The largest dogs in America are not for everyone. For the right family a Leonberger, Mastiff, Saint Bernard, Great Dane, or Newfoundland becomes the centerpiece of the household. They demand space, patience, and a serious commitment to health screening because giant breed lifespans run shorter than those of smaller dogs, a pattern the American Kennel Club and veterinary researchers tie directly to size. This month's No Dog Left Behind Adoption Showcase features five Platinum tier kennels and rescues placing gentle giants right now. Every entity below maintains Platinum tier membership on PuppyReports™ and carries zero active flags as of publication.

This Month's Featured Entities

Sterling Crest Leonbergers
Breeder · Leonberger

Sterling Crest LeonbergersPlatinum

Sample Location

Sterling Crest has been breeding Leonbergers for fourteen years with a working line emphasis and the conformation and temperament balance of a breed that, as the American Kennel Club notes, survived two world wars. The kennel published its full LPN1, LPN2, and LEMP testing chain on PuppyReports™ in 2025 and runs a structured waiting list for two litters per year.

Health testing chain on file: OFA Hips (Good or Excellent), OFA Elbows, OFA Cardiac, CERF or OFA Eyes (annual), LPN1, LPN2, LEMP DNA panel via Embark, vWD-1 clear by parentage. Contract includes lifetime return clause.
Leonberger breed guide on PuppyReports →
Pacific Northwest Mastiff Rescue
Rescue · English and Bullmastiff

Pacific Northwest Mastiff RescuePlatinum

Portland, OR

A volunteer run 501(c)(3) pulling Mastiffs and Bullmastiffs out of overcrowded municipal shelters across Oregon, Washington, and Idaho since 2009. Foster based, with a strict home check process and a specialty in placing seniors and second chance mastiffs whose first families could not manage the size.

Adoption protocol on file: Full vet workup pre adoption (cardiac auscultation, hip palpation, dental, thyroid), spay or neuter complete or escrowed, 14 day post placement check in, return to rescue clause in every adoption contract. Adoption fee range published.
Mastiff breed guide on PuppyReports →
Heritage Saint Bernards of the Rockies
Breeder · Saint Bernard

Heritage Saint Bernards of the RockiesPlatinum

Boulder, CO

A small scale Saint Bernard program emphasizing the smoother coated working type with European pedigree references. Heritage publishes mean kinship calculations for every prospective pairing and refuses to breed any parent without at least three generations of OFA hips and elbows in the line.

Health testing chain on file: OFA Hips, OFA Elbows, OFA Cardiac (advanced cardiologist evaluation), OFA Eyes annual, DCM screening, Degenerative Myelopathy DNA, full Embark or Wisdom Panel breed specific markers. Contract includes mandatory health issue reporting clause.
Saint Bernard breed guide on PuppyReports →
Texas Great Dane Sanctuary
Rescue · Great Dane

Texas Great Dane SanctuaryPlatinum

Austin, TX

A breed specific sanctuary that takes Great Danes other Texas rescues cannot. Medical surrenders, behavioral rehab cases, seniors, and dogs pulled from cruelty seizures. Eighty percent of placements go to families with previous giant breed experience. The remainder go to vetted first time giant owners after a structured mentorship intake.

Adoption protocol on file: Cardiac echo (every Dane over 4 years), bloat risk consultation with the adopter, prophylactic gastropexy escrowed when indicated, full thyroid panel, behavioral evaluation, foster to adopt mandatory for first time giant breed adopters. Adoption fee range published.
Great Dane breed guide on PuppyReports →
Old World Newfoundland Kennel
Breeder · Newfoundland

Old World Newfoundland KennelPlatinum

Sample Location

A traditional Newfoundland program with a strong water work and drafting heritage. Old World breeds for the classic black and Landseer colors only, with a small annual litter count (two to three) and a mentorship process for every placement. Draft work and water rescue training paths are available if the family wants them.

Health testing chain on file: OFA Hips (Excellent emphasized), OFA Elbows, OFA Cardiac (advanced echo), Cystinuria DNA, OFA Patellas, OFA Eyes annual, Subaortic Stenosis screening. Contract includes lifetime return clause and breeding rights restriction by default.
Newfoundland breed guide on PuppyReports →

How These Five Were Selected

Every entity in this Showcase opted in via their Showcase Eligibility toggle inside the PuppyReports™ dashboard. PuppyReports™ editorial reviewed the opted in pool, confirmed Platinum tier status on each candidate, ran a fresh flag check against our community submitted concerns database, and selected this month's theme based on a cross section of breeder and rescue work in the giant breed category. No payment changed hands. No featured entity paid for placement. The PuppyReports™ Showcase exists to surface the kennels and rescues that have chosen radical transparency, not the ones with the biggest advertising budget.

If you are considering one of these breeds, start with the PuppyReports™ profile of any entity above. Confirm their health testing chain. Read their contract. Submit a family side application. Talk to past adopters. Then make your decision the way these breeders and rescues hope you will. Slowly, with full information, and with the long term commitment a giant breed deserves.

See more Showcase entities

Every month, PuppyReports™ features a different cross section of Platinum tier breeders and rescues. Browse the full archive or set up alerts for the breeds you care about.

Browse Showcase Archive →
This is an editorial showcase. Featured kennels and rescues have opted in via their Showcase Eligibility settings. Every featured entity maintains Platinum tier membership and zero active flags as of publication date. PuppyReports™ does not receive payment for inclusion in showcases. For complete information about each entity, including any pending tier reviews or community submitted concerns, visit their PuppyReports profile.

Sources

The breed and health screening references named above draw on the following authoritative sources. Featured entities and their stated test chains are fictitious examples for this placeholder template.

American Kennel Club. (n.d.). Great Dane life span & health issues. Retrieved June 9, 2026, from https://www.akc.org/expert-advice/health/great-dane-life-span/

American Kennel Club. (n.d.). The history behind the Leonberger. Retrieved June 9, 2026, from https://www.akc.org/expert-advice/dog-breeds/history-behind-the-leonberger/

Orthopedic Foundation for Animals. (n.d.). CHIC programs. Retrieved June 9, 2026, from https://ofa.org/chic-programs/

University of Minnesota College of Veterinary Medicine, Canine Genetics Lab. (n.d.). Leonberger health panel. Retrieved June 9, 2026, from https://vetmed.umn.edu/research/research-labs/canine-genetics-lab/canine-genetics-testing/leonberger-health-panel

Reist-Marti, S. B., Dolf, G., Leeb, T., Kottmann, S., Kietzmann, S., Butenhoff, K., & Rieder, S. (2012). Genetic evidence of subaortic stenosis in the Newfoundland dog. Veterinary Record, 170(23), 597. https://pubmed.ncbi.nlm.nih.gov/22645160/

American Kennel Club. (n.d.). Breed specific DNA testing recommendations. Retrieved June 9, 2026, from https://www.akc.org/breeder-programs/dna/dna-resource-center/akc-dna-health/breed-specific-dna-testing-recommendations/

Ward, M. P., Patronek, G. J., & Glickman, L. T. (2003). Benefits of prophylactic gastropexy for dogs at risk of gastric dilatation volvulus. Preventive Veterinary Medicine, 60(4), 319 to 329. https://pubmed.ncbi.nlm.nih.gov/12941556/