Other Health Issues
Basenji Club of America Explains
Basenjis are a natural breed and are relatively healthy when compared to other breeds of dogs. Like all breeds, basenjis have disorders that may occur more frequently than in the general canine population. As responsible dog owners, it is up to us to work together to ensure the best for our breed. The basenji community has a long history of working together to identify and breed away from hereditary diseases. We have learned that regular health testing and open reporting of those results will provide us with the working knowledge necessary to ensure our breeds overall health.Regular health testing of basenjis is essentialfor the breed’s overall health and well-being.
It is important to understand the different types of disorders that may occur in basenjis and the impact these disorders have on their quality of life and reproductive potential. All basenjis, whether affected with a disorder or not, need regular health testing as described in the sections below. Some dogs may carry a genetic component for a disorder but have no symptoms. These dogs will live a normal life, but are still important to track to have a full understanding of the disorder and to avoid passing the disorder on to offspring. Genetic or hereditary disorders can quickly become an issue if the breeds’ population is not health tested regularly.
Below is a list of some health problems known to occur in basenjis. Click each item to learn more information about these disorders. There are separate sections for breeders and owners who are not interested in breeding. If you have any questions about this information, please contact your breeder, regional basenji club, or the Basenji Club of America (BCOA) Health Committee.
What is DNA?
Deoxyribonucleic Acid (DNA) is made up of the genetic building blocks (nucleotides) Adenine (A), Guanine (G), Cytosine (C), and Thymine (T). Simply put, the order of these nucleotides within your DNA make up a code of instructions for building a living organism.
Photo credit http://www.canstockphoto.com
What is a mutation?
DNA is copied every time a cell divides. Sometimes an error occurs in this process. This is called a mutation. If this happens when germ cells (eggs or sperm) are being formed, this mutation is called a germline mutation and can be passed to the offspring of the affected individual. Most mutations do not cause disease, but occasionally these changes can cause problems.
Genetic Disease Research
For the last 30 years Polymerase Chain Reaction (PCR) technology has been available to test for disease mutations. This along with innovations in DNA sequencing caused a revolution in biomedical research. If one could find the mutation responsible for a disease, one could test individuals for the mutation.
Inheritance of Genetic Diseases
Every individual has two copies of every gene, one from their mother and one from their father. In some cases the genetic mutation is dominant, meaning that only one copy of the defective gene is necessary for the disease to occur. Examples of this include: Huntington’s Disease and Marfan Syndrome in humans. Other times the disease is a simple recessive, meaning that two copies of the mutant gene are necessary for the disease to be present. Examples of this are Sickle Cell Anemia and Cystic Fibrosis in humans. In still other cases, inheritance is more complex. It may be polygenetic, meaning that more than one gene is involved in disease expression; X-linked, meaning that the mutant gene is on the X chromosome, which determines sex, and therefore requires two copies for expression in females and only one copy when present in males; or even have variable expression, meaning that sometimes individuals with one copy (carriers) may have the disease or they may not. Some disease causing mutations may only be expressed if the individual is exposed to some specific environmental factor.
Importance of Genetic Testing
Before genetic testing for diseases became more common, breeders were forced to guess at the genetic make-up of individuals based on their own disease history and the disease history of their progeny, siblings, and dogs in their pedigree. In some cases, it was easy to determine the genetic status of an individual in this way, but in other cases it was very difficult. Now, in some cases, we can make more educated choices by testing individual dogs and getting a direct “snapshot” of their DNA.DNA Testing in Basenjis
We are fortunate to have three DNA tests available for basenjis. Sometimes there are multiple mutations that cause the same disease in different breeds, so most canine genetic tests are breed specific.
Fanconi Syndrome: In August of 2011 Fanconi Syndrome in basenjis was discovered to be caused by an autosomal (not x-linked) recessive trait. At that time a DNA test was developed to detect the mutation responsible for the disease. Dogs tested were and continue to be determined to be Normal, Carrier, or Affected. Fanconi is a potentially fatal disease and everyone is encouraged to use this DNA test to determine the disease status of their dogs.
Prior to the current DNA test (2007-August 2011), while researchers were looking for the mutation responsible for Fanconi Syndrome, a linkage test was available through OFA. Unlike the test available now, a linkage test does not directly test for the mutation responsible for a disease. It tests for DNA markers (DNA sequences thought to be physically near the gene of interest) that are thus likely to travel with the gene of interest through the generations and not be separated by crossover events. Because of the way a linkage test works, it is inherently a less accurate test. For this reason, the results that were given to owners were prefaced with the word “probably” or the letter “p”. Results from this linkage test should NOT be used for making breeding decisions.
In 2011 when the current DNA test for Fanconi Syndrome was introduced, it was often referred to as a “direct” DNA test to differentiate it from the previously available linkage test. Since we no longer have any accepted DNA linkage tests available for basenjis, this distinction will be phased out. All DNA tests can be assumed to be “direct” tests unless they are specified to be a “linkage” test.
Progressive Retinal Atrophy (PRA): PRA-BJ1 A test has been developed for one form of PRA in basenjis. PRA-BJ1 is also autosomal recessive and dogs will be determined to be Normal, Carrier, or Affected.
There are at least two different genetic mutations which cause PRA in basenjis, so even if a dog tests normal for PRA-BJ1, this does not mean that this dog will not develop or pass down another type of PRA to their offspring. Research is ongoing to find other genetic causes for PRA in basenjis. In the meantime everyone is encouraged to test for PRA-BJ1.
Hemolytic Anemia (HA): Pyruvate Kinase Deficiency-Hemolytic Anemia is a fatal genetic disease. The test for HA was the first DNA test available to basenji breeders. It is another autosomal recessive trait. Dogs will be determined to be Normal, Carrier, or Affected. The vast majority of basenjis are descended from tested stock; however, the test is still available.
