Hi stranger! Signing up for MypetMD is easy, free and puts the most relevant content at your fingertips.

Get Instant Access To

  • 24/7 alerts for pet-related recalls

  • Your own library of articles, blogs, and favorite pet names

  • Tools designed to keep your pets happy and healthy

or Connect with Facebook

By joining petMD, you agree to the Privacy Policy.

petMD Blogs

Written by leading veterinarians to provide you with the information you need to care for your pets.

The Daily Vet by petMD

The Daily Vet is a blog featuring veterinarians from all walks of life. Every week they will tackle entertaining, interesting, and sometimes difficult topics in the world of animal medicine – all in the hopes that their unique insights and personal experiences will help you to understand your pets.


A recent study published in the journal Nature Communications looked at the impact of free-ranging cats on wildlife in the United States and concluded that "free-ranging domestic cats kill 1.4–3.7 billion birds and 6.9–20.7 billion mammals annually. Un-owned cats, as opposed to owned pets, cause the majority of this mortality. Our findings suggest that free-ranging cats cause substantially greater wildlife mortality than previously thought and are likely the single greatest source of anthropogenic mortality for U.S. birds and mammals. Scientifically sound conservation and policy intervention is needed to reduce this impact."

This study has led to numerous media accounts that refer to cats as "serial killers" or "murderers" and that generally portray cats in a negative light. This media coverage has caused concerns that shelters and rescues may have difficulty finding homes for cats, a task that is already difficult enough given the numbers of homeless cats handled by these organizations. Catalyst Council, a national coalition of animal health and welfare organizations, has issued a press release in which executive director and feline practitioner Dr. Jane Brunt stated:

“We regret the fact that the articles written about the study have maligned cats as a whole, when in fact, the vast majority of the estimated destruction to wildlife was reportedly by feral or stray cats. This works to discourage prospective cat owners from adopting one of the hundreds of thousands of healthy, enjoyable cats that are held in shelters across this nation.”

I agree with Dr. Brunt whole-heartedly that this inflammatory media coverage is damaging. Cats make wonderful pets. It would be truly unfortunate if sensationalistic media accounts result in declines in adoption rates and a reduction of the number of cats kept as pets.

I don’t argue that cats are predatory by nature. I don’t argue that there are declines in many species of birds and mammals that may be prey for cats either. However, I do take issue with the insinuation that the cat population is responsible for the entire situation or even the greatest part of the situation. I think there is adequate reason to doubt the validity of the numbers reported in this particular study. However, even if it is assumed that the results of the study are accurate, there are still many other factors at work here, not the least of which is the destruction of the natural habitats of these declining species by human activities that have nothing to do with cats.

Still, I do feel that keeping cats indoors is the responsible thing to do as a cat owner. My own cats are and always have been indoor cats. They are safer and healthier being indoors and they pose no danger to birds and other wildlife, unless you count the occasional fly, moth, or spider that finds its way inside the house. For cats that enjoy spending time outdoors, supervised walks using a harness are an alternative to allowing your cat outdoors unsupervised. Catios are also gaining in popularity and are an attractive method for allowing a cat outdoors while still keeping cat and wildlife safe.

Another point that is missing in most of these media reports is the fact that many of the prey animals in question are pests such as mice and rats. These animals can multiply rapidly and are frequently carriers of diseases that can infect people such as leptospirosis. Keeping populations of these animals in control — which cats do — is actually beneficial.

rap/neuter/release (TNR) programs are controversial but they do work to keep feral cat populations under control. It is important for these colonies to be adequately managed, with someone providing food and shelter for the cats in the colony. But in areas where managed TNR programs are eradicated and the cats removed, a vacuum rapidly occurs which allows other cats to enter the area, cats which are fertile and unvaccinated. The complete eradication of all feral cats is not a practical solution to the problem, nor is it, in my opinion, a desirable solution.

Obviously, there are problems here that need to be solved. And I don’t pretend to have all the solutions either. I do know that without communication and cooperation between cat lovers and conservationists there can be no real and lasting solution. I don’t want to see birds and other species of animals disappear, but I don’t want to see cats, feral or otherwise, being systematically hunted and destroyed either. I feel reasonably certain that I’m not alone in these desires.

