
A variety of factors affect the health of your Leo. In addition to regular preventative veterinary care, a balanced diet, lots of fresh water, stable clean living conditions, daily exercise, love and companionship will go a long way to keeping your Leo healthy.
This section is not intended as a substitute for veterinary care.
IMPORTANT!
Seek immediate veterinary treatment for your Leo when you first notice your dog is “not quite right”. Timely veterinary care can help prevent health problems.

Allergies
Some Leos may be prone to allergies. These usually manifest as skin conditions but may also involve the gastrointestinal tract. Allergies may be environmental (e.g. dust mites, fleas, pollens) or food related. They typically manifest in the 2-4 year old range. The gold standard for diagnosis is made with skin testing for environmental allergies and an elimination diet for food allergies. Management can then involve allergy shots and careful diets, respectively.
Bloat (Gastric torsion/ Gastric dilation volvulus – GDV)
Bloat is a moderately common problem in Leos. In this very acute condition, the stomach twists and traps gas inside, causing extreme pain. Unless treated very quickly (within minutes to an hour of occurrence), death may result. Irreversible damage to the stomach, intestine and/or spleen, can occur due to the twist. This problem is more common in Leos with deep chests and tucked up waists. In Leos coming from lines with this problem it may be reasonable to consider a procedure to tack the stomach to the abdominal wall to reduce risk, especially if the Leo is to be under anesthesia for another procedure – spay, neuter, dental,
Risk factors of bloat:
https://www.whole-dog-journal.com/health/bloat-in-dogs-is-deadly/
https://www.vin.com/apputil/content/defaultadv1.aspx?meta=Generic&pId=11165&id=3848657
Ear Infections
Ear infections are common in Leos, as with any floppy eared dog. The dark, moist environment generated by this ear style creates a perfect place for yeast and/or bacteria growth. Cleaning ears with an acetic acid (not alcohol) based dog ear cleaner after baths and swimming will help prevent problems. Signs of ear infection include brown, yellow, or green discharge, sore or itchy ear, red and/or swelling in the ear canal, foul smell to the ear, and/or head tilt.
Addison’s
Addison’s disease is a problem where the body does not produce enough corticosteroids, hormones critical to many physiologic functions and control of inflammation. Due to testing and careful breeding choices Addison’s has been basically eradicated. However, spontaneous cases do still occur. It is more common in young to middle aged adult females. Signs may include generalized and muscle weakness, collapse, anorexia, vomiting, diarrhea, hair loss, excessive drinking and/or urinating. Signs can wax and wane and seem worsen with stress. Diagnosis is made with blood tests and it can be controlled with replacement corticosteroids.
Cataracts
Both juvenile and senile cataracts have been found in Leos. This condition involves the formation of a defect in the lens of the eye. Dogs tolerate small cataracts well but can experience difficulty with daily visual functions when cataracts become large. Veterinary ophthalmologists can remove cataracts surgically restoring vision effectively.
Hypothyroidism and Autoimmune Thyroiditis
The thyroid gland is a critical organ present in all mammals and controls the metabolism in most systems of the body. It can stop working in Leos due to gradual loss of functional gland over time with age (regular hypothryoidism) or due to immune stimulated inflammation and replacement of the gland with scar tissue (autoimmune thyroiditis – an inherited disease). Weight gain, poor hair coat (dry/thin), mental dullness, heat seeking, skin problems, weakness, and decreased exercise tolerance are the most common signs. Behavior changes, neurologic findings and gastrointestinal issues can also be found. Regular hypothyroidism commonly manifests in middle to old age; autoimmune form shows up typically between 2 -5 years of age. Diagnosis is made with a blood test and treatment is provision of daily replacement hormone via a pill for the rest of the Leo’s life.