Genetic testing is simple. Most genetic tests can be made with a swab of cheek cells. Tests can also be performed using frozen sperm or blood samples.Cystinuria
Production of urine is the normal process by which a dog's kidneys filter liquid waste from the body. However, if there is a problem with this process, certain amino acids and other substances like minerals can build up, forming crystals. The urine may also lack substances that keep crystals from sticking together. So, as the urine passes through the urinary tract and becomes concentrated, crystals may fix together to become stones in the ureter (the thin tubes that carry urine from the kidneys to the bladder) or the bladder. When the liquid in the dogs urine contains more crystals than can be diluted, the crystals can clump together or become large enough to form stones. In humans, these problems occur more frequently in the kidneys (kidney stones), while in dogs the problems occur more frequently in the bladder (bladder stones).
Urinary stones are usually diagnosed by x-ray and are categorized based on the predominant amino acid(s) and/or mineral(s) found in the stones. Treatment is determined based on the type of stones. Common stones are struvite, calcium oxalate, urate, or cystine.
In most breeds of dogs including basenjis, struvite stones are the most common and usually form in response to an infection, such as a urinary tract infection (UTI). In the absence of a UTI, they may form when dogs pass highly concentrated urine. Your veterinarian may prescribe a specific diet to help dissolve them.
The condition responsible for cystine stone formation is called cystinuria. Cystinuria, a genetically complex disease, is an inherited error of metabolism that keeps the renal tubules in the kidneys from properly reabsorbing the amino acid cystine. In other words, the kidneys are not able to correctly process cystine (an essential building block of protein). When a dog's kidneys are functioning normally, cystine will be reabsorbed by the kidneys and will not be excreted into the urine. However, the genetic defect associated with cystinuria does not allow reabsorption to take place and excess cystine is excreted into the urine. Over time, the unprocessed cystine crystallizes in the urine and clumps together to form grit and stones. These grit and stones can irritate the lining of the bladder causing chronic infection and can block the ureter so that the dog cannot urinate. A blocked urinary tract is a veterinary emergency because the affected dog's bladder may expand to the point of potential rupture. Dogs that block must have their ureters cleared of stones and grit by passing a catheter, or through surgery.
Affected dogs are born with this condition, however it may take years before the situation progresses to physical symptoms. The typical age of symptom onset is 2 to 7 years. The mode of inheritance for cystinuria has been identified in Newfoundlands and Mastiffs, but has not yet been identified in affected Basenjis.
Cystinuria is a life-long defect that cannot be cured, but the condition can be managed to reduce the potential for future stone formation. Cystine stones tend to recur within 1 year of removal if no action is taken to manage the condition. Typically, management consists of attempting to double the affected dog's urine volume through hydration and adopting dietary restrictions and/or drug therapy to reduce the possibility of stone formation. New stones often recur despite attempts at prevention. Not all dogs with cystinuria will form stones, but there is always a chance that stones will reform in a dog previously diagnosed with cystinuria or cystine stones.
Canine Urinary System: © Copyright 2011 LifeLearn, Inc. Used with permission.For the Owner
Often the first symptom of cystinuria in male dogs is a urinary tract blockage caused by a bladder stone or grit formed by cystine crystals. Symptoms of a blocked urinary tract include: frequent urination, straining to try to urinate, passing small amounts of urine rather than a steady stream, visible blood in the urine, a weak or "splattery" urine stream, and/or sudden involuntary incontinence in a previously housebroken male. Sometimes these symptoms are mistaken for UTI's or prostate problems in intact males. If your male basenji exhibits any of these signs, contact your local veterinarian immediately because a blocked urinary tract can be fatal without prompt treatment. In some cases reoccurring urinary tract disorders may be a sign of cystinuria. In most cases dogs with cystinuria will have cystine in their urine which can be seen in a urinalysis. However, there is evidence that some dogs may spill excess cystine only intermittently.
According to the AKC Canine Health Foundation, which has funded research on cystinuria since 1996, there are 3 tests available to help diagnose cystinuria. All the tests are based on urine composition. The first is a basic urinalysis which can be performed at any veterinary clinic and is the cheapest of the three tests. The second is a nitroprusside test, performed at the University of Pennsylvania (for sample submission to screen for Cystinuria using a simple urine sample, see Instructions for Sample Submission.) Urine must be sent to the university which increases the cost of the test. The third is a urine amino acid quantitation test that can only be performed in a human laboratory and is the most expensive method of diagnosis. With respect to all these tests, it is important to note that a negative test result for the presence of cystine does not mean that your dog does not have or will not have cystinuria. Multiple tests may be necessary to "catch' a dog spilling cystine into its urine and even a series of negative tests cannot predict whether a dog will begin spilling cystine at a later date.
In the absence of a DNA-based test for cystinuria in basenjis, the typical mode of diagnosis is stone analysis. If your dog is diagnosed with cystine bladder stones or if you have questions about the condition, information is available online at http://www.caninecystinuria.com.For the Breeder
There is no treatment for the genetic defect that causes cystinuria. Affected dogs do not always form stones. Knowing the history of the condition in your dogs vertical and horizontal pedigree is, at present, the only method for evaluating the risk of the disease. Affected dogs should NOT be used for breeding.Eye Health Overview
Basenji eye examinations are an important part of their routine health care. Regular eye examinations are important because some hereditary eye conditions are diagnosed in basenjis as puppies and some occur later in life. In the United States, it is advisable to have a basenji examined by a veterinary ophthalmologist who is a certified Diplomat of the American College of Veterinary Ophthalmologists (ACVO http://www.acvo.org). These practitioners have advanced training in canine eye conditions and can perform an OFA Eye Certification Registry certificate examination. Dogs that test Normal can receive an Eye Certification (known as Normal). These exams are recommended at 9 weeks of age followed by annual examinations for breeding stock throughout their reproductive lives and every other year thereafter to determine if any genetic eye disorders develop.
