DEAR DR. FOX: A colleague passed along one of your recent columns. In “Questioning Causes of Bird Mortality," a writer claims that the estimates of bird mortality (1.3 to 4 billion birds killed per year) from cats “are bogus and from a discredited study.”

This is a common refrain from opponents of keeping cats exclusively contained. As you can probably guess, it is also false. I invite you to reach out to the study’s authors (Pete Marra, Scott Loss, Tom Will), each employed at respected institutions, to determine the validity of the claim.

The single greatest indicator that the study has not been discredited is that there is no published study making any such statement. On the contrary, a similar study (Ballash, et al., 2013) conducted in Canada came to the same conclusion. Furthermore, if you break down the numbers, the estimates are really not extreme at all.

There are so many cats wandering outdoors, and each of them kills between x and y numbers of birds each year. The estimate seems far-fetched only because there are so many outdoor cats. -- Grant Sizemore, American Bird Conservancy, Washington, D.C.

DEAR G.S.: Peter Marra, one of the authors of this falsely disputed cat predation and bird mortality study, which reflects the current anti-science sentiment in society today, sent the following statement:

"Our study has in no way been discredited by our peers. It is, of course, disliked by outdoor cat advocates because of the inconvenient truth it uncovers. They claim it is discredited with the hopes that this idea will spread, but they can't point to a publication or paper that discredits the study.

"We stand by the mortality estimates and by our statement that cats directly kill more birds in the United States than any other source of direct anthropogenic mortality. To be clear, habitat destruction is still the most significant cause of bird declines over time, but cats far exceed any other cause of direct mortality, and that's a problem we should be able to reverse." -- Peter Marra, Takoma Park, Maryland

MASSIVE RECALL OF RAWHIDE DOG CHEWS

United Pet Group, a division of Spectrum Brands Inc., is voluntarily recalling multiple brands of packages of rawhide dog chew products that were distributed to retail outlets and sold online in the United States.

Manufacturers in Mexico, Colombia and Brazil were using a quaternary ammonium compound mixture as a processing aid in the manufacturing of rawhide chews. The compound is an anti-microbial chemical that is approved for cleaning food-processing equipment, but it has not been approved in the U.S. as a processing aid in the production of rawhide chews for dogs.

The primary complaint received from consumers was that the affected product had an unpleasant odor. Diarrhea and vomiting were also reported. Exposure to quaternary ammonium compounds through direct ingestion may cause the following symptoms in dogs: reduced appetite and gastric irritation, including diarrhea and vomiting. These symptoms may require treatment by a veterinarian, depending on severity.

All of the dog chew products included in the voluntary recall identify an expiration date ranging from June 1, 2019 through May 31, 2020. The recalled brands include American Beefhide, Digest-eeze, Healthy Hide Good-n-Fit brand and Healthy Hide Good-n-Fun brand. If you have these products, contact the United Pet Group consumer affairs team at 1-855-215-4962.

Another recall was subsequently announced on dog chews containing this chemical-treated rawhide for several private-label brands: Companion, Dentley’s, Enzadent or Dentahex, Essential Everyday, Exer-Hides, Good Lovin’ or Petco, Hill Country Fare and Priority Pet.

For more details, visit truthaboutpetfood.com

(Send all mail to animaldocfox@gmail.com or to Dr. Michael Fox in care of Andrews McMeel Syndication, 1130 Walnut St., Kansas City, MO 64106. The volume of mail received prohibits personal replies, but questions and comments of general interest will be discussed in future columns.

Visit Dr. Fox's website at DrFoxVet.net.)

DEAR DR. FOX: I read your recent column about the need to bring more environmental and humane education into schools, and I applaud the efforts of your daughter Camilla with Project Coyote, and the others who are doing this.

I work for Pro Animale in Germany, whose book "Memento" you recently reviewed, and I want to share with you my son’s natural empathy toward animals, which was quite independent of any influences from me during his early years.

Ever since my son started talking when he was 2 years old, I could tell that he had a very special sense and empathy for animals and their feelings and needs. Once, when he saw a just-hatched chick in an incubator at a fair, he did not say “how cute,” he immediately looked concerned and said it was looking for its mother, and we needed to find her. In a wildlife park, he saw two raccoons in an enclosure sitting by the fence and said they looked sad and did not want to be fenced in, but free.