Leonberger Polyneuropathy
A Leonberger with LPN has a disease which affects the nerves and thus secondarily the muscles which are innervated by those nerves. The longest nerves of the body are those affected first and most profoundly. Thus the earliest signs appear in the hind limbs and/or the larynx or “voice box” which is innervated by one of the longest nerves in the body. The classic signs are gradually progressive and include exercise intolerance and gait abnormalities, ranging from a mild sloppiness to an exaggerated “marching” or “marionette-like” step. Less commonly, the forelimbs may become affected as well. With accompanying loss of muscle tone and mass, a Leo can eventually lose the ability to support its own weight. If the larynx is involved, the upper airway becomes compromised resulting in noisy breathing, change in bark and in moderate to severe cases difficulty breathing. This part of the disease can be life threatening so it is very important that the Leo’s ability to breathe be monitored closely as some dogs will benefit by surgery to reopen the narrowed airway. Signs may begin before the age of 3 years or may not occur until a dog is older, in which case the symptoms are generally of a much milder nature.
Through collaboration of breeders, owners and neuroveterinary research scientists from around the world this disease is now recognized as likely being a group of genetically distinct diseases with similar clinical presentations. Find much more information and links to testing for these diseases at Leonberger Health Foundation International website: https://www.leohealth.org/genetic-testing.html
Videos – LEMP, LPN
Panosteitis (Pano, wandering lameness, puppy limp)
An inflammation of the long bones is often seen in Leos from about 5 months to 18 months of age. It is more of a nuisance condition as it does not create any permanent physical damage. However, it is definitely painful and can leave a vigorous Leo pup frustrated because it hurts to play, walk, etc. Lameness without any limb swelling, redness, or heat is the most common finding. The lameness often moves from one leg to another. Some Leos will have it for a few weeks, some for a few months. Since here are other more worrisome things that cause lameness in a Leo puppy (e.g. fractures, dislocations), it is worth having a veterinarian evaluate all lameness. Treatment is rest and some advocate for a lower energy/calorie diet to slow the very rapid long bone growth.
Hip Dysplasia
Hip dysplasia can arise from genetics, environment (diet, poor traction surfaces) or a combination thereof. Breeders of Leos have been diligent trying to eradicate the problem but it is a difficult challenge. The inheritance pattern from parents is unknown so two parents with very normal hips may generate Leo puppies with hip dysplasia. It is not a huge problem in the breed but it is present. Hip dysplasia means that there are characteristic structural defects in one or both hip joints that may predispose the Leo to degenerative joint disease or arthritis. The diagnosis is made on x-rays.
Moist Dermatitis (Hot Spots)
Moist dermatitis or hot spots are a common problem in dogs and Leos are no exception. They can appear in Leos with chronic diseases like hypothyroidism and allergies but they also can appear on the most healthy Leo with the best skin and coat. Hot spots often start when the Leo get fixated on a certain location on the skin (from an insect bite, a small scratch or wound, etc) and begins to lick. Once licking starts the skin gets chapped and integrity is lost. Once the skin barrier is broken, bacteria enter, infection starts and a hot spot is in full bloom. Most Leo owners and veterinarians have their own recipes for management. The basic key is to stop the licking, clean and dry the area and treat any irritation and infection, If you find such a spot on your Leo, a trip to the veterinarian is in order but while waiting start trying to prevent licking.
Osteosarcoma
Bone cancers are common in giant breed dogs and unfortunately Leonbergers are no exception. This malignant disease is most commonly seen in Leos, of both sexes, in the latter half of life. However, an occasional young adult can be diagnosed as well. The most common signs seen in Leos with osteosarcomas are a limp or gait disturbance. This finding will be progressive but may wax and wane a bit at first. This is typically a very painful condition so other signs like depression, decreased activity, and even decreased appetite can be seen. Osteosarcomas tend to metastasize or spread to the rest of the body rather early. Therefore, early diagnosis with x-rays +/- a biopsy is very important. There are many tools available for palliative care of osteosarcoma patients, in the meantime we continue to work toward a cure. Much research progress in ongoing in this area.
