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Mastiff puppies and dogs in Denver, Colorado

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

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Adopt a Mastiff near you Mastiff in cities near Denver, Colorado Other pups in Denver, Colorado Search for a Mastiff puppy or dog near you Browse Mastiff puppies and dogs in nearby cities Browse related breeds in Denver, Colorado Mastiff shelters and rescues in Denver, Colorado Learn more about adopting a Mastiff puppy or dog

Adopt a Mastiff near you in Denver, Colorado

These Mastiffs are available in Denver, Colorado.
We'll also keep you updated on Sabrina's adoption status with email updates.
Special Needs
Photo of Sabrina

Sabrina

Mastiff American Bulldog

Female, 7 yrs 3 mos
Boulder, CO
Size
(when grown) X-Large 101 lbs (46 kg) or more
Details
Needs special attention, Needs experienced adopter, House-trained, Spayed or Neutered, Shots are up-to-date,
Story
Meet Sabrina, a gentle 6-year-old Mastiff mix who’s in need of a special forever home. Sabrina is living with mast cell tumors (MCT) due to cancer and is currently on medication to keep her as comfortable as possible. She requires a loving home that is prepared to offer her hospice care and a peaceful environment. Sabrina can be shy with new people and may give a warning growl or snap if approached when she’s not ready. However, once she builds trust, she becomes deeply affectionate and very attached to her people. She gets along well with mellow dogs and will thrive in a calm household where she can feel safe and loved. If you have a compassionate heart and are ready to provide a supportive and caring home for a special dog like Sabrina, you’ll find a loyal and loving companion in her.

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We'll also keep you updated on Effie's adoption status with email updates.
Photo of Effie

Effie

Mastiff

Female, Young
Denver, CO
Size
(when grown) Large 61-100 lbs (28-45 kg)
Details
Good with kids, Good with dogs, Good with cats, House-trained, Spayed or Neutered, Shots are up-to-date,
Story
Meet Effie, 1 year and 2 month old Mastiff mix who has a healthy appreciation for both naps and play time! She is a bit timid at first, but warms up very quickly. Effie is still young, so she is fairly quick to train and to learn new things. Effie is an amazing, kind dog - She is good with cats, dogs, and kids. After adopting Effie from the Humane Society, we discovered our senior cat was having an allergic reaction to her that worsened his pre-existing medical condition. For the sake of our cat’s health, we have made the difficult decision to find a new home for Effie. Effie thrives in a home with someone who can snuggle, play, and spend quality time with her.

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We'll also keep you updated on Stimpy's adoption status with email updates.
Photo of Stimpy

Stimpy

Mastiff Catahoula Leopard Dog

Female 6 mos
Littleton, CO
Size
(when grown) -
Details
Spayed or Neutered, Shots are up-to-date,
Story
Meet Stimpy, the perfect family dog Stimpy is a 6-month-old Mastiff/Catahoula Leopard Dog mix with the softest heart and sweetest soul. He’s truly not a fearful pup — while he was a bit hesitant about leaving the house or getting into the car at first, he now walks right out and hops in with no problem. He’s been enjoying off-leash trails, meeting other dogs and people, and he’s friendly with everyone. He loves social time and is clearly comfortable exploring new environments. At home, his playful personality really shines — including his signature move: a full-send “Superman jump” off the couch that never fails to make his people laugh (even if we never quite catch it on camera!). Stimpy is gentle and especially tender with kids, melting into cuddles the moment he feels safe. Overall, he’s a sweet, loving, and friendly pup who is still learning appropriate play manners. He’s hopeful, curious, and ready to bring joy, laughter, and cuddles to his forever family If you’re looking for a loving, gentle, big-dog puppy with a heart of gold, Stimpy is your guy. Apply online at www.lolasrescue.com/available-animals please note if you utilize an Iphone there are two scroll bars on the side of the screen to scroll down through available animals.   You can email Info@lolasrescue.com anytime with questions pertaining to animals in our care.  ##2593147##

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We'll also keep you updated on MINZI's adoption status with email updates.
Photo of MINZI

