What your intoor/outdoor cat could be sharing with the local pumas

Image from Pet-peeves.org

Generally not small talk, though I imagine they might be interested in the projections for this year’s salmon run (pause for polite awkward laughter). A new article from PLoS ONE has been discussed, implying that, while direct contact may not be routine, exchange of disease between domesticated and wild cats may be fairly common.

The group of scientists involved were examining the occurrence of Toxoplasmosis, Bartonellosis, and FIV. They went out to rural Colorado and California and trapped 260 bobcats and 200 pumas to take blood samples. They also collected blood from 275 domestic cats that lived in the areas investigated, most of whom were feral and free ranging. They tested the serum of these animals for antigens that indicated infection, and ran a statistical analysis that looked at the prevalence of each disease compared to factors such as age, location, sex, and species. The data was collected over a ten year period.

I’m not going to discuss much of the wild species data, but there are some important trends for those interested in pet health, though it’s not very surprising. The researchers revealed that the prevalence of disease was much higher in domestic animals near urban areas than in those rural. This indicates that even though there is a larger number of hosts and vectors (fleas and ticks primarily) in rural areas, clearly the higher concentration of animals in urban areas and increased interactions between domestic cats and wild species (created by human expansion into undeveloped areas) plays a much larger role in the transmission of infectious diseases.

There are also some cool snippets about FIV here as well. The discussion mentions that male cats were slightly more likely to be carrying FIV, which is to be expected due to the higher rate of sex hormone driven behaviors such as roaming and fighting. The FIV strains found in the wild felids also had greater genetic diversity, suggesting that the FIV we know and vaccinate for may be a relatively new disease (at least in comparison to wild FIV serovars). The data shows that the highest combination of pathogens that the domestic cats tested positive for were FIV and Bartonellosis, and the authors mention that because Bartonellosis and FeLV infection have also been correlated in other studies, this data implies that there may be a relationship between the three. However, that relationship may be as simple as having similar risk factors.

The take home message of the study is that wild populations can serve as an important reservoir for multiple zoonotic diseases, and that exposure to this reservoir is mediated by the domestic cats we frequently come into contact with. Just one more reason to think about convincing your kitten that the outside world is scary, and that they don’t necessarily have to go check out what the big cats are doing. Feel free to check out the paper yourself, its light on jargon and easy to read. I’m actually a little disappointed to see that they collected this data over a ten year span, but chose not to do any comparison of the rates of disease from year to year. It would have been interesting to see how climate differences and population growth may have affected the number of vectors and associated risk. Additionally, because all of the samples were collected opportunistically when wild animals were trapped for other non-related studies, there was no way to ensure sampling without replacement, which may have skewed the data.

Sarah N. Bevins1*, Scott Carver2, Erin E. Boydston, Lisa M. Lyren, Mat Alldredge, Kenneth A. Logan, Seth P. D. Riley, Robert N. Fisher, T. Winston Vickers, Walter Boyce, Mo Salman, Michael R. Lappin, Kevin R. Crooks, & Sue VandeWoude (2012). Three Pathogens in Sympatric Populations of Pumas, Bobcats, and Domestic Cats: Implications for Infectious Disease Transmission PLoS ONE

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