O

O'Boyle, Jane
Catnip for the Soul (cats) {A}

O'Brien, Robert C.
The NIMH Series [later titles written by Jane Leslie Conly] (rats, mice) {IR}
1. Mrs. Frisby and the Rats of NIMH [aka The Secret of NIMH]

O'Brien, Seumas
The Whale and the Grasshopper and Other Fables (various animals) {A}

O'Connell, Lisa B. C.
The Miracle Max Series (dog) {IR}
1. Miracle Max: Missing in Maryland!
2. (not yet published)

O'Connell, Jean S.
The Dollhouse Caper (dolls) {IR}

O'Connor, Kerrie
Through the Tiger's Eye (tiger, monkey, snake) {IR}

O'Dea, Marjory
The Canberra Series (ermines, gryphon, unicorns, dolphins, bees) {YA}
1. Six Days Between a Second
2. Of Jade and Amber Caves

Odgers, Sally
Drummond: The Search for Sarah (teddy bear) {IR}

Odom, Mel
The Sabrina Series [only wrote some in series] (cat) {YA}
15. Harvest Moon
18. I'll Zap Manhattan
31. Mummy Dearest
35. Pirate Pandemonium
40. Dream Boat
41. Tiger Tale

O'Donohoe, Nick
The Crossroads Series (griffons, others) {A}
1. The Magic and the Healing
2. Under the Healing Sign
3. The Healing of Crossroads

O'Donovan, Dermont
Silas Rat and the Nuclear Tail (rats) {IR}

O'Faolain, Eileen
The King of the Cats (cats) {IR}

Ogden, Brian
Short Tails and Tall Stories (pig, others) {IR}

O'Grady, John
Smoky Joe, the Fish Eater (cat) {IR}

Ohlander, Ben
The Price of Freedom [#3 in Wing Commander Series, with William Forstchen] (catmorphs) {A}

Oke, Janette
[Some of these books have recently been republished in abridged, picture book versions, but these listing refer to the lengthier versions for older kids]
Pordy's Prickly Problem (porcupine) {IR}
Trouble in a Fur Coat (bears) {IR}
Ducktails (ducks, geese) {IR}
The Impatient Turtle (turtle, others) {IR}
Spunky's Diary (dogs) {IR}
New Kid in Town (skunk, others) {IR}
Prairie Dog Town (prairie dogs) {IR}
The Prodigal Cat (cats) {YA}
Maury Had a Little Lamb [is this furry?] (sheep) {IR}
Who's New at the Zoo [is this furry?] (gorillas) {IR}

Okuda, Hitoshi
The No Need for Tenchi! Series (rabbit-cats, catmorph) {YA/A}
1. No Need for Tenchi!
2. Sword Play
3. Magical Girl Pretty Sammy
4. Samurai Space Opera
5. Unreal Genius
6. Dream a Little Scheme
7. Tenchi in Love
8. Chef of Iron
9. The Quest for More Money
10. Mother Planet
11. Akeya's Heart
12. No Need for Endings!
The All-New Tenchi Muyo! Series (rabbit-cats) {YA}
1. Alien Nation
2. Doom Time!
3. Dark Washu
4. Girls Get Busy
5. Point and Shoot
6. Pet Peeves

Oldfield, Jenny
The Dreamseeker Trilogy Series (horses) {YA}
1. Silver Cloud
2. Iron Eyes
3. Bad Heart

Oliver, Gary J.
Fears, Doubts, Blues, and Pouts: Stories About Handling Fear, Worry, Sadness, and Anger [with H. Norman Wright] (raccoons, moose, bear, rabbit, others) {IR}

Olmsted, Franklin H.
Father Crow and His Crew, A Story for Children and Wise Grown-Ups (IR/A, as the title says!}

Oltion, Jerry
The Getaway Special (butterflies, trees) {A}

One, Dark
The Animal Mystic Series (various animalmorphs) {A}
1. Animal Mystic
2. Water Wars
3. Klor

Ono, Toshihiro
The Pikachu Series (squirrel, cat, several others) {YA/A}
1. The Electric Tale of Pikachu
2. Pikachu Shocks Back
3. Electric Pikachu Boogaloo
4. Surf's Up, Pikachu

Oppel, Kenneth
The Shade Series (bats) {YA}
1. Silverwing
2. Sunwing
3. Firewing

Orman, Kate
The Year of Intelligent Tigers [with Jonathan Blum] (tigers) {A}

Ormondroyd, Edward
David and the Phoenix (phoenix) {IR}

O'Rourke, Frank
Burton and Stanley (storks) {IR}

Ortoli, Frederic
Evening Tales (rabbits, ducks, others) {IR}

Orton, Helen Fuller
The Little Lost Pigs Series (pigs) {IR}
1. The Little Lost Pigs
2. The Little Lost Pigs in Town

Orville, Florence
Bunnies of Bunnyboro (rabbits, also illustrated with photos of real rabbits, all dressed up!) {IR}

Orwell, George
Animal Farm: A Fairy Story (pigs, horses, others) {A}

Osborne, Jr., M. M.
Ondine: The Story of a Bird Who Was Different (sandpipers) {IR}

Osborne, Mary Pope
The Spider Kane Series (various insectmorphs) {IR}
1. Spider Kane and the Mystery Under the May-Apple
2. Spider Kane and the Mystery at Jumbo Nightcrawler's

O'Shea, Colleen Q.
The 50 Secrets of Highly Successful Cats: or How to Succeed With Humans (Without Really Trying) (cats) {A}

O’Shea, Pat
The Hounds of the Morrigan (fox, frog, dogs, many others) {YA}

Ossendowski, Ferdinand
Memoirs of a Little Monkey: A Diary of the Chimpanzee Ket (chimps) {IR?}

Ostrow, Kim
The Wild Thornberrys Series [only wrote one] (chimpanzee, various others) {IR}
7. Gem of a Mom

Otfinoski, Steven
The Wild Thornberrys Series [only wrote one] (chimpanzee, various others) {IR}
3. A Time to Share

Otterland, Duke
Org's Odyssey: A Tale of Post-Human Earth (various animalmorphs) {YA/A}

Otto, Margaret G.
The Tiny Man (doll, seagulls) {IR}

Outcault, R. F.
Tige – His Story (dog) {IR}

Outhwaite, Grenbry
The Enchanted Forest (various animals) {IR}

Owen, John S.
Gramma: the Autobiography of a Cat (cat) {IR}