MINZI

Mastiff

Male, Adult
Denver, CO
Size
(when grown) -
Details
Spayed or Neutered,
Story
Minzi is the ultimate gentle giant. Sweet as he can be, he's affectionate and friendly. He enjoys long walks and hikes. He tends to walk slowly, but he can break into a trot if he's in the mood. This easy-going gent likes treats - the right ones at the right times. His walkers adore him. One says, `He should be in the movies.` Looking for a big, lovable buddy? This guy's available.December 17, 2025, 5:00 pm

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We'll also keep you updated on BIGGIE's adoption status with email updates.
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BIGGIE

Mastiff

Male, Adult
Denver, CO
Size
(when grown) -
Details
Spayed or Neutered,
Story
Biggie is, well, big. But don't let his size fool you. He's a shy guy who takes some time to adjust to new surroundings. Biggie is affectionate, but he needs a family that will give him time to feel safe and cared for. Because of his size and his intial fear in the shelter, we recommend older kids (10 yrs and up).December 17, 2025, 3:31 pm

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We'll also keep you updated on DOLLY's adoption status with email updates.
Photo of DOLLY

DOLLY

Mastiff

Female, Young
Denver, CO
Size
(when grown) Large 61-100 lbs (28-45 kg)
Details
Spayed or Neutered,
Story
Dolly is an active, fun-loving girl who adores playing fetch and showing off her goofy personality. She already knows how to sit and has lived well with other dogs, making her a playful and charming companion for a household full of funDecember 16, 2025, 3:24 pm

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Or, how about these Mastiffs in cities near Denver, Colorado

These Mastiffs are available for adoption close to Denver, Colorado.
We'll also keep you updated on Sabrina's adoption status with email updates.
Special Needs
Photo of Sabrina

Sabrina

Mastiff American Bulldog

Female, 7 yrs 3 mos
Boulder, CO
Size
(when grown) X-Large 101 lbs (46 kg) or more
Details
Needs special attention, Needs experienced adopter, House-trained, Spayed or Neutered, Shots are up-to-date,
Story
Meet Sabrina, a gentle 6-year-old Mastiff mix who’s in need of a special forever home. Sabrina is living with mast cell tumors (MCT) due to cancer and is currently on medication to keep her as comfortable as possible. She requires a loving home that is prepared to offer her hospice care and a peaceful environment. Sabrina can be shy with new people and may give a warning growl or snap if approached when she’s not ready. However, once she builds trust, she becomes deeply affectionate and very attached to her people. She gets along well with mellow dogs and will thrive in a calm household where she can feel safe and loved. If you have a compassionate heart and are ready to provide a supportive and caring home for a special dog like Sabrina, you’ll find a loyal and loving companion in her.

Learn More

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We'll also keep you updated on Effie's adoption status with email updates.
Photo of Effie

Effie

Mastiff

Female, Young
Denver, CO
Size
(when grown) Large 61-100 lbs (28-45 kg)
Details
Good with kids, Good with dogs, Good with cats, House-trained, Spayed or Neutered, Shots are up-to-date,
Story
Meet Effie, 1 year and 2 month old Mastiff mix who has a healthy appreciation for both naps and play time! She is a bit timid at first, but warms up very quickly. Effie is still young, so she is fairly quick to train and to learn new things. Effie is an amazing, kind dog - She is good with cats, dogs, and kids. After adopting Effie from the Humane Society, we discovered our senior cat was having an allergic reaction to her that worsened his pre-existing medical condition. For the sake of our cat’s health, we have made the difficult decision to find a new home for Effie. Effie thrives in a home with someone who can snuggle, play, and spend quality time with her.

