A Great Leap Forward?

Just four years after Beijing’s brutal roundup of the city’s cats—feral, stray, and pets alike—in preparation for the 2008 Olympic Games, the number of cats on the streets is once again raising concerns. “Somewhere between 500,000 and 5 million feral cats are skulking through its courtyard houses, construction sites, and gated apartment complexes, braving the city’s bitter cold winters and raging traffic,” writes Debra Bruno on The Atlantic’s Cities blog. “Their lives are nasty, brutish, and short.”

“And in a densely populated city like Beijing, the rise in the number of feral cat colonies is not especially welcome. The cats’ nighttime howls keep people awake. They smell. They prey on the Asian magpie and the Siberian weasel, sometimes known as the ‘hutong weasel,’ a ferret-like creature that looks a little like a cute red panda. The cats tend to prefer a perch on the BMWs of the city’s nouveau riche.”

Bruno’s population “estimate” strikes me as little more than a misinformed guess—about as credible as her observation that these cats prefer Beemers. (Commenter Jessica Rapp, who lives in Beijing, isn’t buying the numbers either.) In a February, 2008 story, The Times suggested there were “at least 200,000” unowned cats in the city, citing as its source the Capital Animal Welfare Association, a Beijing-based partner of Humane Society International. [1] Bruno’s credibility is further eroded when she refers to Mother Jones’ “Faster, Pussycat! Kill! Kill!” as if it lived up to the magazine’s commitment to “smart, fearless journalism.”

On the other hand, Bruno’s exactly right when she writes: “groups like the Audubon Society claim that TNR has not proven to be effective in eliminating the population of feral cats anywhere.” (The claim itself, of course, is both factually incorrect and highly misleading.)

The timing here is interesting, though. In January, Bob Sallinger, conservation director of the Audubon Society of Portland—who attracted national attention when he began working with local TNR groups—told the Portland Tribune: “I don’t think rounding up feral cats and killing them is going to solve it better.”

But, back to Beijing’s cats…

Actual Nasty, Brutal, Short Lives
According to CNN.com, Beijing’s animal welfare activists had hoped the Olympic Games would be “a perfect catalyst in expanding animal rights.” Instead, “the authorities… stepped up their campaigns against animals—pets and strays alike—aimed at ‘cleaning up’ the city for the Games.” [2] Among the numerous horrific reports was an instance of 30 cats—90 percent of which were sterilized—being sealed in a “basement with cement because of health and safety concerns during the Games.” [2]

In its investigation of Beijing’s pre-Olympics “clean-up,” the UK’s Daily Mail reported:

“Thousands of pet cats in Beijing are being abandoned by their owners and sent to die in secretive government pounds as China mounts an aggressive drive to clean up the capital in preparation for the Olympic Games. Hundreds of cats a day are being rounded and crammed into cages so small they cannot even turn around. Then they are trucked to what animal welfare groups describe as death camps on the edges of the city. The cull comes in the wake of a government campaign warning of the diseases cats carry and ordering residents to help clear the streets of them.”

When the Daily Mail tried to visit two of the holding facilities, they were refused entry.

“‘No one can come in without official papers,’ staff shouted from behind padlocked steel gates. At another, larger compound in Da Niu Fang village, the sound of cats wailing could be clearly heard coming from a cluster of tin-roofed sheds, but workers denied they were holding any cats. ‘There are no cats here, go away. No one is allowed inside unless you have official permission,’ a security guard said.”

Apparently, the fear among the public bordered on—indeed, in some cases, turned into—hysteria. “The most striking illustration of the city-wide fear of cats,” reports the Daily Mail’s Simon Perry, took place at a kindergarten, where six strays, including two pregnant females, “were beaten to death with sticks by teachers.”

“We did it out of love for the children,” explained one teacher. “We were worried the cats might harm them. These six cats had been hanging around the kindergarten looking for food.” [3]

TNR Comes to Beijing
These days, however, some in Beijing are adopting TNR—and pushing for others to do the same. “Peng, a Chinese-American native New Yorker who has lived in Beijing for the last 20 years,” writes Bruno, “has taken on the mission of convincing Beijing’s residents that [TNR is] the best solution to the feral cat population.”

“‘What are my alternatives?’ asks Peng. As Beijing itself learned in the recent past, she argues, cities that try to exterminate cats often just find that a new cat colony eventually moves into an area where an old one had been taken away. Not to mention, the mass killing of adorable kittens is a tough sell in any society.”

While Bruno suggests that Peng’s efforts are “a drop in the bucket,” I see things rather differently. Indeed, given the recent population increase, Beijing may be the best argument yet for TNR. After all, the alternative has been shown to be remarkably ineffective. Costly, too, I’m sure.

