DEAR DR. FOX: When it comes to litter boxes, I don't understand the "rule" of one per cat, plus an extra.

I have two litter boxes for my two cats, but both use the same one -- even if it's already been used. In my previous apartment, there was no room for more than one box, and even in the house where I had two boxes on each floor, they both used the same one most of the time. I use newspaper instead of purchasing litter; I started with shredded and now use whole sheets that they enjoy shredding themselves. It's very absorbent and cuts the foul stool odor after a short while. -- I.I., Hendersonville, North Carolina

DEAR I.I.: I do not know from which cat expert you received this advice about cat litter boxes, but my experts are my own cats. They will share a litter box amicably and without any complications -- such as pooping outside the box -- provided the box is cleaned out three to four times a day.

I feel for those poor cats whose boxes are not kept clean so they must poke around in their own waste to dig a pit to evacuate and then to cover. Just as bad is having to enter a covered box that has not been kept clean, filled with the fumes of acrid urine and feces. This does contribute to cats developing cystitis from holding their urine; to urinating elsewhere in the home, which is a death sentence for many cats; and to constipation and aversion of using the litter box.

For details, see my article "Cat Litter Box" on this complex but essential aspect of caring for cats posted on my website, DrFoxVet.net.

DEAR DR. FOX: My wife and I recently rescued a 2-year-old Chihuahua-mix with a puppy mill history who needs potty training. We reward and praise her on our walks when she does her stuff. We take her out many times on the same schedule; however, once inside, she has accidents and without any indications of wanting or needing to go outside.

Are there any hints or insights you can provide? She sleeps on the floor in a small fenced enclosure in our bedroom. We get her out immediately when she wakes in the morning -- if we don't, she will have an accident. It would be good if she would sleep an hour or so later as well. -- A.P., Winston-Salem, North Carolina

DEAR A.P.: Good for you taking in a former puppy mill dog. This business is a sickening side of humanity -- sorry, of our inhumanity -- when it comes to so many puppy mill breeders here and abroad who keep these poor dogs in small cages and treat their pups like commodities.

My advice to people seeking a dog or puppy: Never buy a pup without seeing the breeding facility and the pup's parents. There are so many scams you can avoid, such as buying online or from a pet store. Go local -- to the animal shelter or to a local, reputable breeder of a particular breed you have in mind.

As for your Chihuahua's incontinence, it may be physical or behavioral. First, have her urine tested for possible cystitis, a common affliction in young dogs, which can lead to house soiling.

Second, the behavioral consideration: She may have been confined in a small cage, so she got into the habit of urinating inside the enclosure. If she sleeps well in a long and narrow pen or dog crate and does not cry all night to get out, crate training may help.

Since most dogs will not evacuate where they sleep, have her sleeping pad or pillow set at one end of the enclosure and a puppy pee-pad securely laid down at the other far end. Put some of her urine on the first pad you put down so she gets the scent and hopefully understands that this is where she must urinate while confined.

She should not need any food or water overnight in the enclosure, but she may enjoy a chew toy or two. Later, when she is trained, you can leave the crate or enclosure open during the day so she can use it as her den if she wishes, and her toilet, too!

COLORADO CAT TESTS POSITIVE FOR PLAGUE

A Weld County, Colorado, pet cat tested positive for plague, and the cat and its owner are undergoing treatment.

Plague is spread through flea bites and contact with infected animals, so flea control medication is an important preventive measure. So is keeping cats indoors and not allowing them to roam free and unsupervised outdoors.

Remember: The plague, called the Black Death, caused by the bacterium yersinia pestis, wiped out 30 to 50 percent of Europe's population between 1347 and 1351, at which time there was no effective treatment.

FIND OUT IF ADVENTURE CATTING IS FOR YOU AND YOUR CAT

Adventure catting involves taking pet cats on outdoor excursions, and in "Adventure Cats," author Laura Moss explains the particulars, including training cats from the outset, acclimating them to a harness and walks outdoors. Not all cats may be interested, enthusiasts note, but when they are, adventures can provide a great bonding experience for human and pet.

(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: 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.)