From: Keith A. Clark, D.V.M., Ph.D.
Director, Zoonosis Control Division
To: Texas veterinarians
Date: April 21, 1995
Subject: Rabies quarantine; wolf-dog hybrids
On April 21, 1995 the Texas Board of Health reviewed the status of the
statewide rabies quarantine
and enacted some modifications. Enclosed is a summary sheet outlining
the rabies provisions.
its effect on the transportation of dogs and cats is virtually unchanged.
However, for purposes of
the rabies quarantine, wolf-dog hybrids are now placed in the same
category as dogs and cats.
For years, rabies vaccination of wolf-dog hybrids has been a source
of confusion, controversy, and
distress for veterinarians and owners alike. After much deliberation,
the Texas Department of
Health has modified its stance on rabies vaccination of wolf-dog hybrids.
The species of both the
wolf and the dog was determined in 1993 to be Canis lupis, per the
Code of the International
Commission on Zoological Nomenclature and the American Society of Mammalogists.
Karyotyping
and DNA analyses have been unable to distinguish the two animals. Therefore,
it is reasonable
to consider the use of rabies vaccine appropriate for dogs, wolves
and wolf-dog hybrids and to
presume their immune responses would be similar.
The desirability and appropriateness of wolves or wolf-dog crosses as
pets is an issue separate
from their biological ability to develop immunity to the rabies virus.
From a public health standpoint,
failure to vaccinate the increasingly popular wolf-dog hybrid only
raises the possibility of creating
a large pool of animals that could serve as reservoirs for rabies.
From a practitioner's viewpoint, the use of rabies vaccines in non-domestic
canids is still considered
"off-label." The veterinarian should inform the client, preferably
in writing, of this fact and that
protection against rabies is not guaranteed. However, a rabies certificate
may be issued, and the
animal may be moved during the rabies quarantine.
Whether they are vaccinated or not, wolf-dog hybrids will continue to
be classified in the
miscellaneous animal category when addressing the quarantine method
and testing procedure if
the animal has bitten a human, as specified in Section 169.27 (f) of
the Rules of the Texas Board
of Health, Chapter 826, Texas Health and Safety Code. It is specified
in this section that the biting
animal, if in this category, can either be humanely killed and the
brain tested for rabies or the local
health authority may require that the animal be confined for a 30 day
observation period as an
alternate method to killing and testing.
Please feel free to refer any questions you may have to the Texas Department
of Health Regional
Zoonosis Veterinarian (see enclosed map) or the Austin office (512)
458-7255.