she said.
The kitten was in the washer "for about two minutes", vet James Kellow said.
"Bobby has learned his lesson the hard way, he doesn't go anywhere near the washer any more", his owner added.
Vet Tamsin Thomas said: "Bobby was on the verge of collapse as his body was soaked through and his temperature was dangerously low.
"We gently dried him out, kept him warm and gave him IV fluids to treat shock."
Mr Kellow, who treated Bobby, said the kitten had sore eyes from the detergent, but within a couple of hours was "as right as rain".
A kitten that was accidentally trapped in a washing machine on a 60C cycle has made a full recovery.