Keep in mind there can be abnormal conditions found in dogs eyes that do not affect their quality of life. If you have questions about the results of an OFA Eye Certification Registry certificate examination, ask your breeder and canine ophthalmologist. Remember a Normal result from an eye examination does not guarantee that the dog will not later develop a hereditary eye problem. In the pages that follow, there are brief descriptions of some of the more common eye conditions occurring in basenjis.
The OFA Eye Certification Registry certificate examination is part of the Canine Health Information Center (CHIC) list of health tests for basenjis. CHIC is a centralized canine health database jointly sponsored by the AKC/Canine Health Foundation (AKC/CHF) and the Orthopedic Foundation for Animals (OFA).
Parts of a Normal eye (permission by Google images)Coloboma
Coloboma is an inherited eye condition in which a part of the eye does not develop properly. The mode of inheritance of coloboma is not understood. Basenjis typically have an optic nerve coloboma and it does not progress or get worse with age.
Basenji’s eyes should be assessed as a puppy (9 week examination) to determine if they have a coloboma. Basenjis’ eyes sometimes have a unique appearance that is normal for our breed but different than other breeds. Basenjis can, in some cases, have normal optic nerves that are more deeply cupped than other breeds making it is possible to have a false positive diagnosis of coloboma. If a basenji is diagnosed with a coloboma, a second opinion, from an ophthalmologist familiar with basenji eyes, is recommended.For the Owner
The type and location of the coloboma determines if the dog will have vision problems or not. A veterinary ophthalmologist should be consulted in each case to explain how the condition will affect the dog. Basenjis with colobomas generally lead a normal life.For the Breeder
A basenji with a coloboma will not receive certification from the OFA Eye Certification Registry. Breeding dogs with colobomas is NOT recommended by the American College of Veterinary Ophthalmologists (ACVO).Corneal Dystrophy
There are many types of corneal dystrophy in canines. The following paragraphs contain a brief description of the predominate types of corneal dystrophy occurring in basenjis. In some cases the corneal dystrophy may have a genetic cause but we do not know how or if these eye conditions are inherited in our basenjis. You should check with your certified veterinary ophthalmologist for additional details regarding causation, treatment and breeding recommendations for any type of corneal dystrophy.
Definition of Corneal Dystrophy
The term “corneal” refers to the cornea or the outer part of the eye which is made up of several layers. In this case, “dystrophy” is used to describe a wasting of the tissues. The location of the corneal dystrophy is described by indicating the name of the layer(s) of the cornea affected; epithelial, stromal or endothelial.
Description of the Cornea
The cornea is a transparent protective cover on the front part of the eye that allows light to enter for vision. The main layers of the cornea are;
a) Epithelial layer: Epithelial cells comprise the outer protective layer that covers the surface of the cornea. This layer prevents foreign objects from entering the eye.
b) Stromal layer: is the middle, thickest layer and is made of mostly collagen and water.
c) Endothelium layer: this is a single layer of cells making up the inner lining of the cornea. The endothelial layer maintains corneal transparency mostly by pumping excess water out of the stromal layer. These cells cannot be repaired by the body.
Epithelial Corneal Dystrophy
Epithelial corneal dystrophy is a small, shallow and painful erosion or ulceration in the outer layer of the cornea. With epithelial erosions/ulcerations, your dog may show signs of discomfort such as increased tearing, squinting and rubbing the eye. Erosions or ulcerations can be caused by mechanical injury. However if this is a chronic reoccurring condition, it may be genetic. Epithelial dystrophy occurs occasionally in basenjis and can happen anytime during the life span. Treatment depends on the severity of the problem.
Stromal Corneal Dystrophy
Stromal dystrophies usually cause no discomfort and do not generally interfere with vision. Stromal dystrophy can be visible to the naked eye and appears as a tiny whitish spot on one or both eyes. These spots are thought to be lipid (fat) deposits in the stromal layers. Treatment is not generally necessary for this type of dystrophy unless vision is impaired or irritation occurs. It occurs occasionally in basenjis at any time in the life span and the cause is unknown.
Endothelial Corneal Dystrophy
Canine cornea endothelial cells do not repair themselves and when too many corneal endothelial cells become damaged the endothelium cannot regulate the water in the stromal layer and the cornea develops edema (swelling) and subsequently vision problems. This edema is initially painless but without treatment will progress and can cause “water blisters” called bullae that will rupture through the cornea surface causing painful corneal ulcers. The extent of visual impairment is dependent upon the severity and response to treatment.
This type of corneal dystrophy is the most serious of the types described and may have a genetic cause. It is important to keep in mind; the endothelial layer can also be damaged by other eye conditions such as glaucoma, severe inflammation or injury. When endothelial cell damage occurs secondary to another eye problem, it is called endothelial degeneration and is not considered genetic. If it occurs spontaneously it is called corneal dystrophy and has a genetic component. Consult your certified veterinary ophthalmologist to discuss treatment and causation of these conditions.For the Owner
Depending on the type and severity of corneal dystrophy, your dog may or may not exhibit symptoms. Regular eye examinations by a certified veterinary ophthalmologist are essential for early diagnosis and treatment of corneal dystrophy. In addition, when you examine your dog, be observant. If you notice an unusual discharge from their eyes or the dog is rubbing them, have their eyes checked.For the Breeder
Since we do not know how or if these conditions are hereditary, it is very important to keep track of the occurrences by tracking your puppies and disclosing any incidence. Consult a veterinary ophthalmologist regarding breeding recommendations for a basenji with any type of corneal dystrophy.
The 2009 American College of Veterinary Ophthalmologists (ACVO) recommendations for Basenjis with Corneal Dystrophy Epithelial/Stromal is Breeder Option. And the 2009 ACVO recommendations for Basenjis with Corneal Dystrophy Endothelial is that they should NOT be used for breeding.Persistent Pupillary Membrane (PPM)
Persistent Pupillary Membrane (PPM) is a common condition known to be inherited in basenjis. In PPM, a normal membrane in the eye of the unborn puppy does not completely reabsorb and disappear after the puppy is born. As the unborn puppy develops, the part of the eye called the iris initially forms as a solid sheet known as the pupillary membrane. This important membrane contains blood vessels to supply nutrients to the developing lens of the eye before birth. During the first two weeks of life, before the eyes open, the membrane normally reabsorbs and disappears. However some of the pupillary membrane may persist in different forms. The location and extent of the persistent membrane or strands of membrane will indicate whether it affects vision. PPM can and should be assessed by a veterinary ophthalmologist at approximately 9 weeks of age. The OFA Eye Certification Registry certificate examination paperwork will describe the absence or presence, and location of these strands, tags, or sheets.