Hemangiosarcoma
Hemangiosarcomas, are a very vascular malignant tumor, that unfortunately seems to relatively common in Leonbergers in the latter half of life. This tumor tends to arise in organs rich in blood supply, so commonly the spleen and the heart. It seems that in Leos most are found on the spleen. The fortunate aspect of this malignancy is that is causes no pain. However, because it only causes subtle signs it is often difficult to catch these tumors at a potentially manageable size. The typical course for this tumor is slow growth (over months) on the spleen. Once the tumor becomes quite large (golfball size and up) it may start to bleed. If you notice unexplained signs of weakness, lethargy, decrease activity or distention of the abdomen consult your veterinarian immediately
When or if to spay or neuter your Leonberger is often a difficult question. Research conducted by the University of California – Davis reveals that for some dog breeds, neutering and spaying may be associated with the increased risks of certain health conditions such as joint disorders including hip or elbow dysplasia, cranial cruciate rupture or tear, and some cancers, such as lymphoma, mast cell tumor, hemangiosarcoma, and osteosarcoma. The research conclusions are not surprising. Sex hormones are important in the development of any animal. We know they affect psychological development as well as the musculoskeletal, cardiovascular, and the immune system.
Large and giant breed dogs mature slower than smaller breeds. Many owners therefore wait to spay or neuter their dogs until they reach maturity. It is important to speak with your breeder and to be diligent in your research before making your decision.
Following are some resources to help you:
https://www.masterclass.com/articles/dog-neutering
American Veterinary Medical Association
https://www.avma.org/resources/pet-owners/petcare/spaying-and-neutering
Alternatives to regular spaying / neutering:
http://caninechronicle.com/current-articles/new-study-compares-health-effects-of-spay-castration-vasectomy-and-ovary-sparing-spay-in-dogs
https://blog.adoredbeast.com/the-great-spay-neuter-contradiction-fixing-your-animal/
- Buy a Leonberger from a reputable breeder who will stand behind the health of his/her dog. If you adopt from a rescue group, discuss the health and behavioral issues which may or may not affect your new Leo.
- Leos may be picky eaters and most do not overeat. However, make sure you keep your Leo at the right weight. Ask your veterinarian to help you judge the proper weight for your Leo. You will need to use your hands to feel for ribs. You should just be able to feel the ribs of your Leo. Obesity is very harmful for basically the same reasons it is a problem for humans – diabetes, arthritis, high blood pressure, etc.
- Carefully monitor your Leo’s ears. Look at them at least once a week and clean whenever dirty or exposed to water.
- Trim toenails at least once every 10-14 days. Many Leos have black nails which makes trimming more difficult. The best rule of thumb is to trim a small amount 1/8 to 1/4 inch and do it regularly.
- Brush teeth weekly starting at about age 6 months. Brush more frequently if tarter is seen. Focus on the outsides of the upper and lower molars and canines, where tartar tends to form more heavily.
- Test or use preventation for heartworms as your veterinarian indicates is appropriate for your area. Consider flea and/or tick control depending on your Leo’s risk. Both insects carry many worrisome diseases and can help stimulate allergy so it isn’t just the physical bite we are trying to avoid. All flea and tick preventatives have some risk but consider the disease risks of a flea or tick problem. Immunize your Leo for preventable diseases, following your veterinarian’s recommendations for your location and the lifestyle of your dog. Consider factors like exposure to wildlife, dog parks/dog daycare/dog shows, swimming, and type of insect exposure.
- Do not let puppies (0-24 months of age!) jump off tall objects such as beds, couches, tailgates or porches. Growth plates of the long bones are still open and developing and the bones of the “wrist” and “ankle” are also in progress at this stage. Compression injuries can cause permanent injuries. Be careful with stairs – teach them but also teach stair manners (no running, jumping, skipping them or playing on them).
- A Leo is safest in a secure, fenced area and should never left outside without someone being home and awake. Leos love snow and cold weather. This does not prevent them from getting frostbite on pads, noses or ear tips so be watchful for the unusual but occasional cold looking Leo.
- Make sure you continually “puppy proof” your home, forever, to keep your Leo safe from toxic substances.
If there is any sign of a medical problem, contact your veterinarian immediately.
BEWARE of Unprofessional Advice Your veterinarian should be consulted when your Leo becomes ill. NEVER medicate your dog without the advice of a veterinarian. Don’t try home remedies, remedies from the neighbor, internet chat rooms, etc. Don’t use human prescription or nonprescription medicines without the advice of a veterinarian. Even very common over the counter medicines can be deadly to your canine friend.
