Hereditary and genetic disorders of the Havanese breed
The Havanese is generally a healthy long lived little dog. This does not mean he is perfect. Just like every other dog breed, the Havanese is prone to some genetic hereditary disorders. Like other breeds with a small gene pool, some of these issues may be compounded and widespread. As the breed is still quite young in its rebuilding, some disorders are just now coming to light. If you take into account the other breeds that played a factor in the development of the Havanese, like the Maltese, Bichon Frise and Toy Poodle, it stands to reason that the Havanese will have many similar hereditary problems that are encountered in these other breeds
There are many links to and from Havanese ABC's. Such links provide an easy-to-navigate network of information about the Havanese but they are not an endorsement of any particular breeder nor a breeder recommendation. It is important that you do your own research as thoroughly as possible. Choose a breeder with care to ensure you get a quality registered puppy from a reputable ethical breeder.
Heritable cataractsAt this time heritable cataracts is the most serious and widespread of the genetic disorders in the Havanese. There is no clean line; all lines are affected. This is a somewhat unusual cataract. It cannot be defined as a Juvenile cataract; though it may appear as early as 10-12 months of age, it may also appear as late as 7 years of age. The most common age of diagnosis is 3-4 years of age. A big part of the problem is this late age of onset, as by the time a dog is diagnosed as affected, it may already have been bred several times and perhaps even have a 2nd or 3rd generation bred. It is definitely not a senile cataract. In a long lived breed like the Havanese, a senile cataract is unlikely to show up before 9-10 years of age. This heritable cataract appears to be a recessive gene when a dog must get the defective gene from both parents in order to become affected. At this time there is no test. However, Dr Gellat of the University of Florida is spearheading a study into heritable cataracts in the Bichon Frise and Havanese in order to determine the mode of inheritance and then hopefully to develop a test. Until this test becomes available, it is a wise precaution to get a puppy only from two adult dogs who have current CERF's. All Havanese owners are encouraged to annually CERF their dogs whether they have companions or show dogs. The earlier the problem is diagnosed, the better chance there is of being able to treat it before blindness occurs. Mysteriously, upon occasion, a cataract appears and seems quite severe and yet a year later it is dissolving or has disappeared.
Cherry EyeA swollen or prolapsed gland of the third eyelid. The gland protrudes and becomes irritated and inflamed. It is strongly suspected that Cherry Eye is due to a weakness of the connective tissue. It appears to be a heritable problem. If one eye develops cherry eye, then the other eye may also be predisposed. Sometimes the gland can simply be tucked back in but it may prolapse again. The most common treatment is to reposition the gland and surgically tack it into place.
Vitreous degenerationThis can be one of several conditions commonly following some types of inflammation. In certain breeds , including the Havanese, it can occur a primary condition. Vitreous degeneration may be diagnosed upon a regular CERF examination. There has been some suggestion that it may leave a dog more susceptible to retinal detachment. If your Havanese is diagnosed with vitreous degeneration , it is important to continue regular eye exams with an ophthalmologist for monitoring. If retinal detachment should occur, the earlier it is caught and treated the better the outcome.
Excessive tearing and stainingAlso known as Poodle Eye. There are few things more unsightly than rusty tear stains marring the appearance of an otherwise beautifully groomed Havanese. This will of course be most noticeable on white and other light coloured Havanese. Stains are not the only problem, you should take note of tearing and/or eye discharge regardless of the colour of your Havanese. There are a number of reasons for eye discharge and excessive tearing and the unattractive stains that may result. Excessive tearing, blocked tear ducts, acidity or pH of the tears, bacterial or yeast infections, genetics, teething, irritation, allergies, hair in the eyes, environment (smoke & other pollutants) , shampoo and chemicals, diet, food allergy/intolerance are all potential culprits. Camouflaging the stains is a popular option, but in truth, understanding the causes, prevention, and controlling the tear staining are more important than simply covering up. Removing or camouflaging the stains is temporary at best as the stains will reoccur unless the source of the staining is removed. See our Eye Care page in Tid Bits for additional information for preventions on solutions.
MECHANICAL, MOVEMENT and STRUCTURE PROBLEMS
Patella luxationPatellar luxation is the slipping of the kneecap. This may be as a result of injury or be a genetic predisposition. Patellar luxation can affect one or both legs. This condition is quite common in many small breeds. Some signs to watch for are difficulty straightening the leg, a hop / skip in the gait, limping or pain. Mild grades may be almost asymptomatic. Surgery is an option to correct the problem. In most cases the veterinarian can diagnose this condition by physical manipulation of the joint. Luxation may occur at any age. Even in the case of injury related causes, an underlying weakness may have contributed. The predisposition that allows Patella luxation to develop is genetic. Seeing as this condition can occur at any age, breeding dogs should have their patellas checked annually.
