Chytridiomycosis, a disease caused by chytrid fungi, has caused the extinction of 90 species of frogs and other amphibians over the past 50 years, according to researchers from a number of worldwide universities.

The pathogen has caused huge losses of 501 species of amphibians, including the 90 extinctions and 124 other species whose populations have declined by more than 90 percent, according to a report by an international group of scientists published in the March 29 edition of the journal Science (“Amphibian fungal panzootic causes catastrophic and ongoing loss of biodiversity”). See also “Amphibian ‘apocalypse’ caused by most destructive pathogen ever” (National Geographic, March 28).

The highly contagious fungus eats away the amphibians’ skin. Unable to properly respire, they die from cardiac arrest. Amphibians that are resistant to it become carriers, making it nearly impossible to eradicate.

In my opinion, and from a One Health veterinary perspective, this disease is a symptom of frog and salamander immune system dysfunction, enabling this fungus to spread rapidly under the facilitative influence of the lucrative world trade in exotic pets. Amphibians are extremely popular as pets, but some owners later release the animals, having lost interest, or the animals escape and infect indigenous species.

Their immune and reproductive systems have been damaged by agricultural petrochemical insecticides. These and other chemicals are in the rain, acidified with carbon dioxide from the burning of fossil fuels, that falls ever more unpredictably on wetlands and jungle habitats. The documented disappearance of insects due to similar human causes means many insectivorous amphibians are malnourished or starving. The bats of North America dying from white nose fungal disease are casualties of similar causes.

These losses mean the web of life in many ecosystems, the natural biodiversity, is being destroyed. In the absence of adequate biodiversity controls -- namely bats, toads and frogs -- harmful insects such as mosquitoes and ticks proliferate.

The declining quality of air, water and habitats around the world must be addressed, along with climate change, for our own sakes as well as the frogs and salamanders.

Ironically, an unrelated drug-resistant fungus, Candida auris, is now infecting people around the world. The drug resistance found in several strains has been linked with the global application of fungicides to various crops. (“A mysterious infection, spanning the globe in a climate of secrecy,” New York Times, April 7). Remember: “As ye sow, so shall ye reap.”

DEAR DR. FOX: I have a wonderful and loving 12-year-old Weimaraner, who unfortunately has many fatty tumors on his body. Our veterinarian indicated that this is a common problem with this breed of dogs.

Is there anything I could have done to prevent these tumors from developing? Is it too late to correct the problem now? -- V.B., Palm Beach County, Florida

DEAR V.B.: These fatty growths, called lipomas, are not cancerous, but they can become numerous and large in certain breeds. They can require surgical removal when they cause discomfort, interfere with the dog’s range of motion and mobility, or become ulcerated or infected.

There are various theories as to why dogs develop these tumors, including genetic/breed susceptibility, metabolic syndrome with too much starch in the diet, neutering, and lack of regular physical activity.

Pending a pre-surgical risk evaluation, your dog may be in good enough condition for surgery. But if none of the growths are causing any discomfort, and it is only for cosmetic reasons, I would not accept the risk of surgical removal considering your dog’s age.

HOW OWNER PERSONALITY AFFECTS PET HEALTH

Research shows that pets and their owners become more similar over time, and the finding could be used to improve animal welfare and veterinary care, write professors Paul McGreevy and Pauleen Bennett. Owner personality affects how pets are treated and how frequently they receive veterinary care.

“Each clinical case must now be understood in the context of the human background baggage that enters the consultation room,” they write. (The Conversation, March 25)

(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.)

Sun bears can exactly mimic each other’s facial expressions, according to research by Dr. Marina Davila-Ross and Ph.D. candidate Derry Taylor, both at the University of Portsmouth. These findings, published in Scientific Reports, “(cast) doubt on humans’ and other primates’ supremacy at this subtle form of communication,” reads a report on phys.org. (For more, search the site for “facial mimicry.”)

The researchers found that “bears can use facial expressions to communicate with others in a similar way to humans and apes, strongly suggesting other mammals might also be masters of this complex social skill and, in addition, have a degree of social sensitivity,” said the report.

Dr. Davila-Ross said, “Mimicking the facial expressions of others in exact ways is one of the pillars of human communication,” adding that previously, only humans and great apes were “known to show such complexity in their facial mimicry.”

In certain countries, these intelligent bears are abused and exploited by being brutally declawed and defanged, then made to “dance” with a rope tied to a ring in their noses. These practices should be outlawed, and the bears living alone in captivity should be liberated into proper habitats to enjoy some quality of life -- if not returned to the wild.

DEAR DR. FOX: We saw your column, “A Shameful Drug Company,” which ran in the Tulsa World on March 26 and other newspapers over the previous days.

We at Zoetis want you to know that we take the issue of antibiotic resistance very seriously, and support the responsible use of antibiotic medicines in animals and in people. We recognize that animal and human health are interdependent and, therefore, advocate for taking a One Health approach to the responsible use of antibiotics across human and veterinary medicine. We believe that veterinary professionals should be involved in decisions about the use of antibiotic medicines in animals to protect animal and human health, to assure the safety of the food supply and to help reduce the risk of resistance.

We recognize that there are substantial differences in livestock production systems and degrees of food security in countries throughout the world, and that an efficient food production system will be required to continue feeding a growing world population.

