Mastiff (English Mastiff)

The FCI standard describes the Mastiff's behavior as "a combination of grandeur and courage": calm, affectionate to its owners, but capable of guarding; usually indifferent with strangers. Timidity isn't acceptable. Aggressive or overly shy dogs are disqualified. Its use is as a watch and security dog.

The AKC describes the breed as docile and dignified, but also a formidable protector of those it holds dear. It writes that Mastiffs are eternally loyal and protective of family, and that a natural wariness of strangers makes early training and socialization essential. It adds that Mastiffs communicate a great deal with their eyes and are excellent at reading their owner's expressions and body language.

The Mastiff suits calm, patient people who have experience with giant breeds and the space and strength to carry, wash and house a dog this size. The AKC writes that its exercise needs are comparatively low and that it can live happily in an apartment; but at this size, stairs, elevators, vet visits and car transport are a serious logistical job.

According to the FCI, the Mastiff comes from Great Britain, and its use is as a watch and security dog. The AKC writes that mastiff-type dogs have been known around the world for thousands of years, with examples on Egyptian monuments dating to about 3000 BC. For the British type, the AKC describes Julius Caesar noting in his journal the mastiffs that helped defend Britain when he invaded in 55 BC; the Mastiff as we know it took shape in medieval England, working as a big-game hunter, nighttime guardian of estates and war dog. According to the AKC, the breed once dwindled to very few dogs in England (an estimated 14 survived) and was rebuilt with dogs exported back from other countries. The AKC says today's Mastiff is more docile and friendly than its ancient forebears, but no less courageous.

Its close relatives the Bullmastiff, the Dogue de Bordeaux and the Neapolitan Mastiff come from the same mastiff family and from other countries. If you're considering a mastiff-type dog, compare them all.

According to the FCI, the Mastiff is a large, heavy-boned dog with a broad, deep body, full of substance; its head gives a square appearance, and the breadth is in a 2:3 ratio to the length of the head and face. The muscles are sharply defined. The standard says size is desirable only when it's combined with quality and soundness: being big isn't a goal by itself. The eyes are moderate in size, wide apart, hazel brown; loose eyelids are "highly undesirable," and the dog should be free from obvious eye problems.

• Height: According to the AKC, males are at least 30 in (about 76 cm). The current text of the FCI standard gives no numeric height.
• Weight: The AKC gives 160–230 lb (about 73–104 kg).
• Coat: Short and close-lying, coarser over the neck and shoulders.
• Color: Apricot, fawn or brindle; in every case, the muzzle, ears and nose are black, with black around the eye rims. Excessive white on the body, chest or feet is highly undesirable.
• Ears and tail: The ears are small, thin, wide apart and lie flat against the cheeks; the tail is set high, reaches the hocks or a little below, and hangs straight in repose.

The AKC says the Mastiff's short, dense coat is easy to groom, usually needing only a quick brushing every few days. During heavy shedding once or twice a year, more frequent sessions with a strong, toothed comb remove dead hair. The deep wrinkles around the head, eyes and muzzle and the ears should be checked and cleaned regularly, and the nails kept short. On drool, the AKC offers a tip: owners keep cloths at hand to wipe the slobber off the dog's face. See our dog grooming guide for general methods.

• Elbows: The AKC writes that hygromas (harmless natural "cushions" over the elbows) are common when the dog lies on hard surfaces. Put a soft bed over hard floors.
• Teeth: Brush often with a toothpaste made for dogs.
• Hot weather: A big, heavy dog struggles easily in the heat. Shade, air conditioning, plenty of water and walks in the cool hours are a must; our article on dogs in hot weather covers the warning signs.

The AKC calls obedience training and early socialization "musts" for Mastiffs. But it says the repetitions in a typical training class quickly bore them, at which point they may lie down, snoring. It writes that when treated with love, inclusion and respect, Mastiffs can be trained to excel in almost any sphere, and they respond best to gentle training. Eye contact matters in training too: Mastiffs communicate a lot with their eyes.

On exercise, the AKC says they benefit from free play and a daily walk of a mile or two (1.6–3.2 km). Take care not to overtax growing puppies and young adults: don't let them run up and down stairs, jump from heights or take long walks. The AKC suggests starting with no more than half a block for a 2- to 3-month-old puppy. Mastiffs are notorious for plopping down on walks when they're tired or overheated; since you can't carry a 175 lb (80 kg) dog, plan your route accordingly.