Hip displaysiaCanine Hip dysplasia is joint malformation that occurs when the ball and socket are misaligned, loosely fitted, or misshapen often leading to arthritic changes, pain and limited mobility. Displastic dogs may need expensive corrective surgery as they age. Hip displasia is an inherited condition and diagnosis before breeding should be a priority to keep breeding stock healthy and limit the occurrence of the disease in offspring. Hip displasia can be diagnosed only by x-ray of the hip joint. OFA and PENN hip are two registries for hip certification.
Disk diseaseIn between each vertebrae in a dog's backbone is a flexible cushion like disk. Aging and premature disc degeneration can cause the discs can dehydrate losing their cushioning ability. This occurs to some degree in old dogs of all breeds. Dogs with large heads or short legs or long bodies may prematurely develop degeneration of the disks. Problems happen when a portion or the entire disk is displaced from its normal position in the spine and may protrude into the spinal canal causing inflammation, pain and subsequent spinal damage. It can happen very slowly or be quite rapid in its development and can be the result of trauma, or have no apparent cause. The symptoms are dependent on the location and severity of the affected disk(s). Prompt diagnosis and treatment improve the prognosis. Surgical intervention may be necessary.
Legg Perthes diseaseAlso known as Calve-Perthes Disease, Perthes Disease and Avascular Necrosis of the femoral head. This condition is a hip malformation occurring mainly in small breeds in which the head of the femur (thigh bone) deteriorates and dies as a result of insufficient blood supply. Diagnosis is usually by Xray where the vet can clearly see disintegration of the bone. Most often only one leg is affected. Usually this condition strikes young animals of 4-12 months of age. There does appear to be a hereditary component to this disease. Pain, limited movement, atrophy, limping, difficulty walking can all be symptoms. Treatment depends on severity. Some very mild cases can be treated with enforced rest while more severe cases may necessitate surgery. Early intervention is critical. Havanese can be OFA certified at the same time as they are done for their OFA hips as the same X-ray is used.
ChondrodysplaysiaThe most recognizable effect of Chondrodysplasia (CD)is "Dwarfism" This is often misunderstood as many people assume that all small breeds are dwarf breeds. True, some toy breeds are dwarfs; most are not but rather have been miniaturized or are just small. It is not the same thing at all. A miniature breed retains all the breed characteristics and body proportions of its larger counterparts. It has simply been bred down to its smaller size. For instance the toy poodle. Other toy breeds are simply small dogs and have always been so, like the bichon breeds. A midget is a well proportioned but very small example any given breed. A dwarf breed is neither of these. In a dwarf breed the structure has been altered to produce shortened limbs while the body remains unaffected resulting in a dog with a normal to large body with disproportionately short legs. Chondrodysplasia has become a "normal" variation for breeds that man has manipulated, selecting FOR short legs, but medically....it is a disorder of the bone which may result in premature closure of the growth plates. For certain breeds, Chondrodysplasia is the correct build for their breed standard. This includes breeds like the Basset, Corgi and Dachshund. For most breeds this is a structural anomaly. As with other skeletal conditions, signs can be mild or moderate and not easily recognized or it can be quite severe and easily noticed. The growth plates of CD dogs close prematurely and sometimes unevenly. While some may have straight short legs, others may have bowed legs while others may have one straight leg and one bowed leg.
Liver shuntA portosystemic shunt is the most common congenital liver problem. Most often this is the result of blood bypassing the liver and flowing directly into the system. This bypass of the liver is normal during fetal development. The bypass normally closes off shortly after birth. The liver has many functions including metabolism, temperature regulation, circulation, detoxification and waste removal. In the case of a dog with a shunt, the liver cannot do its job properly and resulting in non-detoxified blood circulating freely through the body slowly poisoning the body's tissues and cells. This poisoning can express itself as a wide-ranging impairment of bodily functions including failure to thrive, poor weight gain, sleepiness, vomiting, blindness and seizures. Early diagnosis and prompt treatment offer the best outcomes. The success of surgery depends on the severity and the location of the shunt. Medical management may be tried for inoperable shunts but can be difficult and very expensive with limited success. Responsible breeding can drastically reduce/eliminate this problem.
