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Mastiff puppies and dogs in Waterloo, Illinois

Looking for a Mastiff puppy or dog in Waterloo, Illinois? Adopt a Pet can help you find an adorable Mastiff near you.

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Adopt a Mastiff near you in Waterloo, Illinois

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 Waterloo, Illinois

These Mastiffs are available for adoption close to Waterloo, Illinois.
We'll also keep you updated on Chili Mac's adoption status with email updates.
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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
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.December 26, 2025, 1:09 pm
We'll also keep you updated on Red's adoption status with email updates.
Photo of Red

Red

Mastiff

Male, Adult
Swansea, IL
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
I received the dog in September 2025. I have papers on the dog showing birth, breed, neutered and current shot record. The dog is very timid, does not/will not sleep in a dog bed, and does not take getting shots well. Very good house dog and is house trained. Barks loud! I made my own schedule for taking the dog out daily to pee and poop. I take the dog outside 3 to 4 time daily. Dog does not run!
We'll also keep you updated on Gus's adoption status with email updates.
Photo of Gus

Gus

Mastiff Mixed Breed (Large)

Male, Adult
St. Louis, MO
Size
(when grown) Large 61-100 lbs (28-45 kg)
Details
Good with kids, Good with dogs, House-trained, Spayed or Neutered, Shots are up-to-date,
Story
Meet Gus! Gus is a charming 3-year-old mastiff mix with a heart as big as his paws. This gentle giant is friendly, outgoing, and absolutely loves people. He gets along wonderfully with other dogs and kids—just be prepared for a little “bull in a china shop” energy when he gets excited! Gus is house-trained, kennel-trained, and making great progress with his leash skills. He’s also an excellent car buddy, happy to settle in and enjoy the ride. If you’re looking for a lovable, goofy companion who brings joy wherever he goes, Gus might just be your perfect match! https://www.shelterluv.com/matchme/adopt/NAF/Dog
We'll also keep you updated on Big Dog's adoption status with email updates.
Photo of Big Dog

Big Dog

Mastiff

Male, 3 yrs 5 mos
East ST Louis, IL
Size
(when grown) X-Large 101 lbs (46 kg) or more
Details
Spayed or Neutered,
Story
This pet's adoption fee is sponsored by the Zach Schneider Memorial Fund, created in memory of Zach Schneider, who loved pets and fostered for Gateway Pet Guardians. Waived fees are sponsored by the Zach Schneider Memorial Fund, created in memory of Zach Schneider, who loved pets and fostered for Gateway Pet Guardians! Meet Big Dog — Big Sweetness, Big Fun, Big Love! Big Dog lives up to his name in every way—he’s large, he’s lovable, and he’s overflowing with joy. This gentle giant has a heart to match his size, and around here, we lovingly call him Big Sweetness because that’s exactly what he is. Despite his impressive stature, Big Dog is all softness on the inside. He’s affectionate, friendly, and eager to make connections with everyone he meets. Whether he’s leaning in for pets, flashing his goofy grin, or trotting around with those oversized paws, he brings an irresistible charm that wins people over instantly. And let’s talk about the fun—because Big Dog brings that in a big way, too. He’s playful, spirited, and always ready for an adventure. From giant-sized zoomies to joyful tail wags that practically create a breeze, he knows how to keep life lively and full of laughter. If you’re searching for a dog who will fill your home with love, laughter, and big-hearted companionship, Big Dog is ready to take up space in your house and your heart. Come meet him—he’s Big Everything you could want in a best friend. If you are interested in a meet and greet for adoption for Big Dog, please fill out an application on our website at www.gatewaypets.org/adopt. If you are interested in learning more about Big Dog or the adoption process at GPG, please email placement@gatewaypets.org All of our dogs and cats will be microchipped, spayed or neutered, and up-to-date on vaccinations at the time of adoption. For more photos of Big Dog, follow us on Facebook Gateway Pet Guardians and Instagram @gatewaypets ... #gpgBig Dog. To view other adoptable pets from our shelter, please visit, www.gatewaypets.org/adopt. Gateway Pet Guardians is proud to offer a variety of mixed breed dogs available for adoption. However, please keep in mind that we rarely know the genetic background of the animals we rescue and, as such, we cannot guarantee the exact breed combinations found within this dog. Therefore, we do not know his/her actual genetic makeup. Just know that this dog is probably a variety of several different breeds that have combined to create one very amazing and unique animal.
We'll also keep you updated on Hippie's adoption status with email updates.
Photo of Hippie

