Mastiff Adoption in Union, MO: Mastiff Puppies for Sale in Union, MO

Adopt a Mastiff near you in Union, Missouri

We don't see any Mastiffs available for adoption right now, but new adoptable pets are added every day. Try a different search below!

Or, how about these Mastiffs in cities near Union, Missouri

These Mastiffs are available for adoption close to Union, Missouri.

Compton

Mastiff Labrador Retriever

Male, 3 yrs 1 mo

O'Fallon, MO

Size

(when grown) -

Details

Good with dogs, House-trained, Spayed or Neutered,

Story

𝗔𝗗𝗢𝗣𝗧 𝗖𝗢𝗠𝗣𝗧𝗢𝗡 🤍🐷 𝗪𝗲𝗹𝗰𝗼𝗺𝗲 𝘁𝗼 𝘁𝗵𝗲 𝗳𝗮𝗺𝗶𝗹𝘆 Compton 🤍 We promise to find you a 𝒓𝒆𝒂𝒍 𝗳𝘂𝗿𝗲𝘃𝗲𝗿 𝗳𝗮𝗺𝗶𝗹𝘆 this time 🙏 Compton found his way to our city shelter back in January of 2025 as a stray with a collar and leash still attached, but sadly no one came forward 😞 He quickly showed signs of kennel stress, but luckily was sprung by a foster hero, and then what he thought was his furever home…2 months later he was dropped off for dogsitting, the owner blocked the sitter, and never came back for our sweet ham 😭 He was once again adopted again, and later picked up by the Humane Society as a stray and transferred back to CARE. After 𝗮 𝗳𝘂𝗹𝗹 𝘆𝗲𝗮𝗿 𝗼𝗳 𝗯𝗼𝘂𝗻𝗰𝗶𝗻𝗴 𝗯𝗲𝘁𝘄𝗲𝗲𝗻 𝗸𝗲𝗻𝗻𝗲𝗹𝘀 𝗮𝗻𝗱 𝗵𝗼𝗺𝗲𝘀, Compton is FREE of shelter life, decompressing in a home, and snoring like a grown man 😆 (check out the comments for a video!) This level white noise happens when a shelter dog feels like they can finally relax 🥲 The ONLY reason we were able to help Compton is because a 𝗳𝗼𝘀𝘁𝗲𝗿 𝗵𝗲𝗿𝗼 opened their home 🏡 THANK YOU to all the heroes—you are truly saving a life. All that’s left is to find 𝗳𝘂𝗿𝗲𝘃𝗲𝗿 ♾️👀 _____________________________________________ 𝗚𝗼𝗼𝗱 𝗯𝗼𝘆 𝗾𝘂𝗮𝗹𝗶𝗳𝗶𝗰𝗮𝘁𝗶𝗼𝗻𝘀 𝘀𝗼 𝗳𝗮𝗿: • ~3 yr old ~67lbs happy, hefty hog 🐷 • potty/house trained ✔️ • rides well in the car ✔️ • SUPER food motivated—a fast learner! • AFFECTIONATE! he loves a snuggle • DOG FRIENDLY! • NO CATS ❌ • KID FRIENDLY! hasn’t met tiny hoomans but has done well with the ones he has met!

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Ivy

Mastiff Shepherd (Unknown Type)

Female, 5 yrs

Cuba, MO

Size

(when grown) Med. 26-60 lbs (12-27 kg)

Details

House-trained, Spayed or Neutered, Shots are up-to-date,

Story

Ivy is housebroken, current on vaccinations and will be spayed before adoption. Food motivated, eager to please and likes to be right by your side. She knows how to sit for a treat.

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Luke AG

Mastiff American Pit Bull Terrier

Male, 4 yrs

St Louis, MO

Size

(when grown) X-Large 101 lbs (46 kg) or more

Details

Good with kids, Good with dogs, Not good with cats, Spayed or Neutered,

Story

Hi, I’m Luke, and I’m a big, lovable boy tipping the scales at just over 100 lbs! Don’t let my size fool you—I’m a happy, easygoing pup who just wants to play, explore, and cuddle. I’m all about the good things in life: squeaky toys, water play, long walks, and best of all—snuggle time on the couch. I’m a pro at giving hugs (though I’m working on not jumping up too hard to give them—oops!). I get along great with other dogs and kids, but because of my size and enthusiasm, I’d do best with older children who won’t get accidentally knocked over during playtime. I’m crate trained, housebroken, and walk nicely on a leash—unless there’s a squirrel… then it’s game on! I do have a slight prey drive, so a little guidance goes a long way. If you’re looking for a big-hearted, playful companion to fill your home with love (and maybe take up some space on your couch), I’m your guy. Let’s make forever happen! 🐾 Local adoption fee is $200(in TX) Out of state adoption fee is $450 (includes transport to your area)