Heart diseaseCardiomyopathy occurs when one or more diseases cause inflammation and scarring of the heart muscle which become less efficient in supplying the body and organs with blood. The heart eventually weakens leading to congestive heart failure and death. Heart disease appears to be genetic. Though the disease itself may start at an early age ( 2-5 years) the signs may not appear for several more years (9-12 years of age) when the disease becomes severe and signs appear rapidly over a matter of days. By then, the dog may already be in the stage of severe heart failure. Symptoms of unexplained lethargy, sudden weight loss, cough, fatigue, and shortness of breath may be signs of a dog developing a heart problem. Congestive Heart failure is life threatening. A visit to the veterinarian is essential to diagnose the problem and begin medical treatment. Medications are not curative but rather may help compensate for the increasing failure of the heart .
Heart murmurMurmurs are the turbulent sounds created from blood flowing through a faulty or leaky valve. Congenital murmurs ( present at birth) are identified as puppies are clearly genetic. In Havanese, for the most part, non-congential murmurs appear to be an insufficiency of the mitral valve which may develop at any time. Murmurs are quite common in elderly dogs (over 10 years) because of normal aging processes. In some Havanese , the mitral valve ages prematurely, and murmurs may develop in middle age ( 6 to 9 yrs). In other instances, Havanese are developing murmurs in young adulthood ( 2 to 5 yrs) . This very premature aging of the heart valves is likely genetic in nature. By the time this is discovered a dog may have already been bred one or more times. Heart murmurs discovered in young dogs may or may not impact their quality of life, though it is likely to increase the chances of heart failure as they age and may lessen their life span. Like Cerf and patella checks, an annual cardiac check is a wise precaution in any breeding dogs. A single check is not sufficient to predict future cardiac health.
Neurological disorderssuch as epilepsy have been diagnosed in the Havanese but are relatively uncommon at this time. The most evident symptom of epilepsy is seizures. Seizures can be inherited or they may be caused by medical diseases such as diabetes, liver disease, etc They may be seen as spells in which the dog demonstrates repeated jerking of the entire body or just one part, followed by a period of disorientation. Multiple seizures are usually required to make a correct diagnosis. Determining the cause is essential to make appropriate treatment choices as well as future breeding decisions. Not all seizures are due to epilepsy. Hypoglycemia low blood sugar - is a common cause of seizures in toy breeds. Dehydration, electrolyte abnormalities, kidney or liver disease may also produce seizures as can internal parasites, infections, food allergies and chemical toxins.
If no other reason can be found, then epilepsy is the likeliest cause of the seizures. Treatments for epilepsy include medications to prevent and control seizures.
Thyroid difficiencyHypothyroidism - low thyroid is a common cause of skin and hair problems. Some Havanese with low thyroid will show no symptoms at all or only a few symptoms, while others show numerous symptoms. Possible symptoms include dry brittle hair, hair breakage and thinning coat, dry flaky skin, skin infections, unusual weight gain with low/normal food consumption, inconsistent bowel movements, lethargy and fatigue, irregular heat cycles, and heat and cold sensitivity. A blood test from your Veterinarian is the only way to determine a thyroid deficiency. Thyroid replacement therapy is very simple and effective. Once replacement therapy is started, it must continue for life.
AllergyThis condition is a disorder of the immune system leading to hypersensitivity to assorted environmental allergens. The primary sign in most dogs is itching. This symptom can exhibit many forms, licking or chewing of the feet, and groin area; chewing tail, excessive rubbing and scratching the face, ears, and chest; and rubbing body along furniture. Dogs with allergies can also display reversed sneezing, reddened weepy eyes, skin irritations, extensive shedding and hair loss. The most common environmental allergens are dander, pollens, dust and moulds and certain chemicals. These can be seasonal and be much worse at certain times of year. Other allergies or intolerances can occur in response to food such as wheat, corn and soy or chemical and artificial additives and preservatives. Food allergies can show up as the itching above but may also produce vomiting diarrhea , gas, corpophagia, and loose and frequent stools. Ideally, avoiding the irritating substance is the best means of treatment. This can be achieved in some cases (particularly food) , but in most cases of environmental allergens, this is not always possible or practical. There are a number of medical treatments including bathing in special shampoos, herbal preparations, steroids and antihistamines.
Skin disordersProblems of the skin are among the most troublesome and difficult to diagnose and treat. Among these is a perplexing condition called SEBACEOUS ADENITIS . In SA, the skin's sebaceous glands which normally produce fatty secretions to help prevent drying of the skin, become inflamed and are eventually destroyed. Clinical signs vary with severity. In long-coated breeds like the Havanese, the condition develops as dry, scaly, flaky skin and silvery dandruff along with patches of hair loss. More severely affected Havanese will have extensive hair loss and a moth eaten look. They may also have areas of thickened skin ("hyperkeratosis") accompanied by a rancid, musty odour and secondary skin infections. Sebaceous adenitis is primarily a cosmetic disorder as it affects the appearance of the dog rather than general health. SA affected dogs can be otherwise healthy and happy but are distressing to look at and unpleasant to smell and touch which make it a frustrating condition to cope with. SA cannot be cured. Symptomatic treatments are long term and can be extensive, time consuming and expensive. SA is best diagnosed by the examination of skin biopsies.
