DEAR READERS: Cats infected experimentally with SARS-CoV-2 transmitted the virus to other cats, researchers reported in The New England Journal of Medicine. But the cats did not develop clinical signs of illness.

In 2016, an H7N2 influenza outbreak in New York City cat shelters highlighted the public health implications of cat-to-human transmission to workers in animal shelters. Cats may be a silent intermediate host of SARS-CoV-2, because infected cats may not show any appreciable symptoms that might be recognized by their owners.

In early May, a cat in Spain that died from a common feline respiratory condition tested positive for SARS-CoV-2, according to the results of a necropsy, making the cat one of a handful worldwide to test positive for the coronavirus. The cat belonged to a family whose members had tested positive for the virus, but the viral level was low, and there is no evidence pets can transmit the virus to people, says professor Joaquim Segales of the Animal Health Research Center in Catalonia.

So vigilance and more monitoring are called for, where there are cats in homes where people are infected with the coronavirus. Such cats should be kept indoors and not allowed to roam outside. To date, there is no evidence that cats carrying this coronavirus can infect people, but if allowed outdoors, they could contact other cats who are infected -- whether with this coronavirus or other diseases -- that they might bring back to the families with whom they live.

DEAR DR. FOX: This is my second time writing to you, thanking you for your valuable work. The mistreatment of animals is a potent cause of disease. Included in this mistreatment is taking away their natural habitat.

The New York Times had two interesting articles a few weeks ago on this same topic: “Our Cruel Treatment of Animals Led to the Coronavirus” and “Animal Viruses Are Jumping to Humans. Forest Loss Makes It Easier.”

I am older now, and retired. A few years ago, I adopted a dog because his owner could not look after him. The dog showed me that all animals have human qualities in some measure, and all deserve to be treated humanely. I wish more people would adopt animals so they could see this for themselves. Then maybe we would transition away from eating our friends to a diet consisting of Earth’s bounty.

Keep up the good work. -- B.C.S., Nassau, Bahamas

DEAR B.C.S.: I very much appreciate your comments and references to articles that connect public health with our continued exploitation and consumption of other animals, wild and domesticated. Many consumers are now waking up to this tragic reality and are changing over to eating less, or no, animal produce, and see that a plant-based diet is the wave of the future.

Several people sent me this relevant article from Time magazine, which I encourage readers to find online: “We Need to Rethink Our Food System to Prevent the Next Pandemic.”

I also appreciate what you say about the dog you adopted and what the dog taught you. It is an obfuscation and denial that other animals do not have emotions, and cannot suffer as we do. That animals do “have feelings” has been proven by ethologists and other scientists. So it is no lie to contend that they have the capacity to experience fear and anxiety, as well as affection and security. By extension, therefore, they have interests and rights to humane treatment, which is our collective and singular responsibility.

Lying, denial, obfuscating -- concealing the truth -- have become commonplace in these times, from the highest levels of public office to our own personal lives. A life unexamined is a life unlived. We must all examine the truths we live by, especially in relation to the rest of the animal kingdom, and begin to make amends.

One truth is that there are too many of us on Earth to live on the meat-based diets that are now documented to be a major contributing factor to climate change, habitat loss and species extinction -- plus a host of food-borne illnesses, which the current COVID-19 pandemic affirms. This truth is inescapable, but is denied by vested interests, including those who believe that animals were created for man’s use.

(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 DrFoxOneHealth.com.)

DEAR READERS: As we are learning with the COVID-19 pandemic, such pandemics and epidemics from wild and farmed animals can cause millions of human deaths and much suffering, emotionally and socioeconomically. They are a consequence of our mistreatment and exploitation of animals and nature.

Aside from America’s documented lack of preparedness for this pandemic, no less urgent is the need for national and international prevention of future pandemics. The Centers for Disease Control and Prevention estimates that three-quarters of new human diseases originate in animals. Factory-farmed animals are not only the main source of influenza epidemics but also, since they are fed antibiotics, they contribute to the problem of antibiotic-resistant bacteria. Some 2.8 million Americans are sickened by such bacteria annually, of whom 35,000 die, according to the CDC.

We cannot continue to rely on ever more vaccinations and pharmaceuticals, both of which take a very long time to develop -- and to prove effective, with no harmful consequences and side-effects. Rather, we must focus on prevention. This path involves phasing out factory farms and feedlots, and prohibiting the farming and harvesting of wildlife species for human consumption and international trade.

For another voice supporting this view, see Fareed Zakaria’s recent column in The Washington Post entitled, “The real scandal isn’t what China did to us. It’s what we did to ourselves.” This is the big story of our time; we have disrupted nature, and it needs to stop.

Already, we are witnessing a positive consequence of this pandemic: improved global air quality due to less travel by road, rail, air and sea. This means less pollution from fossil fuels and their associated emissions. Improved air quality, in turn, means lower susceptibility to lung and other infections. It also means slowing down climate change.

Changing our travel and dietary habits (switching to more plant-based, home-prepared, unprocessed whole foods) are positive consequences of this pandemic. If these trends continue, rather than returning to the status quo, much agricultural land currently used to produce GMO commodity crops like corn and soybeans to feed factory farmed animals could be recommissioned to produce organically certified foods for human consumption. And millions of acres of “carbon sink” wetlands, forests and grasslands could be restored. This will improve water quality and help temper droughts and floods.

