years ago (1994), the JRT world was oblivious about Jack Russell Terriers
having deafness. In early 1994, Genie and I found out through Farmcliff
Snowflake that deafness does exist in Jack Russell Terriers. Below
is a re-run of an article we submitted to the JRTCA's "True Grit"
publication in August, 1994 describing our discovery.
1995 JRTCA National Trailing and Locating Championship
in Jack Russell Terriers
is our all around terrier who does everything - hunting, racing, obedience,
agility, G-T-G and trailing and locating. At three years of age, we
bred Snof and produced a fine litter, but as early as four weeks of
age, we began to notice that a couple of Snowflake's pups did not react
to loud noises and seemed to be sound sleepers. We also do puppy temperament
testing at seven weeks and during these tests we really began to suspect
that two of these pups did not near normally.
with our Vet, who happens to breed Bull Terriers - a breed that has
a definite deafness problem - revealed that Tufts University Veterinarian
School in Massachusetts has capability of testing for deafness in young
puppies as well as older dogs. Subsequently, we tested Snowflake's four
pups, Snowflake, Farmcliff Kermit
(the father of Snowflake's pups), two other pups from another litter
(one of which was a sound sleeper) and Chip (the father of the latter
suspect puppies from Snowflake's litter turned out to be TOTALLY DEAF!
They were normal in visual examination of ear canal, but nerve deficiencies
rendered them totally deaf in the normal hearing range for canines.
We then found that the sound sleeper from the other litter was also
totally deaf. What this told us is- if we suspect a puppy is deaf, it
were totally shocked to learn that one of the other puppies from Snowflake's
litter was unilaterally deaf - that is, deaf in one ear only. This pup
was seemingly normal in all respects. Both Kermit and Chip, the sires
of these puppies, had normal bilateral hearing as did the other two
puppies. But, the real kicker came when Snowflake tested unilaterally
deaf! She could hear only from her right ear and we never had a glimmer
of suspicion. Even her obedience/agility instructor, who had worked
with Genie and Snof for two years, could not believe that Snof was unilaterally
we arranged for a hearing clinic by having the Tufts Veterinarian bring
her testing equipment to our house. In this clinic, we tested another
59 Jack Russells that either result directly from Farmcliff Kennel's
breeding or are directly related to our dogs having sired litters for
one of our bitches or whelped puppies from our studs. All these dogs
and puppies appeared normal in all respects except for one that had
a blue eye and seemed to be especially high strung. Among these 49 Jack
Russells, we found five with unilateral deafness - including the suspect
blue-eyed dog. One of these unilaterally deaf dogs was our Peewee, Snowflake's
half brother, who is a fine JR in all respects. We had no idea Peewee
had a problem. Further, the blue-eyed dog testing unilateral was Peewee's
our battery of testing, we tested Gretel (Snowflake, Peewee and Chip's
dam) and their maternal grandmother and maternal great-grand mother
as well as Chip and Peewee's sire as they were littermates. We also
tested Kermit's parents and his maternal grandmother and great-grandmother
plus two of Kermit's siblings. ALL OF THESE RELATIVES OF SNOWFLAKE,
PEEWEE, CHIP AND KERMIT TESTED NORMAL BILATERAL HEARING.
procedure used by Tufts is the same hearing testing often done on humans.
The procedure is called BAER Testing. BAER means Brainstem Auditory
Evoked Response and involves measuring brain activity with electrodes
attached to the skin on a dog's skull. These electrodes are connected
to a computer to measure the brain's electrical response to sound stimulants
played through earplugs inserted into a dog's ears. Subsequent computer
screen imprints and computer print-outs record hearing response of each
dog. BAER testing is totally harmless to the dog and is available at
some state vet. Schools and a few local veterinary neurologists are
now purchasing the $30,000 equipment.
test takes about 10 minutes unless the dog has to be sedated. Only two
of the 49 JRs tested at our clinic had to be sedated. Cost of testing
at our clinic was $35 for each adult and $25 for puppies. Individual
testing at Tufts is slightly higher.
been in contact with two canine hearing specialists - George M. Strain,
PhD, LSU Vet. School, Baton Rouge, LA; and Kim Knowles, DVM, Tufts Vet.