Examples of PPM findings in an eye exam:
- Iris to iris strands (are the mildest PPM and the dog WILL pass the OFA Eye Certification Registry certificate examination)
- Iris to lens strands (will NOT pass OFA Eye Certification Registry certificate examination)
- Iris to cornea strands (will NOT pass OFA Eye Certification Registry certificate examination)
- Iris sheets (will NOT pass OFA Eye Certification Registry certificate exam and, although rare in basenjis, are the most severe form of PPM).
Ask the veterinary ophthalmologist conducting the examination to what extent your dog’s vision may or may not be affected by the PPM findings.For the Owner
Most PPM has no effect on a dog’s life. PPM does not progress, and in fact puppies with mild PPM often have it reabsorb and disappear completely as they age.
PPM severe enough to cause visual problems is normally visible to a non-specialist veterinarian and occasionally to the naked eye. PPM that severe is extremely uncommon. Puppies with more severe PPM (PPM visible to the naked eye) may have loss or blurring of vision but basenjis generally adapt and live normal lives.For the Breeder
While most PPM does not have a negative effect on a dog’s life, severe PPM can. Severe PPM is quite rare in basenjis, but it was more common early in the breed’s history. The exact way PPM is inherited is not known.
Breeders should be aware of the PPM status in their stock, to prevent severe PPM from becoming common again. It is recommended for breeders to have an ACVO certified veterinary ophthalmologist check their puppies at approximately 9 weeks of age, to determine the presence or absence of PPM.
A basenji with iris to iris PPM (the mild form) will receive a Normal eye exam result. All other grades of PPM (iris to lens, iris to cornea, and iris sheets) will not. Most basenji breeders will not disqualify a dog from breeding solely due to mild PPM. A OFA Eye Certification Registry certificate exam will show current PPM status, but it does not tell you whether or not the dog will produce offspring with PPM.Progressive Retinal Atrophy (PRA)
Progressive Retinal Atrophy (PRA) is an inherited eye disease that occurs in many breeds of dogs. In basenjis, it causes progressive vision loss leading to blindness. Inherited PRA occurs in both eyes (bilateral) and the part of the eye affected is the retina. With PRA the retina deteriorates (atrophies) over time (progressive) and ultimately causes blindness. The progression of vision loss may take a number of years and there is no treatment.
Research has shown there are at least two different forms of PRA in basenjis. In March 2013 a gene test (seeGenetic Testing section) for one form of PRA (PRA-BJ1) was made available to the basenji community. This gene accounts for approximately 50% of all PRA disease affecting basenjis. Currently there are multiple research teams around the world working to identify the causes of the other type or types of PRA in basenjis.
Basenjis affected by PRA usually do not exhibit changes in their vision until they are well into middle or even old age (5 – 8 years or even older). Due to the late onset of PRA it is important to have the genetic test for PRA-BJ1 completed before breeding. We can decrease the incidence of blindness in our breed with this one simple, inexpensive test.
As breeders and owners it is our responsibility to test our basenjis for PRA-BJ1 and share our test results so the disease can be prevented through informed breeding choices.
The gene test for PRA-BJ1 is offered by multiple labs. The Orthopedic Foundation for Animals offers this DNA test under the name ”Basenji Night Blindness/PRA DNA Test” located at the following link (http://www.offa.org/dnatesting/basenjipra.html). OptiGen offers the same test but it is called Bas_PRA1 and is located at the following link (http://www.optigen.com/opt9_basenjipra.html).
Unlike OFA, Optigen does not require disclosure of results. We encourage all breeders and owners to list their results on the OFA website, because only through disclosure of results are we able to eradicate genetic diseases. Both the OFA and Optigen tests determine whether the tested dog is genetically Normal/Clear, Carrier, or Affected for PRA-BJ1.
Since we know we have at least two forms of PRA in basenjis, a Normal/Clear or Carrier result only means the dog will not be affected by PRA-BJ1. Keep in mind, this dog or its offspring may still develop a different type of PRA. Testing for other type(s) of PRA must be done by regular OFA Eye Certification Registry certificate examinations and is explained in more detail below.
In addition, it is important to keep in mind, not all retinal changes are due to PRA; some changes may occur through injuries, caused by parasites, or due to a different disorder. Normal basenjis may also have an unusual looking retina that can be confused with PRA. When a clinical diagnosis of PRA is made with an ophthalmic examination, it is wise to have a second opinion conducted a year later to verify the findings and determine if retinal degeneration is progressing.
Many basenjis with PRA also develop cataracts (cloudiness on the lens of the eye). Owners may think their basenji’s cataracts are the reason for its vision loss, when in fact the dog could have PRA, as well. Both conditions affect vision and should be evaluated by a veterinary ophthalmologist.
The PRA-BJ1 test is part of the Canine Health Information Center (CHIC) list of health tests for basenjis. CHIC is a centralized canine health database jointly sponsored by the AKC/Canine Health Foundation (AKC/CHF) and the Orthopedic Foundation for Animals (OFA).For the Owner
Puppy buyers should insist their breeder test for PRA-BJ1. At least one parent needs to be Clear/Normal and both parents should have been examined by an American College of Veterinary Ophthalmologists (ACVO) certified Diplomat within the year prior to the breeding. Ask for a copy of the OFA Eye Certification Registry certificate examination.
