DEAR READERS: Manufactured since the 1940s by DuPont, 3M and other companies, PFAS (per- and polyfluoroalkyl substances) are used to make thousands of products resistant to stains, heat and water. They are also used in firefighting foams. Unfortunately, they have been linked to high cholesterol, ulcerative colitis, various cancers, thyroid disease and other health problems in the human population since they contaminate our environment, food and water.

The nonprofit Environmental Working Group calls these “forever chemicals” because they do not break down in nature and they accumulate in our bodies. According to a study by the EWG and Northeastern University’s Social Science Environmental Health Research Institute, more than 100 million Americans in 1,400 communities have been exposed to drinking water tainted with PFAS.

Along with flame-retardant PBDEs (polybrominated diphenyl ethers), especially in furniture upholstery and carpets, PFAS have been found at high levels in cats suffering from hyperthyroid disease, an all-too-common affliction of older cats. Indeed, our animal companions serve as bio-sentinels of human exposure to such chemicals. The impacts on aquatic and terrestrial wildlife are probably very considerable.

The U.S. House of Representatives passed a sweeping bill Jan. 10 to address this national pollution health crisis, because the government’s Environmental Protection Agency failed to meet a February 2019 deadline to come up with an action plan to address this issue. But even if the bill were to pass the Senate, the White House indicates Trump would veto the bill over ”litigation risk” and “unwarranted” cost concerns (Minneapolis Star Tribune, Jan. 11)

It is notable that scientists have recently linked high levels of PBDEs with lower IQs in American children and it is likely that PFAS are also a factor. The investigators analyzed PBDE, organophosphate, lead and methylmercury exposures in blood samples from women of childbearing age and from 5-year-olds. Everyday contact with these substances during the 16-year study resulted in roughly 1.2 million children affected with some form of intellectual disability.

They estimate such childhood exposure cost the nation $7.5 trillion in lost economic productivity and other societal costs.

”Although people argue against costly regulations, unrestricted use of these chemicals is far more expensive in the long run, with American children bearing the largest burden,” says senior study author Leonardo Trasande, MD, MPP, Professor of Pediatrics at NYU Langone Health.

Published Jan. 14 in the journal Molecular and Cellular Endocrinology, the new study is the only long-term neurological and economic investigation of its kind, the authors say.

DEAR DR. FOX: Thank you for your article about the horrific decision of the Westminster dog show to award an inbred English bulldog with Best in Show.

I am an avid dog rescuer, and delete friends when they buy French bulldogs, Labradoodles etc. My adopted dogs are my life. I’m a semi-pro paddleboarder, and I paddleboard with my rescues and use it to bond with them. They learn to trust me early on, and they always love it. I also pick the neediest, most decrepit ones that no one else wants. I currently have a 150-pound mix rescued from a horrific breeding situation and an 18-year-old pit bull I bought from a homeless man in New York.

My question to you is: Do you think it would ever be possible, in any country, to completely ban the breeding of dogs until the shelter population is culled down? Maybe just for certain breeds that are so horribly overbred?

Anyway, being on the water frequently, I know this administration has wreaked havoc on the water. Locally, jellyfish and nitrates are up exponentially -- I see big jellyfish now, alien-looking red ones with tentacles.

It ain’t right! So, I appreciate your work in trying to enlighten us all. -- J.L., Pine Beach, New Jersey

DEAR J.L.: It is a challenge on many fronts to change public taste, especially when it comes to the issue of various breeds of dogs and cats who suffer from genetic deformities, endure a lower quality of life and mean considerable expense for veterinary treatment for a variety of health issues.

In the U.K., the British Veterinary Association is confronting drug, pet food and other companies about their use of certain breeds with brachycephaly, and related health issues, to advertise products on TV and other media. The group is also discouraging use of these breeds in movies and television shows.

Breed popularity can also be reduced through public education. Indeed, in many communities and circles here in the U.S., it is now considered “cool” to take in a rescued dog from the local shelter rather than purchase a particular breed or “designer” variety. Also, in some communities, pet stores are prohibited from selling pups from commercial puppy mill breeders, and can only sell dogs and puppies who come from local animal shelters.

As for your experience paddleboarding and seeing jellyfish everywhere, this is a sign of ecological dysbiosis (imbalance) in the marine ecosystem, which is spreading globally. For more details, see my articles about the hazards of plastics and other chemical contaminants in the marine environment posted on my website, drfoxonehealth.com.

