DEAR DR. FOX: Our family dog has bad hips. He is a Lab-golden retriever mix. He is about 9 years old. We don't know much about his early years because he came to live with us later in life.

How do humans know when a dog is in pain? He does not flinch, whine or show any different behavior when I feel his hips or hind legs. He just limps badly. Thank you for your advice. -- Y.P., Houston

DEAR Y.P.: Pain is a highly subjective phenomenon. Some dogs, like some people, have very high pain thresholds and can tolerate injuries that totally incapacitate others.

Your dog's limping is probably a combined protective response to minimize pain and a mechanical limitation in the range of joint mobility due to arthritic changes.

Some dogs show fear or appear depressed and withdrawn when experiencing pain, while others become snappy and show defensive aggressive behavior -- just like some people!

My book, "The Healing Touch for Dogs," and some of the supplements posted on my website, DrFoxVet.com, have helped many dogs with chronic joint issues like your canine companion.

DEAR DR. FOX: Four years ago we adopted two barn kittens (male and female siblings). The female is a healthy, happy cat (though not a lap kitty). The male, Cappy, who was the runt of the litter, appeared healthy until last year, when he was diagnosed with struvite (urinary tract stones).

He had had a couple of occurrences of urinating outside the litter box, but at the time of the diagnosis, he was unable to urinate and spent two days in the emergency animal hospital. Following this, both cats have been exclusively on a special prescription food (canned and dry) on the advice of our vet. Since then, Cappy seems to be fearful of the litter box. He avoids urinating in it as long as possible, then ends up going a huge amount in inappropriate places, most often a throw rug, occasionally on a bed. He will also sometimes defecate outside the box.

Cappy is a very loving cat, and his issues seem unrelated to anything in the household or our routine. Because he's very smart and has a good memory, I think he remembers when using the litter box was painful.

How do we rehabilitate him? And what role does diet play in struvite? His sibling seems happy enough on the current diet and shows no particular interest in other foods, but Cappy clearly would love a different kind of food and misses the treats he can no longer have.

What can you suggest? Thank you. -- T.N., Winston-Salem, North Carolina

DEAR T.N.: First, please check my website for some additional background information on struvite that may be helpful to you.

As an alternative to special manufactured prescription diets, transitioning your cats onto a raw food diet may be the best long-term solution. For details, visit feline-nutrition.org. Check my website for good cat treats. I would advise freeze-dried salmon and meats.

The litter box aversion is common in cats who associate pain from cystitis, blocked anal glands and urinary tract calculi or stones with being in the box. It can be helped through keeping the cat for a few days in the bathroom, for example, with no rugs on the floor and the bath and sink containing an inch or two of water to deter the cat. Provide a new disposable paper litter box or cut-down cardboard box containing a different brand of litter. Give the cat time out for play, feeding and grooming under strict supervision. Give some calming catnip to eat. Clean soiled areas with a product like Miracle Clean enzyme cleaner.

MORE CANINE HEALTH CONCERNS WITH EARLY NEUTERING

The University of California Davis School of Veterinary Medicine has posted a study by veterinarian Benjamin L. Hart and associates on the incidence of various cancers and joint problems in golden retrievers and Labradors in the open-access journal PLOS ONE.

Veterinary hospital records were examined over a 13-year period for the effects of neutering during specified age ranges: before 6 months; during 6 to 11 months; in year 1; or years 2 through 8. The joint disorders examined were hip dysplasia, cranial cruciate ligament tear and elbow dysplasia. The cancers examined were lymphosarcoma, hemangiosarcoma, mast cell tumor and mammary cancer.

In Labrador retrievers, where about 5 percent of gonadally intact males and females had one or more joint disorders, neutering before 6 months doubled the incidence of one or more joint disorders in both sexes. In male and female golden retrievers, with the same 5 percent rate of joint disorders in intact dogs, neutering at less than 6 months increased the incidence of a joint disorder to 4 to 5 times that of intact dogs.

The incidence of one or more cancers in female Labrador retrievers increased slightly above the 3 percent level of intact females with neutering. In contrast, in female golden retrievers, with the same 3 percent rate of one or more cancers in intact females, neutering at all periods through 8 years of age increased the rate of at least one of the cancers by 3 to 4 times. In male golden and Labrador retrievers, neutering had relatively minor effects in increasing the occurrence of cancers. Comparisons of cancers in the two breeds suggest that the occurrence of cancers in female golden retrievers is a reflection of particular vulnerability to gonadal hormone removal.

(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.

Visit Dr. Fox's website at DrFoxVet.com.)

DEAR DR. FOX: My dog was diagnosed with gastritis. What dog food is easily digested? Our vet suggested Hill's Prescription i/d. Do you have a recommendation? -- T.D., Fort Myers, Florida

DEAR T.D.: "Gastritis" is a term describing a condition without an identifying cause -- part of the magic and obfuscation of medical terms derived principally from Latin nouns and adjectives. A costly endoscopic probe might confirm that there is inflammation and possibly erosion and ulceration of the lining of the stomach.

But what is the cause, and what are the signals or symptoms that lead to this diagnostic conclusion? Is the dog vomiting immediately after eating or some time after? Is there blood or yellowish bile in the vomit? Is your dog bloated and belching? It could be acid reflux, which treatment with an antacid should quickly resolve. It could be a gastric or intestinal bacterial or viral infection -- yes, dogs can show such symptoms with salmonella "food poisoning," or have a food allergy.

If there is bile being vomited, there could be a problem with the liver; other causes of vomiting can be associated with conditions such as pancreatic disease and kidney disease -- especially in older dogs.