Learn More

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We'll also keep you updated on Stimpy's adoption status with email updates.
Photo of Stimpy

Stimpy

Mastiff Catahoula Leopard Dog

Female 6 mos
Littleton, CO
Size
(when grown) -
Details
Spayed or Neutered, Shots are up-to-date,
Story
Meet Stimpy, the perfect family dog Stimpy is a 6-month-old Mastiff/Catahoula Leopard Dog mix with the softest heart and sweetest soul. He’s truly not a fearful pup — while he was a bit hesitant about leaving the house or getting into the car at first, he now walks right out and hops in with no problem. He’s been enjoying off-leash trails, meeting other dogs and people, and he’s friendly with everyone. He loves social time and is clearly comfortable exploring new environments. At home, his playful personality really shines — including his signature move: a full-send “Superman jump” off the couch that never fails to make his people laugh (even if we never quite catch it on camera!). Stimpy is gentle and especially tender with kids, melting into cuddles the moment he feels safe. Overall, he’s a sweet, loving, and friendly pup who is still learning appropriate play manners. He’s hopeful, curious, and ready to bring joy, laughter, and cuddles to his forever family If you’re looking for a loving, gentle, big-dog puppy with a heart of gold, Stimpy is your guy. Apply online at www.lolasrescue.com/available-animals please note if you utilize an Iphone there are two scroll bars on the side of the screen to scroll down through available animals.   You can email Info@lolasrescue.com anytime with questions pertaining to animals in our care.  ##2593147##

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We'll also keep you updated on Luna's adoption status with email updates.
Photo of Luna

Luna

Mastiff Rottweiler

Female, Adult
Golden, CO
Size
(when grown) X-Large 101 lbs (46 kg) or more
Details
Spayed or Neutered,
Story
Luna is a big dog who loves the snow! She will enjoy a gentle transition where she can take life one step at a time and not be expected to be a social butterfly right off the bat. If considered for a multi-dog household, we will require a meet at the shelter prior to departure, and at this time, she will only be rehomed to a family without children or with kids at least 10 years of age. Primary Color: Fawn Weight: 92.4 Age: 5yrs 0mths 2wks

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We'll also keep you updated on Maggie's adoption status with email updates.
Photo of Maggie

Maggie

Mastiff American Bulldog

Female, Adult
Golden, CO
Size
(when grown) Large 61-100 lbs (28-45 kg)
Details
Spayed or Neutered,
Story
If you've been searching for a dog who will make you smile every single day, say hello to Maggie! This bright-eyed, tail-wagging sweetheart is the perfect mix of playful energy and loving companionship.Maggie is an active, joyful, and endlessly curious pup who's always ready for fun. Whether it's a game of fetch, playing with other dogs, or exploring a new trail, she's happiest when she's moving and sharing life's adventures with her favorite humans. Primary Color: White Secondary Color: Black Weight: 71.6 Age: 4yrs 3mths 0wks

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We'll also keep you updated on MINZI's adoption status with email updates.
Photo of MINZI

MINZI

Mastiff

Male, Adult
Denver, CO
Size
(when grown) -
Details
Spayed or Neutered,
Story
Minzi is the ultimate gentle giant. Sweet as he can be, he's affectionate and friendly. He enjoys long walks and hikes. He tends to walk slowly, but he can break into a trot if he's in the mood. This easy-going gent likes treats - the right ones at the right times. His walkers adore him. One says, `He should be in the movies.` Looking for a big, lovable buddy? This guy's available.December 17, 2025, 5:00 pm

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These pups are in Denver, Colorado too!

Below are our newest added Mastiffs available for adoption in Denver, Colorado. To see more adoptable Mastiffs in Denver, Colorado, use the search tool below to enter specific criteria!
We'll also keep you updated on Zen's adoption status with email updates.
Photo of Zen

Zen

Neapolitan Mastiff Mastiff

Male, 7 yrs 2 mos
Boulder, CO
Size
(when grown) X-Large 101 lbs (46 kg) or more
Details
Not good with dogs, Needs experienced adopter, Spayed or Neutered, Shots are up-to-date,
Story
Zen is a 6-year-old male Neo Mastiff mix who’s as big-hearted as he is big in stature. Rescued from a shelter after his previous owners surrendered him for being “too big,” Zen is now on the hunt for his forever home where he can truly shine. Zen is a sweet, playful giant with a lot of energy for his breed. He’s very intelligent and learns quickly, making him a joy to train. However, Zen prefers to be the only dog in the home; he can get jealous and aggressive with other dogs, wanting all the attention for himself. When he's your one and only, he’s incredibly loving and will shower you with affection. Though he’s not reactive to other dogs on leash, Zen does best in a home without canine companions. He appreciates careful introductions to new people, especially those who approach unexpectedly. Zen’s ideal owner will be someone experienced with his breed and capable of continuing his training and socialization. If you’re ready to welcome a devoted and energetic companion into your life, Zen could be the perfect fit. He’s looking for a loving home where he can be the center of attention and enjoy all the love he has to give!

