|| Go back to the Wolf Dog Coalition's main page || Back to Letters & Background Info ||

Wolf Dog Coalition Logo

Wolf Dog Coalition - USDA's Response

USDA letter refrencing: Panel of April 4, 1996


Dear Ms. Bendit and Mr. Sydnor:

The Animal and Plant Health Inspection Service (APHIS) has been considering the information presented at the meeting on April 4, 1996, concerning approval of rabies vaccines for use in wolves and wolf dog crosses. Developing a position on this has not been easy due to the scarcity of scientific information in some areas and certain conflicts in the data presented.

Although there was a great deal of support for the position that dogs are a subspecies of wolves, there was not complete agreement that wolves and dogs are the same. A gradient of similarities appears to exist between the species in the genus Canis with little to differentiate between dogs, wolves, red wolves and coyotes. One criterion put forth for determining if animals are of the same species is that progeny from the two can reproduce. Yet the taxonomists at the meeting, in spite of evidence of interbreeding between wolves and coyotes, were adamant that these animals were different species.

During the panel discussion, the scientists agreed that the rabies vaccines currently licensed for use in dogs should protect wolves. the many similarities between wolves and dogs partially supported this. However, when asked to endorse using modified live vaccines against canine distemper, adenovirus, parainfluenza, and parvovirus in wolves, these same scientists unanimously said that they would not recommend this procedure. They were concerned that modified live vaccines could cause disease in wolves. This position appears to contradict the position that dogs and wolves are identical.

Since data provided to APHIS on this issue have been conflicting and inconclusive, they do not support a change in APHIS policy concerning the approval of recommendations for the use of rabies vaccines in wolves at this time.

At the meeting, discussion touched on the types of studies that APHIS would require to have a canine rabies vaccine recommended for wolves. The preferred study would be to carry out vaccination and challenge according to the Standard Requirements for Rabies Vaccine, killed virus, contained in Title 9, Code of Federal Regulations, Part 113.209. Other alternatives, which would lead to approving all vaccines now licensed for dogs for use in wolves and wolf-dog crosses, include establishing that the immune systems of the two groups are virtually identical. This could be shown through studies that establish normal total white cell counts, white cell differential values, b and t lymphocyte populations, and ratios of helper t cells to cytotoxic t cells. Properly controlled antibody studies would be supportive. Other information regarding the safe use of licensed modified live virus vaccines for other canine diseases in wolves would also be helpful.

Similar to other requests for label use changes, this data should be provided by licensed veterinary biologics manufacturers or other qualified persons or groups. The data for establishing normal constituents of the immune system and animal safety must be scientifically valid and statistically significant.

The U. S. Department of Agriculture has the responsibility for approving label indications and recommendations for products that it licenses. Our decision regarding whether wolves and dogs are the same species and identical in their response to vaccinations is only one of the issues to be resolved. For example, if we approve rabies vaccines for wolves and wolf-dog crosses, State and local agencies could still require destruction of a wolf or wolf cross that had bitten someone to determine if the animal had rabies. This is still a problem for ferret owners in many States.

We appreciate your interest in our regulations and regulatory processes and encourage your support in the development of the additional data needed to resolve this issue.


David A. Espeseth
Robert B. Miller
Chief Staff Veterinarian
Veterinary Biologics
Biotechnology, Biologics,
and Environmental Protection

Copy of original signed letter is available upon request.
Contact The Wolf Dog Coalition ( psykowuf@erols.com ).

Copyright © 1996-1998 Wolf Dog Coalition. All rights reserved. Permission to reprint this letter in its entirety granted.

Go to the top of the page