St. Bernard Mixed With Rottweiler: Complete Guide to This Giant Cross

The St. Bernard mixed with Rottweiler — sometimes informally called a "Saint Rottie" or "Rott Bernard" — pairs two of the most imposing working breeds in the canine world. One parent hauled barrels of brandy through Swiss alpine passes; the other drove cattle and guarded homesteads across southern Germany. The result is a dog that can tip the scales past 150 pounds, carries a deep-chested barrel body, and demands an owner who understands giant-breed management.

This guide covers what prospective owners actually need to know before bringing home a St. Bernard mixed with Rottweiler: realistic size projections, the temperament lottery inherent in any crossbreed, inherited health conditions from both parent lines, and the true cost of caring for a dog this large.

Parent Breed Breakdown: What Each Side Brings

Understanding a crossbreed starts with understanding its foundation breeds. The St. Bernard and Rottweiler differ significantly in drive, energy expression, and social behavior. Here is how they compare across the traits that most affect daily life with their offspring:

The key tension in this mix: the St. Bernard contributes a laid-back, people-oriented disposition while the Rottweiler contributes protective instinct and physical intensity. Which parent a given puppy favors is the central question of owning this cross.

How Big Will a St. Bernard Mixed With Rottweiler Get?

Both parent breeds are classified as giant or large-breed dogs, so there is no scenario where this mix stays small. However, the range is wider than many buyers anticipate.

A puppy that inherits the Rottweiler's more compact frame may plateau around 100 lb, while one that draws heavily from the St. Bernard's skeletal structure can easily surpass 150 lb. Paw size at 8–10 weeks offers a rough indicator — oversized paws relative to body typically predict the larger end of the range — but this is far from scientific.

Coat Types, Shedding, and the Hypoallergenic Question

Let's answer the hypoallergenic question immediately: no, this mix is not hypoallergenic, and neither parent breed carries low-shedding genetics. There is no Poodle, Bichon, or Portuguese Water Dog in this lineage. Anyone with significant pet dander allergies should look elsewhere.

The coat itself falls into one of three possibilities depending on which parent genes express:

• Short, dense double coat (Rottweiler-dominant): Flat-lying black outer coat with rust/mahogany markings. Moderate year-round shedding with seasonal "blows" in spring and fall. Lower grooming time but visible fur on furniture and clothing daily.
• Medium-length rough coat (St. Bernard rough-coat dominant): Slightly wavy, thicker outer coat with possible white chest, blaze, and collar markings. Heavy shedding. Requires brushing 3–4 times per week to prevent matting at the ruff, breeches, and tail.
• Intermediate coat: Most common outcome. Slightly longer than a Rottweiler's but shorter than a rough-coated St. Bernard's. Moderate-to-heavy shedding. Expect a mix of the Rottweiler's black-and-tan coloring with some white flash from the St. Bernard side.

Regardless of coat type, plan for:

• Brushing sessions 2–4 times weekly using an undercoat rake (the Furminator Large or Safari Undercoat Rake work well for this coat density)
• Professional deshedding treatment every 6–8 weeks during heavy shed seasons ($60–$90 per session)
• A high-suction vacuum rated for pet hair — the Dyson V15 Detect or Shark Navigator Lift-Away handle large-breed volume effectively

Temperament: The Best Case and the Challenging Scenarios

This is where crossbreed unpredictability matters most. A St. Bernard mixed with Rottweiler can land anywhere on a spectrum between two very different behavioral profiles.

Key temperament factors that apply to most individuals of this cross:

• Family loyalty: Both breeds bond intensely. Expect a dog that follows you room to room and wants physical proximity.
• Child tolerance: Generally good with children they are raised with, but the sheer size creates accidental injury risk for toddlers. A 130 lb dog bumping into a 30 lb child will knock the child over. Supervision is non-negotiable for children under 8.
• Same-sex dog tolerance: Rottweilers can show same-sex aggression, particularly male-to-male. Early socialization and neutering reduce but do not eliminate this risk. Plan introductions with existing dogs carefully.
• Guarding instinct: Moderate to high. Even the more easygoing St. Bernard side contributes alertness. Expect barking at door knocks and wariness of delivery drivers. This is not a breed mix for people who want an "open door" household without management.
• Exercise tolerance: Moderate. Expect 45–60 minutes of daily activity (two 20–30 minute walks plus yard time). Avoid forced running or high-impact exercise before 18 months to protect developing joints.

Health Considerations: Hybrid Vigor Myth vs. Reality

The idea that crossbreeds automatically enjoy "hybrid vigor" — meaning they inherit fewer health problems than purebreds — is an oversimplification. While outcrossing can reduce the probability of recessive disorders that require two copies of a gene, both parent breeds of this mix share several significant health risks. A crossbreed inherits the combined risk pool, not a magically reduced one.

Here are the conditions to screen for and budget around:

Responsible breeders of this cross should provide:

• OFA or PennHIP hip and elbow scores for both parents
• Cardiac clearance (OFA cardiologist evaluation) for both parents
• OFA ophthalmologic evaluation for the St. Bernard parent
• DNA screening for known breed-relevant mutations where available

Always consult your veterinarian for a health screening schedule tailored to your individual dog's age, size, and inherited risk factors.