The collapse of ocean fisheries harming many communities worldwide, in large part due to pollution and overfishing, is a tragedy that could have been avoided by better stewardship. Also harmed are whales, dolphins and other marine mammals, and birds, whose numbers are plummeting from the consequences of malnutrition, starvation and pollution.

(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: According to an October report, about 23% of Americans polled by the Consumer Technology Association said they planned to purchase pet-related technology as a holiday gift. And the number of pet-tech products shipped during the fourth quarter of last year was expected to be 60% higher than in the fourth quarter of 2018. Products include automatic food or water dispensers, automatic pet doors, and pet monitoring systems. (Las Vegas Review-Journal, Dec. 31)

A cat litter box on display at a recent electronics show is equipped with a video camera, connects to voice-enabled assistants and uses artificial intelligence to analyze the cat’s waste for signs of illness. (The Verge, Jan. 7)

The more such electronic devices are put into the home environment -- and monitors put on companion animals’ necks, along with remote sensors, training devices and invisible fence shock-collars -- the more health and behavioral problems I predict. And worse, equipment failures could put animals at risk.

There is no substitute for attentive human care. Electropollution in the home environment is a growing concern, with both dogs and humans developing adverse reactions -- for instance, to “smart” water meters. As for “smart” diapers put on infants, we need only look at the rising incidence of brain tumors in young people, and other neurological disorders in the population, to be more cautious about buying into new electronic products. The health and environmental safety of such products must be questioned by all involved.

Microchipping animals for identification is as far as I would go with long-term application of such technology. Short-term applications of radio-collars for animal health and wildlife research purposes is carefully monitored by experienced veterinary and other practitioners.

DEAR DR. FOX: I have a 4-year-old pit bull, weighing 60 pounds. She is on Trifexis to control fleas, and has been acting lethargic through the day.

She also has grain allergies, and is fed grain-free salmon or bison and Hill’s Science Diet for sensitive skin.

Can I feed her raw meat? Will the dog be inclined to go after cows and chickens after tasting that food? -- P.G., Trenton, New Jersey

DEAR P.G.: I would take your dog off the Trifexis at once. Her lethargy may well be associated with this insecticidal cocktail of poisons.

Here are some of the side effects posted by the manufacturer:

“As with all medicines, sometimes side effects may occur. In some cases, dogs vomited after receiving Trifexis (spinosad plus milbemycin oxime). If vomiting occurs within an hour of administration, re-dose with another full dose. During field studies, no severe or prolonged vomiting occurred. Additional adverse reactions observed in the clinical studies were itching, decreased activity, diarrhea, inflammation of the skin, redness of the skin, decreased appetite and redness of the ear.” All reactions were regarded as mild, according to the statement from trifexis.com.

Transition your dog onto my home-prepared diet and I think you will see a significant improvement. This is posted on my website, drfoxonehelath.com.

Well-formulated raw meat diets are good for dogs, and no, they do not make the dogs want to go out and kill the live animals whose flesh they have eaten raw.

(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 cats have been scratching themselves continually for the last few weeks. I thought it was from fleas, so I purchased flea medication and applied it to their necks. It didn’t do anything for them. I bought flea and tick traps, but caught nothing.

I read your recent column about itchiness possibly being food-related, and I will try your recipe for a feeding alternative. They currently eat Fancy Feast canned, Meow Mix Tender Favorites, and Blue Buffalo Adult Salmon and Brown Rice.

I hope your recipe will help them. -- Diane S., Lake Worth Beach, Florida

DEAR D.S.: When two or more animals in the same household develop the same symptoms, you have a provisional diagnosis of a shared condition. The possibility of fleas should be determined using a flea comb: check the fur for flea poop, which looks like shiny black particles of coal dust. Put some of these particles on a wet piece of white paper, and if they make a reddish-brown stain, you have the answer: digested cat blood in the flea poop.

Too many people apply anti-flea pesticides to their cats and dogs as soon as they see them scratching. That can make the animals ill, or even kill them, and may not have been warranted in the first place. There are other reasons why animals start to scratch themselves and lick and groom excessively.