When we were on a boat ride to see seals on a sandbank, the tour operators suddenly let down a net to the sea floor and fished out crabs and other creatures to show to the riders. Yukon, then 3 years old, got mad at the operators and asked them to let the crabs back into the water because they did not want to be taken out. Unfortunately, the tour operators did not listen -- even when I said that it is very harmful for the creatures on the bottom of the sea when they let down a net every time they have a boat ride to the sandbanks. The operators did not understand; they thought that since they put the creatures they fished in a tank with water and later back into the sea, it was OK. When one person said to Yukon, “Look at these interesting animals in the tank,” he responded: “I look at the animals who are in the sea where they want to be.”

I was amazed that a 3-year-old could be more understanding of animals and their needs than grown-ups. I am sure you can tell I am very proud of him. -- S.B., Sennfeld, Bavaria, Germany

DEAR S.B.: Many parents reading your letter will have had similar experiences with their young children’s reactions to animals, affirming my contention that they have a natural affinity for fellow creatures, which is the foundation for empathy and compassion as they mature.

But cultural norms regarding accepted treatments of animals and the attitudes and reactions of adults can either facilitate or inhibit the development of empathy. Indeed, empathy can be a burden, especially when not supported by others and when not expressed in appropriate action or choice.

Your son reminds me of my younger daughter, Mara, who, around the same age as Yukon, said that she was going to a friend's house for Thanksgiving to eat turkey. Her stepmother and I asked her if she knew what the word turkey meant. Since she did not, we gently told her that a turkey was a bird. Her immediate response was one of shock, and she exclaimed that she would never eat a bird or any animal. She later told us that at the gathering, she refused to eat any turkey and was told that it was OK because the farmer had killed the bird. From that time on, with no prompting from us, she decided to become a vegetarian. My other two children, Camilla and Mike Jr., decided at a later age to become vegan for ethical, humane and environmental reasons.

In sum, all children, with rare exception, have the capacity to identify with others and empathize, the absence of which has been linked to a lack of conscience, feeling for others, dissociation and sociopathic behaviors in later life. It is an attribute best guided by example, and enabling the child to make informed choices and to share and question openly, without ridicule, how he or she feels about animals and how they ought to be treated is best for them.

For more discussion, see my article “The Animal Insensitivity Syndrome: Its Recognition and Prevention,” posted on my website, DrFoxVet.net, and the book "Cruelty to Animals and Interpersonal Violence" by my former graduate student Dr. Randall Lockwood, co-authored with Frank K. Ascione.

SCIENTISTS EXPLORE EMOTIONAL CONTAGION TO UNDERSTAND ANIMAL-HUMAN CONNECTION

Researchers have increasingly become interested in emotional contagion -- the idea of the spread of emotions between people and animals or among animals -- and they've uncovered evidence that swine, horses and dogs experience physiologic responses to stressful situations involving other animals or humans.

Psychology professor Ted Ruffman says it's a primitive type of empathy that humans likely selected when domesticating animals, and it may explain why dogs can be so effective as therapy animals for veterans with post-traumatic stress disorder and others.

(Send all mail to animaldocfox@gmail.com or to Dr. Michael Fox in care of Andrews McMeel Syndication, 1130 Walnut St., Kansas City, MO 64106. The volume of mail received prohibits personal replies, but questions and comments of general interest will be discussed in future columns.

Visit Dr. Fox's website at DrFoxVet.net.)

DEAR DR. FOX: Three years ago, I adopted Sadie from an animal rescue organization. They told me she had just turned 1, but based on her weight gain, I would guess she was closer to 6 months when I adopted her.

She weighs about 30 pounds now. I specifically looked for a smaller dog because my previous dog weighed almost 60 pounds, and I couldn't lift him in his last days with me.

I found out after I agreed to adopt her in early October that Sadie had spent the summer at a no-kill shelter. After I brought her home, she was shy and afraid of most things in the first few days.