1. Early socialization: As a puppy, give it short, positive meetings with different people, children, sounds, vehicles and calm dogs, and keep this up for the first two years.
2. Basic cues: Come, wait, drop it and walking without pulling are the foundation of safe life with a dog that can top 150 lb (70 kg). Our guide to loose-leash walking explains it step by step.
3. Joint-friendly movement: Limit stairs and jumping from heights while it's a puppy; go for short, frequent walks on flat ground.
4. A routine for visitors: Use rewards to teach it to go to a calm spot when the doorbell rings; never leave guests alone with the dog.
5. Vet prep: Use rewards early on to get it comfortable with being handled and having its mouth, ears and folds checked; at this size, a dog is hard to hold at the vet.

The AKC writes that for rapidly growing giant breeds such as the Mastiff, proper nutrition is critical through puppyhood and up to 2 years of age. If fed a densely caloric diet lacking an appropriate calcium-to-phosphorus ratio, Mastiff puppies and young adults are prone to skeletal disorders. Most breed experts recommend starting puppies on an adult dog food formulation; make a growth plan with your vet and breeder covering the type of food, the protein level and the amount. The AKC also recommends scheduled meals rather than free-feeding, which is how you avoid excess weight.

• Controlled growth in puppyhood: Fast growth strains the joints; raising the puppy lean and steady matters.
• Lower the risk of bloat: Splitting the daily food into several small meals and keeping things calm right before and after eating is commonly advised for large, deep-chested dogs; talk through the details with your vet.
• Ideal weight: If you can feel the ribs under a thin layer of fat and see a waist from above, the weight is about right.

Also check our list of foods that are dangerous for dogs.

According to the AKC, responsible breeders screen the Mastiff for seasonal allergies, eye anomalies, heart disease, cancer, hip and elbow dysplasia, von Willebrand's disease (a blood clotting disorder), degenerative myelopathy (a progressive spinal cord disease) and epilepsy. The AKC also lists bone cancer, lymphoma, canine multifocal retinopathy (retinal folds), cystinuria, which can cause kidney stones, and progressive retinal atrophy. The information below is for awareness only; ask your vet about diagnosis and treatment.

Cancer

In the owner-survey study of mastiff-type dogs (Bell and Hesketh, 2021), the most common cause of death was cancer (47%); the most commonly recorded type was bone cancer. If you notice a new lump, limping, loss of appetite or weight loss, show your vet.

Bloat

The stomach can fill with gas and fluid and twist on itself (gastric dilatation-volvulus, or GDV). The AKC writes that Mastiffs can experience it too. The Merck Veterinary Manual describes it as an acute, life-threatening emergency that affects large and giant breeds, needing immediate care, with a mortality rate around 20% even in treated animals. Retching without bringing anything up, heavy drooling, restlessness and a swollen belly are the main signs.

Eyelids and eyes

A UK study of eyelid conformation disorders (O'Neill et al., 2025) reported that, even though breed standards were updated more than three decades ago to improve eyelid conformation, the reported incidence of inward- and outward-rolling eyelids in the Mastiff has still increased in the last decade. The FCI standard calls loose eyelids "highly undesirable." If you notice watering, redness or squinting, show your vet.

Joints and heart

In hip and elbow dysplasia, the joints don't develop properly and painful arthritis can follow. Limping and trouble getting up can be signs. When choosing a puppy, ask for the parents' hip and elbow X-rays and heart and eye exam results.

A 2024 study using data on about 585,000 dogs in the UK (McMillan et al.) found a median lifespan of 9.0 years for the Mastiff and listed the breed among those at highest risk of early death (hazard ratio 2.3). In the giant-breed study using UK data from 2019 (O'Neill et al., 2026), the median age of 56 Mastiffs that died was 9.64 years. In the owner-survey study of mastiff-type dogs (Bell and Hesketh, 2021), the median age at death was 8 years. The AKC gives 6–10 years.

Mixed-breed dogs in the same study had a median of 12 years, so the Mastiff lives several years less than the average mixed-breed dog. A puppy from screened parents, a healthy weight, regular checkups and knowing the signs of bloat are the most concrete steps.

• Consider a shelter: Purebred and large dogs end up in shelters and rescues too. With a dog this size, seeing an adult's temperament and health up front is a big advantage. Our guide to adopting a dog from a shelter walks you through it.
• If you buy from a breeder: Meet the parents in person and make sure they're calm and steady. Ask for hip and elbow X-ray results and heart and eye exams, and ask about cancer in the family. See that the puppies are raised in a home around people.
• Red flags: Promises of an extra-large puppy ("record size"); dogs sold as "guard" or "tough" dogs; sellers who won't show you the mother or can't provide paperwork.
• Time and budget: Food, vet care, medication and transport costs are serious; make sure the dog will fit in your car and that your vet will take a dog this size.
• Registration: Rules vary by country. In Türkiye, owned dogs must be microchipped and registered in the PETVET system. Details are in our article on PETVET registration and microchips.