American Birding Podcast



ICYMI: Open Mic: A Veterinarian’s Perspective on the Feral Cat Issue

The ABA Blog has been in existence for almost 10 years, and there’s a lot of good content back in the archives that deserves an audience now that it might not have received way back when. So, semi-regularly we will bring some of that stuff back. Here’s a guest post by veterinarian Brian Monk from March 2013 on a topic that is always relevant.

At the Mic: Brian Monk

Let me make myself perfectly clear:  I love cats. I am a veterinarian, quite a few of my patients are cats, and I count five of them as my pets. I believe that cats have an inherent value to us, both as living things and as companions. I also love birds, and have been watching them before I was old enough to know what they were. Without question, birds also have inherent value, both to our planet and our hobby. My position as both a birder and a veterinarian lends me a unique perspective about the current controversy surrounding feral cats, and the various solutions offered up to address this issue.

660px-Domestic_cat_eating_bird_on_lawn-8A recent study has determined that 1.4-3.7 billion birds are killed by feral cats per year, and its publication has pitted wildlife conservation groups against feline advocacy groups. The controversy centers around the most important question, “What is the
solution to this problem of cat overpopulation?” The only thing that these two groups seem to agree on is that feral cat overpopulation exists.

Feral cats lead short and brutal lives. Kittens suffer a 50-75% mortality rate.  Disease is prevalent in feral cat populations, as expected.  They are plagued with parasitism by various worms, arthropods, and protozoa; viral diseases like Feline Leukemia, Feline Immunodeficiency Virus, Herpes, Distemper, and Rabies; bacterial infections such as Toxoplasmosis, and Haemobartonellosis. Traumatic injury is common. Feral cats suffer
attacks from dogs, other cats, and other wildlife. And they suffer from the inexplicable cruelty of some humans. Personally, I have seen cats poisoned (both inadvertently and intentionally), caught and tortured, shot (with arrows and bullets), and set on fire. Many feral cats are chronically malnourished.  Regardless of the debilitation, feral cats for the most part receive no veterinary care for their illnesses, even in “managed”  colonies, and suffer needlessly. Feral cats rarely live more than 6 years, and rarely die peaceful deaths.

Rabies in feral cat colonies is a serious concern. Rabies is an untreatable and uniformly fatal disease. Prophylatic preventative therapy is long, painful, and expensive. Though cats are not a primary carrier of the disease (like raccoons or bats), they are easily infected due to their interactions with other wildlife. And because cats are generally accepted, humans are easily exposed. According to the Centers for Disease Control, cats are the only species with an increasing frequency of rabies infection.

Feline advocacy groups are in favor of continued tolerance of feral cats, citing the effectiveness of Trap-Neuter-Release programs (TNR) and managed colonies in reducing feral populations. Trap-Neuter-Release programs are intended to reduce cat populations by surgically sterilizing as many feral cats as can be caught. These cats are then released back into the environment. In some instances, the groups attempt to “manage” these feral populations by feeding cats in a specific area, the intention being to keep them from preying on other animals.

This solution on its face has a certain moral palatability and logical origin. If all feral cats are prevented from reproducing, then eventually the population will be reduced to zero, and this can be accomplished without killing a cat. But the flaws in this thinking should be apparent. Not all cats can be captured, and these continue to reproduce.  New individuals can enter the TNR area at will, and they will reproduce. And surgical sterilization does nothing to prevent continued predation on native wildlife.  TNR can neither eliminate feral cats, nor reduce predation, and does not address illness or disease, facts supported by actual scientific study.

Proponents of TNR ignore these facts. They downplay or deny outright the problems with rabies and other diseases. They counter that feral  cats are a natural part of the ecosystem and play an important role in the biologic control of pest species, that the estimation of wildlife killed by cats is grossly exaggerated, and that conservation groups have more important things to worry about. They have provided no studies that refute the numbers of wildlife killed. The studies that they do refer to regarding the effectiveness of TNR are of limited scope, and often contradictory in their findings. All of these studies openly admit that TNR will not be effective at eliminating feral cat populations.

What is not in dispute is that domestic cats are an invasive species, with a population of 60-70 million in North America. Derived from the desert-dwelling wild felines of northern Africa, and brought to this continent by European settlers, cats are exceptionally well adapted to a  predatory lifestyle, having keen eyesight, acute hearing and sense of smell, incredible strength and speed, lethal weaponry, and an incredible rate of reproduction. Cats are beautiful, efficient, and almost-perfect predators. And they are an alien species, altering the landscape, and causing- environmental, agricultural, and economic harm. There is no other small cat native to North America similar to Felis sylvestris, and thus
they have a huge and disproportionately damaging effect on wildlife.

