DEAR READERS: On July 10, Merck Animal Health said that the U.S. Food and Drug Administration approved its once-yearly injectable product to treat and protect dogs older than 6 months of age from fleas and ticks. Bravecto Quantum is expected to be available soon nationwide. The product was first approved in Australia and New Zealand in 2023, then by the European Union in 2024, and is now approved in more than 50 countries.

Bravecto Quantum’s active ingredient is fluralaner, which works by targeting the nervous systems of insects and parasites, leading to their paralysis and death. Common adverse reactions in field studies include lethargy, decreased appetite, vomiting, diarrhea, elevated liver enzymes and itching.

Fluralaner is part of the isoxazoline class of antiparasitic drugs, a class linked to adverse neurological reactions like tremors, loss of coordination and seizures. Caution is advised for dogs with a history of seizures or neurologic disorders.

There is a growing body of evidence suggesting this class of insecticides may impact the canine gut microbiome, potentially leading to dysbiosis. In some cases, dysbiosis may contribute to the development of food allergies and skin conditions. Research indicates that isoxazolines might reduce the beneficial part of the gut microbiome by 50%, creating an environment where harmful bacteria can thrive.

My concern is that this insecticide only kills fleas, ticks and mosquitos after they have bitten a dog, cat or another treated animal, and therefore does not stop infective insects from transmitting various diseases and triggering allergic reactions.

I use Earth Animal’s Flea and Tick Herbal Bug Spray on my dog -- and on myself -- when we go for walks in our bug-infested woods. It works, and is nontoxic! Earth Animal also has this product as a spot-on, as well as a Daily Internal Powder Supplement to put in pets’ food. The supplement includes ingredients that I have long touted as helpful in repelling biting insects. Such natural products do not contaminate the environment, which is a rising concern when dogs treated with insecticides contaminate lakes and rivers when they go for a dip.

Some insecticides, along with glyphosate-contaminated pet foods, can trigger sudden aggression in dogs. This may be a consequence of the depletion of the "bonding hormone," oxytocin (as detailed in my post here: drfoxonehealth.com/post/antiparasitic-products-and-the-gut-microbiome). From a One Health perspective, I think it would be advisable to check oxytocin levels in persons engaging in acts of violence. Of course, there are multiple factors in the etiology of human aggression, but oxytocin deficiency and its role what I call the empathy deficit disorder should be considered. (For more, see the study "Neurobiology of aggression and violence" by Larry Siever, published in the American Journal of Psychiatry in 2008.)

On July 17, the FDA approved a liquid form of this insecticide -- Exzolt, a fluralaner oral solution -- to be given in the drinking water of poultry for the treatment and control of northern fowl mites in laying hens and replacement chickens.

"In addition to establishing that fluralaner is safe and effective in laying hens and replacement chickens," reads a statement from the agency, "the FDA determined that residues in edible tissues or eggs from birds treated with Exzolt will not represent a public health concern when the product is used according to the label."

The overcrowding of birds in commercial factory farms creates ideal conditions for this mite to spread and infest the entire flock. Less crowding, and the provision of dust-bathing areas that include food-grade diatomaceous earth, would probably prevent the spread of these mites as effectively as insecticides, and with zero risk.

Many avian species regularly dust-bathe, and some engage in reciprocal preening to rid themselves of various external parasites. For details, go to bhwt.org.uk/blog/health-welfare/chicken-dust-bath.

(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: You will be interested in a recent article in The New York Times by Rachel Nuwer: "We Love Our Dogs and Cats. But Are They Bad for the Environment?" (Link: nytimes.com/2025/07/29/climate/dogs-cats-pets-environment-impact.html.)

Here is a sample passage:

"Gregory Okin, a geographer at the University of California, Los Angeles, calculated in a 2017 study that the estimated 163 million cats and dogs in the United States consume a whopping quarter of the country’s animal-derived calories. 'If U.S. dogs and cats were their own country, they would rank fifth in global meat consumption,' he said in an interview. ...

"To reduce these effects, Dr. Okin recommends pet food brands that meet dietary requirements but contain less animal-derived protein."

What is your opinion? -- P.S., San Francisco

DEAR P.S.: Thanks for alerting me to this significant article. Dogs and cats are part of the recycling of the remains of farmed animals and seafoods from the vast tonnage most people consume, contributing to the loss of biodiversity and associated climate change. Less animal-derived protein in pet foods will mean less human consumption at top of the food chain.

We also must consider the impact on biodiversity of free-roaming cats hunting and killing wildlife, and of dogs and cats spreading diseases to indigenous carnivores. The latter puts these predators at risk, many of which are also being killed by farmers and ranchers.

