For more information

If you are interested in more information about this breed contact the SPDR Breed Rep here.




Is the English Mastiff The Right Breed For You?

You're interested in a Mastiff. Owning a Mastiff can be the beginning of a wonderful relationship with years of happiness or it can be the beginning of overwhelming responsibility for which you may not be prepared. Mastiffs are loving, slobbery, gentle giants. They are the largest of the dog breeds and can range in size from 26 inches to 36 inches at the shoulder. They weigh anywhere from 120 pounds to 225+ pounds. Once they are over their major growing stage, they will eat between 6-8 cups of high quality food per day.

They are very sensitive dogs and the sternest of voices is all you need for discipline.

There are several questions you must ask yourself to determine if you are ready to become a Mastiff owner. Answer honestly to insure yourself, your family, and your Mastiff the future you all deserve.

Do I Really Want a Mastiff? Why Do I Want a Mastiff?

Mastiffs are wonderful companions. They are not dogs to be left outside chained to a doghouse or to be left alone in a fenced yard. They desperately need lots of human companionship to be properly socialized, trained, and "owned". If your house is too small for a 150-230 lb. dog, then a Mastiff is not the dog for you. We have found that behavioral problems occur when a Mastiff is not a member of the family but is relegated to the backyard with only occasional human contact.

Mastiffs slobber, some more than others, but all do after they eat or drink.

Are you prepared to wash your walls, ceilings, etc. after the slobber flies when they shake their heads? Slobber rags must always be handy in strategic locations all over the house. They always seem to drink when you are ready to walk out the door for work!

Mastiffs will snore and sometimes you think a train is going through the house.

Are you a light sleeper or one that needs constant quiet to sleep? If so, consider another breed. They will want to keep you warm at night on the bed of course. If not on the bed, then they will want to sleep in the same room. They can be amazingly agile at 2:00 am!

Mastiffs are NOT guard dogs.

They will protect their family more along the lines of a watch dog than guard dog. If your intent is to have a dog that is a guard dog then you must think about another breed. They will often bark and let intruders know they are not accepted. Once you accept the guest, chances are good that they will too. Their mere presence and bark will scare the bravest of burglars.

Mastiffs are wonderful dogs with children.

They are very gentle and quite tolerant of ear and tail pulls, sitting on their backs (not a good idea), and they adore licking kid's faces. They will protect their children. Of course, please make sure that you supervise and train your children to respect and treat the dog well. In rescue, we will not place a dog with a family with small children unless the dog has been raised with them in the previous home. The swinging tail of a Mastiff can knock a small child over. If you have very small children who are just learning to walk, you may want to wait until they are older before getting a Mastiff whether it's a puppy or a rescue dog.

Mastiffs can be territorial dogs.

They will protect their yard, house, car and family from people or dogs. They want it to be known that this is their yard. They are dogs that can be very good with other dogs and with cats as long as they have had good experiences with them. If you have an adult male dog already and you are getting a rescue, you might want to consider a female Mastiff and vice a versa. This is not to say that two males cannot get along but males especially have a tendency to want to dominate each other if they have been recently neutered.

Can I Really Afford To Keep a Mastiff?

An adult male Mastiff can go through 40-70 pounds of dry dog food a month. That's a rough estimate of $35 to $70 a month in food alone.

A Mastiff due to its size will cost you more money at the Vet's office also.

Remember the antibiotic for Aunt Mary's toy poodle only cost her $10.00 but since most dosages are based on weight, a week's supply of antibiotics for your Mastiff can cost upwards of $50 to $100. Heartworm medicine costs more, shots can sometimes be more costly, etc. You can expect to spend approximately, (depending on the age and medical conditions of your Mastiff) $200 to $500 per year at the Vet's office.

Do I Have Time To Spend Training, Exercising, And Grooming a Mastiff?

A Mastiff needs obedience training. It is imperative that obedience training be done. After all do you want to be pulled down the street legs streaming behind you when your 185 lb. male wants to chase that squirrel? The obedience training must be the positive reinforcement type. Mastiffs respond well to love, praise, and especially treats. The training should not be negatively based nor should it be the type where the dog is jerked around using different types of collars. Who is capable of jerking a large dog around anyway, at least not without some major muscle strain?

Exercising a Mastiff is not as difficult as exercising one of the various sporting breeds who seem to have endless energy.

A Mastiff is happy to go on 2 walks a day of about 20 - 30 minutes. Some love to hike, swim, but jogging companions they are not! They will not jog and should not be asked to as it can be very difficult on their joints. About a mile or so walk twice a day is enough unless it's an older Mastiff, then play it by ear. Their exercise can be walks with you around the neighborhood, hikes in the forest, swims in the local lake, or chasing a soccerball. Remember Mastiffs are like some of us... a couch is their idea of the perfect place to spend a day but exercise is important to keep them fit and help them live longer.

Grooming a Mastiff is very easy. One to two times per week with a shedding blade or comb is sufficient.

Cutting nails is important and should be done regularly. It should be started early in life as wrestling with a large dog is very interesting! Teeth cleaning should also be done regularly.

No matter what; a Mastiff wants to be with you.