School, N. Grafton, MA. Dr. Strain, a recognized authority on BAER testing
of canines, has published several papers on canine deafness. Dr. Strain
is willing to travel just about anywhere in the USA with his equipment
to conduct BAER clinics for travel expenses plus a modest charge for
each test conducted.
exception, it is impossible to determine unilaterally deaf dogs without
testing. Dr. Strain's articles indicate that in Dalmatians and several
other breeds, unilaterally deaf dogs exists at a rate of almost three
times higher than do totally deaf dogs. Question we are asking ourselves
is how many unilaterally deaf dogs are out in our Jack Russell world
right now being bred? We unknowingly bred unilaterally deaf dogs and
we produced a high incidence of afflicted puppies.
past 10 years of so, Farmcliff dogs have been involved in producing
around 400 puppies - about one-third of which we whelped ourselves with
the other two-thirds coming from breedings by our studs. We are aware
of eight totally deaf puppies from this number, three of which came
from this last round of litters - a situation that shocked us out of
complacency about deafness. Since we began BAER testing , we are now
aware of seven unilaterally deaf individuals, but there are undoubtedly
more unilaterally deaf individuals we do not know about. Snowflake,
a unilaterally deaf bitch, produced 20% of our known deafness in just
the JRTCA and/or individuals to sponsor hearing clinics, such as the
one we had, on a regional basis. Farmcliff Kennel plans to test every
puppy we whelp from now on. Only BAER normal puppies will be provided
with pedigrees (assuming, of course, all other aspects of any individual
are judged to be normal). Snowflake and Peewee will no longer be shown
in conformation and will never again be bred. However, both will continue
to hunt, compete in other aspects of the JR world and be great pets.
continuing to research canine deafness and will pass anything we learn
through future articles in "True Grit". We encourage the JRTCA
Breeders Committee to study this issue and develop recommendations of
how JR breeders should proceed to keep deafness from becoming a major
problem for Jack Russell Terriers.
about Snowflake in 2004
is now 13 years old and is alive and well. She holds a JRTCA Natural
Below Ground Hunting Certificate to Ground Hog. She is a very noisy
and enthusiastic racer and GTG participant at JRT trials. Snowflake
was JRTCA National Trailing and Locating Champion in 1995, National
Open Obedience winner on several occasions including 2003, twice Reserve
National Over Agility High Point winner (1997 and 1999) and was National
Over Veteran Agility High Point Champion in 2001. At local JRT trials
she has been Agility High Point winner many times. Snowflake finally
achieved her ADCH (Agility Dog Champion) title though the United States
Dog Agility Association in 2003. She also has placed in the top ten
in her class at three different National USDAA trials - once as high
as third place. These are accomplishments not many JRTs can equal.
one and only litter of puppies, was a disaster in some respects. However,
at age 10, all four of the pups from this litter are doing well. The
two totally deaf pups are happy in separate pet homes. Sugar, the only
BAER Normal in the litter, has had a successful career in agility and
racing and was JRTCA National Under Veteran Agility High Point Champion
in 2003. Griffin, the unilaterally deaf pup in the litter, is now accomplished
in agility, obedience (Utility level), herding, GTG and is presently
ways, this Snowflake litter was a very fortuitous event for the JRT
world. In just 10 years since this litter was made public by Farmcliff,
BAER testing is well known and many JRT trials have BAER clinics regularly.
Most major JRT breeders BAER test every puppy they produce and no knowledgeable
buyer of JRTs would consider purchasing a puppy that has not been BAER
tested. Exact statistics are not known, but we believe JRT deafness
is around 8% - 2% total and 6% unilateral. Most likely there are very
few - if any - JRTs that are not carriers of deafness. But, by never
breeding totally deaf or uni individuals, never repeating any particular
breeding that produced deafness and not breeding individuals that consistently
produce deafness, we should see gradual improvement and reduction of
deafness in JRTs.
is known about the exact genetics of Canine Deafness, but studies are
currently underway to try to determine DNA markers for deaf and carrier
individuals. The Jack Russell Terrier Research Foundation is now funding
a study by Dr. Strain to specifically study deafness in JRTs. Several
of Dr. Strain's LSU web sites containing excellent articles on deafness
are listed on our articles page. Dr. Strain's web site also lists all
available BAER testing facilities in the USA.
article was originally printed in "True Grit" in August, 1994.