The Basenji Club of America African Stock Project

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HEREDITARY DISORDERS OF THE BASENJI

Dr. Russell Brown

Chester, Virgina

 Every breed of dog has a number of hereditary disorders. Any one that would say that their 
breed does not have is probably uninformed. We are fortunate in the Basenji breed to have a good
breed club and a good breed journal that can keep breeders informed. It may be a misconception
on my part, but I believe that Basenji owners and breeders as a group are more concerned about
the welfare of their breed than the breeders of many breeds. Most of our people care. In writing this
article, I have no desire to throw a scare into anyone, but simply to offer information so that Basenji
people may continue to be informed.
Our best known problem is Pyruvate Kinase Deficiency Hemolytic Anemia. When I first
started testing for Hemolytic Anemia, twenty per cent of all the dogs that I tested had the recessive
gene for HA. I expect we are now down below two per cent. HA probably arose as the result of
many mutations and maintained itself, even increased in frequency in Africa, because it probably
gave the Basenji protection against various parasites. However, we do not have the parasite pro-
blems in this country that the Basenji faced in its native Africa and it would be desirable not to be
faced with the anemia problem.
We have made great strides in eliminating hemolytic anemia, However, we do need to keep up
the effort. The tests for the HA gene are not at all simple and are subject to error. There is a small
chance that a dog carrying the defective gene may be tested as clear. Two, or more generations of
clear tested parents are needed before we can assume that a dog is clear and does not need to be
tested. Many breeders have reached this point and we all need to. Recently in what was thought to
be routine testing of clear stock, some carriers (all littermates) turned up. Some of these had been
bred, so the problem is not so simple. Retesting of the parents revealed that one was a carrier and
had been tested as clear some years ago. It happened that I had not tested it originally, but I am
sure that occasional errors occur in my lab too. Two generations of testing should catch these sorts
of errors before they lead to serious problems.
Once in a great while, in preparing blood samples for HA testing, I notice a blood sample that
contains a great deal of lipids or fat. An unusually high amount of fat in the blood is not too un-
common where a dog has been fed a fairly high fat diet a short time before bleeding. But that type of
fat will float to the surface of the blood when the blood is spun in a centrifuge. But in these more rare
events where the lipid is very high, spinning the blood does not float off the lipid material. These ca-
ses are due to high levels of cholesterol and triglycerides in the blood. The most common cause of
this in a dog is associated with thyroid problems. Basenjis, as a breed, are known to have a greater
thyroid turnover than other dogs, but this is not the cause of the high blood lipids, but of just the op-
posite, or insufficient thyroid. Thyroid problems are probably not very common in Basenjis, I notice
a few every year and would estimate this to be found in less than one per cent of the blood samples
that I receive.
Another well known problem in Basenjis is persistent pupillary membrane (PPM). It is present
in other breeds. The eye forms from an invagination, or the development of a pocket on each side of
the head of the embryo. At one point it is like two teacups inset in the sides of the head. The pocket
deepens and the rims of the cup come together until they meet forming the eye under a double layer
of tissue. The iris forms. The iris is the colored part of the eye and has a hole in the middle (the
pupil) through which light travels to the photosensitive rear part (the retina) . The pupil and iris are
under a membrane at this time. When the eye is formed, before birth, the eyes move with the devel-
opment of the face to the front of the face and the membranes disappear shortly before birth. Some-
times part of the membrane remains and can be seen over the pupil. This is called a persistent pup-
illary membrane. If something were to happen to the bitch during her pregnancy that slowed down
the rate of fetal development, then some events that take place in the embryos might be slowed
down leading to PPMs. The sorts of things that could occur would be poor nutrition, disease, para-
sitic infection, etc. We know that there are some genes that control or effect the rate of develop-
