8 Large Dog Breeds Known for Sweet Temperaments

An infographic comparing the weights and heights of Newfoundlands, Bernese Mountain Dogs, Great Danes, and Saint Bernards. — Compare the weight and average lifespan of four massive dog breeds in this helpful and clear infographic.

At a Glance: Size and Lifespan of Gentle Giants

If you want a quick visual comparison of these magnificent dogs, use this chart based on standard breed averages. Keep in mind that individual dogs can fall slightly outside these ranges.

Breed	Typical Weight (lbs)	Typical Height (inches)	Average Lifespan (years)
Newfoundland	100–150	26–28	9–10
Bernese Mountain Dog	70–115	23–27.5	7–10
Great Dane	110–175	28–32	7–10
Saint Bernard	120–180	26–30	8–10
Mastiff	120–200+	27.5–30+	6–10
Leonberger	90–170	25.5–31.5	7–11
Irish Wolfhound	105–180	30–35	6–8
Great Pyrenees	85–100+	25–32	10–12

A watercolor illustration of the humorous mess a giant dog can make in a house, including drool and knocked-over items. — A massive dog drips water and drool across the kitchen floor while its owner looks on in dismay.

What Can Go Wrong

Living with a giant breed requires substantial lifestyle adjustments. While their personalities are universally appealing, their massive biology introduces several distinct challenges you must prepare for before bringing one home.

Gastric Dilatation-Volvulus (Bloat): Giant breeds with deep chests face a high risk of bloat, a sudden and life-threatening condition where the stomach fills with gas and twists. You will need to monitor their eating habits, feed them smaller meals, and prevent heavy exercise immediately after they eat.
Orthopedic Stress: Carrying 150 pounds puts immense strain on a dog’s joints. Conditions like hip dysplasia, elbow dysplasia, and arthritis are common. You must prevent puppies from overexerting themselves while their growth plates are still open.
The Financial Footprint: Everything costs more when your dog weighs as much as an adult human. Heartworm medication, flea prevention, antibiotics, and anesthesia are dosed by weight. You will also spend significantly more on premium food, heavy-duty leashes, and oversized orthopedic beds.
Shorter Lifespans: The hardest reality of loving a giant breed is the heartbreak of an accelerated aging process. Many of these breeds only live seven to ten years, meaning you get a shorter window of time to enjoy their company compared to smaller dogs.