The Basenji Club of America African Stock Project
Heriditary Problems Presented to the AKC Board:
For Consideration in Reopening the Basenji Stud Book
| July 10, 1989 |
To whom it may concern:
I have been asked to make a few comments regarding the hereditary disorders found in the Basenji dog. In 1968, I was employed by the University of Missouri in the schools of Medicine and Veterinary Medicine and the university operated Sinclair Comparative Medicine Research Farm. My position as Geneticist and Coparative Pathologist was to study hereditary diseases in animals that mimiced similar diseases known in man. This involved many animals, such as cattel, pigs, monkeys, mice, rats, etc. But also included dogs.
In 1969, I began working with the Basenji dog. At that time, it was the only animal, other than man, known to have an hereditary hemolytic anemia due to a deficiency of the pyruvate kinase enzyme. I established a research and breeding colony of Basenjis through the loan and donation of registered Basenjis. I have worked with this breed continuously since that time.
In 1970, I estimated the incidence of the gene for hemolytic anemia to be more than 20 percent in the American dogs tested. Many, but not all, major breeders submitted blood samples for their dogs for testing. Biochemical tests for pyruvate kinase activity indicated the presence of the defective pyruvate kinase gene. Soon, many breeders refused stud service to untested bitches, or refused to breed their bitches to males that had not tested clear of the disorder. By 1975, the incidence of the gene causing hemolytic anemia was less than one percent in pups born that year. The incidence of the anemia is now rather rare, but the gene causing it is still around in a reduced frequency. This breeding away from anemia essentially eliminated certain families of Basenjis, but more on that later.
In the late 1960s and early 1970s, it became rather obvious that many basenjis had an eye problem, Persistent Pupillary Membranes. It appeared to be hereditary and was more common in some lines. In most cases, it had no effect on vision, but some dogs did have blindness in one or both eyes. This condition is quite common in man and only occassionally effects vision. It is now being treated successfully by laser therapy in man. Many breeders have been having their Basenjis tested for this disorder and have been trying to breed away from the problem. The exact genetic nature has not been studied. It is not a life threatening problem.
Hypothyroidism is rather commonly found in some families of Basenjis. It is an hereditary disorder. It leads to lessened activity, obesity, and bad coats. A veterinarian may prescribe hormone therapy and alleviate the symptoms. Sometimes a dog will be bred before the condition is diagnosed. Occasionally an owner will breed a dog knownig it has the condition. There has not been a concerted effort by breeders to eliminate the problem. The Basenji breed is unique in its thyroid function. It has been well documented that the Basenji breed has a more rapid thyroid turnover than any other breed of dogs. Certainly the breed has a reputation of being a "hyper" breed and it is quite likely due to thyroid function.
Malabsorption syndrome has been very commonly reported in the Basenji breed. This has received several different names. Basically it involves impaired absorption of nutrients across the membranes of the intestines. It may occur in the first year of lie or sometimes not until later. The symptoms are chronic diarrhea and loss of weight. A dog may appear hungry, but will eat very little. The dogs reach a rather pitiful condition. It can be treated with a combination of antibiotics, vitamins and minerals and a dog may sometimes exist quite well in a stabalized condition for several years with daily treatment. It may well be a form of Fanconi Syndrome (to be discussed next) since a similar condition is known in some humans with Fanconi syndrome.
Fanconi Syndrome is an hereditary disorder of the kidney in men and dogs. The basic problem is a failure to transport proteins, amino acids, and electrolytes across the kidney membranes. Body fluids are indiscriminately lost into the kidney, but in the proximal tubules, proteins, amino acids, calcium, and various electrolytes (potassium, sodium, and bicarbonate) are recovered and returned to the bloodstream. Individuals with Fanconi disease important materials into the urine. In dogs this poses no important problem until about four to six years of age when the dog begins to also lose increasingly larger amounts of glucose into the urine. This is accompanied by increased consumption of water (polydipsea) and increased urination (polyurea) and weight loss. Eventually a dog may be unable to hold its urine and become a management problem in the case of a household pet. Eventually a shutdown of the kidney and/or liver will lead to death. This can lead to a long, painful ordeal for the concerned dog owner. This disorder cannot be cured, but can be put into remission by daily medication. The incidence of the Fanconi gene seems at this time to be more than 70 percent of the population in the United States. In humans, there are two forms of Fanconi syndrome. One form also includes intestinal malabsorption. this has not been verified in the dog, but the treatment for both disorders is the same in the dog.