Each country enacts regulations appropriate for their market needs and standards, and we work with the national regulatory authorities in international countries, including India, to understand, respect and comply with local regulatory interpretation and oversight. We are committed to working with regulatory authorities, veterinary professionals and livestock producers in developing countries such as India to help advance the understanding and implementation of sustainable production systems and practices with a goal of raising healthy animals.

We understand that the Indian authorities are in the process of reviewing the laws that regulate the use of antibiotics in medical feed additives to be given to animals. In parallel, Zoetis is currently reviewing our company’s medicated feed additive product regulatory claims. -- Elinore White, senior director of corporate communications, Zoetis

DEAR E.W.: Your response is appreciated. Having worked in India, I can attest to the difficulties that can arise due to corruption and disinformation, and sympathize to a degree with your company’s progress there.

You state that your company “advocates a One Health approach to the responsible use of antibiotic medicines across human and veterinary medicine.” But in my professional opinion, you have failed to act responsibly because of the cross-species, farmed-animal-to-human risk of antibiotic-resistant bacterial infections, especially when the antibiotics are sold in high volume to put into farmed-animal feed to promote growth.

When I gave the keynote address in 1994 to the Indian Veterinary Academy, I was shown data at the Veterinary College in Hisar of increasing antibiotic resistance in calves because of the overuse of antibiotics. That was 25 years ago! Enough.

To readers: I must add that India is the second-largest exporter of beef in the world, and also exports many dairy products and other animal products for human consumption in the U.S., Europe and many other countries. This increases the risk of widespread dissemination of “superbugs” -- bacteria from farmed animals resistant to most, if not all, antibiotics -- that cause food poisoning with fatal organ failure.

(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: I am concerned that meat from animals testing positive for Chronic Wasting Disease (CWD) will be recycled into pet food, which could put pets and humans alike at risk.

In Minnesota, the next deer harvest limit has been set by the state’s Department of Natural Resources at a “harvesting” figure of 200,000, and deer hunting is on the decline. So there soon could be a glut of venison on the market -- some of it disease-free, and some not. (No test is failsafe.) Where will all this venison go, and how many deer will avoid being shot, leading to an overpopulation problem?

We must redouble protection and conservation efforts for wolves and other predators because, as documented, wolves and cougars will selectively cull deer with early signs of CWD. Wolves also help manage the overpopulation of species such as white-tailed deer, mule deer and elk.

The coming deer and elk seasons will see rising populations with habitat degradation from overgrazing, because there will likely be fewer hunters and fewer people wanting to consume venison because of the fear that CWD infection could spread to humans.

CWD is caused by the same family of brain-damaging prions that caused mad cow disease in the U.K., which infected over 200 consumers of contaminated beef. Dogs and cats are not immune to these prions, and the high-heat manufacturing processes used in making pet food do little to destroy them. Pet owners could be at risk of feeding infected venison or veal (used in some popular frozen and freeze-dried pet foods) to their dogs and cats. All such pet foods and treats should indicate on the container: “Contains only venison tested negative for Chronic Wasting Disease.”

State and federal authorities need to put wolves and cougars under permanent Endangered Species Act protection, as advocated by several organizations such as the Center for Biological Diversity (biologicaldiversity.org) and Howling for Wolves (howlingforwolves.org). Also, coyote-killing contests and open-season hunting and trapping should be prohibited for reasons well-articulated by Project Coyote (projectcoyote.org).

For more information on CWD, check my website: drfoxonehealth.com.

DEAR DR. FOX: We have adopted an 8-year-old Welsh terrier, Morgan, from a breeder. Morgan was returned to the breeder when her previous owner died.

Our vet gave her a clean bill of health, and we kept her on the kibble and wet food the breeder sent home with her. After about four weeks, she started dragging her butt every once in a while. Our vet recommended Apoquel (3.6 mg). The med worked to cut down on the butt-dragging, but made our Morgan lethargic. The vet then recommended we give her half of a pill. After a week, she still drags her butt occasionally, but seems to have some of her spunk back.

We live in an adult community, no fenced yards, and she gets walked five or six times a day. She is fed morning and evening. We try to keep to a regular routine, but her scooting on the carpet continues, making me think we might have her on the wrong medicine.

The vet says it is the best product for her problem. Any suggestions from you? We are too much in love with Morgan to even think of returning her. -- T.C., West Palm Beach, Florida

DEAR T.C.: I am surprised that the veterinarian prescribed Apoquel for your dog’s condition, as I have had several reports of adverse reactions to this medication.

A safer alternative for many skin conditions is vitamin D supplement and fish oil for omega-3 fatty acids. But in your dog’s case (and I had a wonderful Welsh terrier in my youth), most likely the anal glands are either inflamed, infected or the duct that empties out each anal sac is blocked.

The standard treatment is to gently and firmly squeeze these glands, the pressure usually releasing any duct blockage and giving immediate relief to the dog. If this does not work, then the ducts must be opened up and the sacs irrigated with the dog under light sedation. On occasion, a cancerous growth may be detected or an anal fistula may develop if the glands are not properly seen to.

You may wish to seek a second opinion. In some instances, as with chronic ear infections and skin problems, there is an underlying food allergy. Above all, getting plenty of exercise will help -- your dog must run, ideally with other friendly dogs in a safe area. Regular, firm bowel movements will also help. In the process of being voided, they squeeze the anal sacs, releasing the glandular secretions through the two ducts on each side of the rectum.

(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.)