DEAR DR. FOX: After a lot of trial and error with bones and chews, I settled on frozen beef marrow bones as a way to keep my dogs' teeth clean and satisfy their urge to chew. Most of the other things I've tried upset their stomachs, had a splinter risk or had something else about them that wasn't good.

I have been buying frozen bones labeled bovine growth hormone- and antibiotic-free from a family-owned pet store, but they just stopped carrying them, and butcher shops are now the only places locally to buy frozen beef marrow bones. Those bones may come from cattle given bovine growth hormone (BGH) and antibiotics. I do not know whether those things would make it to the bones and present a hazard to my dogs.

I found a pet store 60 miles away that carries the BGH- and antibiotic-free frozen bones and ordered enough to last a few months. If butcher shop bones would be safe, that would be cheaper and easier. On the other hand, if there is a possibility of BGH and antibiotics harming my dogs, I will keep making the drive. What do you think about giving dogs bones from BGH- and antibiotic-fed cattle? -- S.H., Minneapolis

DEAR S.H.: In my opinion, there is little or no risk for dogs regarding BGH and antibiotic residues in bones and bone marrow. I appreciate your vigilance, though. The recombinant bovine growth hormone is more an issue in cows' milk -- ditto antibiotics. Anabolic steroids and growth stimulants are the big issue in beef, but the bones are spared -- they accumulate lead and fluoride the longer the animal lives!

I advise allowing dogs to chew only raw (first scalded to kill surface bacteria) beef soup shank bones at least 4 inches long. Short "rings," commonly sold for soup making, can get caught behind dogs' canine teeth. Allow only short periods of chewing or gnawing to avoid cracked teeth, and store the bones in a plastic bag in your refrigerator.

CAT GAMES AND ENVIRONMENTAL ENRICHMENT

You don't have to spend a small fortune on cat toys and furniture to make your cat's life more stimulating.

Cats do like to sleep a lot, but fun for them is watching, hiding, ambushing, chasing and catching -- all elements of hunting behavior -- and engaging in short bursts of physical activity, ideally with another cat or with an understanding caregiver.

Here are a few activities your cat would love:

-- Hiding inside a big cardboard box with a small hole cut in the side, or under a towel.

-- Chasing a fluffy toy or large feather on the end of a string tied to a cane, which you can also poke under a towel or throw rug on the floor.

-- Chasing and catching a spiral of pipe cleaner, which some cats will even retrieve.

Beware of loose, long threads and balls of wool that cats may lick and swallow. The best source of environmental enrichment for a cat is another cat. For more details on cat games and even IQ tests for cats, see my book "Supercat: How to Raise the Perfect Feline Companion."

(Send all mail to animaldocfox@gmail.com or to Dr. Michael Fox in care of Universal Uclick, 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.)

DEAR DR. FOX: My aunt suggested I reach out to you and tell you a little bit about my dog, Jasmine. She's a 6-year-old Cavalier King Charles spaniel mix whom I rescued as a puppy.

In the last few years, she has become obsessed with swimming. She's gone swimming in pools, lakes, ponds and the bay -- she's even jumped in the ponds in Central Park once or twice.

She developed a cough last June. I didn't take her to the vet right away, but when we finally went in July, she was put on an antibiotic. The vet listened to her heart and said all was good. The cough did not go away; in fact, it started to sound worse and almost like when a human has bronchitis, so I took her to a second vet.

The new vet took chest X-rays and told me her heart was "pristine," though he did see a little bronchitis in her lungs. He put her on a different antibiotic, a bronchial dilator and a cough suppressant. We went back a few times and had another set of X-rays done that were sent to a specialist. The specialist suggested a trans-tracheal wash and a bronchoscopy.

I took her for a third opinion. This vet put her on yet another antibiotic and agreed with the trans-tracheal wash. He also wanted to do a sonogram of the heart to rule out a heart issue common in Cavaliers.

I saw the third vet less than a week ago, and her cough has worsened. She is not eating her food, but I believe it has more to do with the antibiotic bothering her stomach. I have decided to stop the antibiotic so that she can get it out of her system, and so that we can get in to have the trans-tracheal wash and sonogram done sooner.

Have you ever heard of a dog having a cough for so long? Do you have any feedback about Jasmine's situation? -- K.G., New York City

DEAR K.G.: Considering her record of loving to get into any kind of water for a swim, your dog is a prime candidate for having a water-associated fungal infection called blastomycosis, which thrives in rich, moist soils around ponds, along waterways and in swamps.

Antibiotics will not eradicate this proliferating fungus from your dog's lungs and possibly other internal organs.

This disease is quite common in many parts of the United States, possibly aggravated by warmer weather and climate change. The fungus can enter the body via a cut on the skin, or more often via inhalation. So have the veterinarian check for this and let me know the outcome.

DEAR DR. FOX: We have a 16-year-old domestic cat whom we have had since he was 6 weeks old. He has been in good health his entire life, although he's a bit overweight at 17 pounds. He sees our vet once a year to be checked over.

We recently noticed that he may not be seeing that well. I noticed when I gave him a treat, he did not seem to be able to see it, but he could smell it. After a couple of weeks, we took him to the vet to check his eyes, and we were told he had a detached retina in one eye, but he was responsive to light.

We had his bloodwork done, and his blood pressure was high (over 200). He was placed on medication (amlodipine). We also checked him for thyroid issues, and he was determined to be borderline. Our vet suggested monitoring it, but no medication was prescribed. After two weeks on amlodipine, we took him back to check his blood pressure, and it was back in the normal range. He is now taking the amlodipine daily.