Cats have their own biology, ecology, and ethnology, and their behaviors directly impact the biome.  There are 60-70 million feral cats in the North America. Feral cats draw their sustenance almost entirely from wildlife that they catch and kill.  A cat will eat as often as possible, and  must eat several times a week (at least) to survive. These are facts, undisputed by both sides. One shouldn’t need to use statistics or  years-long  research to see how quickly the numbers of dead prey add up.

Clearly, given the stated facts, feral cats must be completely removed from the environment, and by that I mean active extermination. From an ethical perspective, this may sound like a difficult thing to do, and I understand the visceral response concerning the outright extermination of an individual life.   But only the complete elimination of feral cats will provide the solutions that both conservationists and feline advocates want. Disease, health problems, public safety, and environmental concerns are all addressed successfully by eliminating the feral feline population. I  have considered all other possible solutions from the perspective of both a veterinarian and a conservationist, and they are either impractical or impossible.

The removal and eradication of harmful invasive species has become an important part of most conservation plans, and is actually supported by federal, state, and local law. These laws mandate the protection of native wildlife, and as such require the active elimination or control of alien species. Laws currently exist that allow specifically for the control, prevention, and elimination of feral cat colonies, while protecting pet cats and their owners.

Feline advocacy groups like Alley Cat Allies approach this situation without compromise. They use vague moral reasoning and use this to generate guilt in their audience, tearfully pleading that no one needs to kill the poor, defenseless little kitty-cats. Questions about the effectiveness of TNR and the health of feral cats are dismissed, or met with a furious, venomous, and illogical character assassination. They state  as loudly as possible that “cats re not a threat to wildlife” and scream that the science behind cat-predation studies is flawed, all without offering up any evidence to the contrary.  Fingers are pointed to habitat loss, cell-phone towers, and anything else that might play a role in population or biodiversity loss, and admonishments handed out to the guilty conservationists.  With these methods, they apply pressure the public to adopt TNR. Unfortunately, this has been effective at even the legislative level.  A bill is currently being explored in the Florida legislature that would make the creation of feral cat colonies much easier, regardless of their effect on wildlife, disease, or property rights, and it has gained some traction, already receiving unanimous passage by the Florida House Agriculture & Natural Resources Subcommittee. They are essentially being treated as a naturally occurring wild species.

This problem of feral cats is a difficult one. Although it is only a part of the greater question of avian conservation, it is obviously an important part. Further, it seems to be a part where real progress could be made, with benefits that are not so vague as biodiversity for biodiversity’s sake. Improving feline health in general, while keeping our precious wildlife safe, is a noble goal, that we can only approach ignobly. Feral cats exist because of man’s ego and carelessness. But TNR does not adequately address the issue. It does not ease feline suffering or eliminate feline predation on our wildlife to a point that is acceptable, to me as a veterinarian and a conservationist, or to anyone else who considers the facts.  As difficult as it may be, the elimination of feral cats via Trap and Euthanasia is the only truly viable solution.

EDITOR’S NOTE: We are aware that this subject prompts passionate responses and we welcome strong opinions about ideas, but we ask that commentors please stay courteous and refrain from personal attacks. Otherwise we will delete your comment and ask you to resubmit using more civil language. 


Loss, Will, & Marra; The impact of free-ranging domestic cats on wildlife of the United States. Nature Communications, Volume: 4:1396, Jan 2013 

Hildreth, Vantassel, Hyngstrom; Feral Cats and Their Management. University of Nebraska-Lincoln Extension Service; Publication EC1781.

Levy, Gale, Gale; Evaluation of the effect of a long-term trap-neuter-return program on a free-roaming cat population. Journal of the American Veterinary Medical Association, 2003:222, pp 42-46, Jan 2003.

Foley, Foley, Levy, Paik; Analysis of the impact of trap-neuter-return programs on populations of feral cats. Journal of the American Veterinary Medical Association, 2005:227, pp 1775-1781, December 2005.

HB 1121 Passes Through First Committee Stop;

Nutter, Levine, Stoskopf; Reproductive capacity of free-roaming domestic cats and kitten survival rate. Journal of the American Veterinary Medical Association, 2004:225, pp1399-1402, November 2004.

Horn, Mateus-Pinella, Warner, Heske; Home range, habitat use, and activity patterns of free-roaming domestic cats. The Journal of Wildlife Management, 75:5, pp1177-1185, July 2011.

Barrows, Jessup, Winter, Levy, Crawford, Stoskopf, Nutter; Animal Welfare Forum:Management of Abandoned and Feral Cats. Journal of the American Veterinary Medical Association, 2004:225, pp1354-1383. November 2004. 


Brian Monk is a veterinarian, birder, photographer, and professional orchid grower and lecturer. He received his DVM from Virginia Tech in 1997 and currently resides in Ft. Lauderdale, Florida, with his wife Mary-Margaret and his 5 rescued cats.