DEAR DR. FOX: I have a 13-year-old female Chorkiepoo (a Chihuahua-Yorkie-poodle mix). She is spayed and has a heart murmur. She takes furosemide, theophylline and enalapril daily. She mostly eats baked chicken thighs and sometimes canned Purina Beyond dog food.

My dog likes to eat dirt. I have to be careful with commercial potting soil, because she will eat that, too. I asked the veterinary technician if she had ever heard of this, but she hadn't and had no idea why my dog would do this. I heard that people with a condition called "pica" eat things like laundry starch due to a vitamin deficiency.

Any ideas as to what causes this? Is there anything I should do about it? -- P.R., Ste. Genevieve, Missouri

DEAR P.R.: I am surprised that the vet tech with whom you spoke seemed clueless about this common condition in animals -- dogs in particular.

Geophagia (eating dirt) is a normal behavior insofar as animals, including humans, will develop this form of pica when they are anemic or have some digestive problem or other internal issue that may be relieved by consuming some dirt. Some animals will carefully select the kind of dirt, possibly to get an infusion of soil bacteria that can help with digestion or of various minerals that will correct some deficiency or imbalance.

I doubt your dog is being properly nourished, so I would give her digestive enzymes, which a teaspoon of shredded unsweetened pineapple in her food would provide. Also, try a couple of good-quality probiotic capsules; a tablespoon of live, plain organic yogurt or kefir; and a crushed pediatric multivitamin and multimineral tablet. I would also urge you to transition your dog to my home-prepared diet, as posted on my website, DrFoxVet.net, reducing the grain amount by 50 percent.

Most important with the kind of dog you have is good dental care. Chronic oral disease can lead to a variety of health complications if it's not addressed.

DEAR DR. FOX: I have visited your website, and with your academic background, you are surely qualified to speak about environmental and conservation issues. But is this right for your Animal Doctor column, which I thought was an advice column for pet owners? -- R.E., Silver Spring, Maryland

DEAR R.E.: From my perspective, how we treat the natural environment ultimately affects the health and well- being of companion animals as well as our own species. Considering environmental issues and conservation of healthy ecosystems and their restoration and protection -- long ignored by organized medicine -- are now essential aspects of the One Health movement, which is now being embraced by health professionals and long advocated by the veterinary profession.

PETS CAN PREVENT ALLERGIES AND OBESITY IN CHILDREN

According to Canadian researcher H.M. Tin and associates, having one or more mammalian species in the home during and after pregnancy gave infants higher levels of beneficial gut bacteria (Ruminococcus and Oscillospira), which have been linked to lower rates of allergy and obesity in children.

Early-life exposure to household pets has special benefits for infants following caesarean delivery. Additionally, potentially harmful Streptococcaceae, associated with normal vaginal birth, were substantially and significantly reduced by pet exposure.

(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 READERS: The Clean Label Project completed a study of over 900 pet food products from 71 brands. Products were screened for over 130 toxins. See cleanlabelproject.org/product-ratings/pet-food for more information and handy infographics about the results.

In my opinion, the high and concerning levels of lead, cadmium, arsenic, pesticides, nickel, chromium and mercury in some pet foods, and the low levels in others, can be traced to the kinds of animal parts and byproducts being recycled into pet foods.

I am referring to the vast tonnage of factory- and feedlot-raised animals and fish killed and discarded as unfit for human consumption; remains of euthanized horses; and hundreds of thousands of worn-out milk cows, exhausted breeding sows and spent laying hens. The older the animal, the greater the bioaccumulation in the bones, livers and other body parts. By inference, the safest animal parts come from those killed at an early age. This enormous fraction from the animal industries is widely used by the pet-food industry to recycle the low-cost animal remains of a carnivorous culture that still refuses to accept the adverse health and environmental consequences of including beef as a dietary staple.

The Clean Label Project's rating of pet foods, according to pet-food consumer advocate Susan Thixton, raises some suspicion by giving many waste-ingredient pet foods high ratings. Regardless, this is an alarm bell to the pet-food industry and to pet owners and veterinarians. The older the farmed animals are and the higher in the marine food chain the fish are, the more loaded with these and other toxic chemicals they will be. This is a classic example of environmental and food-chain contamination due to our continued, collective sins of omission and commission with regard to social responsibility and effective planetary stewardship.

DEAR DR. FOX: Large dogs have larger brains than small dogs. Are large dogs potentially smarter than small dogs? -- R.P., Washington, D.C.

DEAR R.P.: It would be logical to assume that the bigger the brain, the greater the intelligence, but biologically, it has more to do with the ratio between body size and brain size.

Small dogs have more compact bodies and brains than large dogs and are relatively equal in terms of overall intelligence. Intelligence tests, as I detailed in my book "Superdog," are compounded by animals' motivation and cognitive abilities, attention span and how easily they are distracted.

Domesticated animals generally have smaller brains than their wild counterparts of similar body size. Poor nutrition in early life and prenatally can impair brain development and later cognitive abilities in humans and other animals.