The health benefits of vegan and vegetarian diets have been well documented. Many also choose these diets on the grounds of compassion for animals, and in favor of reducing their carbon footprint.

Another dietary health consideration: A new study suggests that animal fats might drive the growth of certain cancer cells more than vegetable oils do. Melanoma growth was accelerated in mice fed lard, beef tallow or butter, but not in mice fed coconut oil, palm oil or olive oil, reads the study.

“Our study provides an important proof of principle that dietary fat can regulate immune function in obesity-related cancers,” write the authors. While this is "a significant conceptual development," they write, "we cannot draw conclusions about how changes in human consumption of a particular fat, such as palm oil, will impact immune function or tumor growth." (See the full study: "The source of dietary fat influences anti-tumour immunity in obese mice" by Britta Kunkemoeller et al., published in Nature Metabolism in 2025.)

INTEGRATED CLINIC EXPANDS ACCESS TO CARE

The Seattle One Health Clinic, which offers free medical and veterinary care in the same facility, increased access to preventative care as well as housing and services for young homeless people and their pets, researchers reported in the Journal of Primary Care and Community Health. More than two-thirds of health clinic visits were initially for veterinary care, and nearly 80% of all visits resulted in human health care. (Full story: University of Washington, Seattle, Aug. 4)

This is the essence of compassion-in-action that all communities can emulate for the common good.

(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: The spirits of animals -- whether wild, captive, tamed or domesticated -- have only recently been considered by, or factored into, conventional veterinary medicine. The same is true for the spirits of humans.

Spiritual well-being is evident in animals' vitality and responsiveness, including curiosity and playfulness; in humans, it is expressed in various forms of creativity. An environment of security and trust is essential, along with good nutrition -- all integral elements of good nurturing, which complements nature: the innate spirit or psyche of every sentient being.

Just as nature and nurture are interwoven, so are temperament and personality. Temperament is innate, genetically “hard-wired,” to a degree, while personality is formed from life situations and can change over time. The “personhood” of nonhuman animals has yet to be fully recognized by society at large. Doing so might redeem us for causing the extinction, suffering and death of trillions of animals throughout human history. It might also inspire us spiritually to better respect and care for each other in a boundless circle of compassion. After all, anthropocentrism is a self-terminating disease!

There are spiritual wounds that can challenge animals and humans alike, especially in animals that have been abused and neglected, like the dispirited creatures held captive in zoos and circuses. Like people, many animals can suffer from post-traumatic stress, depression, fear and anxiety, along with behavioral abnormalities such as compulsive disorders, self-mutilation and other afflictions of the spirit. They may also benefit from psychotropic and psychotherapeutic interventions, including behavior modification and what I call the healing touch (as per my books on massage therapy, “The Healing Touch for Dogs” and “The Healing Touch for Cats”).

This spiritual ice age of rational materialism and objectification will never melt away without our reverential respect for all life and compassion-in-action when called for. The embrace of loving-kindness can fill the void of fear and suffering with spiritual enlightenment.

Our destruction of nature is the theological equivalent of our separation from God. German mystic and philosopher Meister Eckhart said, “Every creature is full of God.” Pope Francis stated, “There will be no new relationship with nature without a new human being, and it is by healing the human heart that one can hope to heal the world from its social and environmental unrest ... One thing about ecological conversion is that it makes us see the general harmony, the correlation of everything: everything is connected; everything is related.”

A “new human being” is evolving from the egocentric to the ecocentric, as we face the realities of climate change and develop a new language that speaks to all sentient beings from the empathic core of reverential respect and understanding. May a passion for justice and compassionate action lead the way.

Without effective family planning and lack of infrastructure and basic resources, millions of people around the world are dying prematurely. An estimated 733 million people -- roughly 1 in 11 people on Earth -- face chronic hunger, meaning they lack consistent access to sufficient, safe, and nutritious food. The situation has worsened in recent years, according to Concern Worldwide U.S. (ConcernUSA.org).

Countries the world over are already struggling to adapt to the ravages of climate change (floods, fires, droughts, etc.). This will only worsen if political leaders give tax incentives to increase birth rates rather than accepting immigrants, and continue to subsidize the burning of fossil fuels while blocking green energy initiatives.

Hyperinflation and hyperconsumerism go hand in hand as our carbon footprint stamps out life on planet Earth. The politics of planetary CPR -- conservation, protection and restoration -- should be center stage, not just a cry in the wilderness of a ravaged planet. For details and some solutions, see my book “One Health: Veterinary, Ethical and Veterinary Perspectives.”

(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.)