As soon as she realized she was staying with me forever, Sadie found her voice. Now she barks whenever my neighbor's dogs are outside. More troubling is her behavior when she gets outside and her doggy pals or my neighbor are outside, too. Sadie gets in a zone and runs circles around my yard. She has worn out a path along about 20 feet of the fence line, another 10 feet along my bromeliad patch and about 10 feet in front of my carambola tree.

When I try to call her to stop running, she ignores me and continues to run. I tried to prevent her from this obsessive behavior by putting down lava rocks and some pavers along the fence, but she continues to run in circles.

I think she gets enough exercise. We walk every morning for about 1.5 miles, and I play ball with her at least once a day. How can I break her of this obsessive habit of running in circles? -- J.S., Lake Worth, Florida

DEAR J.S.: This kind of obsessive-compulsive behavior can result from a dog being confined and frustrated or anxious for an extended period of time. It has elements of an addictive behavior, because running produces feel-good neurochemicals such as brain cannabinoids.

What your dog may want and enjoy is some regular, daily off-leash playtime in a safe area with other dogs. Check for doggy play groups in your area or ask about a friendly neighbor's dog coming over.

Possible pharmacological treatment with fluoexetine may help, or you can try St. John's wort, which a veterinarian familiar with psychoactive herbs may prefer to prescribe. A calming herbal supplement called @Ease elevates brain serotonin and is available from petzlife.com.

Keep me posted on your dog's progress.

DEAR DR. FOX: I have just returned from the Bwindi Impenetrable National Park in the southwest corner of Uganda, where many of the world’s remaining mountain gorillas live.

Having heard that germs can jump from humans to gorillas with ease, often with devastating consequences, our small group all brought surgical masks to wear -- not because we didn’t think the guides would supply masks, but more for our own personal hygiene in case theirs were being reused.

We were surprised to find that not only were we the only people in the group wearing masks, but the guides, guards and other tourists had no idea of the risk. We were allowed to get within touching distance of the animals.

Have I been misinformed? Is there no threat from germs to these incredible creatures? -- F.C., Golden Valley, Minnesota

DEAR F.C.: I greatly appreciate your vigilance and sensibilities. This is a problem wherever tourists come into close contact with wildlife that could be infected by potentially lethal strains of illness -- influenza virus in particular -- be they the penguins of Antarctica or the gorillas of East Africa.

The genetic relatedness of mountain gorillas and humans has led to concerns about interspecies transmission of infectious agents. Human-to-gorilla transmission may explain human metapneumovirus in two wild mountain gorillas who died during a respiratory disease outbreak in Rwanda in 2009. Surveillance is needed to ensure survival of these critically endangered animals, of whom fewer than 900 exist in the wild.

It is enlightened self-interest for the tourism industry to wake up to this serious issue and take immediate steps to provide footwear covering, face masks and gloves for their wildlife-visiting clients. Local guides may feel that the gorillas and other wildlife are not at risk because they often enter and raid villages for food, and make indirect contact with indigenous peoples hunting and tending their livestock in their dwindling habitats. All such tourism companies should dedicate a significant percentage of their profits to conservation and support of organizations such as Conservation Through Public Health, founded by veterinarian Dr. Gladys Kalema-Zikusoka (ctph.org) and gorillaconservationcoffee.org. All who are concerned with gorilla protection and conservation can donate to them with the endorsed assurance of the International Primate Protection League.

An essential aspect of wildlife conservation is to limit contact between wild species and people, indigenous and tourist, and domestic animals -- dogs, cats, livestock and poultry -- to prevent the transmission of a number of communicable diseases.

The ultimate protection of gorillas and other endangered species and their habitats calls for a united environmental nation’s armed paramilitary police force to prevent poaching and all forms of human encroachment, coupled with more effective family planning, since our species has become an infestation on planet Earth. (See Population Connection, popconnect.org, for more information.)

(Send all mail to animaldocfox@gmail.com or to Dr. Michael Fox in care of Andrews McMeel Syndication, 1130 Walnut St., Kansas City, MO 64106. The volume of mail received prohibits personal replies, but questions and comments of general interest will be discussed in future columns.

Visit Dr. Fox's website at DrFoxVet.net.)