Any new floor and upholstery cleaners used in the household, or air fresheners/deodorizers, could trigger such behavior in your cats -- cats are highly chemical-sensitive. A new carpet can release irritating volatile chemicals; carpets have caused cats to begin to self-mutilate from excessive scratching and self-grooming.

You may be correct that both cats have a food allergy or intolerance. You need to be sure that the problem is not the fish or beef, especially, in the canned food you are feeding to them: Many cats are allergic to beef and do not like fish. Also, beware of the phrase “meat byproducts” on the label, as that can mean other animal protein from pigs and rendered remains of dead, diseased and dying animals were recycled into the cat food.

Try my home-prepared cat food diet or freeze-dried cat foods from The Honest Kitchen. Cats are generally finicky eaters, so it is important to transition them gradually onto a new diet.

I presume you are a responsible cat caregiver, and do not allow your cats to roam free outdoors, where they could pick up heaven-knows-what -- especially allergy-triggering pollens -- and suffer the consequences.

DEAR DR. FOX: Errors of fact abound in the letter from “R.Q., Tulsa” published in one of your recent columns.

Sadly, your reply was also riddled with counterfactual assertions. You missed a golden opportunity to reassure your readers with facts and give perspective on life with some common sense.

I recommend to you Hans Rosling’s book “Factfulness,” which documents, with government data, a steady improvement in the state of the world for the last 200 years. I also recommend Matt Ridley of The Rational Optimist, whose column “We’ve Just Had the Best Decade in Human History. Seriously” was just published on Dec. 21, 2019.

R.Q.’s despair about the “extinction crisis worldwide” is simply not in the real-world data. Estimates on the number of species worldwide range from 8 to 10 million, with thousands of new species discovered yearly. The International Union for Conservation of Nature has documented the extinction of about 560 species. Most of those actual extinctions were in the 16th through the 19th centuries, on islands newly visited by hungry sailors with dogs, carried by ships with rats.

This is not to say that overfishing is not a problem. It deserves attention and careful stewardship, but not despair.

Likewise with all the problems mentioned in R.Q.’s letter and your response: All of them deserve care and attention. None of them warrant panic and despair.

Rosling’s excellent book documents the phenomenal improvements in air quality over the last 200 years. I can testify to that myself. The pea-soup fogs (actually coal-smoke smog) of London, the foul air of the Kanawha Valley in West Virginia, the biting industrial atmosphere I knew in St. Louis in the 1960s -- all gone. The snow in Pittsburgh is white in winter, not black with cinders, as it was in the 1940s. Likewise, the nation has the cleanest water since the Industrial Revolution. Water-borne diseases such as typhus, cholera, etc. are horror stories from the past, not present threats. And to describe the minor policy tweaks of the present political administration to reduce the EPA’s overreach as “gutting the Environmental Protection Agency” is counterfactual hyperbole.

You close by advocating “principles of planetary and cultural CPR.” CPR is given to people in cardiac arrest who are about to die. The planet is not about to die. To perform CPR on a patient who is not in cardiac arrest is medical malpractice. To advocate “planetary CPR” on a beautiful world as healthy as ours is shameful panic-mongering. -- D.R.McI., Tulsa, Oklahoma

DEAR D.R.McI.: I had to shorten your communication for the column.

Unfortunately, my own knowledge base, drawn from reading the scientific literature in several areas -- from biophysics and biodiversity to evaluations of the release of pesticides, GMOs, industrial pollutants, plastics and, more recently, electropollution -- does not make me feel as good as you do about the rapidly deteriorating state of planet Earth.

To respond to two of your points:

The snow in Pittsburgh may be white now, but now -- as recently discovered as far away as the Arctic -- snow contains microplastics. As for the “pea-soup fogs of London,” which I experienced as a student: London and other cities now have lung-damaging microparticulate matter in the air and increasing intensities of electro-smog, which will intensify with 5G telecommunications, Amazon’s drone deliveries, self-driving “smart cars” and public surveillance systems.

I am neither a “rational optimist” nor a pessimist, but a realist -- yes, an apocalyptarian, if you wish! Nowhere in your deliberated communication, which I appreciate, did you mention the core issue of human overpopulation and, where there is more income, overconsumption. My often-used term “planetary and cultural CPR” refers to Conservation, Protection and Restoration: actions long overdue to save biological and cultural diversity in this beautiful world.

(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.)