Email from Prof.Strain ~ ONE

To the Controlling Body of the Canine Association of WA,
Jenny Griffiths and Brad Pryde have requested that I also address
you myself on the issue of a bitch being scientifically and clinically
bilaterally deaf by the use of the BAER test even though she is showing behavioural
reactions where her vet has declared her as not being totally deaf.
The BAER is the only objective method available in wide usage for assessing
hearing in dogs. Behavioral testing is unreliable. If the BAER test is
performed by a trained professional it should be considered the gold
standard - behavioral or other tests are not as reliable. No one, veterinarian
or not, can with certainty assess hearing with behavioral tests - there
are too many ways for the dog to detect production of sounds without hearing.
They feel vibrations, they see movements, they feel air movements, they
react to the reactions of the people around them, and the examiner often
thinks he/she sees a response that is not really a response. I gladly
give Jenny Griffiths and Brad Pryde permission to speak for me on this
issue.
The only way to medically and scientifically know that a condition is
not hereditary is to perform breeding trials to confirm that affected
offspring are not produced. I do not see how with the evidence already
available on the family tree, how any veterinary officers who understand
hereditary disorders could make such a declarations.
People appear to be looking for loopholes here. The goal is to remove
from breeding consideration with a probable genetic defect - hereditary
deafness.
This is an issue affecting the overall good of the breed, not the reputation
of an individual owner or breeder. Deafness may be acquired from a
number
of non-genetic causes. A dog found to be deaf in either one ear or
both ears by BAER testing must be assumed to have congenital deafness
unless objective proof exists for the presence of hearing at an earlier age
(but after 5 weeks of age, the age at which hereditary deafness is present).
Further, if that deafness occurs in a dog from a breed known to have
hereditary deafness as a breed problem, the deafness must be assumed to
be hereditary. The criterion must not be "total deafness" in both ears
by all conceivable behavioural testing methods, but total deafness in
one or both ears by testing the dog with the BAER test.
I hope that this helps.
-------------------------------------
George M. Strain, PhD
Associate Vice-Chancellor for Research & Economic Development
and Professor of Neuroscience
Louisiana State University, Baton Rouge, LA 70803 USA
Voice: 504-388-5833 Fax: 504-388-5983

Email from Prof.Strain ~ TWO

Date: Friday, 28 February 1997 8:58:18 -0600
To: Jennifer Griffiths
From: (George M. Strain, Ph.D.)
Subject: Behavioural Hearing
________________________________________________________
Behavioural assessment of auditory function is the only option available
in most practices, but it is fraught with difficulty and
error when used. Recommendations are specifically for the BAER test to be used. If
behavioural auditory testing is necessary,it is
important to blindfold the animal or insure that test sounds
are generated outside of the animal's visual field. Whistles or jingling
keys are better stimuli than hand claps or items dropped
on the floor or banging things together because of the likelihood
of miscues. This testing can be used with marginal confidence. More
objective assessment of auditory function requires electrophysiological
assessment, BAER, since behavioural audiometry using operant conditioning
is not practical. The most commonly utilised test is the
'Brainstem Auditory Evoked Response BAER'.
Bilaterally deaf dogs become quite adept at "looking for" and detecting
other correlates of sound : visual cues, vibrations, even air movements.
Thus, a deaf dog may appear to respond to sound when it is actually
picking up a cue with some other sensory modality.
The dog you have mentioned has a genetic defect, so if bred it will
almost certainly pass it on to offspring. Many people look for loop
holes - reasons to not comply with an issue they at heart know is right
or wrong. The bottom line is that one should not breed an animal with
a very well known genetic defect. NO EXCUSES.
>The reason for my pursuing of this is to get through a recommendation
>that totally deaf dogs are not to be used for breeding, and so use the BAER
>test as the tool to define this. I hope you can put me straight on this as it
>would help alleviate the confusion we are having. I look forward to your
>response.
George M. Strain, PhD
Associate Vice-Chancellor for Research & Economic Development
and Professor of Neuroscience
Louisiana State University, Baton Rouge, LA 70803 USA

