In the classic Dr. Seuss children's book, Horton Hatches the Egg, lazy bird Mayzie finagles hapless Horton the Elephant into sitting on an egg she's too bored to hatch while she flies off to Palm Beach for a frivolous vacation.

Says Horton to Mayzie: "Me on your egg? That doesn't make sense. Your egg is so small, ma'am, and I'm so immense." But being the faithful elephant he is, he sits down to get the job done nonetheless.

When a similar scenario recently unfolded in the upstate New York town of Geneseo, a sizable Doberman Pinscher named Ruby-who was nursing six of her own puppies at the time-had no qualms about adding a tiny newborn kitten whose mother was nowhere to be found to her hungry brood.

Ruby's owner Brittany Callan breeds Dobermans on her family's farm. Even though the breed is best known for being consummate guard dogs, when she happened on the lost kitty, her thoughts turned to Ruby, whose pups were less than a week old.

After a careful introduction, the infant cat Callan had named Ramblin' Rose settled in next to her adoptive siblings for a feed and Ruby was only too happy to accommodate the extra little mouth.

"[Ruby] took right to her and didn't seem to mind at all," Callan told Daily Paws, adding, "She grew up with small animals [and learned] to be nice and just lick them and be friendly with everything… She's just an extremely, extremely compassionate dog."

While the occurrence of interspecies nursing is rare, it's certainly not unprecedented.

Back in 2012, two abandoned Siberian Tiger cubs were adopted by a Shar-Pei named Cleopatra at a Russian zoo in the Black Sea resort of Sochi.

Two years later, a determined farm feline from County Offaly, Ireland took on three motherless ducklings and raised them as kin along with her kittens.

CHECK OUT: Irish Farm Cat 'Nurses' Three Baby Ducklings

Unprecedented or not, Callan believes Ruby's í¼ber-developed maternal instinct is something truly special. "She was meant to be a mother to anything," Callan told the Rochester Democrat and Chronicle.

"We've had baby bunnies, guinea pigs, chickens, ducks… Ruby licks them like she's cleaning them, like she's their mother."

Since taking over mom duties for Ramblin' Rose, Ruby has started carrying the kitten around by the scruff of the neck and protectively separating her from her puppy litter mates when their behavior gets too rambunctious for the itty-bitty kitty.

Under Ruby's loving care-with a little extra nutrition in the form of kitten formula administered by Callan-Ramblin's Rose's weight has gone from 4.37 ounces to 7.27 ounces in the span of one week.

When Horton's egg finally hatches at the end of his tale, the creature that emerges is part bird and part elephant.

Her impressive growth rate notwithstanding, it's not likely Ramblin' Rose will catch up with her adoptive mom's stature or take up barking-but she might just make someone a pretty fierce guard cat when she's fully grown.

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