Most PRA affected basenjis do not exhibit symptoms of PRA (any type) until they are at least 5-6 years old. The first symptom usually exhibited is difficulty seeing at night. You may also notice dilated pupils (large pupils) even in good lighting. The disease will progress slowly and you will notice over time your dog loses vision during the day and will eventually become completely blind. This progression of vision loss may take a number of years and there is no known treatment or cure. Fortunately basenjis with PRA adapt to their vision loss and with a stable, predictable environment, can continue to have a high quality of life even after they lose much of their vision.
If you suspect your basenji has visual changes, have them examined by a veterinary ophthalmologist. If your basenji is diagnosed with PRA other than PRA-BJ1, please contact the BCOA Health and Research Committee as we are trying to collect information to learn more about this disease.For the Breeder
All breeding stock should be tested for PRA-BJ1. This is a one-time test consisting of a simple cheek swab preformed at home and sent into one of the sites indicated above. At least one parent used in any litter should test Clear/Normal for this mutation.
Since there is at least one other form of PRA in Basenjis, it is recommended all breeding stock be examined by a veterinary ophthalmologist prior to each breeding to assess for retinal atrophy and other eye conditions. An examination by a veterinary ophthalmologist can detect early retinal deterioration before your dog exhibits symptoms or changes in its behavior due to vision loss. This examination is the best tool breeders can use to identify the other type(s) of PRA for which we have no genetic test. Since PRA can occur later in life, the exam cannot predict whether or not a dog will develop the problem in the future.
We do not know how many other type(s) of PRA are inherited, so dogs that are diagnosed with PRA by veterinary ophthalmologist exam, but have not been identified as affected with the PRA-BJ1 form of the disease, should NOT be used for breeding.Fanconi Syndrome
Fanconi syndrome is an inherited disease in which the kidneys do not properly reabsorb electrolytes and nutrients back into the body, but instead spill them into the urine. Symptoms include excessive drinking (polydipsia), excessive urination (polyuria), and glucose in the urine (glucosuria). If left untreated, muscle wasting, acidosis (increased acidity in the blood), and poor condition occurs.
The disease, typically progresses slowly, despite treatment and eventually results in death from kidney failure. However, if caught early and put on treatment (Fanconi Treatment Protocol), dogs with the disorder can do well and often have a nearly normal lifespan.
The Orthopedic Foundation for Animals (OFA) offers a genetic test to determine whether your dog is Normal/Clear, a Carrier, or genetically Affected with Fanconi Syndrome. Fanconi Syndrome is genetically inherited as an autosomal recessive disease (see Genetic Testing above). Dogs that inherit only one abnormal gene in the pair are considered Carriers. Although Carriers will not develop the disease, they can pass the abnormal gene to their offspring. Those genetically Affected are at risk for developing the disease.
For more information about this test go to this page (information dated 2011).
The Fanconi Syndrome gene test is part of the Canine Health Information Center (CHIC) list of health tests for basenjis. CHIC is a centralized canine health database jointly sponsored by the AKC/Canine Health Foundation (AKC/CHF) and OFA.
Although Fanconi Syndrome found in basenjis is typically inherited, there have been cases reported in small, non-basenji breeds where the disease is acquired due to idiopathic (unknown) means or from medication side effects. In many cases it is hard to differentiate between genetic and idiopathic causes. Specifically Hooper and Roberts (2011, J. Am Animal Hosp. Assoc. 2011 Nov-Dec 47 No 6:178-18) presented evidence of Fanconi Syndrome in four non-basenji dogs exposed to chicken jerky treats. The symptoms of the acquired forms of Fanconi Syndrome vary, depending on the cause.
Understanding the Orthopedic Foundation for Animals (OFA) test results for Fanconi Syndrome:
In August 2011 OFA began offering the DNA test which reveals whether a dog has the gene responsible for causing Fanconi Syndrome. Between July 2007 - August 2011, OFA offered a linked marker test as part of the research to identify the actual gene responsible for Fanconi.
The OFA database provides a public record of results. When looking up an individual dog, the OFA # tells you:
BJ = breed (Basenji)
FAC = Fanconi test (both gene or linked marker)
sequential number of sample assigned by OFA/
age at time of test in months
M or F for male or female
test related code
The test related codes are:
PI = permanent identification in the form of tattoo or microchip.
NOPI = no permanent identification.
VPI = animals that are permanently identified AND have had the identification verified by the attending veterinarian at the time of the test.
For example, an OFA # BJ-FAC9999/35F-NOPI would be a female Basenji tested Clear/Normal for Fanconi at the age of 35 months but with no permanent identification and was the 9999th dog sampled by OFA. While an OFA # BJ-FAC9989/45M-CAR would be a male Basenji tested Carrier for Fanconi at the age of 45 months with a tatoo and/or microchip identification and was the 9989th dog sampled by OFA.
Effective 1/1/08, only dogs with verified permanent identification (VPI) will have their OFA data transmitted to the AKC for inclusion in their database.
Clear by parentage
For current DNA gene tests only (since August 2011 to date), the OFA will issue clearances to untested offspring: if the sire and dam have both been DNA tested Normal/Clear, if the sire and dam’s DNA disease test results have been OFA registered, and if all three (sire/dam/offspring) have been DNA identity profiled and parentage verified. The resulting OFA certification will contain the suffix “CBP” (Clear by parentage), indicating that the dog itself was not tested but that the clearance was based on the sire and dam’s test results and known science at the time. Because of the possibility for new mutations, or as of yet undiscovered gene mutations, only first generation offspring will be designated CBP.For the Owner
Owners should insist that at least one parent of any puppy they purchase be tested "Normal/Clear" for Fanconi using the gene test (see above). Pets can be DNA tested to verify a Fanconi diagnosis or to help assess their likelihood of coming down with Fanconi [http://www.offa.org/dnatesting/fanconi.html]. Owners of DNA tested “Affected” dogs and dogs of unknown status should periodically 'strip test' (see information on strip testingbelow) their dogs for glucose in the urine starting as early as age 1 year. Strip testing indicates only the current presence or absence of glucose in the urine. It does not diagnose Fanconi or predict future results. A dog that strip tests "normal" now may later develop Fanconi.