Unfortunately, his vision does not seem much better. Our vet said his detached retina looked better, and he is still responsive to light. Our vet felt his vision should improve some over time, but said it's difficult to determine how much better (or worse) he sees.

He seems fine and gets around the house without issue, but it does appear that he walks right up to objects before he sees them.

Is there anything else we can do to help with his vision loss? -- G.P., Arlington, Virginia

DEAR G.P.: Your cat's eye problem is all too common in older cats who develop high blood pressure, which, among other things, can lead to detachment of the retinas.

Being overweight or obese results in the production of inflammatory substances in the fat cells, which can cause harm to the kidneys (which play a major role in regulating blood pressure), to the heart and blood vessels, and to the pancreas, leading to secondary cardiac and circulatory issues and diabetes. Further complications can arise with inflammation of the joints, fatty degeneration of the liver and cognitive impairment associated with changes in the brain, which can resemble Alzheimer's disease.

Giving kittens (and their pregnant mothers) biologically appropriate diets rather than high-cereal diets and poor-quality animal protein might prevent these problems. Some fish oil supplement or a couple of canned sardines every other day would help your cat, and I would not change the blood pressure medication other than having the pressure monitored every three to four months.

BETTER HANDLING MEANS BETTER CARE FOR CATS

Many people don't know how to properly and safely restrain terrified cats, which can be a problem with staff in animal shelters and even veterinary hospitals.

I applaud the initiative being taken by the American Association of Feline Practitioners (AAFP) to correct this serious issue and to facilitate more cats having regular wellness examinations. Far too many cats never see a veterinarian until they are seriously, often terminally, ill. To learn more, cat handlers, owners and veterinarians alike should visit AAFP's Feline Friendly Handling Guidelines, available at catvets.com/guidelines/practice-guidelines/handling-guidelines, and the Cat Friendly Practice Program, available at catvets.com/cfp.

(Send all mail to animaldocfox@gmail.com or to Dr. Michael Fox in care of Universal Uclick, 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.)

DEAR DR. FOX: We're having a behavioral problem with our 3-year-old Airedale terrier. She came from a litter in Arkansas when she was just 7 weeks old. She's our third Airedale, so we feel we have a good grip on what their personalities are like. She was raised with love, affection, discipline and a huge 1 1/2-acre yard to enjoy. She's been through obedience training and passed with no problem. (OK, maybe a little stubbornness -- but what Airedale isn't stubborn?)

However, within the past few months, Lola has begun acting afraid or threatened by people she's known all her life -- my son, my mother, my grandchildren and neighbors -- who she's always greeted with nothing but a wagging tail and wet kisses. She'll greet them at the door, but when they try to pet her or say hello, she gives low growls and leaves the room. Her entire demeanor changes. It's especially upsetting to my mother. Lola used to greet her, but now runs and stands behind me or runs to her bed. Sometimes she allows my son to approach her -- he always holds out his hand for her to smell first -- but after a few minutes, she gives that low, guttural growl and backs away.

There are only two things we can think of that may have caused this change: We kenneled her in June of last year, for eight days. She's been kenneled before in the same place without a problem -- there are now new owners, but the previous owners still lived on-site, and Lola was familiar with them. Also, my son has moved back home with his Boston terrier. Both dogs were well acquainted with each other, and interacted so well together that we felt it was OK to have the Boston come live here. We don't see any signs of aggression toward him; it's only certain people Lola has known all her life. I'd appreciate any thoughts you can give us. -- D.L., Asbury Park, New Jersey

DEAR D.L.: Sometimes one never gets to identify the cause of a dog's apparent change in behavior, such as your dog's evident fear of people. I would guess that there was some traumatic event at the boarding facility, and your poor dog has post-traumatic stress disorder.

First, I would have your attending veterinarian do a full physical, checking the eyes for any signs of disease and ruling out hypothyroid disease, which can afflict younger dogs. This affliction is all too prevalent, and it can cause sudden changes in temperament. Check your records regarding your dog's booster vaccinations and anti-flea drugs, especially those given just before boarding. These can cause problems, the latter affecting liver enzymes and brain function. Some dogs get terrified when treated with an external anti-flea drug.

Try supplements such as 5-htp to elevate brain serotonin, plus lightly cooked or raw ground turkey as the main dietary protein. Also, the supplement L-theanine, as in PetzLife's product @Eaze, may be beneficial.

If these measures do not improve her condition in three to four weeks, couple them with a prescription of Xanax (alprazolam) or Valium. Let me know the outcome.

DEAR DR. FOX: I wanted to mention, after reading the article about the limping beagle, the benefits of feeding whole sardines.

My 13-year-old shepherd suffers from arthritis in his knees -- his hips are OK. I have been feeding him five to six whole sardines with daily meals. (I get them online. Shipping is a little costly, but with anything frozen, there is extra cost.) The difference I've seen in the past year has been fantastic. The addition of this natural source of fish oils to his diet has done wonders.

I believe this advice is valuable enough to pass along. Thanks for the great guidance. -- D.C., Winston-Salem, North Carolina

DEAR D.C.: Thanks for sharing your experience of the benefits of fish oils for an arthritic old dog. It's good for similarly afflicted cats and people.

The smaller the fish, the better -- big fish (who eat little fish) concentrate more harmful pollutants, such as mercury, in their tissues, and fat-soluble pesticides and other chemical contaminants of human industry, notably dioxins, are in their oils. Cheap fish oils, especially from farmed rather than wild salmon, are potentially more harmful than beneficial as a food supplement for humans and other animals.

(Send all mail to animaldocfox@gmail.com or to Dr. Michael Fox in care of Universal Uclick, 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.)