AN OVERVIEW OF HEALTH PROBLEMS IN THE SHIBA INUBy Jacey Holden
As a breed, Shibas can rightfully be described as sturdy, healthy little dogs, able to withstand the rigors of outdoor life as well as enjoying the comfort of indoor dwelling. They are easy keepers, requiring no special diet other than good commercial dog food, and they can run for miles with an athletic companion, or take their exercise chasing a tennis ball around the back yard. Their catlike agility and resilience provide a good resistance to injury, and the "natural" size and symmetrical proportions lessen susceptibility to conditions caused by structural imbalance.
They are easy, natural whelpers, excellent mothers, and exceptionally clean, easy-to-care-for puppies. Despite all these assets, Shibas have some surprising hereditary defects of which all potential owners and breeders should be aware. Of the serious conditions common to the breed, patellar luxation is the most prevalent and potentially devastating. This condition is evidenced when the patella (kneecap) is or can be displaced from its normal position in the femoral trochlea. Severity can range from a grade one where the patella can be displaced manually but returns to normal when released to a grade four where the patella will be luxated all the time and the dog exhibits lameness and conformational abnormality, usually bowed legs. The majority of afflicted Shibas are grade one where clinical symptoms may not be evident or there may be a slight "hitch in his git-along." But, Shibas have been known to have such severe luxation that surgical intervention was necessary at five weeks of age so the puppy could walk. Since there are many causes for patellar luxation ranging from skeletal abnormalities to soft tissue changes, diagnosis cannot be made by radiograph alone. Palpation by an experienced veterinarian is mandatory to diagnose this condition. There is much variation within the "normal" range and too vigorous manipulation of the kneecap, especially on a young puppy, can actually do damage. All diagnosis are not equal. The amount of looseness to be tolerated varies with the individual veterinarian. When in doubt, a second opinion may be warranted.
Hip dysplasia occurs with surprising frequency in the Shiba, considering the small size of the dog. OFA's Executive Director, Dr. E. A. Corley, reports the following through December 31, 1997. 1998 figures will be posted when they are released by OFA.
Number of Shibas evaluated - 889
3.5% mildly dysplastic
3.5% moderately dysplastic
0.6% severely dysplastic
Studies show that between there is possibly 8 - 15% more dysplastic dogs than OFA statistics indicate due to the fact that many of the x-rays of dysplastic dogs are not submitted to OFA for evaluation.
Hereditary eye defects are widespread among the canine population. It is a personal feeling that no breed is completely free of eye problems, and a breed that claims to have no eye problems is probably just not checking for them. The Canine Eye Registry Foundation (CERF) presents a very clear picture of the incidence of eye problems in a breed. Any dog that is examined by a certified veterinary ophthalmologist has the results of his examination sent to CERF. These results remain confidential with CERF, but their information is used for statistical evaluation of certain eye conditions.
In 1991-'97, 553 Shibas were examined and the results sent to CERF. Of those examined, 454 dogs, or 82.10 percent were considered normal, while 99 dogs, or 17.90 percent were afflicted with one or more problems. Interestingly, only 14.52 percent of the males examined were afflicted, while 20.51 percent of the females had a problem. It is very possible that the statistics will vary as the numbers examined increases. The majority of dogs examined were between the ages of six months and five years. The only conditions discovered prior to the age of one year were persistent pupillary membranes, distichiasis (inwardly growing eyelashes), and entropion, (inwardly rolled eyelids) Sometimes entropion occurs in small puppies of three to four weeks of age. At that time the eyeball may be too small for the eye socket, and if the eyelid is tacked up for two weeks, the eyeball grows and the problem disappears.
It is obvious the most common eye defect is cataracts. This was formerly called juvenile cataracts to distinguish it from the cloudiness occurring at old age and is normal in most dogs. "Juvenile" cataracts most commonly occur around two years of age and are potentially blinding. Often people would have their dogs check at one year of age, and, finding that dog normal, no longer feared for "juvenile" cataracts. For this reason, the ophthalmologists dropped the word "juvenile" from the terminology and they are now just called "cataracts." This condition is potentially blinding and no dog with cataracts should be used for breeding.
Diagnosis of eye defects are usually definitive, accurate, and not left to the whims and vagaries of palpation and radiology. The statistics are alarming enough to warrant examination of all breeding Shibas on an annual basis.
The CERF breakdown from January 1991 to December 1997:
Distichiasis - 0 male 18 female
Entropion - 0 male 3 female
Corneal dystrophy - 1 male 5 female
Persistent pupillary membrane - 8 male 12 female
Total Cataracts - 23 male 42 female
Progressive retinal atrophy (generalized) - 2 male 2 female
Progressive retinal atrophy (suspicious) - 1 male 3 female
Probably the most common health problem of the Shiba is not as dramatic or potentially crippling as hip dysplasia or patellar luxation, or possibly blinding like progressive retinal atrophy, but it frustrates many owners across the country. It is allergies such as flea allergy dermatitis (FAD). In the warm, moist areas of the country, where fleas can only be controlled but never eradicated, dogs suffering from FAD are scratching and chewing their way through life causing distress to themselves and all others around them. When the myriad of topical products are exhausted, often the only solution is a sustained regime of cortisone injections. FAD sufferers react to a single fleabite that causes intense itching at the nerve ends, especially at the base of the tail, on the stomach and between the hind legs. This sets up a chain reaction where fleas are attracted to these irritated areas and the dog licks and chews until the skin becomes discolored and hair loss occurs.
Food and inhalant allergies also occur causing runny eyes, loss of Hair on the face and intense itching around the muzzle, ears and between the toes. On casual observation, it may be mistaken for demodectic mange mites, but the reaction stops when the allergen is removed. Pollen is a common cause and can be detected by its seasonal occurrence. Dust mites are also an allergen and keeping the dog in an outdoor environment will quickly reverse the symptoms. Discovering the cause of food and inhalant allergies is often a random process and frequently needs the assistance of a specialist.
Discussion of whether poor dentition is a health problem or conformation problem could spark much controversy among dog breeders. It is probably both. Bad bites and missing teeth are evident in every breed of dog, but when the problem is severe enough to interfere with the dog's ability to eat, it then becomes a health problem. Typically, small breeds of dogs have dental problems with weak jaws, poorly aligned teeth and early tooth loss. This also occurs in the Shiba, and can be distressing in a breed that is supposed to be a hunting dog. As many as 11 missing teeth have been reported as well as premature tooth loss. For the health of the dog, the quality as well as the quantity of the teeth should be considered.
A variety of other health problems have been reported in the breed, but not on a widespread basis. Heart murmurs, kidney failure, liver disease, double-jointed (popping) hocks, leg perthes disease, thyroid disease and other autoimmune disorders. The outlook for the Shiba is not grim, but the breed's genetic makeup contains many of the problems common to other breeds. After all, they are dogs.
The best remedy for the public is to deal with reputable, recognized breeders, and ask informed questions of these breeders regarding health issues to insure a happy and healthy pet.