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Finn AKA Gage JuM

Mastiff Shepherd (Unknown Type)

Male, 6 yrs 11 mos

St Louis, MO

Size

(when grown) Large 61-100 lbs (28-45 kg)

Details

Good with dogs, Spayed or Neutered,

Story

Finn may look like a rockstar with his striking Mastiff–Shepherd good looks, but at heart, he’s a big, soft lovebug. Weighing in at about 60 pounds, Finn has grown into a handsome boy with a beautiful gray and tan coat, soulful eyes, and an even bigger personality. Despite his star-quality appearance, Finn is more of a laid-back, easygoing guy—think Eeyore vibes, but with engines revved and ready to love. From the moment he wakes up, he’s prepared to shower his people with affection… and trust us, it’s A LOT of love! Finn does well with other dogs and does need a slow, proper introductions to new friends—both two-legged and four-legged. Once he knows you, he loves you deeply. He’s happiest when he has a buddy (human or canine) to share his world with. Affection is Finn’s specialty. When someone comes to greet him, he lights up, runs over with enthusiasm, and hands out slobbery kisses and big hugs like they’re backstage passes. His joy is genuine, his heart is huge, and he’s always thrilled to see his people. If you’re looking for a big, lovable, slightly goofy rockstar who will adore you endlessly, Finn is ready to take center stage in your heart. Local adoption only $200 (in TX)

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Chili Mac

Mastiff

Male, Puppy

St Louis, MO

Size

(when grown) X-Large 101 lbs (46 kg) or more

Details

Good with dogs, House-trained, Spayed or Neutered, Shots are up-to-date,

Story

Chili Mac is currently enrolled in the 12-week Puppies 4 Parole program through the Mo Department of Corrections. He will graduate around May 1st and will be available for adoption at that time. If you are interested in adopting Chili Mac, please complete an application and the foster parent will contact you. Meet Chili Mac! This 11-month-old Cane Corso is a big, lovable goofball with a heart as giant as his paws! Chili Mac is equal parts cuddle bug and class clown — he’ll make you laugh one minute and melt into your lap the next. He can be a little shy when meeting new people, but once he decides you’re cool, he’s all in! He’s great with dogs big and small (seriously — from 6 lbs to 120 lbs!), crate and potty trained, and already knows some basic commands. Due to Chili Mac's size and clumsiness, he would do best in a home with older children. He would also be best with someone who has breed/guardian experience given some mouthy behaviors which are normal for the breed. Chili Mac would love an active home with another dog friend or a human adventure buddy. Whether you’re hiking, road-tripping, or just lounging on the couch- as long as you don’t mind a little drool, he’s ready to be your ride-or-die! If interested, please complete the Adoption Application on our website at www.NeedyPaws.org and we will contact you. Adopters must live within an hour’s drive of St. Louis, MO. Our $295 adoption fee includes up-to-date vaccinations, heartworm testing and preventative, spay/neuter and microchip. We are a 100% foster-based rescue and all of our dogs live in approved foster homes. We are dedicated to finding the best Forever Homes, and will perform home visits and conduct veterinarian and reference checks for each potential adopter.Visit this organization's web site to see any additional information available about this pet.February 22, 2026, 12:15 am

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Jax

Mastiff

Male, 1 yr 2 mos

Columbia, IL

Size

(when grown) Large 61-100 lbs (28-45 kg)

Details

House-trained, Spayed or Neutered, Shots are up-to-date,

Story

Jax is a lovable goofball who does not realize his own size! He is full of puppy energy, loves running and playing, and would do best in a home without small children. He is housebroken, dog selective, and looking for an experienced adopter who can give him structure, exercise, and lots of love.Jax is one year old and weighs 74 pounds.The adoption fee for adult dogs, seven months and older, is $250. All pets are microchipped, up to date on vaccines, and will be altered prior to adoption. If you are interested in meeting a dog, please stop by the shelter during open hours. Dogs may be in a foster home, therefore scheduling an appointment is recommended. If you have an existing dog at home, we recommend bringing it along to meet your possible new family member.helpingstrays.org

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Mastiff puppies and dogs in Union, Missouri

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Adopt a Mastiff near you in Union, Missouri

We don't see any Mastiffs available for adoption right now, but new adoptable pets are added every day. Try a different search below!

Or, how about these Mastiffs in cities near Union, Missouri

These Mastiffs are available for adoption close to Union, Missouri.

Search for a Mastiff puppy or dog

Mastiff puppies and dogs in nearby cities

Related breeds in Union, Missouri

Mastiff shelters & rescues in Union, Missouri

Looking for a specific shelter or rescue?

Want to learn more about adopting a Mastiff puppy or dog?

Mastiff basics

Mastiff basics