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. 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. Some disorders are common and others much less so.
Eye Problems
Heritable cataracts
Heritable cataracts appear to be a fairly widespread genetic disorder in the Havanese. This is a somewhat unusual cataract. It is not a Juvenile cataract, though it may appear as early as 10-12 months of age. It is most commonly diagnosed at 3-4 years of age but may appear as late as 7 years of age. With such a late age of onset, 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. This is definitely not a senile cataract. In a long lived breed like the Havanese, a senile cataract is unlikely to show up before 10+ years of age. This heritable cataract appears to be due to a recessive gene when a dog must get the defective gene from both parents. It is a wise precaution to get a puppy from parent dogs with current eye exams. All Havanese owners are encouraged to annually eye test their dogs whether they have companions or show dogs. Mysteriously, upon occasion, a cataract appears and seems quite severe and yet a year later it is dissolving or has disappeared.Cherry Eye
Cherry eye is a relatively uncommon condition in Havanese. It is a swollen or prolapsed gland of the third eyelid where 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 usual treatment is to reposition the gland and surgically tack it into place.Vitreous degeneration
This can be one of several conditions that develop following some types of inflammation, though in the Havanese, it can also occur as a primary condition. Vitreous degeneration may be diagnosed upon a regular eye 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 staining
There are few things more unsightly than rusty tear stains marring the appearance of a beautifully groomed dog. This will of course be most noticeable on white and other light coloured 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, environmental pollutants, chemicals, diet, food allergy/intolerance are all potential culprits. Camouflaging the stains is a popular option, however, 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 and solutions.Mechanical, Movement and Structure Problems
Patella luxation
Patellar luxation is the slipping of the kneecap. It can be the result of an injury or be a genetic predisposition and can affect one or both legs. This condition is quite common in many small breeds inlcuding the Havanese. Some signs to watch for are difficulty straightening the leg, a hopping gait, limping or pain. In most cases the veterinarian can diagnose this condition by physical manipulation of the joint. Mild grades may be almost asymptomatic. Surgery is an option to correct more severe luxations. Even where luxation is caused by injury, an underlying genetic weakness may have contributed. Seeing as patellar luxation can occur at any age, breeding dogs should have their patellas checked annually.Hip displaysia
Canine 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. This condition tends to occur more often in larger breeds but can and does occasionally occur in smaller breeds including the Havanese. 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 disease
In 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. It can happen in Havanese but is realtively uncommon. 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 disease
Also known as Calve-Perthes Disease, Perthes Disease and Avascular Necrosis of the femoral head. This relativley uncommon 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 appears 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 rest while more severe cases may require surgery. Early intervention is critical.Major Organ Issues
Liver shunt
A portosystemic shunt is a congenital liver problem, the result of blood bypassing the liver and flowing directly into the system. This bypass of the liver is normal during fetal development but 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, resulting in non-detoxified blood circulating freely through the body slowly poisoning the body's tissues and cells. This 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. Severe shunts are thankfully rare. Responsible breeding can drastically reduce or eliminate this problem.Heart disease
Cardiomyopathy 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 escalate rapidly. 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 can be 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 murmur
Murmurs are the turbulent sounds created from blood flowing through a faulty or leaky valve. Congenital murmurs (present at birth) 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. In other instances, Havanese are developing murmurs in young adulthood. This 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 may increase the chances of heart failure as they age and may lessen their life span. Like eye 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.Other Conditions
Neurological disorders
Epilepsy and other neurological disorders have been diagnosed in the Havanese from time to time but are relatively uncommon. Seizures 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. 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), dehydration, electrolyte abnormalities, kidney or liver disease may also produce seizures as can internal parasites, infections, food allergies and chemical toxins.Thyroid difficiency
Some Havanese with low thyroid levels 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, inconsistent bowel movements, lethargy and fatigue, irregular heat cycles, and heat and cold sensitivity. A blood test 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.Allergy
An allergy is a disorder of the immune system that leads to hypersensitivity to assorted environmental allergens. The primary sign in most dogs is itching but can exhibit many forms, licking or chewing of the feet, tail and groin area, excessive rubbing and scratching the face, ears, and chest; and rubbing body along furniture. Dogs with allergies can also display sneezing, reddened weepy eyes, skin irritations, extensive shedding and hair loss. The most common environmental allergens are dander, pollens, dust, 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, especially when a know food ingredient is the culprit. In many cases of environmental allergens, this is not always possible. There are a number of medical treatments including special shampoos, herbal preparations, steroids and antihistamines.Skin disorders
Problems 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. 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.
Deafness
Affected Havanese generally are not completely deaf but rather are hearing impaired and 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. We do not know if deafness found in Havanese may be colour/ pattern linked as in other breeds. 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, one-time test that can be done at anytime after a puppy is about 6 weeks old.Testing takes approximately 10-15 minutes. Three tiny electrodes and two small earphones are all that is needed. It is a wise precaution to test breeding dogs and to test puppies. Testing has disclosed a small percentage of unilaterally affected dogs and very few bilaterally affected dogs, however this number may rise as untested affected dogs are bred and produce bilaterally affected offspring.
Short haired gene
A Havanese that 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, but this is not an official term.
Ockham syndrom
OS 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, skeletal malformations, and potentially other issues as well. Not enough is known at this time to know whether it is truly an all-emcompassing condition which links many disorders found in Havanese.Putting it in perspective
At 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 cataracts while others like Legg Perthes are much more limited in their occurrence. While all of the above 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 and 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. If you have any medical issues with your Havanese, please see your veterinarian.