In the meantime, if you’re thinking about adopting a cat or kitten, please don’t let these reports change your mind about the suitability of keeping a cat as a pet. I’ve had the pleasure of sharing my home with many cats over the years and currently live with six of them. They’re wonderful companions and I have absolutely no regrets.

Dr. Lorie Huston

Image: BMJ / via Shutterstock

Comments  13

Leave Comment
  • cats & wildlife
    02/11/2013 08:40am

    I'm not sure how you can possibly come up with those numbers in the first place. Who really knows how many feral cats there are and how many people have outdoor cats? Personally, I think it's a gross extrapolation but I'm sure there was some "systematic" way of coming up with the numbers. Thanks for trying to make sure that kitties aren't maligned by this info. I love my guys and would certainly have more if hubby would tolerate them.

  • Only part of the picture
    02/11/2013 01:54pm

    Over the years we have rescued a number of strays, and one in particular used to annoy me no end by constantly bringing me dead birds. In reality, he couldn't climb trees and at the end of his life a radiograph showed he had damaged his collarbone before we knew him. Back then, because we lived in a protected gated community, we continued to let him rule his territory, and what I learned over time was that in spite of the fact that he hadn't been outdoors long enough to hunt anything, he was bringing home dead, (cold), birds that had probably succumbed in their sleep and dropped to the ground from perches. I am sure any neighbour who saw him with his trophies would think he was a mighty hunter of a cat, but nothing was further from the truth. The song bird had probably died of salmonella that is common in our area.

    Then we have another scenario in our present situation where both birds and squirrels love to hang out under one particular bush. As local outdoor cats have learned about this they too have decided to hang out there. In the past I used a slingshot and the smallest of gumballs to 'encourage' the cats to move on, partly because we have an at risk species of small squirrel that is living in this area. Even the cats contained on our deck have managed to kill two of those little squirrels that chose to explore the deck. Wildlife is prey for our house cats, even if just as trophies to bring mom.

    And then, to top it all off, that bush I mentioned above has been discovered by local bob cats that now see it as the local McDonalds for bob cats. This meant that the one persistant outdoor cat was attacked by the larger bob cat and had to be rescued.

    So in the years we have experienced cats interacting with the outdoors, there has been a major threat of salmonella coming into the house, and as cats can't resist hunting, even in play, they also run the risk of encountering larger preditors that will damage them beyond repair, let alone cost major veterinary bills.

    I don't see the numbers being quoted are necessarily accurate when it comes to cats killing wildlife. For instance, when studies are done, do they check the prey for pre-existing disease that could have caused death? But we have learned, over the years, that keeping our cats contained is the only option we are willing to consider.

  • 02/12/2013 04:29am

    i really liked your idea and input here in this pet communtiy. Especially your suggestions are good for the pet owners.

  • Views on cats in NZ
    02/11/2013 02:14pm

    Recently, before I heard of the outcome of this US study (though perhaps inspired by it), an entrepreneurial, well-known New Zealander suddenly started an anti-cats campaign, citing the decreasing numbers of NZ wildlife (NZ has many endemic species and the majority are birds so we do need to look after them). It went a little viral and even reached the news in the UK.

    Anyway, long story short, I'm really dumbfounded by the overwhelming view of New Zealanders that you either have a cat and let it kill birds or you just don't have a cat. I have seen nowhere on comments (apart from my own) people advocating the lives of indoor cats. My cats are indoor cats (one of them goes outside maybe once a week to have a break from her brother). From knowing Americans and reading these American blogs (and others) I gather that in the US it is actually the norm to have your cats indoors. There are many good reasons to keep cats indoors (mine stemmed from a bad road accident, and pooing in the vege gardens!), but New Zealanders don't seem to understand this middle ground.

  • 02/11/2013 02:24pm

    Yes. Years ago I read that in New Zealand there aren't the same preditors to create a dangerous environment for cats, (no vet bills to deter owners), and also I don't think that there is the same salmonella risk there. At least there wasn't at the time I looked into this. I too found it hard to comprehend that New Zealanders weren't taking in the need to control cats.

  • 02/11/2013 03:07pm

    I'm not sure what you mean by the bit about predators to cats. I guess we don't have wild cats or other larger animals in the wild that would attack feral/stray cats, if that's what you mean. Also, the bit about vet bills... not sure what you mean there. We definitely have large vet bills!

