Clinicians at the Chicago Zoological Society’s Brookfield Zoo in conjunction with the University of Wisconsin-Madison’s School of Veterinary Medicine are conducting an epizootiological study of malignant nasal tumors in Mexican grey wolves. The wolves, housed at the Zoo, participate in a Species Survival Plan program, which falls under the auspices of the Association of Zoos & Aquariums’ (AZA) conservation and science initiatives.
The propagation effort is part of US Fish & Wildlife Service recovery program for the subspecies.
The current AZA program is a continuation of a bi-national (US-Mexican) captive breeding program that was launched in the late 70’s with founder stock comprised of wild wolves captured in Mexico. The wolves or “lobos” were rendered functionally extinct in the US prior to recovery efforts.
This subspecies of grey wolf is the rarest and most genetically distinct of the 37 recognized subspecies of grey wolf–the largest extant member of the family Canidae.
The Brookfield Zoo will spearhead the research investigating the prevalence of the nasal tumors through CAT scans in conjunction with routine check-ups on the Mexican wolves in its collection.
Researchers will also conduct CT scans on approximately 150 archived osteological specimens currently stored at the Museum of Southwestern Biology (University of New Mexico) and a few specimens archived at the Field Museum in Chicago.
Nasal carcinoma, which is reported in 1-2% of domestic dogs has also been reported in Mexican wolves. There is believed to be a genetic link to the disease in canids.
The data from the study will be analyzed to help develop population management plans for the subspecies held in living institutions, including breeding of the wolves and the transfer of individual animals. The findings will also likely influence the use of CT scans in the early diagnosis of this type of cancer.
Currently, 283 wolves of this subspecies are housed at 52 institutions across the United States.
The wolves were listed as an Endangered Species shortly after the passage of the Endangered Species Act and remain a testament to the recovery of a species on the verge of extinction. The Mexican wolves have been reintroduced to Southwestern states in the US and the Mexican state of Sonora.