They thrive on being house dogs sharing your life. They will follow you from room to room as you do your work. As you do things, they will follow and hope that you will spend more than a moment in each room. After all it takes a lot of effort to keep getting up after they've been lying down! They are devoted to their owners and want to have contact with them frequently. Some want to touch you all the time to reassure themselves that you are still there. Will a Mastiff Fit Into My Lifestyle And My Home? Mastiffs want to be with you. They love their masters and are very devoted to them. Do you own a big car or van so your Mastiff can go for rides with you to the park, beach, post office, etc?

As stated earlier, the Mastiff is a house dog. A small house is suitable as long as the Mastiff goes for walks and plays outside. The yard should be fenced and the Mastiff obedience trained through the basics: come, sit, stay, down, and he should walk on leash without dragging you down the street.

You must like big wet slobbery kisses as they love to give them. They love to sneak on the bed when you are deep in sleep. Snuggling is a favorite pastime as well as touching some part of their human, whether it be to sit on their feet, a head on the lap, or a paw to say Hi!

Owning a Mastiff is a major responsibility but they will reward you a million times over with their love. They are not the breed for everyone however, due to their size and their need to be a major part of your family.

Please remember that your rescue Mastiff has been traumatized by the changes that have occurred in their life. Mastiffs have a difficult time with change. They are not ready to be the perfect pet you have read about in books. Be understanding and help them through the rough spots. Your efforts in doing this will be greatly rewarded.

Mastiff Health Information Sheet

In keeping with the spirit of the MCOA Code of Ethics, Mastiff breeders are encouraged to inform puppy buyers of developmental conditions that may or may not be hereditary or genetic, that are known to exist in Mastiffs, as well as methods to test and/or monitor some of these conditions.

It is hoped this Health Information Sheet will guide buyers to ask pertinent questions, encourage their review of testing certifications and enable them to make educated decisions before purchasing a Mastiff.

Preferably buyers should be asked to read this before committing to a purchase and encouraged to ask questions. It is important that the buyer understand the potential for these conditions or problems to develop in any Mastiff, regardless of the line, pedigree, breeder, or testing of ancestors and thus the need for testing and reporting the results of those tests to the breeder and participating in ongoing research efforts. Please keep in mind that all purebred and mixed breed dogs can have health concerns including show dogs, working dogs, family pets, and service companion animals.


  • Canine Multi-focal Retinopathy (CMR), also known as Retinal Dysplasia/Retinopathy - Abnormal development of the retina present at birth and recognized to have three forms: folds, geographic, and detachment. A Mastiff with folds will currently pass CERF and the folds may disappear over time while the geographic and detached forms may cause loss of vision or blindness. There is a DNA test available though OptiGen for CMR in Mastiffs.
  • Cataract - Lens opacity that may affect one or both eyes and some forms may cause blindness.
  • Distichiasis - Eyelashes abnormally located in the eyelid margin which may cause ocular irritation.
  • Ectropion - Conformational eyelid defect, which may cause ocular irritation due to exposure.
  • Entropion - Conformational defect where eyelid margins invert or roll inward, toward the eye causing eyelashes and hair to rub against the cornea which may result in ocular irritation and pain.
  • Macroblepharon - Abnormally large eyelid opening; may lead to secondary conditions associated with corneal exposure.
  • Persistent Pupillary Membranes (PPM) - Persistent blood vessel remnants in the anterior chamber of the eye which fail to regress normally in the neonatal period.
  • Progressive Retinal Atrophy (PRA) - Degenerative disease of the retinal visual cells which leads to blindness. In Mastiffs the age at which PRA can be detected varies from as young as 6 months to as late as 42 months. Typically Mastiffs with PRA go blind gradually, first loosing their night vision and then their day vision. Many do not go completely blind until they are 8 years old or older. There is a DNA test available through OptiGen for PRA in Mastiffs.