It has been estimated that the Basenji breed was based on a maximum of 18 or 19 dogs imported from Africa. Some of these dogs probably had no influence on the breed and may be absent from the pedigrees of present dogs. When I first began working with the Basenji breed at the Univeristy of Missouri, the dogs in that area were fairly uniform in type, color, eye color, etc. Most were closely related to a champion dog imported from Norway. A visit to major breeder on the west coast indicated a rather different type of Basenji and very different pedigrees. I did not see the dogs in the east at that time. As breeders began to test for hemolytic anemia and stopped breeding carriers of the defective gene, breeders began hunting for clear stud dogs. the Norweigian imported stud turned out to be a carrier of hemolytic anemia. He and at least half of his decendants were no longer used for breeding. Today one practically never finds his name in a pedigree. Breeders turned to a few clear dogs of exceptional show quality for stud service. A few dogs produced over a hundred litter apiece and 50 to 100 champion offspring each. Most of these dogs may have been carriers of Fanconi Syndrome. They are not now available for testing and most of their sons are also dead. But one of the record sires of the breed produced offspring with Fanconi Syndrome and was surely a carrier of the gene. Almost all of the top stud dogs today trace back very quickly to these record sires. It would appear that as breeders avoided dogs that might carry hemolytic anemia, they turned to a small group of dogs that carrier the gene for Fanconi Syndrome. While many breeds are known to have the gene for Fanconi Syndrome (Greyhound, Whippet, Saluki, Elkhound, Siberian Husky, Akita, etc.), it may be a more serious problem in the Basenji for two reasons: the high levels of thyroid hormone found in the typical Basenji exacerbates the physilogic effect, and the very limited pedigree structure of the Basenji breed.
I have had the opportunity to examine the pedigrees of many Australian Basenjis in cooperation with a breeder in Australia. In that country, the breed stemmed originally from eight dogs from England or from England by way of New Zealand. All of the dogs that developed hemolytic anemia traced back to just one male imported from England. Incidentally, this male's littermates went to the United States where several were leading sires. In recent years, some Australian breeders have imported stock from the United States in order to increase their gene pool and diversify their qualities. I worked with a researcher at the Royal Danish Veterinary School. He tested the Basenjis in that country where hemolytic anemia was known to be a serious problem. His comment to me was that almost all dogs carried the gene and that many breeders were abandoning the breed because there were almost no dogs free of the disorder.
Just a few persons in England imported Basenjis from Africa and rather quickly had the breed recognized and the registry base established. There were probably a limited number with desirable conformation and these may well have carried genes for serious health problems. Certainly in Denmark almost all of the dogs originally imported from England carried the gene for hemolytic anemia. Probably only one of eight did in Australia. These are probably two extremes. In the United States, quite a few dogs were imported from England, but mostly from just one breeder well known as a writer, judge and promoter of the breed. From a pratical standpoint, the Basenji breed in the United States probably has less than a dozen original African ancestors.
In recent years, several trips have been made to Africa by knowledgable breeders and native African Basenjis have been brought back to the United States. I have seen a few of these dogs and note that they seem somewhat calmer than typical Basenjis and they seem to have a more agreeable temperament. Certainly some of them would not win in the show ring, but appear to excell in the role of mans best friend. I am told that dogs were seen in Africa that would definitely be show quality in the United States. Most of the people with these recent African dogs have submitted blood and urine to my laboratory for testing for hemolytic anemia and Fanconi Syndrome. All of these have been free of hemolytic anemia and all but one import were free of the Fanconi Syndrome gene. (ed: this data is incorrect, as no gene has been located for Fanconi Syndrome) It would thus appear that from the standpoint of hereditary disorders in the Basenji breed, a judicious introduction of African stock to the Basenji gene pool would be very beneficial.
It is not popular to talk to Basenji breeders about the temperament problems in the breed. That is an understatement. I have had the opportunity to study behavioral disorders, such as fear biting, in several breeds. I have observed fear biters, or "manshy" dogs in Basenjis rather commonly. As an AKC Basenji judge, I have dismissed dogs with aggressive temperaments. In one family, I was able to observe and follow agressive behavior through three generations where every dog shown was dismissed from the ring. I have been particularly struck by the temperament of the African imports that I have seen. It will be unpopular with breeders for me to say this, but I think that temperamentwise, the breed could only benefit from additions to the gene pool of the Africans I have seen.
Russell V. Brown, PhD
Copyright © 1989 Russell V. Brown,
All Rights Reserved.