About Fanconi Syndrome

Fanconi syndrome is a disorder in which the proximal renal tubules of the kidney do not properly reabsorb electrolytes and nutrients into the body, but "spill" them instead into the urine. Symptoms include excessive drinking (polydipsia), excessive urination (polyuria), and glucose in the urine (glucosuria). Untreated Fanconi syndrome results in muscle wasting, acidosis, poor condition, and eventually death.

The onset of Fanconi syndrome is typically between four and eight years of age, although onset has occurred as early as two years and as late as twelve years. The earlier the disease is detected, the less damage is done to tissues and organs, and the better chance of the dog living a long and healthy life. An early diagnosis is crucial!

DNA Testing for Fanconi Syndrome

Shown above is the FTA DNA test card you will receive from the OFA. Also in the kit will be instructions and a return shipping label.

Beginning in June 2015 all purebred Basenjis in our care under 10 years old will be DNA-tested for Fanconi syndrome unless the dog has already been found to be symptomatic and diagnosed by abnormal venous blood gases accompanied by sugar in urine and normal blood sugar. (Owners of dogs over 10 should continue to strip test monthly. Or, for peace of mind, have your dog DNA-tested.)

If you own a Basenji under the age of 10 we strongly encourage you to order the DNA test from the Orthopedic Foundation for Animals (OFA) and administer the test at home. Anyone can order this easy-to-use test; you do not need a prescription from a veterinarian. The fee for each test is $65 and includes the test kit, instructions, and a return shipping label to the University of Missouri (where the test is performed). All test results are reported by email. The results of the test will be clear/normal, carrier, or affected.

If the results of the DNA test come back clear/normal, the dog is highly unlikely to develop the disease. Dr. Gonto states that strip testing is not necessary on a regular basis for any dog of any age if it has been cleared using the gene test, but “you can never say never”; there is a miniscule chance that the dog may develop the disease, so you may want to continue strip-testing monthly or at least periodically. There is a very slim possibility of testing error – no test is 100% foolproof.

Carrier means the dog has a normal gene set from one parent, and the gene set for Fanconi from the other parent.  A carrier doesn't have the full set of genes for the disease, so the dog is highly unlikely to develop the disease. But again, never say never. Slim testing errors always exist.

Affected means that while your dog may be asymptomatic, he will almost certainly develop Fanconi at some time in his life. Don't panic. If diagnosed early the dog can live a long and healthy life. See the link to the Fanconi Renal Disease Management Protocol for Veterinarians below. Your vet should read and understand the Protocol and if necessary work with Dr. Gonto to start a plan of attack.

Strip Testing Your Basenji’s Urine for Glucose

If you do not wish to DNA test your Basenji and prefer to continue to strip test for glucose in the urine read, below. It is generally recommended that strip-testing for glucose begin at age three, but you may want to begin earlier just to get used to the routine. Again, if caught early and put on the Gonto Treatment Protocol, affected Basenjis can do very well and live a normal life. Early detection and treatment is vital to your dog's health and well being.

If you adopt a Basenji from BRAT under ten years old, it has been DNA tested. If the dog is over ten we have strip-tested it prior to adoption and you should continue the practice monthly until the dog is at least twelve. (Some owners continue strip testing their dogs beyond that age.) Fanconi syndrome is life-threatening if untreated, so it's important to test monthly. Designate a "Strip Test Day,” perhaps the same day you give heartworm preventative each month.

The strips you'll want to use are Bayer Diastix Reagent Strips for Urinalysis (not blood) Glucose. The colored end of the strip should be placed in the Basenji's urine stream as he urinates. If it is not possible to place the strip directly into the urine stream, the owner may catch the urine in a clean pie pan or ladle.

The Diastix strips should be read 30 seconds after being exposed to the dog’s urine or according to the instructions on the box or bottle. NOTE: Any color change is significant. A positive result (glucose present) suggests only the possibility of Fanconi syndrome; it is not sufficient for definitive diagnosis, but indicates a need for further testing, to include a blood glucose level and possibly venous blood gas studies.

Again, strip-testing indicates only the presence or absence of glucose in the urine at the time of testing. It does not definitively diagnose Fanconi syndrome, and it cannot predict whether or not a dog will later develop the disorder. A dog that strip-tests normal now may develop Fanconi syndrome in the future.

Where to Buy Glucose Test Strips

Drugstore chains such as Wal-Mart, Walgreen, CVS, Target, and many supermarket pharmacies may have these strips. The strips are usually located behind the pharmacy counter, so you may have to ask. If your drugstore does not carry them, ask your pharmacist if he can order them for you. They can also be found at Amazon.com; search on Diastix Reagent Strips for Urinalysis (Glucose). They come in boxes of 50 and 100. A box of 50 should run you about $15-$20.

Either way, be sure to buy glucose test strips, not ketone test strips.

Testing Expired Test Strips

The Diastix bottle shows results of a urine test as a color scale. The far left color is labeled Negative, the same color as the test strip. After the strip is wet with urine, compare the stick to the colors on the bottle for exactly 30 seconds. Any color change from the Negative color is significant.

At some point you may wish to make sure your test strips are functional. This can be done by dissolving one drop of plain honey in one tablespoon of water, or one drop of Karo syrup in one teaspoon of water, and then testing the solution. Both of these products will change the strip color if the strips are still reactive. Do not use table sugar; it is a different molecule and will not change the strip.

The Fanconi Syndrome Treatment Protocol

In 1989, Steve Gonto, MMSc, Ph.D. of Georgia developed a treatment protocol for dogs, later adapted to treat Fanconi syndrome in humans. Dr. Gonto was given lifetime membership in the Basenji Club of America in recognition of the importance of his work. He was the honored guest speaker at the 2007 BRAT convention in Orlando, Florida, at which time he was presented with a plaque for his contributions to Basenji health. He made a second presentation at the 2015 BRAT convention in Columbia, South Carolina where he presented a revised protocol.

The Protocol involves acid neutralization, replacing lost electrolytes and nutrients with sodium bicarbonate and other supplements in specified doses, to re-establish the body's acid/base balance and keep electrolytes at appropriate levels.

The Gonto 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. Because elevated urine glucose is also found in diabetes, Basenjis with Fanconi syndrome are sometimes misdiagnosed with diabetes. Diabetes will show high blood glucose along with urine glucose. In Basenjis, a combination of urine glucose and normal or low blood glucose strongly suggests Fanconi syndrome. Venous blood gas studies can verify an electrolyte imbalance consistent with Fanconi syndrome.

Take This Information To Your Vet!

Because it is relatively uncommon in other breeds many vets are unfamiliar with heritable Fanconi syndrome. If your Basenji’s urine tests positive for glucose, or if your dog's DNA test results are "affected", review all the following documents and information:

Dr. Gonto is available for consultation with your veterinarian at no charge by calling (912) 598-5067 or e-mailing Dr. Gonto to get advice and a veterinary protocol treatment card. (The 912 area code serves the southeastern portion of the state of Georgia.)

REMEMBER: The DNA test is best; second best is to strip your dog EVERY month – your Basenji’s life may depend on it!

If you have any questions about Fanconi syndrome and your Basenji, write to us.

Revised and links checked 01/22/16 CM/JK