One wonders how the lessons learned in Beijing will be “interpreted” here in the U.S.—where The Wildlife Society, American Bird Conservancy, and U.S. Fish and Wildlife Service, among others, continue to oppose TNR, in favor of the roundup of stray, abandoned, and feral cats.

Too much will, I fear, be lost in translation.

Literature Cited
1. Macartney, J. (2008). Cats are out as Beijing starts to preen itself. The Times, p. 4.

2. Jiang, S. (2008, August 4). An animal lover’s Olympic nightmare. CNN.com, from http://edition.cnn.com/2008/WORLD/asiapcf/08/03/oly.beijjingcats/

3. Perry, S. (2008, March 12). Olympics clean-up Chinese style: Inside Beijings shocking death camp for cats. Daily Mail, from http://www.dailymail.co.uk/news/article-528694/Olympics-clean-Chinese-style-Inside-Beijings-shocking-death-camp-cats.html

Crazy Is As Crazy Does

An article in The Atlantic describes fascinating research into the effects of Toxoplasma gondii infection, but what role do domestic cats really play?

Although we’re not even halfway through February, an article in the March issue of The Atlantic is already getting a lot of attention. But with a title like “How Your Cat Is Making You Crazy,” that’s no surprise. (Don’t get me wrong: the article is a great read.)

What is surprising is that the story hasn’t been picked up by the American Bird Conservancy or, more likely, The Wildlife Society.

Not yet, anyhow. Surely, it’s only a matter of days before ABC, TWS, and others (mis)use the article to stir up their witch-hunt against free-roaming cats. A careful read, however, suggests such a move would be both premature and misguided (as if that makes any difference).

At the center of “How Your Cat Is Making You Crazy” is the intriguing research* of Jaroslav Flegr, an evolutionary biologist at Charles University in Prague, who’s spent the past 20 years or so exploring the possible connections between infection with Toxoplasma gondii, a parasite cats can pass in their feces, and human behavior.

“Healthy children and adults,” explains writer Kathleen McAuliffe, “usually experience nothing worse than brief flu-like symptoms before quickly fighting off the protozoan, which thereafter lies dormant inside brain cells—or at least that’s the standard medical wisdom.”

But if Flegr is right, the ‘latent’ parasite may be quietly tweaking the connections between our neurons, changing our response to frightening situations, our trust in others, how outgoing we are, and even our preference for certain scents. And that’s not all. He also believes that the organism contributes to car crashes, suicides, and mental disorders such as schizophrenia.

As I say, it’s just a matter of time—and not much of it, I suspect—before TNR opponents jump all over this, shaping it to fit their (tired) message.

I expect to see the lengthy quote from Joanne Webster, a parasitologist at Imperial College London, parsed very carefully, for example. Webster and her colleagues discovered that Toxo-infected rats are actually attracted to cat urine, a phenomenon they dubbed “fatal feline attraction.” Commenting on Flegr’s research, Webster is, in McAuliffe’s words, “more circumspect, if not downright troubled.”

I don’t want to cause any panic. In the vast majority of people, there will be no ill effects, and those who are affected will mostly demonstrate subtle shifts of behavior. But in a small number of cases, [Toxo infection] may be linked to schizophrenia and other disturbances associated with altered dopamine levels—for example, obsessive-compulsive disorder, attention-deficit hyperactivity disorder, and mood disorders. The rat may live two or three years, while humans can be infected for many decades, which is why we may be seeing these severe side effects in people. We should be cautious of dismissing such a prevalent parasite.

I imagine those first two sentences will be among the first to be dropped from any ABC or TWS reference to the article. As will this response from Robert Sapolsky, a professor of biology and neurology at Stanford:

…I’m not too worried, in that the effects on humans are not gigantic. If you want to reduce serious car accidents, and you had to choose between curing people of Toxo infections versus getting people not to drive drunk or while texting, go for the latter in terms of impact.

Infection in Humans
“Humans,” explains McAuliffe, “are exposed not only by coming into contact with litter boxes, but also, he found, by drinking water contaminated with cat feces, eating unwashed vegetables, or, especially in Europe, by consuming raw or undercooked meat. According to the Centers for Disease Control and Prevention, the infection rate in the U.S. among those 12 and older is estimated to be 22.5 percent.

And while Toxoplasmosis “can come from cats,” the CDC points out that “people are more likely to get it from eating raw meat or from gardening.”

Nowhere in McAuliffe’s article does she mention the proportion of people infected through contact with cat feces, as compared to those infected from eating raw or undercooked meat. For the purposes of Flegr’s work, the source is largely immaterial. (And, virtually impossible to know, I gather—which would explain why I’ve never seen so much a guess.)