Because elevated urine glucose is also found in diabetes, basenjis with Fanconi are often misdiagnosed with diabetes. Diabetic dogs will have high blood glucose levels, as well as urine glucose levels. In basenjis, a combination of urine glucose and normal or low blood glucose strongly suggests Fanconi Syndrome. The venous blood gas test (a simple blood test that estimates systemic carbon dioxide and pH levels) can verify an electrolyte imbalance consistent with Fanconi Syndrome. A veterinarian should evaluate dogs that have Fanconi symptoms but are not spilling sugar.For the Breeder
All breeding stock (both sire and dam) should be DNA tested for the Fanconi gene using the current DNA test. The current DNA test for Fanconi is available through the OFA at http://www.offa.org/dnatesting/fanconi.html and test results are in the searchable open database on that site. Results from the DNA linked marker test (available between 2007 to August 2011) should NOT be used for making breeding decisions. The current (as of August 2011) gene test, which tests for the actual mutation responsible for this disease, will tell you the genetic state of the dog. The test will determine if the dog is Normal/Clear, a Carrier, or genetically Affected. This is particularly important prior to the development of symptoms if the dog is Affected. Catching the onset of the disease early and starting treatment can, in some cases, lessen the severity of the disease.
Any planned basenji litter should have at least one parent that DNA tests Normal/Clear, to eliminate the chance of producing Affected puppies.Fanconi Treatment Protocol
In 1990 (updated in 2003 and 2012) Dr. Steve Gonto developed a treatment protocol for dogs with Fanconi based on the therapy human Fanconi patients received. The protocol uses dietary supplements for acid neutralization and replacement of lost electrolytes and nutrients. This is accomplished with bicarbonate and other supplements in specified doses to re-establish the body's acid-base balance and keep electrolytes at appropriate levels. Dr. Gonto was given lifetime membership in the Basenji Club of America in recognition of the importance of his work.
The Gonto protocol was studied and validated for the veterinary literature by Jennifer Yearley, DVM, while she was completing her professional studies. This was an important step in expanding the awareness of the treatment. The protocol has been very successful in improving both quality and length of life for Fanconi-affected basenjis. The disorder can be controlled by the protocol, but it cannot be cured.
Urine Strip Testing
Urine glucose test strips (not blood test strips), such as those used by diabetics, are inexpensive and can be purchased at most pharmacies. The strip should be placed in the basenji's urine stream and then read as specified in the strip instructions. If it is not possible to place the strip in the urine stream, then the owner may need to catch the urine. Some owners use a pie pan, ladle, or serving spoon.
A positive result (glucose present) suggests the possibility of Fanconi, but is not sufficient for definitive diagnosis. Owners should then go to their vet for further testing, which would normally include a blood glucose level.Pyruvate Kinase Deficiency – Hemolytic Anemia
Pyruvate kinase deficient - hemolytic anemia was first diagnosed in basenjis in the 1960s, although prior to that date basenjis had died of a then-unknown form of anemia. Research on this anemia began in the 1960s and there is a DNA test available.The inherited form of the disease now is extremely rare.
Pyruvate Kinase Deficient - Hemolytic Anemia (PK-deficient HA) is different from idiopathic autoimmune hemolytic anemia (IAHA), a non-inherited hemolytic anemia that occurs in all breeds of dogs. Because of the great reduction in the frequency of the inherited form, the non-inherited form is now the likeliest cause of any hemolytic anemia in basenjis.
Affected dogs may faint, are likely to have low energy levels, typically have very white gums and mucous membranes, and have light, "golden" colored stools. Affected dogs typically die by age 2, with age 4 being the outside limit of survival.For the Owner
The disorder has been virtually eliminated from the breed and testing has been largely discontinued. Owners can ask for information about whether or not the dogs have been tested or are entirely descended from tested normal stock. Because a DNA test is available, a definitive diagnosis can be made to rule out PK-deficient HA.For the Breeder
Testing for PK-deficient HA can still be obtained at some DNA testing labs. Most basenjis are now descended from tested normal stock. A few carriers still exist in the gene pool, so it is a good idea to use only dogs descended from tested normal stock or dogs that have themselves been tested. A list of labs that perform the HA test (pyruvate kinase deficiency) is online at http://www.offa.org/dnaother.html. OFA has an open registry for hemolytic anemia DNA status.
All new imports from Africa were DNA tested prior to inclusion in the AKC studbook.
This DNA testing gives a definitive reading of the dog's status as Clear, Carrier, or Affected, so the testing does not have to be repeated. The gene is inherited as a simple recessive.Hip Dysplasia
Hip dysplasia (HD) is a complex hereditary condition in which the hip socket is badly formed, often leading to lameness and arthritis. It is believed to be polygenic (with multiple genes), as well as having environmental factors involved in its expression. According to the OFA, the basenji ranks 157th of 172 breeds in incidence of Hip Dysplasia. Of 2,651 hip evaluations performed by OFA between January 1974 and December 2013; 23% were rated Excellent and 3.5% were rated Dysplastic.For the Owner
When purchasing a puppy, the parents should have been tested for hip dysplasia and the x-rays should have been read by the Orthopedic Foundation for Animals (OFA.) Results can be found by looking under the dogs AKC registration number at http://www.offa.org. Your breeder should be able to provide a link to the results for the parents of your pup.For the Breeder
Breeding stock should be x-rayed for hip dysplasia. The OFA has a web site that permits downloads and searches of dogs that have passed with a grade of Fair, Good, or Excellent. In addition, the OFA has recently added the option of having results placed in an open health registry, so that Borderline and Dysplastic ratings can be made public.
Good and Excellent are the preferred grades for breeding stock, although Fair is not considered dysplastic. Affected or untested animals should never be used for breeding. OFA status at 2 years of age is generally considered definitive of that dog's hip status. However, there is a small chance a dog can become dysplastic later in life.