Email from Prof.Strain ~ THREE

Brad Pryde, Jenny Griffiths:
In response to your messages-
No matter how the deafness is inherited, it shows variable or
incomplete expression: an animal inheriting the defect may not end up deaf
in both ears, but only deaf in one ear. It is even possible that the
defect is inherited but for some reason both ears are spared, but we have
no way to know this. This means that a dog deaf in one ear in a breed with
hereditary deafness nevertheless has the genetic defect and SHOULD NOT BE
BRED! It goes without saying that bilaterally deaf dogs should not be
bred. In my studied with the Dalmatian, having one unilaterally deaf
parent nearly doubled the likelihood of deafness in offspring.
The issue for Rottweiler breeders in Australia seems to be the
validity of the brainstem auditory evoked response (BAER). Behavioral
tests of hearing simply are not reliable: dogs quickly quit responding when
they do hear, and they frequently give the appearance of hearing with
behavioral testing because of detecting other cues (visual, vibrations,
even air current movements) - plus sometimes you see what you hope to see.
The stimulus used with the BAER is a click that activates receptors for
most of the audible frequencies, but does not include the very highest
frequencies that a dog can detect. All studies of congenital deafness have
shown that an affected ear becomes totally deaf - there is no documented
partial hearing loss in these circumstances. On rare occasions the
deafness appears to preserve some hearing at the very highest frequencies.
This is quite rare and should be viewed as a moot point in addressing
policy on breeding affected animals. If performed the BAER test is very
reliable. If the dog is deaf by the BAER, even if a vestige of
high frequency hearing persists, it has to be assumed to have a genetic
defect. For the good of the breed it should not be bred. Anyone pointing
at some appearance of a vestige of hearing is grasping for straws, looking
for an excuse to not eliminate the dog from breeding. These dogs are for
all practical purposes totally deaf and should be treated that way. The vet
who stated that because a BAER-deaf dog (bilateral) showed behavioral
evidence of hearing is not totally deaf and could be bred, does not have logic
or science on his side.
The message from Brad and Jenny refers to the Dalmatian policy.
Dal people in the US are only just now starting a hearing registry. Their
stated official policy is that breeders should put down bilaterally deaf
puppies.
If a multigeneration pedigree of the dogs producing multiple deaf
offspring can be compiled with reasonably complete hearing status data for
most, it might be possible to deduce the mode of inheritance in the breed.
That would be very useful information.
I hope this is of some help.
George M. Strain, PhD
Associate Vice-Chancellor for Research & Economic Development
and Professor of Neuroscience
Louisiana State University, Baton Rouge, LA 70803 USA

Email from Gillian D. Muir, D.V.M, Ph.D.

Dear Jennifer Griffiths,
Thank you for your message. As a neurophysiologist, I would assess
the flat line BAER test, being a negative result, bilaterally
deaf or as you call it totally deaf, it means that there is no functional
connections between the ear and hearing centres in the brain. As a veterinarian,
I would also recommend that this dog is totally deaf and to not be bred
if there is any question over her deafness.Behavioural testing, once a BAER
test is done, I would not even humour that option, the BAER is too reliable,
using two bowls or having a dog crying, well there is no comparison
between the two tests. Congenital deafness is a trait that we (and by we,
I mean veterinarians, breeders and anyone who cares
about dog breeds) do not want to maintain in any dog breed and so we need
to take it on ourselves to eliminate the possibility of breeding dogs which
are predisposed to deafness. The fact that this bitch has a a hearing
abnormality certainly raises the possibility that some of
her offspring would be deaf, or at least carry the genes for deafness.
For the sake of the Rottweiler breed, I think that your group should
think very carefully about this issue.
Hope this is of help.
Sincerely,
Gillian Muir
***************************
Gillian D. Muir, D.V.M, Ph.D.
Veterinary Physiological Sciences
University of Saskatchewan

Email from Mary O. Smith BVSc

Dear Jennifer:
I have no hesitation in stating that Dr. Strain,
is internationally recognized as an expert on deafness in dogs,including the
use and interpretation of BAER. I am a veterinarian and
am board-certified in veterinary neurology (Diplomate American College
of Veterinary Medicine, subspecialty of Neurology).
A BAER that is performed and shows a flat line
response illustrates bilateral deafness (totally deaf) and
is the most definitive test for deafness that I know of,
and is greatly superior to behavioral response testing.
It seems patently foolish to me for veterinarians or others to claim that
apparent behavioral response to sound is superior to results of BAER,
since there is a vast scientific literature in numerous species, including
dogs, that BAER is the superior and OBJECTIVE (not subjective) method for
testing hearing. To argue otherwise is akin to arguing that the earth is
flat and is a great detriment to the welfare of your breed. To perpetuate
such nonsense is highly irresponsible.
I would second Dr. Strain's remarks that the person who claims that the
dog responds to auditory stimuli when a performed BAER
shows a flat line being totally has neither clinical experience, not scientific
fact on his/her side, the only conclusion you would have to have
is that the bitch is totally deaf.
Dr. Mary O. Smith
Dept. Clinical Sciences
Colorado State University
*****************************************************************

Email from Dr. Betsy Dayrell-Hart, VMD

Dear Ms. Griffiths,
I received your query about BAER testing, and I agree with
Dr.Strain that absence of a response on BAER is evidence of inability to
hear which is scientifically termed as bilateral deafness (totally deaf).
I cannot explain the observations when behavioural testing is
done, except the logical answer is their body senses the vibrations
and of course visual contact. I, too, would be loth to say that a dog
with no response to a BAER test although reacted to behavioural testing
was not totally deaf.
I recommend from my own research as well as the studies from Dr.Strain
that you could not possibly rely on behavioural testing, my
confidence would surely be on the world known BAER test, personally I
would most certainly declare the bitch as totally deaf.
Sincerely,
Dr. Betsy Dayrell-Hart, VMD