A final thought on the topic: “There is always a silver lining in every cloud, and for COVID-19, I think it just might be a quantum leap for the One Health philosophy.” -- Craig N. Carter, DVM, MS, Ph.D.; professor of epidemiology in the Department of Veterinary Science, University of Kentucky

DEAR DR. FOX: I have a neighbor who has a dog with a serious skin condition, which seems to be worse every time I see them walking the dog. I am sending photos that I took one day when their daughter was out with the dog. She said her parents never take care of his skin, and she wishes they would take him to the vet. What should I do? This dog is very sweet and is only 6 years old. -- L.K., via email

DEAR L.K.: I applaud your vigilance and concern about this dog. I wish all people were like you and would intervene when there is an animal health and welfare issue, and possible neglect or abuse.

From my impression of the photo you sent, the issue looks like demodectic mange. It could be sarcoptic mange, transmissible to humans, but I do not see signs of scratching, which that skin parasite causes.

Either way, the dog should be taken to a veterinarian because this is an animal health and welfare issue: an evident health problem that the owner has a responsibility to address, and to possibly prevent the skin disease from spreading to others in the home.

ADOLESCENT DOGS ACT A LOT LIKE TEENAGE HUMANS

A study published in Biology Letters supports anecdotes that adolescent dogs behave differently than puppies or adult dogs -- becoming recalcitrant, much like human teenagers do. Adolescent dogs that displayed stress when separated from caregivers were especially likely to disobey their caregiver but obey a stranger, and findings might mean that dogs are good models for studying human adolescence.

As a parent and animal caregiver, I have always respected the adolescent impulse for independence, encouraging freedom of spirit with boundaries that respect the rights of others. Such respect comes not from sheer discipline or moralistic indoctrination, but from awakening the empathy for others we -- and our dogs and other social animals -- possess. This is done through various games involving social play and learning to be gentle. Over-indulgence can lead to delinquent and irresponsible adolescents, be they dogs or humans who have not learned the nature of love.

(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 DrFoxOneHealth.com.)

DEAR DR. FOX: My daughter adopted a 6-month-old cat from a local charity in Asbury Park, New Jersey. From day one, the cat had weepy eyes and was sneezing and wheezing.

My daughter brought him to the vet the day after adopting him. The cat had an eye infection and an upper respiratory infection. With testing, meds and multiple office visits, treating the cat cost her almost $1,000. She was fine with that; we know that you have to plan on spending money on your pets. One week later, my daughter noticed a spot on the cat’s ear and went back to the vet. It was ringworm: more meds, more money.

She contacted the charity, which basically told her, “We don’t care, don’t publish this info on social media” and “How dare you accuse us of giving you a sick cat.” Well, a week later, the charity posted that they were closed indefinitely due to an outbreak of ringworm.

The cat has had eye infections and sneezing requiring vet visits two more times in the past five months. We were told that this could be a lifelong eye condition. My question is, could the ringworm have anything to do with the eye infection and the sneezing/wheezing? Any input as to how to help this kitty avoid constant, lifelong meds would be appreciated. My daughter does make his cat food with chicken, veggies, eggs and olive oil, and supplements that with an organic dry food. -- C.W., Long Branch, New Jersey

DEAR C.W.: This is indeed a sad story for your daughter’s cat, and a costly experience for her. This should not deter people from adopting animals from animal shelters, but should put all shelters on notice to properly quarantine incoming cats before putting them into the adoption area with other cats. Each incoming cat’s health and needs must be evaluated by a veterinarian.

It is vital to minimize stress while the animals are awaiting adoption. Veterinary supervision and good nutrition are crucial to ensure that viral infections, in particular, do not flare up in cats with stress-compromised immune systems, and then spread to other cats in the facility. Good ventilation, sanitation and socialization --with hideaway boxes for shy and fearful cats -- are all good protocols to follow.

Cats are especially prone to upper respiratory, eye and sinus infections from herpes and various viruses, often followed by secondary bacterial infections and other complications. There are supplements that can help prevent and subdue the severity of some viral infections, notably L-Lysine for cats, which may also help humans.

For our own protection, my wife and I take several immune system-boosting supplements like vitamin D3, vitamin C, selenium, magnesium, zinc and CoQ10, along with probiotics and plenty of fresh fruits and vegetables. Also, we take omega-3 fatty acids from marine algae (we are vegetarians). Cats, as obligate carnivores, have a deficiency in these essential fatty acids when fed dry kibble, so I always advise giving them a few drops of fish oil in their food daily. This may also help your daughter’s cat stay healthy and reduce future bills for veterinary care.

Ringworm is another challenge in animal shelters, and routine screening for this should be part of the screening protocol for incoming animals. There are oral medications for ringworm, as well as bathing treatments with hydrosols of some antifungal essential oils. But these call for expert veterinary handling. Ringworm can also be transmitted to humans, as happened to my wife when she was working with animals in India.

Have your daughter visit ahvma.org to find the nearest holistic veterinarian, who may be able to help her keep her cat healthy without resorting to costly and potentially harmful medications.

TESTING ANIMALS FOR COVID-19 INFECTION

American veterinary diagnostics firm IDEXX has a test that veterinarians can use on dogs, cats and horses for infection with SARS-CoV-2, the virus that causes COVID-19, if an infection is suspected. (Note: This is not a kit that can be purchased for in-home pet testing.)

(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 DrFoxOneHealth.com.)