Simply trying out a special and costly manufactured prescription diet like the one suggested by the veterinarian is one approach. If it works, then problem solved. But again, what is the cause? It could possibly be an ingredient in your dog's regular food or a contaminant or even jerky treats made in China. It is also quite possible that one or more ingredients in the prescription diet are also in your dog's regular food that is responsible for his gastric malady, such as soy, corn or wheat. For details, check out the book that I co-authored with two other veterinarians, "Not Fit for a Dog."

I would give him a regular human Tums antacid before meals and transition him to my home-prepared diet posted on my website DrFoxVet.com. If this dietary change does not improve his condition, then we can rule out diet as a possible factor and consider other possible causes.

Let me know the outcome.

BOOK REVIEW

"Growl: Life Lessons, Hard Truths, and Bold Strategies from an Animal Advocate" by Kim Stallwood.

This poignant book is a memoir filled with humor, humility and self-examination. It is the story of one man's journey as a participant and eventual leader and visionary in bringing social change in our attitudes toward other animals -- nonhumans -- and to how animals are exploited by the global animal industry complex.

This book stands out as an eloquent testimony to personal transformation and provides a scholarly and illuminating history of the animal rights movement in the United States, Europe and the United Kingdom. Stallwood sees compassionate action, honesty, nonviolence and justice as the keys to a successful revolution in our relationships with and treatment of other sentient beings. Conflicts between ideologies of regulation and prohibition of various forms of animal exploitation are best resolved by adopting the moral absolutes of compassion and ethical consistency. He states: "We may not be able to save the world. But we can save the world that is ours."

(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.

Visit Dr. Fox's website at DrFoxVet.com.)

DEAR DR. FOX: After reading your column about what to do when a gentle dog turns aggressive, I decided to share the following saga with you:

My dog, P.D., a 6 1/2-year-old 27-pound neutered mixed-breed dog, had always been a sweetie. When we got him, he was about 10 to 12 weeks old, and had 52 ticks on his little body. As a pup and young dog, topical flea and tick preventatives made him sick, so for the ensuing years we have fed him brewer's yeast and garlic tablets.

He has never had fleas or ticks during that time. However, after applying Frontline Tritak on him -- as required by a boarding kennel -- his behavior suddenly and drastically changed for the worse. The scientific literature search below will explain what we learned and how P.D. returned to his normal, sweet self. Approximately 60 days after the Frontline was discontinued, his aggressive behavior completely stopped. It has not reoccurred.

I'm including part of what I have learned about fipronil, the main active ingredient in Frontline Tritak for dogs.

An Australian study, conducted on behalf of the Australian Pesticides and Veterinary Medicines Authority (APVMA), reports about dogs treated with fipronil: "Neurological clinical signs included ataxia, lethargy and two instances of biting or aggression. Gastrointestinal signs included vomiting and diarrhea."

From the Journal of Pesticide Reform: "fipronil is a relatively new insecticide. It is used in cockroach baits and gels, flea products for pets, ant baits and gels, termite control products, turf and golf course products, and agricultural products. ... In pets, poisoning symptoms include irritation, lethargy, incoordination, and convulsions. ... In tests with laboratory animals, fipronil caused aggressive behavior, damaged kidneys, and 'drastic alterations in thyroid function.' The fipronil-containing product Frontline caused changes in the levels of sex hormones.

"The offspring of laboratory animals exposed to fipronil during pregnancy were smaller than those of unexposed mothers. They also took longer to mature sexually.

"The U.S. Environmental Protection Agency classifies fipronil as a carcinogen because exposure to fipronil caused benign and malignant thyroid tumors in laboratory animals.

"One of fipronil's breakdown products is ten times more toxic than fipronil itself.

"People can be exposed to fipronil when they pet an animal that has received a flea treatment. Fipronil persists for at least 56 days on pets.

"Studies of fipronil contamination of water are limited, but it has been found in rivers near rice fields where it is used in Louisiana. It has also been found in an urban stream in Washington.

"Fipronil is toxic to birds, lizards, fish, crawfish, shrimp, bees, and other animals. Minute concentrations (as low as five parts per trillion) have caused adverse effects."

I believe, and my vet agrees: Fipronil is what caused P.D.'s aggressive behavior. -- B.B., St. Louis

DEAR B.B.: I very much appreciate your observations and possible confirmation of the anti-flea product making your dog become aggressive. The aggression could have been fear-induced because the fipronil made your dog more fearful or anxious. He could engage in so-called defensive fear-biting, with possible involvement of the adrenal glands, or be more irritable and prone to offensive aggression, which could have been due to the drug's effects on the thyroid gland or central nervous system.

Fiprinol is one of a class of chemicals that block nerve conduction (so-called GABA-gated chloride channels) to which many species of insect are highly susceptible. Merck drug company is promoting Bravecto, a new oral drug for dogs that kills fleas and ticks, available only from veterinarians. The company claims that one dose works for 12 weeks, and that it is safe for pregnant and lactating dogs. It reports that the most common adverse reactions recorded in clinical trials were vomiting, decreased appetite, diarrhea, lethargy, polydipsia and flatulence. The active insecticide in this product is an isoxazoline called fluralaner, which is in the same isoxazoline class of insecticides as Fiprinol. The same is true of the drug afoxolaner in Merial's NexGard.

Your research summary findings on Fiprinol, available to anyone with Internet access, support my quest for a sane, safe and effective approach to flea control, as detailed in the review article posted on my website, DrFoxVet.com. Consumers in general, and the pet-owning public in particular, need to be more mindful and questioning rather than trusting what they are told by manufacturers and our government regulatory authorities.

(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.

Visit Dr. Fox's website at DrFoxVet.com.)