Questions and Answers
December, 1998
Dear Dr. Mark Silverio,
I read you article about Canine Herpesvirus on the Internet and I
have several questions to ask you. I am French, and maybe by
English won’t be perfect. I hope you will excuse me.
I would like to know first how this infection is transmitted
between adults. In France, they worked a lot about Herpes in dogs
and they mention natural mating but they are not sure sperm
cannot transmit it. Anyway, they advise artificial inseminations
for breeders and over here now, many breeders don’t do
natural mating anymore.
What do you think about it?
Another question: in a litter from a mother infected, does the
alive puppies from this litter will be carriers? In that case, we
could suppose that an infected adult dog or bith could have got
it from his parents?
From what I read in France, this infection is like a sort of
“Sida” and if one dog (or bith) of your Kennel has it,
he (or she) must be completely stopped in whelping and he could
have passed it to his offspring. If a puppy survive and live
well, is it possible that he is in latency? You speak of a long
latency period. Does this mean that a dog who produced subsequent
litters and who is sero negatif could be a carrier as well at
this time of the test and transmit it?
So, how can we know with which dogs to mate our bitches?
I noticed as well, in several articles the fact that “most
bitches who lose litters to herpesvirus will have normal
subsequent litters”. I don’t understand well the
question of antibodies. From what I read in France, a dog that
got this virus will keep it during his whole life. So, I suppose
that there is a part of chance in mating an infected bitch or
dog. I we test him (or her) before the mating and if the result
is negative, can we be sure that he (or she) won’t infect
his partner? From what I read, an infected dog can be sero
negative sometimes.
So, how can we decide to do natural mating with dogs living in a
kennel where a case has been found and who has been used with an
infected bitch (even if his test is negative)?
My last question is about the visible signs on puppies from an
infected bitch. Are the puppies smaller than the normal size? I
heard of cases with bitches whelping dead puppies and alive ones
with very small size (but normal in appearance and quite alive).
As this problem is raised a lot in my country but not at all in
countries like Germany (where they don’t like too much
Artificial Inseminations), I would like to know as much as
possible about his virus. I have seen many “it should be”
in my researches and it looks really like there is much risk to
do natural mating but I don’t think that it is a good
evolution for our ndogs to do only artificial inseminations nand
stop completely natural behavior.
I thank you by advance for your answers. I would like very much
to understand better this insidious disease.
Jeannine Savigny
Dear Jeannine,
Unfortunately, the canine herpes virus does not behave the same
in all dogs that become infected. Therefore, there is no simple
answer to many of your questions. In addition, there is a lot
that is still unknown about this infection. Hopefully, I can
answer some of your questions in a useful way.
Transmission between adults occurs by direct contact with an
infected dog (venereally or simply by licking and sniffing each
other) and occasionally by contact with recently contaminated
objects (the virus doesn’t live long outside the dog’s
body). The adult dog who is infective may have genital lesions,
may show signs of respiratory disease, such as sneezing or runny
nose, or there may be no outward signs of disease at all. This is
the main reason the virus will probably always be with us. We can’t
identify most of the carriers on the basis of a physical exam. In
addition, they may not have a measureable antibody titer, as you
already mentioned. Some dogs that do develop a titer will have
the disease so well controlled that they’re not contaigious
at all. Therefore, blood tests are not very useful for
identifying potentially susceptible or infective individuals.
It is generally accepted that once a dog is infected with herpes
virus, it is probably infected for life. He or she will probably
have the first clinical signs in the first few weeks, but they
may be mild and go unnoticed. Most dogs exposed as adults will
probably have a measureable antibody titer within weeks and then
a much lower level, maybe even undetectable, for years.
Recrudenscence, or recurrence of signs, can occur during periods
of stress or at any time, and is probably associated with a
higher chance of infectivity. In other words, one obvious
precaution is to isolate animals that are showing signs of
disease. However, removing them from your breeding progam forever
may not be warranted.
Regarding transmission to puppies, the virus can be passed from
their mother either just before or just after whelping. As
mentioned in my previous article (SPO Magazine, Oct. 1997), early
infection leads to fairly rapid death. When infected after 2-3
weeks of age, they usually survive. To answer one of your
questions directly - these individuals are expected to become
long-term carriers. Recrudescence can occur, as described for
dogs that are infected as adults. If there is no serious organ
damage, these puppies are as “normal” as dogs that
become infected as adults. I was unable to find any description
of surviving puppies as being normal in appearance but small or
stunted. That doesn’t mean it can’t occur.
It’s worth re-iterating one more fact mentioned in my
prvious article and in your letter - once a bitch has suffered
through one litter affected by herpes virus, she develops enough
immunity to protect all future litters. She could be bred to
males that are likely carriers (AI or natural) with minimal
chance of disease. If you have had no problems with this disease
in your kennel, then the most practical advice is to breed only
to animals from kennels with no known problems. As you mentioned,
using only AI may not prevent virus transmission (and may
decrease conception rates), so I would advise against changing
from natural breeding to AI, unless there is some other reason to
change your method of breeding.