  • Anterior Cruciate Ligament (ACL) Rupture - The knee along with the external support (i.e., collateral leg) has two ligaments inside the joint that help prevent forward movement (i.e., cruciate). Insult/injury can cause this ligament to rupture and result in acute lameness (not want to bear weight) on the limb.
  • Degenerative Myelopathy (DM) - This is a progressive, degenerative, late onset disease of the spinal cord seen in older dogs. The symptoms usually begin with hind end weakness, lack of coordination and shuffling or dragging of the rear feet. There is a DNA test for DM through OFA
  • Elbow Dysplasia - Elbow dysplasia encompasses several different conditions, all of which are indicative of abnormally formed or fused elbow joints and all can cause lameness and pain:
    • Fragmented Coronoid Process (FCP) - This form of elbow dysplasia is generally the most difficult to treat if the fragments are actually loose in the joint.
    • Osteochrondritis Dissecans (OCD) - A defect in the joint cartilage overlaying or attaching to the bone. OCD most commonly occurs in the elbows, shoulders, hocks and stifles.
    • Ununited Anconeal Process (UAP) - In giant breeds such as Mastiffs the Anconeal Process can close later than in smaller breeds, often as late as one year of age or older.
  • Hip Dysplasia - Hip dysplasia is a painful condition caused by abnormally formed hips. The animal may become lame in the hind quarters due to the pain associated with the degeneration of the hips.
  • Hypertrophic Osteodystrophy (HOD) - A developmental disorder that manifests with toes turning in or out, roached toplines, pinched rears, and in advanced stages fever, lethargy, pain in joints, inability to stand or function. This is a problem of intake in calories versus output of energy - too many calories consumed and/or unbalanced diet disrupted by supplementing.
  • Panosteitis (Pano or Wandering Lameness) - A developmental problem that affects the long bones during rapid growth periods typically between 6-16 months of age. The exact cause is unknown although genetics, diet, stress, infection, and metabolic or autoimmune problems have been suspected. Lameness can occur in one limb or over time in all limbs. It often is intermittent affecting one leg then another and back again. It is self-limiting and spontaneously disappears.
  • Spondylosis - is a degenerative disease that causes excessive bone production of osteophytes along the spinal vertebrae which can cause lameness. In advanced cases the vertebrae can fuse together. In many cases there are no clinical symptoms, but the acute expression of the disease such as lameness, severe pain and disabilities are often seen in adults and older Mastiffs.
  • Wobblers Syndrome - Cervical Vertebral Instability (CVI) is caused by pressure and pinching of the cervical spinal cord and the nerves in the neck due to ligament problems and/or vertebrae malformation. The compression on the spinal cord in the neck may cause the Mastiff to stand and move abnormally. This is believed to be an inherited genetic disorder with environmental influence. Rapid growth and nutrition may influence the expression of the disease.


  • Allergies - Some Mastiffs have allergies to certain foods, pollens, etc. Allergies are due to autoimmune problems and since they often run in certain lines they are believed to be inherited.
  • Cancer - Most forms of cancer have been diagnosed in some members of the breed. Cancer can be hereditary while others occur spontaneously or even due to environmental toxins. Although there are several forms of cancer found in Mastiffs, the most common types are: Osteosarcoma (Bone Cancer), Lymphoma, Hemangiosarcoma, Mast Cell Tumors, Squamous Cell Tumors, & Breast Cancer. Today there are advanced medical treatment options such as radiation, chemotherapy and medications to reduce the size of the tumors and offer pain management to help maintain a good quality of life.
  • Cystinuria - An inherited metabolic disease caused by a defective kidney transporter for cystine and some other amino acids. Because cystine readily precipitates in acid urine, crystals and later calculi (stones) can form in the kidney and bladder. Cystinuria in Mastiffs primarily affects males and can result in serious illness and may be life threatening.
  • Epilepsy - A seizure disorder which can have multiple causes. The age of onset of the inherited form is normally around 6 months to 5 years of age. Epilepsy is often difficult to treat successfully in Mastiffs and other large breeds.
  • Gastric Dilation, Torsion, Volvulus (Bloat) - Bloat is a hideous killer of giant breed animals, and Mastiffs are no exception. Without warning, the stomach fills with air (dilation), can twist 180 degrees (torsion) on its long axis, or more than 180 degrees (volvulus) thereby cutting off blood and oxygen to vital organs. Bloat can be primary or secondary, caused by emotional or physical stress, improper nutrition or feeding habits, guzzling water, inappropriate exercise, as well as other causes that we do not understand. Every Mastiff owner needs to familiarize themselves with bloat symptoms and have a plan of action to get the animal to an emergency medical facility at the onset of the first symptom. A dog that is bloating often has approximately 3 hours to live without medical intervention.
  • Heart Disease - The most common heart problems in Mastiffs are cardiomyopathy, aortic stenosis and mitral valve dysplasia. Early detection and treatment are essential for a good prognosis. Some mastiffs have heart murmurs that are mild and not a cause for concern. If a heart murmur is detected it is essential to have it checked to see if it is an "innocent" murmur or a serious problem.
  • Hypothyroidism - Hypothyroidism is the result of an abnormally functioning thyroid gland resulting in a lower than normal level of thyroid hormone. This lack of thyroid hormone can have serious health consequences including coat and skin problems, intolerance to cold, weight gain or loss, infertility, sudden aggression, and immune system malfunctions. The inherited form is autoimmune thyroiditis where the body's own immune system attacks and destroys the thyroid gland or reduces its function. Autoimmune thyroiditis is diagnosed by measuring the FT4D, cTSH & TgAA. Acquired hypothyroidism can be caused by various problems such as stress for long periods of time, poor nutrition, prolonged infections, and chemical agents.
  • Reproductive Issues - There are several reproductive problems that can affect Mastiffs and it is encouraged that you research this area if you plan to breed. Some of the most common are pyometria (uterine infection), cryptorchidism (undescended testicles), failure to conceive, and vaginal hyperplasia.
  • von Willebrand's Disease (vWD) - An abnormal bleeding disorder due to a lack of normal clotting. An animal's life can be threatened by bleeding due to an injury, or during spaying/neutering or any other condition resulting in bleeding.
Breed Details

SPDR is a registered Washington state 501(c)(3) charitable organization   |   PO Box 3523, Redmond, WA 98073   |    206.654.1117
Copyright © 2017 Seattle Purebred Dog Rescue