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We'll also keep you updated on Babs's adoption status with email updates.
Photo of Babs

Babs

St. Bernard

Female, 3 yrs 7 mos
Denver, CO
Size
(when grown) X-Large 101 lbs (46 kg) or more
Details
Good with dogs,
Story
Babs is an absolute sweetheart at 18 months young. She came in after her owner decided her energy no longer matched his own. She is a pretty active girl that needs someone to continue to work on training with her. Her current foster mama says she is very sweet little tornado 🌪 💜. She weighs in around 110 lbs and still needs to be spayed and have her gastropexy before she is ready to be adopted out. However, she is available to meet. She does have some resource guarding we are working through when it comes to food, and she is still learning how to be polite on a leash.

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We'll also keep you updated on Mortimer's adoption status with email updates.
Photo of Mortimer

Mortimer

St. Bernard Shepherd (Unknown Type)

Male, 5 yrs 4 mos
Denver, CO
Size
(when grown) Large 61-100 lbs (28-45 kg)
Details
Good with dogs, House-trained, Spayed or Neutered, Shots are up-to-date,
Story
Hi there!  Mortimer here, checking in after arriving in Colorado! Im between 1 and 2 years old (no one ever told me my real birthday so the nice doctor at the vet's office took a guess) and the rescue people asked me to tell you a little bit about myself. I love tug of war!  I figured i would start with that since its really important that my new home like to play that with me.  I also like to play with other dogs, but can get a little scared if they are super loud and in my face at first.  I am "crate-trained" whatever that means, and enjoy these things called "leash walks" where i get to go out and smell and see new things.  My foster parents say that i have decent leash "manners". I've seen a cat a few times, and wasn't overly interested in it, but i have never lived with one, so I don't know how i would feel about that. I ended up in Colorado after someone dumped me in a very rural part of new Mexico.  A nice lady there found me and gave me food and water and shelter which was very nice, but she couldn't keep me so she found some nice people in Colorado to help me find a new forever home!  If i sound like the kind of dog you would like to hang out with fill out the application below and be sure to mention my name! If you are interested in fostering or adopting Mortimer, please fill out an adoption application at gotdrool.org

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Search for a Mastiff puppy or dog

Use the search tool below to browse adoptable Mastiff puppies and adults Mastiff in Denver, Colorado.

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Mastiff puppies and dogs in nearby cities

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Related breeds in Denver, Colorado

Bullmastiffs in Denver, Colorado Neapolitan Mastiffs in Denver, Colorado Saint Bernards in Denver, Colorado

Mastiff shelters & rescues in Denver, Colorado

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

Here are a few organizations closest to you:

Rescue

6 miles

Ace of Hearts Dog Rescue - CO Transport Stop

711 Walnut St, Boulder, CO 80203

Pet Types: dogs

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Rescue

7.6 miles

L.O.L.A.'S Rescue

6005 S. Taft Way, Littleton, CO 80127

Pet Types: dogs

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Shelter

7.8 miles

Foothills Animal Shelter

580 McIntyre St., Golden, CO 80401

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

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Shelter

10.6 miles

Humane Colorado

2080 S Quebec St, Denver, CO 80231

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

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Rescue

15.9 miles

Big Dogs Huge Paws, Inc

PO Box 460699, Aurora, CO 80046

Pet Types: dogs

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Shelter

49.2 miles

Grand County Animal Shelter

3475 CR 57, Granby, CO 80446

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

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Looking for a specific shelter or rescue?

If you're not seeing what you're looking for, try our shelter and rescue search. We have more than 17,000 organizations in our database with furry pals waiting for a new home!

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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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