Being raised in physically, emotionally and intellectually stimulating environments may, as biologist Charles Darwin theorized, account for the larger brains seen in some species compared to their domesticated counterparts.

CATS FED DRY FOOD ONLY MAY HAVE ELEVATED DIABETES RISK

A survey of the owners of more than 6,700 cats in Sweden found a higher risk of feline diabetes in cats fed primarily dry food than in cats fed mostly wet food, researchers reported in the Journal of Veterinary Internal Medicine.

Obesity was a key risk factor, but the dry food link to diabetes held among normal-weight cats, and the animals were also more likely to have feline diabetes if they ate a lot of food, primarily stayed indoors and got minimal exercise.

(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 READERS: I sent the following note of support to the growing list of professional scientists and signed a letter to secure the expansion of the Cascade-Siskiyou National Monument, enacted by President Obama on Jan. 12, 2017, and now threatened by the new administration:

“Across the North American continent, this and other bioregions rich in biodiversity need CPR (conservation, protection and restoration). Spiritually, these places are sacred. Scientifically, they are unique habitats rich in animal and plant diversity essential to sustain our need for clean air and water and to help correct and stabilize climate change. Economically, they are a biobank for society, not only for tourism, but also for biologics and microbiota of potential medical, agricultural and other industrial use. Ethically, they are monuments of Earth's creation that society must cherish -- if not for nature's sake, then at least out of enlightened self-interest.

"Environmental CPR of all federal- and state-owned and -leased lands should be a top national security issue and priority. If we do not secure the present, there can be no future.”

I would add that educationally, these natural national monuments are galleries and libraries of inspiration and information. But we will not have a jungle for the last of the tigers or forest for America’s lions a generation from now if planetary CPR is not adopted by every nation-state, kingdom and principality. The health of one affects the health of others. A United Environmental Nations paramilitary force to police and protect the last of the wild from annihilation by the rich and poor alike may be our last hope. Activist organizations like Sea Shepherd and Greenpeace cannot do it alone.

Young children must be informed as to why it is in everyone’s best interests to care for all animals and the environment and what they can do to help. Regrettably, major organizations like the Humane Society of the United States and the American Society for the Prevention of Cruelty to Animals have reportedly pulled out of supporting humane education. But my friend Jane Goodall has set up environmental and humane education programs in many schools around the world (visit rootsandshoots.org for more information), as have others concerned about animals and the natural environment. These include the National Humane Education Society (nhes.org/education-2); my daughter Camilla Fox’s Project Coyote (projectcoyote.org/programs/keeping-it-wild); and one of my former graduate students, Marc Bekoff, (search "Rewilding Our Hearts: Building Pathways of Compassion and Coexistence").

All educators need to engage young minds with these concerns and sow seeds of hope for their own good and for the revolution in planetary consciousness, conscience and conservation. Wisdom speaks when we listen with our hearts and when we empathize with fellow creatures.

DEAR DR. FOX: Recently, my pug started acting strangely: circling, drooling, watery eyes, torticollis; I believe she wasn't seeing correctly, if at all, at times. I took her to the vet.

At first they suspected toxicity of some kind, but all her blood work came back 100 percent normal. They now suspect encephalitis. They started her on prednisone, phenobarbital and doxycycline and released her the same afternoon. I gave her another phenobarbital at around 10 that night, and by 1 a.m., she was acting almost completely normal. She has continued to act normally, aside from the occasional throwing the head back a few times a day.

She was spayed and vaccinated a few days before this all started. I read an article about vaccines possibly triggering this. I was wondering if there was any way other than an MRI to diagnose this disease. She's still acting fairly normal except for being rather lethargic, which is not like her or any 2-year-old pug, for that matter.

I would like to know exactly what was wrong and do whatever I can to help her or prolong her life or make sure she doesn't suffer if she does have this disease. She hasn't had any seizures that I know of. She is so cute and fun and usually full of life. -- M.T., Hobbs, New Mexico

DEAR M.T.: Considering the time between her being vaccinated and the onset of neurological problems, I would suspect she has a vaccinosis, an adverse reaction to whatever vaccines she was given.

It is not advisable to vaccinate an animal who is ill or subjected to the stress of general anesthesia for any major surgery as for spay/neuter. The vaccinations should have been done three to four weeks prior to or after surgery, but for convenience sake, this protocol is not always followed.

The treatment prescribed is satisfactory, but she must be slowly weaned off the prednisone and not suddenly taken off of it. Give her probiotics to help correct any adverse consequences to her gut bacterial flora from the antibiotic. For good measure, I would add a few drops of fish oil to her food and up to a tablespoon daily of coconut oil, which may help stabilize brain function and can help prevent seizures.

NEW YORK CONSIDERING BAN ON FELINE DECLAWING

New York legislators are considering a bill that would make their state the first to ban the declawing of cats. Some countries and a number of U.S. cities ban the procedure, but the New York State Veterinary Medical Society argues declawing must remain a last resort for families that might otherwise take their cat to a shelter.

(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.)