Management

Dogs and cats with unilateral deafness make excellent pets, with owners often unable to detect any impairment. However, owners of these animals should be discouraged from breeding them to prevent further affected animals and an ultimate increase in the prevalence of the disorder. Some animals will show directional localization deficits and may not awaken to sounds if sleeping with the good ear against the ground. Animals with late-onset acquired deafness generally adapt well, but precautions must be observed to prevent vehicular injury or death and bite injuries to humans, especially children, when deaf dogs are startled. Animals bilaterally deaf from both congenital and acquired causes place greater reliance on visual and vibratory sensory information to cope with the loss of auditory input. Dogs are easily trained to hand signals and other visual cues, such as flashing porch lights; some cats can similarly be trained. Obedience-training shock collars set to the lowest shock level can be used for recall of dogs.

Despite the worry of animal owners and those concerned with animal rights, the quality of life of deaf dogs and cats is not demonstrably diminished. Likewise, these animals do not have diminished mental capacities, any more than the average deaf or blind human has diminished mental capacity. The brain responds to the loss of a sensory modality by various forms of plasticity, whereby CNS structures that would have received input from that sensory modality constrict and adjacent structures expand to take advantage of the available space (Hata & Stryker, 1994).

A dilemma often occurs when bilaterally deaf puppies are identified in a litter. The official position of the Dalmatian Club of America is that such animals should be euthanized, and individual owners of other breeds often concur, but this position is not universally accepted. The recommendation for euthanasia is more difficult to accept after placement of a deaf dog in a home and the ensuing development of emotional attachments. Some variation may result from differences in personalities between breeds, but dogs that are bilaterally deaf from birth may develop anxious or aggressive personalities from continuously being startled. They are prone to vehicular deaths, may scare-bite, and require significantly greater effort to rear and protect. It is not uncommon for these animals to end up in animal shelters because of the inability of owners to cope with the deficit.

Genetic counseling for owners of at-risk breed dogs and cats will be difficult until the mechanisms of inheritance are identified or a DNA blood test is developed. In general, unilaterally deaf animals should not be bred, since they have the genetic defect and will pass it on to their offspring. Some breeders view hearing as just one of the spectrum of desirable or undesirable markers evaluated in breeding decisions, but the high prevalence of deafness in at-risk breeds suggests that a higher premium should be placed on hearing status for the overall benefit of the breed.

Supporting Letter from Owner of Deaf Dog ~ 1

From:Sharon Ashley
To:Jenny Griffiths
Subject:Confidence in BAER testing although my dog does react to
certain vibrations 'she is totally Deaf most certainly'.
Date:Wednesday 26th February 1997 13:29:25
Jenny:
I have the pleasure of sharing my life with a 4 year old deaf dog named Emmy.
Emmy was BAER tested at about 5 months old. The BAER testing
showed that she was bilaterally deaf. Many times her reactions make you
wonder if she is totally deaf but we know that she is. Her other senses
have more than adequately made up for her hearing loss. She too will
respond to loud noises. If you really pay attention to it, you also can
feel vibrations as a result from sound. Due to this fact, banging pots--and
crying dogs--is totally ineffective in determining deafness. Emmy is able
to detect the presence of someone behind a closed door before my other 2
hearing dogs can. From observing her, she watches for changes of light under
the door. If someone is being very quiet trying to fool the dogs, she is
the first one to figure it out. She also uses her sense of smell more
keenly than the hearing dogs. I like to quietly come near her while she is
sleeping, close enough for her to catch my scent. It is fun to watch her
wake up because she caught my scent near her.
From my experience, I have total faith in the BAER testing. I feel that any
dog that tests bilaterally or unilaterally deaf should NEVER be bred.
I hope that this helps.
Sharon Ashley

Supporting Letter from Owner of Deaf Dog ~ 2

From: Susan Cope USA
To: Jenny Griffiths
Subject: Confidence in BAER testing although my dog does react to certain vibrations
'she is totally Deaf most certainly'.
Date: Monday 24th February 1997 19:38:11
Jenny
I would like to add that this is the same test that is used on children
to detect deafness and measure hearing. Spanky was 4 months old when
she had the test done. A loving, licking puppy became the thing that
wanted to eat the technicians face, so she was sedated. There is a known
listing of available BAER testing centers for dogs. This is one thing I
hope to compile as well for the 'Deaf Dog Training Book'.
Sometimes I wonder why Chris and I put Spanky through that test when we
knew Spanky was deaf.....but in all honesty, there were times that we
truly thought she could hear. Or perhaps there were certain levels of sounds
that she could hear. As it turned out, both lines on her test were flat.
She can't hear a thing. It's just that at four months, she had become more
attuned to her surroundings and the normal vibration, and therefore, was
more reactive and responsive to sight, smell and vibrations as she grew older.
Good Luck, I hope they stop this bitch from being bred and shown, surely
she is not an example anyone wants to set for what a Rottweiler should be like.
Susan

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