For permanent results, dogs can be x-rayed for hip dysplasia at 2 years of age or older, with the films reviewed by the OFA for the definitive reading. Dogs can be x-rayed earlier for preliminary results if they are being bred prior to 2 years of age. Hips can also be examined by PennHip and PennHip results can be included in the OFA database.
Breeding from tested unaffected stock and using vertical pedigrees to consider the scores of relatives are the recommended methods of controlling hip dysplasia. The rate of incidence of HD within a litter has been shown by OFA to be strongly correlated to the hip scores of the parents with litters of parents both rated Excellent having the least chance of having HD.
In the chart below each parent is assigned a numerical score 1=excellent, 2= good, 3=fair, 4=borderline, 5=mildly dysplastic, 6= moderately dysplastic, and 7= severely dysplastic. Parental scores were then added together and the % dysplastic progeny calculated for each score. So, excellent x excellent = 2 and the chart shows a 3.58% incidence of dysplasia in progeny of excellent x excellent breedings from the OFA database.
This chart represents hip phenotype data on 490,966 progeny in the OFA database for which the hip phenotype for both parents are known. It is reprinted here from Dr. Keller’s talk with the permission of OFA.
A hip x-ray evaluated by three board certified radiologists is part of the Canine Health Information Center (CHIC) list of health tests for basenjis. CHIC is a centralized canine health database jointly sponsored by the AKC/Canine Health Foundation (AKC/CHF) and the Orthopedic Foundation for Animals (OFA).
Immuno-Proliferative Small Intestinal Disease and Exocrine Pancreatic Insufficiency (EPI)
Immuno-Proliferative Small Intestinal Disease and Exocrine Pancreatic Insufficiency are presented together because they are both disorders of maldigestion or malabsorption.
IPSID stands for Immuno-Proliferative Small Intestinal Disease but it is a disease of many names. It is also called Basenji Enteropathy, Immunoproliferative Lymphoplasmacytic Enteritis, Basenji Diarrheal Syndrome, and malabsorption. IPSID is a type of inflammatory bowel disease (IBD), which results in the dog not being able to utilize and absorb nutrients correctly from food.
A predisposition to IPSID is inherited, but inheritance appears to be only one of the factors involved. A dog genetically predisposed to IPSID and its resultant immunological impairment might present with usual IBD and eventually progress to IPSID. Physical and/or emotional stresses may be aggravating triggers.
Exocrine pancreatic insufficiency (EPI) can be confused with IPSID but the treatment is very different. A dog with EPI is not able to produce the enzymes needed for digestion. EPI occurs when a dog's exocrine glands in the pancreas become atrophied and can no longer produce or secrete pancreatic digestive enzymes. Some food particles then remain undigested and unabsorbed causing Small Intestinal Bacterial Overgrowth (SIBO). That results in the dog, although eating copious amounts of food, being constantly undernourished and literally wasting away. Without proper treatment, the EPI dog can suffer greatly and even die a painful death from malnourishment, starvation or organ failure.
EPI should be ruled out before a diagnosis of IPSID is made. The only way to confirm EPI is with a TLI (Trypsin-Like Immunoreactivity) blood test. If your dog is diagnosed with pancreatic insufficiency or if you have questions about the disorder, information is online at http://www.epi4dogs.com.For the Owner
IPSID symptoms can include diarrhea, vomiting, weight loss, increased or decreased appetite, gas, and depression. EPI symptoms are very similar and include weight loss despite a strong appetite, greasy globs of voluminous yellowish stools, diarrhea, vomiting, and personality changes. The type of symptoms and their severity differ from dog to dog, and from one episode to another. Dogs with IPSID or EPI often will have good periods as well as bad spells. Rarely will a dog present with profound weight loss but no other symptoms. Testing for EPI and IPSID can rule out instances where a dog suffering from either condition is not suffering from other outward symptoms like vomiting and diarrhea.
Diagnosing IPSID involves investigating and eliminating other possible causes of the dog's symptoms. Blood serum protein levels may be low. Intestinal biopsy is the only reliable way to diagnose IPSID; it is done to rule out irritable bowel syndrome, inflammatory bowel syndrome and other diseases, lymphangiectasia (which most basenjis with IPSID have as a secondary condition), colitis, cancer, and systemic fungal infections. Endoscopic biopsies are preferred to prevent complications with healing.
Traditional methods of treating IPSID include systemic prednisone and antibiotics. Some dogs do well on a holistic regimen; it is important to discuss a long-term treatment plan with your veterinarian. Symptoms may diminish or increase over time. A veterinarian must oversee treatment and changes to treatment. IPSID affected dogs can harbor microorganisms that may cause problems for other dogs in the household; proper household hygiene is important.
A change to the dog’s diet may be required to optimize nutrient utilization. Some veterinarians suggest switching diets on a monthly basis. A homemade diet also can be used and additional vitamin supplementation may be indicated.
EPI should be confirmed with a trypsin-like immunoreactivity blood test. This test detects trypsinogen and trypsin levels in the pancreas. Values below 2.5 µg/L indicate EPI. Values between 3.5 and 5.7 µg/L may be indicative of other pancreatic disease.
Treatment for EPI includes supplementation with enzymes and changes to the dog’s diet. Antibiotics and supplementation with vitamin B-12 (cobalamin) may also be required. The most common enzymes used to treat EPI dogs are porcine-based (from pigs). However, some EPI dogs do not tolerate porcine enzymes. These dogs are often helped by plant-based (soy) enzymes that aid digestion.
