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

Great Danes, like most giant dogs, have a fairly slow metabolism. This results in less energy and less food consumption per pound of dog than in small breeds.

Great Danes have some health problems that are common to large breeds. Bloat (a painful distending and twisting of the stomach (Gastric volvulus)) is a critical condition that can affect Great Danes and results rapidly in death if not quickly addressed. It is a commonly recommended practice for Great Danes to have their stomachs tacked (Gastropexy) to the interior rib lining during routine surgery such as spaying and neutering if the dog or its relatives have a history of bloat, though some veterinary surgeons will not do the operation if the actual sickness has not occurred. Elevated food dishes are often believed to help prevent bloat by regulating the amount of air that is inhaled while eating, although one study suggests that they may increase the risk. Refraining from exercise or activity immediately before and after meals may also reduce risk. They can live between 8-12 years.

Another problem common to the breed is in the hips (hip dysplasia). Typically an x-ray of the parents can certify whether their hips are healthy and can serve as a guideline for whether the animals should be bred and are likely to have healthy pups.

Dilated cardiomyopathy (DCM) and many congenital heart diseases are also commonly found in the Great Dane. Also, some Danes may develop yeast infections, when not fed all needed nutritional requirements. The yeast infection may also lead to minor recurring staph infection(s).

Great Danes also suffer from several genetic disorders that are specific to the breed. For example, if a Great Dane lacks color (is white) near its eyes or ears then that organ does not develop and usually the dog will be either blind or deaf. Many pure white Danes are deaf.