DeafnessIn the past several years, deafness has been identified in Havanese. Affected Havanese generally are not completely deaf but rather are "hearing impaired", they may still have some hearing at certain levels and tones. In terms of quality of life, "hearing impaired" Havanese appear to fare better than breeds that have total deafness. It appears to be a heritable disorder but one with a complex mode of inheritance. At this time, we do not know if deafness found in Havanese "may" be colour/ pattern linked as in other breeds, but more studies will be needed to determine if this is so in Havanese. You cannot check hearing yourself. Most people with unilaterally affected dogs are completely unaware that there is any problem until a bilaterally deaf puppy is produced. There is a test available to check hearing. It is the BAER test. It is a very simple test and can be done at anytime after a puppy is about 6 weeks old. Unlike CERF, the BAER test does not need to be repeated yearly. It is a one time test. It is a wise precaution to test breeding stock and test the pups. It is generally felt that affected dogs should not be bred. BAER testing clinics can be difficult to locate though are generally available at veterinary colleges. A single test may be expensive but prices are usually substantially lower if done at a hearing clinic. Some veterinarians recommend sedating the dogs to preform the test. In Havanese, sedation is generally unnecessary. Even our 8 week old puppies took it all in stride. At this time, there appears to be a small number of unilaterally affected dogs and very few bilaterally affected dogs, however this number may rapidly rise as untested affected dogs are bred and produce bilaterally affected offspring. Testing takes approximately 10-15 minutes. Three tiny electrodes and two small earphones are all that is needed.
Short haired geneA Havanese which inherits two copies of this recessive gene will appear as a short coated Havanese. The coat is smooth on the face and legs with longer fringes on the ears, body and tail. In appearance, it is very different from a typical long haired Havanese. This gene appears to have been a spontaneous genetic mutation several generations ago. The trait is genetic. Dogs with only one copy of the gene will be long haired though they still carry a copy of the short haired gene which can then be passed along to offspring. Breeders indicate that coat differences within a litter can usually be discerned at about 6-8 weeks of age. Short haired Havanese seem to have all the same personality traits and all attributes of the Havanese except the long coat. The degree of short hair appears to vary with some having minimal fringing and others having more. The short coat does shed. Some people have nicknamed them "Shavanese" for Short Haired Havanese. In future years, more may be leanred about the genetics behind this anomaly and also the possibility of genetic testing. At this time, it appreas to be a recessive trait but more factors may be at play. Until such there are more definite answers, breeding a shorthaired dog may pose unknown risks.
Ockham syndromOS is said to be a syndrome which encompasses a myriad of symptoms including cataracts, liver & heart problems, some birth defects, missing dentition, skin conditions, Legg Calve Perthes Disease, patellar luxation, chondrodysplasia, and potentially other issues as well. Not enough is known about this condition at this time to know whether it truly is a condition which links many disorders found in Havanese. Studies are ongoing.
Putting it in perspectiveAt first glance all this may appear alarming and certainly there is cause for concern but at the same time one must not lose sight of the fact that ALL breeds have heritable disorders and that some are more serious and widespread than others. The conditions mentioned here have all been diagnosed in Havanese and all have a hereditary component. Some are widespread like the cataracts while others like Legg Perthes are much more limited in their occurrence. While all of the above have a genetic component and may be heritable, one must also keep in mind that some of these conditions can be caused or aggravated by environment, lack of education and lack of care. A blow, serious tumble or head trauma can lead to Epilepsy. Other types of seizures can be caused by chemicals, poisoning etc. Luxating patellas can be caused by unlimited jumping before the growth plates are closed. Hip dysplaysia will be aggravated by obesity and lack of exercise. Poor diet can contribute to Diabetes as well as allergies. Allergies can also be due to chemical products used in the house and yard. Getting a puppy from a reputable breeder is only the first step. Care and attention to training, activities and feeding are just as important in keeping your puppy in as good health as possible.
This information was presented to inform about both upsides and downsides of owning a Havanese and to stress the importance of researching a breed thoroughly before choosing to add a Havanese or any dog to your family. Please choose a breeder with care to ensure that you are getting a quality puppy from a reputable ethical breeder who tests their breeding stock regularly for heritable disorders. Though these cannot be eliminated completely, careful breeding practices help to minimise problems. Do not choose a puppy on impulse.