Infection in Cats
In the infamous “University of Nebraska-Lincoln paper,” published in 2010, the authors report—correctly, according to their source—that “most feral cats (62 percent to 80 percent) tested positive for toxoplasmosis.” [1] Trouble is, testing positive—seroprevalence—is simply not a useful measure of their ability to infect other animals or people.

“Most cats only shed oocysts for about one week in their life” (Note: The Atlantic suggests a three-week duration, as noted below) and seroconvert afterward. [2] “Thus, it is a reasonable assumption that most seropositive cats have already shed oocysts.” [2] “Testing positive,” in this case, is nothing more than the detection of antibodies resulting from seroconversion. Furthermore, because “most seronegative cats shed millions of oocysts after exposure to T. gondii… seropositive cats are likely to be less of a public health risk than seronegative cats.” [3]

Environmental Contamination
Because Flegr’s work doesn’t involve environmental contamination, McAuliffe only touched on the subject (“the parasite is typically picked up from the soil by scavenging or grazing animals—notably rodents, pigs, and cattle…”). For many TNR opponents, however, this is a hot topic—as some have suggested a direct connection between the presence of domestic cats and toxo-related infections in other animals, primarily land and marine mammals. (See, for example, my post from May 17 of last year.)

As a recent paper reports, bluntly: “Cats are the definitive host: the disease only occurs when cats are present.” [4] In fact, this claim is contradicted by a number of studies:

  • High levels (75 percent) of congenital transmission of T. gondii, for example, in a “wild population of mice,” led UK researchers to conclude “that this phenomenon might be more widespread than previously thought.” [5] Infections in sheep also point to congenital transmission, which “may be more important than previously considered.” [6]
  • The “high incidence of T. gondii found, among others, in free-living ruminants suggests a possibility of other, so far unknown, paths of transmission of this protozoan.” [7] “Due to the fact that they are widespread, and tick-bites occur frequently both in humans and in animals, ticks might play an important role in toxoplasmosis transmission.” [7]
  • Of particular interest are studies in the Arctic, where the prevalence of T. gondii infection in arctic foxes, Svalbard reindeer, sibling voles, walruses, kittiwakes, barnacle geese, and glaucous gulls “indicates that infection by oocysts is not an important mode of transmission on Svalbard.” [8] “T. gondii most likely is brought to Svalbard by migratory birds that become infected in temperate agricultural areas in the winter. However, marine sources of infection may exist. The high seroprevalence of T. gondii in the arctic fox population on Svalbard may be due to: (1) infection from migratory bird species through predation; (2) vertical transmission; and (3) tissue cyst transmission within the Svalbard ecosystem through scavenging and cannibalism. Together, these transmission routes cause a surprisingly high seroprevalence of T. gondii in a top predator living in an ecosystem with very few cats.” [8] Researchers studying infection rates in polar bears concluded: “It would… be inconceivable to assume that the few cats would play a major role in the epidemiology of T. gondii in the vast high Arctic. This is apparently the case in East Greenland as well.” [9]

In the Spring 2011 issue of The Wildlife Professional’s special section, “The Impact of Free Ranging Cats,” the authors argue: “Based on proximity and sheer numbers, outdoor pet and feral domestic cats may be the most important source of T. gondii oocysts in near-shore marine waters. Mountain lions and bobcats rarely dwell near the ocean or in areas of high human population density, where sea otter infections are more common.” [10] What the fail to acknowledge is that the most common type of T. gondii found to be infecting sea otters is the Type X strain, [11] which has yet to be traced to domestic cats, [12] or that “dual infections of T. gondii and S. neurona were more frequently associated with mortality and protozoal encephalitis than single infections, indicating a role for polyparasitism in disease severity.” [13]

Now What?
So, what are we to make of all this?

Or, as McAuliffe poses the question: “Given all the nasty science swirling around this parasite, is it time for cat lovers to switch their allegiance to other animals?”

Even Flegr would advise against that. Indoor cats pose no threat, he says, because they don’t carry the parasite. As for outdoor cats, they shed the parasite for only three weeks of their life, typically when they’re young and have just begun hunting. During that brief period, Flegr simply recommends taking care to keep kitchen counters and tables wiped clean. (He practices what he preaches: he and his wife have two school-age children, and two outdoor cats that have free roam of their home.)

Certainly, there’s still plenty we don’t know about T. gondii. A May 2011 article in Scientific American, for example, concedes simply: “The exact link between T. gondii and psychiatric diseases is tantalizing but remains murky.” [14]

Most telling of all may be the reaction of the pharmaceutical industry. Or, lack of a reaction, to be more precise. “Until solid proof exists that Toxo is as dangerous as some scientists now fear,” observes McAuliffe, “pharmaceutical companies don’t have much incentive to develop anti-Toxo drugs.” And if Big Pharma doesn’t think there’s money to be made here, how worried should we really be?