There are many web resources for dogs and owners dealing with EPI, including discussion lists for owners of affected dogs. See, for example: http://www.epi4dogs.com/.For the Breeder
While IPSID and EPI are not common, they are serious diseases. Dogs with IPSID or EPI should NOT be used for breeding. While the mode of inheritance is not known, susceptibility to these diseases, rather than direct inheritance, may be involved.Patellar Luxation
Patellar luxation occurs when the kneecap pops out of place. As of December 2013, 0.9% of those basenjis checked have been reported Affected by the Orthopedic Foundation for Animals.For the Owner
Patellar luxation can be diagnosed by a veterinarian.For the Breeder
The Orthopedic Foundation for Animals has an open registry of dogs whose patellas have been evaluated at 12 months of age or older. The exam is non-invasive and inexpensive. Patellar luxation is suspected to be heritable, though the mode of inheritance is unknown.Thyroid Problems
The thyroid glands (there is a pair) secrete and regulate the hormones responsible for metabolism and some organ function. Thyroid gland disease in dogs is most often hypothyroid (underactive / low functioning gland). It may be the only symptom of the disease or it may be a part of a broader autoimmune disorder. One form of hypothyroidism is caused by autoimmune thyroiditis and is known to be an inherited disease. But idiopathic (cause unknown) thyroid gland atrophy can also occur. An underactive thyroid generally means that the dog's metabolism is slower than normal.
Hypothyroidism can be controlled very easily by medication.
Some or several of the following symptoms may be observed: weight gain without an increase in appetite, symmetrical hair loss and poor coat, ear and skin changes (including dryness, chronic bacterial infections, discoloration, or thickening), lethargy and lack of interest in physical activity or play, and/or significant behavioral changes like aggression.
Testing is available to learn the current thyroid status of your dog but the blood test cannot predict future changes.
A comprehensive thyroid panel is used and should include:
- total thyroxine (T4 or TT4 which is total thyroxine hormone)
- thyroid-stimulating hormone (TSH),
- free T4 (or FT4 which is the free or active thyroxine hormone) by equilibrium dialysis, and
- cTGAA (Canine Thyroglobulin Autoantibody or TAA) levels show negative or positive for thyroglobulin antibodies.
Elevation of TgAA levels are used to diagnose autoimmune thyroiditis; however, as the disease progresses, these levels may decrease due to complete destruction of the thyroid gland. Dogs that have had autoimmune thyroiditis for several years but have never been tested might not show the elevated TSH and TgAA needed for definitive diagnosis. Your veterinarian may test other thyroid levels when making a diagnosis.
The minimal thyroid level necessary for healthy function varies depending on breed of dog, age, and reproductive phase. Sometimes it can even vary between pedigree lines. Puppies have higher normal thyroid levels, while seniors and sighthounds have lower normal thyroid levels.
Basenjis require a thyroid panel including at least TT4, FT4, TGAA, and TSH, to be accurately diagnosed.
When testing your basenji, TT4 and FT4 must be analyzed in conjunction with TSH. Basenjis typically have a lower reference range for TT4 than other breeds. Research conducted by the University of Sydney found that basenjis and some other sighthounds have lower normal levels of TT4 than other dog breeds (Seavers, A.; Snow, D.H.; Mason, K.V.; Malik, R. 2008. Evaluation of the thyroid status of Basenji dogs in Australia. Australian Veterinary Journal: 11, 429-434). Given the difficulty of accurately measuring TT4 concentrations that low, TSH level measures are essential to properly assess thyroid function. Otherwise, your basenji may be diagnosed as hypothyroid by the standard all-breed normal range and be medicated for no reason.
Autoimmune thyroiditis disease has variable onset but tends to become symptomatic at 2 to 5 years of age. Dogs that are negative at 1 year of age may become positive at 6 years of age. Dogs may be clinically normal for years, only to become hypothyroid at a later date. Therefore, periodic retesting every year or two is recommended. Since the majority of affected dogs will have autoantibodies by 4 years of age, annual testing for the first 4 years is recommended. After that, testing every other year is recommended.
The Orthopedic Foundation for Animals has an open registry for dogs that have been tested for autoimmune thyroiditis at 12 months or older, using approved labs. For the current list of laboratories approved to perform analysis for OFA thyroid certification, see http://www.offa.org/thy_labs.html.
The autoimmune thyroiditis test is part of the Canine Health Information Center (CHIC) list of health tests for basenjis. CHIC is a centralized canine health database jointly sponsored by the AKC/Canine Health Foundation (AKC/CHF) and the Orthopedic Foundation for Animals (OFA).For the Owner
Hypothyroidism may be treated with a thyroid supplement under veterinary supervision including periodic adjustment of the dosage. Pet owners may want to have their vet periodically check their dogs, especially if they show any symptoms that suggest hypothyroidism.For the Breeder
It is a good idea for breeders to periodically check their breeding stock with a full thyroid panel beginning in early adulthood. Testing for breeding stock is done primarily to rule out autoimmune thyroiditis, which is known to be inheritable. The thyroid panels test does not indicate if a dog can produce offspring with hypothyroidism.
It is recommended to perform a thyroid wellness test before the bitch begins any signs of her heat cycle. A thyroid imbalance often occurs as a result of whelping. For puppies, the first wellness thyroid panel should be done 3 months after the first heat, for dogs & bitches.Umbilical and Inguinal Hernias
Umbilical hernias are very common in basenjis, with most being minor hernias that do not normally cause problems for the dog. Inguinal hernias, although uncommon, can be serious. Both types of hernias are hereditary.For the Owner
Umbilical hernias can be repaired at any time; the surgery is often done when a pet is spayed or neutered or during any other procedure requiring anesthesia. Small closed hernias generally do not cause problems, however large or open hernias can cause problems if a loop of intestine gets caught in the hernia. Some breeders routinely repair even small closed hernias. Dogs which have had umbilical hernias repaired are still eligible for participation in AKC conformation events.
Inguinal hernias are uncommon in basenjis and can be diagnosed by your veterinarian. They generally do require surgical repair. Dogs with repaired inguinal hernias are not eligible for participation in AKC conformation events.For the Breeder
Small closed umbilical hernias generally are not an issue in breeding, although selection away from umbilical hernias is desirable. The use of individuals with large or open hernias should be carefully considered.