Hippie

Mastiff

Female, 8 mos
East ST Louis, IL
Size
(when grown) Med. 26-60 lbs (12-27 kg)
Details
-
Story
This pet's adoption fee is sponsored by the Zach Schneider Memorial Fund, created in memory of Zach Schneider, who loved pets and fostered for Gateway Pet Guardians. Big Girl = Big Love! Hippie is all peace and love, baby! Every square inch of her screams "I love you, do you love me too?!" We just adore her friendly disposition and outgoing personality. If you're looking for a true bestie, Hippie is definitely the right fit for you. If you are interested in a meet and greet for adoption for Hippie, please fill out an application on our website at www.gatewaypets.org/adopt. If you are interested in learning more about Hippie or the adoption process at GPG, please email placement@gatewaypets.org All of our dogs and cats will be microchipped, spayed or neutered, and up-to-date on vaccinations at the time of adoption. For more photos of Hippie, follow us on Facebook Gateway Pet Guardians and Instagram @gatewaypets ... #gpgHippie. To view other adoptable pets from our shelter, please visit, www.gatewaypets.org/adopt. Gateway Pet Guardians is proud to offer a variety of mixed breed dogs available for adoption. However, please keep in mind that we rarely know the genetic background of the animals we rescue and, as such, we cannot guarantee the exact breed combinations found within this dog. Therefore, we do not know his/her actual genetic makeup. Just know that this dog is probably a variety of several different breeds that have combined to create one very amazing and unique animal.
We'll also keep you updated on Bellatrix's adoption status with email updates.
Photo of Bellatrix

Bellatrix

Mastiff

Female, 8 yrs 1 mo
St. Louis, MO
Size
(when grown) Large 61-100 lbs (28-45 kg)
Details
Spayed or Neutered,
Story
Meet Bellatrix – The Gentle Giant with a Harry Potter Twist! Bellatrix may share a name with a famous witch, but don’t worry—she’s all love and loyalty, no dark magic here! This 8-year-old Mastiff is a wise and gentle soul who prefers cuddles over curses and cozy naps over chaos. She absolutely adores people and will happily be your most devoted companion. Bellatrix is potty and crate trained, though she hardly needs her crate it because she’s such a well-mannered lady. Her ideal home? A calm, loving environment where she can relax and feel like the queen of her own Great Hall. She would do best as the only dog in the home. Bellatrix enjoys short strolls, comfy spots like the couch, and being near her favorite humans—she’s basically your very own magical protector. If you’re ready to add a little enchantment (and a lot of love) to your life, Bellatrix is waiting to cast her spell on your heart. Her adoption fee is fully sponsored. Ready to meet Bellatrix? She’s more Hufflepuff than Slytherin—bring her home today! Visit Istodaymydayrescue.org to learn more or fill out an application.

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Use the search tool below to browse adoptable Mastiff puppies and adults Mastiff in Waterloo, Illinois.

Mastiff puppies and dogs in nearby cities

Related breeds in Waterloo, Illinois

Mastiff shelters & rescues in Waterloo, Illinois

There are animal shelters and rescues that focus specifically on finding great homes for Mastiff puppies in Waterloo, Illinois. Browse these Mastiff rescues and shelters below.

Here are a few organizations closest to you:

Rescue

14.9 miles

Needy Paws Rescue

St Louis, MO 63125

Pet Types: dogs

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Rescue

18.1 miles

Nala and Friends Dog Rescue - ST. LOUIS transport

St. Louis, MO 63118

Pet Types: dogs

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Shelter

19.2 miles

Gateway Pet Guardians

725 N 15th St, East ST Louis, IL 62205

Pet Types: cats, dogs

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Rescue

20.2 miles

Is Today My Day Rescue

St. Louis, MO 63139

Pet Types: dogs

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Shelter

20.6 miles

CARE STL

2700 Walnut Place, St. Louis, MO 63103

Pet Types: cats, birds, dogs, farm animals, rabbits, small animals

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Shelter

21.9 miles

Animal Protective Association of Missouri

1705 South Hanley Road, St. Louis, MO 63144

Pet Types: cats, dogs, rabbits, small animals

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Shelter

29.6 miles

Humane Society of Missouri - Maryland Heights

11660 Administration Dr., (Page Ave. and Schuetz Road), Maryland Heights, MO 63146

Pet Types: cats, birds, dogs, rabbits, small animals

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Rescue

29.6 miles

Gods Dogs Rescue of TX for St Louis Transport Stop

St Louis, MO 63146

Pet Types: dogs

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Rescue

35.2 miles

Charming Pet Rescue - MO Transport Stop

St. Louis, MO 63303

Pet Types: dogs

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Shelter

39.6 miles

St Charles County Humane Services

4850 Mid Rivers Mall Dr, St. Peters, MO 63376

Pet Types: cats, birds, dogs, rabbits, small animals

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

We've got all the info you need on adopting and caring for a Mastiff puppy. Check out the links below for everything you ever wanted to know about Mastiff puppies and adults.

Mastiff basics

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Where do Mastiffs come from? How many types of Mastiffs are there? From the history of the breed to question about average height, weight and size, brush up on these basic facts about the Mastiff.

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