Health

The median longevity of Beagles is about 12.3 years, which is a typical lifespan for a dog of their size. Weight gain can be a problem in older or sedentary dogs, which in turn can lead to heart and joint problems. Beagles may be prone to epilepsy, but this can be controlled with medication. Hypothyroidism and a number of types of dwarfism occur in Beagles. Two conditions in particular are unique to the breed:

Funny Puppy, in which the puppy is slow to develop and eventually develops weak legs, a crooked back and although normally healthy, is prone to range of illnesses

Chinese Beagle Syndrome in which the eyes are slanted and the outer toes are underdeveloped but otherwise development is as normal.

Hip dysplasia, common in Harriers and in some larger breeds, is rarely considered a problem in Beagles.

In rare cases Beagles may develop immune mediated polygenic arthritis (where the immune system attacks the joints) even at a young age. The symptoms can sometimes be relieved by steroid treatments.

Their long floppy ears can mean that the inner ear does not receive a substantial air flow or that moist air becomes trapped, and this can lead to ear infections. Beagles may also be affected by a range of eye problems; two common ophthalmic conditions in Beagles are glaucoma and corneal dystrophy. "Cherry eye", a prolapse of the gland of the third eyelid, and distichiasis, a condition in which eyelashes grow into the eye causing irritation, sometimes exist; both these conditions can be corrected with surgery. They can suffer from several types of retinal atrophy. Failure of the nasolacrimal drainage system can cause dry eye or leakage of tears onto the face.

Health

Cavaliers can notably be prone to mitral valve disease, which leads to heart failure. This appears in many Cavaliers at some point in their lives and is the most common cause of death. Some serious genetic health problems, including early-onset mitral valve disease (MVD), the potentially severely painful syringomyelia (SM), hip dysplasia, luxating patellas, and certain vision and hearing disorders are health problems for this breed. As today's Cavaliers all descend from only six dogs, any inheritable disease present in at least one of the original founding dogs can be passed on to a significant proportion of future generations. This is known as the founder effect and is the likely cause of the prevalence of MVD in the breed. Additionally, bad breeding increases the chance that a Cavalier will develop MVD, so it is important to find a responsible breeder who uses dogs with healthy hearts rather than use the first breeder you come across. The health problems shared with this breed include mitral valve disease, luxating patella, and hereditary eye issues such as cataracts and retinal dysplasia. Cavaliers are also affected by ear problems, a common health problem among spaniels of various types, and they can have such other general conditions as hip dysplasia, which are common across many types of dog breeds.