“Inside, cats make excellent pets; loose on the landscape, they are — by no fault of their own — unrelenting killers and cauldrons of disease.”

That’s actually a fairly restrained quote. Peter P. Marra, director of the Smithsonian Migratory Bird Center at the National Zoo, and his co-author, Chris Santella, mince no words in their combative new book, “Cat Wars: The Devastating Consequences of a Cuddly Killer.”

Laying out an argument that outdoor cats — mostly feral animals but also pets allowed to roam outside the house — kill between 1.3 billion and 4 billion birds in the United States every year, they describe cats as an “invasive species” that is “contributing to the catastrophic downward spiral of many bird and mammal populations,” possibly even to a “sixth mass extinction” that could affect the whole planet.

In a chapter titled “The Zombie Makers: Cats as Agents of Disease,” the authors warn not only that cats are capable of spreading rabies and plague to humans but that they are host to “even more-insidious disease organisms” such as Toxoplasma, a parasite they link, to varying degrees, to extinction of other species and to fever, fatigue, headaches, blindness and even mental illness in people. “Cat-transmitted pathogens have impacted millions of humans,” they write, “and pose one of the least understood but most critical public-health challenges of our time.”

That’s pretty inflammatory language. But this is not a screed — it’s well written, extensively footnoted and usefully indexed, and the praise on the back cover is impressive.

(COURTESY OF THE PUBLISHER)

Jared Diamond, whose Pulitzer Prize-winning “Guns, Germs and Steel” focused on how environmental forces shaped human society, says, “If you are a cat lover, a bird lover, a philosopher, an ethicist, or just anyone interested in gut-wrenching dilemmas, you will find this a gripping book.”

And best-selling novelist Jonathan Franzen, who made the problem of cats killing songbirds a key plot element in his novel “Freedom,” calls it a “compassionate handling of a highly fraught issue.”

“Compassionate” seems an odd word for a book that says, “In high priority areas there must be zero tolerance for free-ranging cats. . . . If the animals cannot be trapped, other means must be taken to remove them from the landscape — be it the use of select poisons or the retention of professional hunters.”

Hmm. In a country where the authors estimate that 90 million or so cats live in homes — a society that’s also obsessed with cute-kitten videos — do you think anyone’s going to have a problem with this? You can’t help but wait for the fur to fly.

An earlier version of this story omitted the reference to “high priority areas” in the next-to-last paragraph.