Health

As a consequence of selective breeding, French Bulldog are disproportionately affected by health related problems:

Brachycephalic airway obstructive syndrome
The skull malformation brachycephaly was increased by breeding selection which led to the occurrence of the brachycephalic airway obstructive syndrome. Therefore many French Bulldog often pant sticking out their tongue even at slight efforts like walking. The brachycephalic syndrome causes them to have multiple side effects, as in difficulty breathing (which includes snoring, loud breathing). It happens because they have narrow nostril openings, a long soft palate, and fairly narrow tracheas. This issue can lead to death in French Bulldog if they are not undergoing proper treatment.

In order to treat these dogs and create a smoother airway to the lungs, a procedure must be done that takes out a portion of their soft palate. The results of the procedure show a minimum of 60% better airway passage to the lungs.

In 2013, a UK Medical Study reviewed the health of 2228 French Bulldog under veterinary care in the UK. The study found that 1612 (72.4%) of these French Bulldog had at least one recorded health issue: "The most common disorders recorded were ear infections (14.0%), diarrhea (7.5%) and conjunctivitis (3.2%). Skin problems were the most commonly reported group of disorders (17.9%). This study of over two thousand French Bulldog provides a framework to identify the most important health priorities in French Bulldog in the UK and can assist with reforms to improve health and welfare within the breed."

Temperature regulation-related issues
The French Bulldog has only a single short coat, which combined with their compromised breathing system, makes it impossible for them to regulate their temperature efficiently. This means the dog may easily become cold, and are prone to heat stroke in hot and humid weather. French Bulldog are also prone to allergies, which can cause eczema on the body.

As they are a brachycephalic breed, French Bulldog are banned by several commercial airlines due to the numbers that have died while in the air. This is because dogs with snub noses find it difficult to breathe when they are hot and stressed. The temperature in a cargo space in an aircraft can rise as high as 30 °C (86 °F) when waiting on the runway.

Birth and reproduction
French Bulldog sometimes require artificial insemination and, frequently, Caesarean section to give birth, with over 80% of litters delivered this way.

Back and spine
French Bulldog are prone to having congenital hemivertebrae (also called "butterfly vertebrae"), which will show on an X-ray.

In October 2010, the UK French Bulldog Health Scheme was launched. The scheme consists of three levels: the first level, Bronze, designates a basic veterinary check which covers all the Kennel Club Breed Watch points of concern for the breed. The next level, Silver, requires a DNA test for hereditary cataracts, a simple cardiology test, and patella grading. The final level, Gold, requires a hip score and a spine evaluation. The European and UK French Bulldog fanciers and Kennel Clubs are moving away from the screw, cork-screw or 'tight' tail (which is an inbreed spinal defect), and returning to the short drop tail which the breed originally had. The UK breed standard now states that the tail should be "undocked, short, set low, thick at root, tapering quickly towards tip, preferably straight, and long enough to cover anus. Never curling over back nor carried gaily."

The French Bulldog may develop skin fold dermatitis.

Health

At all stages of development, the Mastiff should show the breed characteristics of massiveness and sound, if cumbersome, movement. The Mastiff is a particularly large dog demanding correct diet and exercise. Excessive running is not recommended for the first 2 years of the dog's life, in order not to damage the growth plates in the joints of this heavy and fast-growing dog, which in some weeks may gain over 5 lb. However, regular exercise must be maintained throughout the dog's life to discourage slothful behaviour and to prevent a number of health problems. A soft surface is recommended for the dog to sleep on to prevent the development of calluses, arthritis, and hygroma (an acute inflammatory swelling). Due to the breed's large size, puppies may potentially be smothered or crushed by the mother during nursing. A whelping box, along with careful monitoring, can prevent such accidents. The average lifespan of the Mastiff is about 7 years, although it is not uncommon for some to live 10–11 years.

Major problems can include hip dysplasia and gastric torsion. Other problems include obesity, osteosarcoma, and cystinuria. Problems only occasionally found include cardiomyopathy, allergies, vaginal hyperplasia, cruciate ligament rupture, hypothyroidism, OCD, entropion, progressive retinal atrophy (PRA), and persistent pupillary membranes (PPM).

When purchasing a purebred Mastiff, experts often suggest that the dog undergo tests for hip dysplasia, elbow dysplasia, thyroid, and DNA for PRA.

A Mastiff may be kept in an apartment, but care must be taken to give it enough exercise. Mastiffs should be fed two or three times a day; it is believed that one large meal per day can increase the chance of gastric torsion.