•     •     •

If history is any indication, “How Your Cat Is Making You Crazy” will be badly misrepresented by some TNR opponents, used to further vilify free-roaming cats as a public health threat. Not that they’ll offer anything in the way of a solution, of course—just more fear-mongering.

Now, if ABC, TWS, and all the rest are really concerned about toxo, why not propose a meat-free diet? OK, now that’s crazy.

*As opposed to, say, the unconvincing claims attempting to link T. gondii to brain cancer, published in a paper last summer. As expected, TWS took the bait.

Literature Cited
1. Hildreth, A.M., Vantassel, S.M., and Hygnstrom, S.E., Feral Cats and Their Management. 2010, University of Nebraska-Lincoln Extension: Lincoln, NE. elkhorn.unl.edu/epublic/live/ec1781/build/ec1781.pdf

2. Dubey, J.P. and Jones, J.L., “Toxoplasma gondii infection in humans and animals in the United States.” International Journal for Parasitology. 2008. 38(11): p. 1257–1278. http://www.sciencedirect.com/science/article/B6T7F-4S85DPK-1/2/2a1f9e590e7c7ec35d1072e06b2fa99d

3. Vollaire, M.R., Radecki, S.V., and Lappin, M.R., “Seroprevalence of Toxoplasma gondii antibodies in clinically ill cats in the United States.” American Journal of Veterinary Research. 2005. 66(5): p. 874–877. http://dx.doi.org/10.2460/ajvr.2005.66.874

4. Duffy, D.C. and Capece, P., “Biology and Impacts of Pacific Island Invasive Species 7. The Domestic Cat (Felis catus).” Pacific Science. 2011. 66(2 (Early View)): p. 000–000. http://pacificscience.files.wordpress.com/2011/09/pac-sci-early-view-66-2-6.pdf

5. Marshall, P.A., et al., “Detection of high levels of congenital transmission of Toxoplasma gondii in natural urban populations of Mus domesticus.” Parasitology. 2004. 128(01): p. 39–42. http://dx.doi.org/10.1017/S0031182003004189

6. Hide, G., et al., “Evidence for high levels of vertical transmission in Toxoplasma gondii.” Parasitology. 2009. 136(Special Issue 14): p. 1877-1885. http://dx.doi.org/10.1017/S0031182009990941

7. Sroka, J., Szymańska, J., and Wójcik-Fatla, A., “The occurrence of Toxoplasma gondii and Borrelia burgdorferi sensu lato in Ixodes ricinus ticks from eastern Poland with the use of PCR.” Annals of Agricultural and Environmental Medicine. 2009. 16(2): p. 313–319.

8. Prestrud, K.W., et al., “Serosurvey for Toxoplasma gondii in arctic foxes and possible sources of infection in the high Arctic of Svalbard.” Veterinary Parasitology. 2007. 150(1–2): p. 6–12. http://www.sciencedirect.com/science/article/B6TD7-4PYR4P2-2/2/fcc91fcf1d1426cd1b750bd3840bdb31

9. Oksanen, A., et al., “Prevalence of Antibodies Against Toxoplasma gondii in Polar Bears (Ursus maritimus) From Svalbard and East Greenland.” Journal of Parasitology. 2009. 95(1): p. 89–94. http://dx.doi.org/10.1645/GE-1590.1

10. Jessup, D.A. and Miller, M.A., “The Trickle-Down Effect.” The Wildlife Professional. 2011. 5(1): p. 62–64.

11. Conrad, P.A., et al., “Transmission of Toxoplasma: Clues from the study of sea otters as sentinels of Toxoplasma gondii flow into the marine environment.” International Journal for Parasitology. 2005. 35(11-12): p. 1155-1168. http://www.sciencedirect.com/science/article/B6T7F-4GWC8KV-2/2/2845abdbb0fd82c37b952f18ce9d0a5f

12. Miller, M.A., et al., “Type X Toxoplasma gondii in a wild mussel and terrestrial carnivores from coastal California: New linkages between terrestrial mammals, runoff and toxoplasmosis of sea otters.” International Journal for Parasitology. 2008. 38(11): p. 1319-1328. http://www.sciencedirect.com/science/article/B6T7F-4RXJYTT-2/2/32d387fa3048882d7bd91083e7566117

13. Gibson, A.K., et al., “Polyparasitism Is Associated with Increased Disease Severity in Toxoplasma gondii-Infected Marine Sentinel Species.” PLoS Neglected Tropical Diseases. 2011. 5(5): p. e1142. http://dx.doi.org/10.1371%2Fjournal.pntd.0001142

14. Koch, C., “Protozoa Could Be Controlling Your Brain.” Scientific American. 2011. http://www.scientificamerican.com/article.cfm?id=fatal-attraction