ment. These genes could have something to do with PPMs. Thus PPMs could be genetic or envir-
onmental. It could be both. Perhaps a line has a tendency to PPMs, but will not have them unless
the bitch (or embryos) are stressed at a certain time in embryonic development.
How serious is PPM and what should we do about it? I discussed PPMs with a respected
MD-Ophthalmologist. He told me that about twenty per cent of the humans born have PPMs. He
said that about one in a thousand, or less, have some visual impairment as a result. This may mean
that one out of every five Basenji owners has a PPM (or had one, as they can disappear after birth).
When I think that there is a twenty percent chance that I had one at birth, but passed the toughest
air force eye examinations, I can't get too steamed up about it. On the other hand, I do not think we
should ignore the problem. I have had all my dogs examined. I have never bred a bitch that did not
have a CERF certificate. But I am not going to advertise this, as there just isn't enough known about
PPM for me to believe that my females can't have PPM puppies. I don't think that I could recom-
mend that a truly outstanding Basenji with a PPM not be bred. I would recommend that two dogs
with PPMs not be mated to each other. As we can, without hurting the quality of the breed, we
should be weeding out the dogs with PPM.
I have had inquiries from a number of people about Franconi Syndrome. This is a kidney pro-
blem found in Basenjis. Some real headway is being made in the study of this disorder, A group,
headed by Dr. Bovee, at the University of Pennsylvania, have published their first article on it. The
article appeared in SCIENCE, Volume 201, September 22, 1978, and was entitled, "The Franconi
Syndrome in Basenji Dogs: A New Model for Renal Transport Defects " . Dr. Bovee and his coll-
eagues will have another article out this spring in THE JOURNAL OF THE AMERICAN
VETERINARY MEDICAL ASSOCIATION.
Symptoms of this disorder are polydipsia (frequent drinking, Polyuria (frequent urination), de-
hydration, weight loss and weakness. This occurs in adult dogs. There is an excess of glucose and a
decrease in salt in the urine. These symptoms are similar to diabetes mellitus, but the defective cells
in the pancreas that cause diabetes are not found in Franconi syndrome . I expect dogs that were
thought to have diabetes may actually have had Franconi syndrome.
It is the job of the kidney to filter body fluids, reclaiming amino acids, salts and various impor-
tant chemicals and and letting the wastes go into the urine. With Franconi syndrome, the kidney
does not function properly so that things that should be reclaimed go into the urine. The body thus
loses vital constituents needed for normal functions. There is a loss of body fluids leading to de-
hydration. Without the reclaiming of nutrients by the kidney there is a loss of weight and eventually
weakness.
Franconi syndrome has not been found in other breeds to my knowledge. It seems to run in
certain families . Problems of this sort are generally inherited and Franconi syndrome seems to be.
However, the exact mode of transmission is not known. It maybe a recessive trait or several genes
may be involved. Based on what little I know about it, I might make a wild guess and estimate that
about one or two percent of Basenjis have it. I expect that some lines may be completely free of it
and others may have a high incidence. One breeder I know had a foundation bitch die of it. A
daughter died of it and two littermates are know to have it. It is not a rare disease to that breeder
since all the dogs of this family had it.
What to do about Franconi syndrome? Help is at hand. Dr. Bovee and his colleagues are test-
ing Basenjis for Franconi syndrome. Dr. Patterson, also at the University of Pennsylvania, is studying
the genetic basis. Dr. Bovee will test your dogs for you at no charge. Here is what you do. Write to
Dr. Kenneth C. Bovee, Professor of Medlalne, The School of Veterinary Medicine, University of
Pennsylvania, 3800 Spruce Street, Philadelphia, Pennsylvania 19104. Tell him how many dogs you
want to test. He will send you information and test strips of filter paper. Dr. Bovee can tell you if
your dog has Franconi syndrome. He can probably tell you if it is going to have it, even though it is
now perfectly healthy. He has some strong suspicions as to how to detect a dog that carries the
gene, but is trying to work this out. It will take some time, lots of test matings, etc. to nail this disease
down as to its genetic nature.


 

Reprinted from
The Basenji
Volume XVI Number 4 April 1979 pp. 4, 6 & 8
Copyright © 1979 The Basenji, All Rights Reserved
Used with permission.