Assisted Reproduction for Conserving Small Cats
Turning Potential into
Reality


From Wildlife Explorer, Jan/Feb 2005

Assisted reproductive technology (ART), including techniques such as artificial insemination (AI), in vitro fertilization (IVF), embryo transfer (ET), and embryo and semen cryopreservation, has been touted over the past 25 years for its potential usefulness in endangered species conservation. In theory, ART can provide powerful tools for population management by allowing cryopreservation of sperm and embryos and routine generation of offspring from this frozen genetic material. At the Lindner Center for Conservation and Research of Endangered Wildlife (CREW), our goal is to turn the potential of ART into reality for conserving small-sized cats.

One of CREW’s highest priorities is research on the five small cat SSP species - the ocelot, fishing cat, Pallas’ cat, black-footed cat and sand cat. A two-step approach – systematic knowledge acquisition followed by technique development – forms the basis of our research strategy. Studies with domestic cats as a research model provide basic reproductive information about felids in general. Over the past ten years, our laboratory research has focused on detailed characterization of early embryo growth (cleavage rate, embryo survival, metabolism) and pregnancy (hormonal and histological traits, fetal development) in naturally-mated domestic cats. With these data, we are developing a feline-specific culture medium to optimize embryo development in vitro and identifying appropriate recipient synchronization protocols to improve pregnancy success after ET.

Extrapolation of these findings to endangered non-domestic cats requires a fundamental understanding of the reproductive similarities and differences among felid species. For each small cat, analysis of fecal hormone metabolites (testosterone, estrogen, progesterone) is being used to non-invasively
characterize testicular function in males and ovarian activity and pregnancy in females. In some species, periodic semen
collection and analysis also are being used to provide additional basic data. Among other findings, these studies have shown that Pallas’ cats have a very distinct reproductive seasonality and that female fishing cats often ovulate spontaneously (unlike most other cat species).

In our applied studies in non-domestic cats, we now are assessing the suitability of our standard ovarian stimulation, IVF, and sperm and embryo cryopreservation protocols. Our earlier studies showed that ocelot embryos could be produced by IVF, frozen and then thawed years later to produce offspring after ET. This approach now is being explored as one means to import genetic founders from Brazil to establish a Brazilian ocelot population in U.S. zoos. Most recently, we have demonstrated that our IVF techniques are applicable to generating embryos in black-footed cats, Pallas’ cats and fishing cats. We also have found that Pallas’ cat, fishing cat and ocelot sperm remain fully functional after freezing and thawing and can be used successfully for IVF.

These findings have laid the groundwork for taking the next step in applying ART to small cat conservation – using frozen sperm from free-living, wild males to produce offspring in
captivity. CREW currently collaborates with field researchers and veterinarians working with Pallas’ cats in Mongolia, ocelots in Brazil, black-footed cats in South Africa, and fishing cats in Thailand. As shown in our initial field expedition to South Africa (see black-footed cat sidebar on page 8) and earlier research with wild ocelots in Mexico and cheetahs in Namibia, male cats may be captured in the field for short-term anesthesia and semen collection before being returned back into the wild. We anticipate using a similar strategy with all five small cat species within the next three years. These studies will provide information about the reproductive, nutritional and health status of wild cats while facilitating genetic exchange between wild and captive populations – both benefiting small cat survival.

Acknowledgements
The Cincinnati Zoo & Botanical Garden’s small cat conservation program involves the dedicated collaboration of a global network of colleagues. We gratefully acknowledge the assistance of our collaborators and the SSP coordinators working with ocelots (Cristina Adania, Claudia Yumi, George Bellix, Cristian Ugaz, Dulce Brousset, Arturo Caso, Ken Kaemmerer), fishing cats (Khongsak Thiangtum, Namfon Boontua, Budsabong Kanchanasaki, Wanchai Tunwattani, JoGayle Howard, Rose Bauer), Pallas’ cats (Meredith Brown, Bariushaa Munkhtsog, Suzanne Kennedy-Stoskopf, Janine Brown, Martha Caron), sand cats (Kim Clark), and black-footed cats (Alex Sliwa, Beryl Wilson, Corne Anderson, Paul Bartels, Nadine Lamberski, Steve Wing).