Generations, Breeding, and What F1 Means for This Mix

Most St. Bernard mixed with Rottweiler litters you will encounter are F1 — a deliberate pairing of two registered purebred parents. This is generally the healthiest generation because it maximizes genetic distance between parents. However, it also means the most variability: one puppy may be a 100 lb Rottweiler-looking dog with a St. Bernard's temperament, while a littermate may be a 160 lb St. Bernard-looking dog with a Rottweiler's guarding intensity.

This variability is not a defect — it is an inherent feature of first-generation crosses. Buyers who need predictability should consider adopting an adult dog whose size and temperament are already established, or choosing a purebred breed instead.

Cost: Purchase Price and Lifetime Ownership Budget

This is not an inexpensive dog to acquire or maintain. Giant breeds carry higher costs across every category of care.

Estimated first-year total cost: $4,500–$9,000 (including puppy purchase, initial veterinary care, supplies, food, and insurance). Ongoing annual cost after year one: $3,000–$5,500.

Training, Socialization, and Daily Care

A 140 lb dog that pulls on leash is a liability. Training is not optional for this mix — it is a safety requirement. Here is a practical framework:

1. Weeks 8–16 — Critical socialization window: Expose the puppy to 100+ novel experiences (surfaces, sounds, people in hats, umbrellas, wheelchairs, other dogs of all sizes). Follow the American Veterinary Society of Animal Behavior's socialization guidelines. Enroll in a positive-reinforcement puppy class immediately — do not wait for the full vaccine series; the behavioral risk of under-socialization outweighs the disease risk in controlled class environments.
2. Months 4–8 — Foundation obedience: Focus on loose-leash walking, recall, "leave it," and settle/mat training. Use high-value treats (real chicken, cheese, freeze-dried liver). Giant breeds can be slower to physically mature, so keep training sessions short (5–10 minutes) to avoid frustration.
3. Months 8–18 — Adolescent management: This is the highest-risk period. The dog is near full size but lacks impulse control. Maintain structured routines, continue classes, and manage the environment (use baby gates, tether training, and crate time to prevent rehearsing unwanted behaviors).
4. Ongoing — Maintenance training: Weekly practice sessions, periodic advanced classes, and enrichment activities like scent work or cart-pulling (a natural fit given both breeds' working heritage).

Methods to use: Positive reinforcement, clicker training, shaping, counter-conditioning for reactivity, and LIMA (Least Intrusive, Minimally Aversive) principles.

Methods to avoid: Shock collars, prong collars, alpha rolls, and dominance-based training. These techniques increase fear and aggression risk — the last thing you want in a 140 lb dog with protective genetics.

Who Should (and Shouldn't) Own This Mix

This mix thrives with owners who view dog training as an ongoing practice, not a one-time event. The ideal household has prior experience with powerful breeds, a secure outdoor space, and the physical ability to handle a dog that can pull with 150 lb of force if startled.

Frequently Asked Questions

What two breeds make up the St. Bernard mixed with Rottweiler?

One purebred St. Bernard and one purebred Rottweiler. Both are AKC Working Group breeds originally developed for draft work, cart pulling, and farm guarding in alpine and southern European environments.

How big will this mixed breed get?

Most adults fall between 100–150 lb (45–68 kg) and stand 24–30 inches (61–76 cm) at the shoulder. Males trend toward the upper range. Full size is typically reached between 18 and 24 months, though some individuals continue filling out through 30 months.

What will the temperament be like?

Variable. Expect a loyal, family-oriented dog with moderate-to-high alertness. The best outcomes combine St. Bernard gentleness with Rottweiler trainability. Challenging outcomes combine Rottweiler protectiveness with St. Bernard independence. Early socialization and consistent positive-reinforcement training are the strongest predictors of a well-adjusted adult.

Is the St. Bernard mixed with Rottweiler hypoallergenic or low-shedding?

No. Neither parent breed carries low-shedding genetics. This mix will shed moderately to heavily year-round, with increased shedding during seasonal coat blows. It is not suitable for households with pet dander allergies.

What health issues might this mix inherit?

The highest-priority concerns are hip dysplasia, elbow dysplasia, gastric dilatation-volvulus (bloat), dilated cardiomyopathy, osteosarcoma, and eyelid conformation disorders (entropion/ectropion). Health screening of both parent breeds before breeding significantly reduces — but does not eliminate — risk.

How much does a St. Bernard mixed with Rottweiler cost?

Expect $1,200–$3,000 for a puppy from a breeder who health-tests both parents. Adoption through breed-specific rescues ranges from $200–$600. First-year total ownership costs (purchase + veterinary + supplies + food + insurance) typically run $4,500–$9,000.

Is this mix recognized by the AKC?

No. The American Kennel Club does not register crossbreeds. Some designer registries (ACHC, IDCR) will register the cross, but these registrations carry no health or quality guarantees. Focus on the health testing of the individual parents rather than registry status.