  • 02/11/2013 03:09pm

    Oh I think I see what you mean. You're saying that in the US there are even more reasons to keep your cat inside i.e. larger predators ---> larger vet bills if your pet cat is attacked. Yes, I suppose that is correct. I think if there was a risk that Fluffy would get eaten by a wolf or a fox or a bobcat then more New Zealanders would probably keep their cats indoors. Though another one of the reasons I keep my cats inside is the fights they get into with just the other neighbours' cats!

  • 02/11/2013 06:31pm

    The #1 reason I keep my cat indoors is coyotes, and they do live all over the US, in urban and rural areas alike, although are much more common in some areas, like my neighborhood. They prey on small pets as well as rodents.

    The #2 reason I keep him inside is cars, and #3 would be not wanting him to get into fights with other outdoor cats.

    In all the time he did used to go outdoors he hunted mice, occasionally rats and once a small gopher, but I never saw him with a bird and never found bird remains in the yard. In fact the study clearly shows that rodents far outnumber birds as the victims of cats. I question the facts in studies like these, and it's very unfortunate that they've been used to limit the use of Trap/Neuter/Release programs, presumably in favor of trap/destroy. It's shameful.

  • ABS manufacturing stats
    02/11/2013 02:42pm

    What I find really troubling is that certain bird societies are not putting out information that is false. They are putting out stories stating that feral cat populations are one of the largest rabies threat in the world. Despite the fact there is not 1 documented case of feline to human rabies in 30-40 years. Rabies in feral cats is not nearly as common as these stories are reporting. I'm afraid this will cause many people to start thinking feral cats are rabid.

    My sister worked in the veterinary world for a long time and has interacted quite a bit with a local cat only shelter. She confirmed what I've read that rabid cats are very very rare. They tend to run from animals that do carry it. They can only contract it through contact with larger animals that they do not prey on.

  • Outdoor Kitties
    02/11/2013 06:55pm

    I suspect that the anti-outdoor-kitty numbers and articles are most likely spurred by people that don't much like cats. I wonder what the results might be if a cat-lover did the study.

    The unfortunate result, though, is that people read these articles and assume them to be completely factual. And, of course, if a study were done that had a positive outcome for the feline population, it wouldn't make the news.

  • Big Birds Kills Sylvester
    02/12/2013 11:44pm

    The good news is that these anti-cat people are small minority. The Bad news is that journalism around the world no longer has integrity and has adopted lowlife tactics for capturing readers--sensational headlines. Reporters have jettisoned journalistic practice of conducting thorough research on both sides of the story. We know cats are predators and will kill a bird. But not Billions of birds. There are numerous studies that point to urbanization, global warming, and HUMANS as the cause.

    You know we can counter by creating our own sensational headlines "Big Bird eats Sylvester the Cat" Birds are now attacking innocent, homeless Cats--that's our storyline. You know I don't think this is a stretch. Surely there is some evidence of that somewhere we could "repackage" like the Smithsonian and Nature Communications does so well. But then we are stooping to their level. Oh well. It was a passing thought.

  • 02/13/2013 12:10am

    Here we have to keep an eye on the larger hawks, and a Bald Eagle family nests down in the inlet every year. Just a couple of days ago I caught them on camera riding the thermals over our house -- looking to see if the cats were on the deck, no doubt.

    We have seen crows terrorize abandonned cats who were trying to catch a meal left out by caring people, so yes, there are a number of birds that are very intimidating to cats.

    "Mrs Hoot" loves to sit about 25' away from our deck at night, on the TV cable like along the street, and she isn't even intimidated by my presence at all. She just sits and stares back, waiting for an opportunity to try a little cat meal.

  • cats and birds
    02/20/2013 01:17am

    A few years back, when I was living in a place with a cat who went outdoors at times, I would observe my cat. He often chased birds, but mostly they would get away. Sometimes he would get them and do what cats do. I can only conclude that cats get those birds that are older, weaker, etc., and would have less survivability in any case. My cat was far more successful with mice and eliminated a mouse problem my girlfriend had before I moved in with her. On the other hand, I frequently observed the cat chasing squirrels but I don't believe he ever got one. Cats do love to chase. We had some birds make a nest right over the back door. My GF was out there trying to shoo the cat away as the fledglings were learning to fly. One fell down and she accidentally stepped on it. Nothing was ever again said about cats and birds in our household. I am sure that other factors than cats are responsible for our shrinking bird population.

Meet The Vets