DEAR DR. FOX: I'm writing in response to a letter by F.A.V. of Honolulu, who had a 13-pound, 6-year-old Brussels griffon with oxalate crystals in his bladder and urethra. The dog had to have surgery every two years.

Three years ago, our 9-year-old female Jack Russell terrier had the same problem, but only one surgery. After surgery, our vet prescribed Royal Canin Urinary SO dog food. This has solved the problem and keeps her urine clear. She has not had any problems since going on this prescription food. I give her both dry and canned servings of it.

This prescribed dog food might be something that F.A.V. may want to explore as an option. -- N.H., Middleburg, Va.

DEAR N.H.: There is a confounding combination of genetics affecting dogs' metabolism and kidney function. The artificial acidification of some manufactured dog foods, done to help prevent struvite crystal formation, may make dogs prone to developing oxalate crystals in their lower urinary tracts. High dietary calcium and low fluid intake when a dog is fed dry food only may also be contributing factors.

The best prevention is a home-prepared diet, as I offer on my website, DrFoxVet.com. Alternatives to the costly, and for some dogs, unpalatable, prescribed diet foods are available at secure.balanceit.com.

DEAR DR. FOX: What is your opinion on clumping litter and cat eye problems? Thank you. -- D.D., Naples, Fla.

DEAR D.D.: I have received several letters questioning the safety of clumping litter for cats. The most common concern is about them swallowing small particles of the litter that may adhere to their paws or fur and the risk of intestinal blockage. I have found no clinical evidence to support this concern, and I regard its perpetuation as an unfounded fear.

I use World's Best Cat Litter for my two cats, and I believe that it is one of the best. It has very little dust compared to the various clay-based cat litters. Your cat should have no problems with this brand, unless it is allergic to corn.

Any cat with eye issues may experience eye irritation and develop litter box aversion if his box has an odor-trapping cover. Covered cat boxes create an ammoniated and dusty interior space for cats, and I advise against using them.

DEAR DR. FOX: For years, St. Louis has displayed dogs in the dreadful Beggin' Barkus Pet Parade, an annual February fundraiser for the Open Door Animal Sanctuary, a no-kill shelter.

I see no humor in humiliating our furry friends and spraying them with harmful chemicals (paint, etc.). In my opinion, this is animal abuse.

Could you please address this in your column? I find it very upsetting that it seems to become more extreme every year. -- H.S., St. Louis

DEAR H.S.: Having walked our dogs in fundraising and July 4 celebration parades, I can attest to the fact that most temperamentally stable dogs really enjoy the experience. Many seem to enjoy wearing various costumes (like children, they appreciate the extra attention they receive). But I do not like the idea of sprayed-on dyes to color their coats.

The most important considerations are noise and weather. People blowing antique car horns or playing instruments in marching bands should be separated from the dog part of any community parade. I would like to see an end to all fireworks.

In hot, sunny weather, very hot pavements must be avoided and dogs should wear protective boots -- the same goes for very cold weather. Drinking water and evaporative-cooling wet coats can provide comfort for dogs in summer, and umbrellas give shade. Where there is flexibility in terms of setting a fundraising walk, the mild months of spring and fall are wise, humane choices.

Speaking of St. Louis -- a city where I was a psychology professor at Washington University during the 1970s -- I will be giving a fundraising talk for Stray Rescue on May 5, titled "The Great Healing: Animal Feelings and Feeling for Animals." For more details, email jenn@strayrescue.org. For tickets, visit strayrescue.org/UrbanWanderersTailEnd2013.

(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: I just read the letter sent to you by a reader called M.D. expressing his opinion on letting domestic cats roam free. The ignorance and stupidity he showed in his attack on you spiked my blood pressure!

First of all, my wife and I enjoy sitting on our front porch in the summer. Many times, we watch the local free-roaming domestic cats stalk and attempt to kill fledgling robins while both parents squawk and do what little they can do to protect the baby bird. Whenever I can, I intervene and run the cat off. These cats also defecate and urinate around our shrubbery. The smell is terrible.

But that is not why I'm writing. I had an experience a few summers ago that I will never forget:

I was working in the yard and had left the outbuilding door open. When I finished, I closed and locked the door. A few days later, I entered the outbuilding for something, and I noticed a few items had fallen from the shelves. Frankly, I was hesitant about entering the building because I thought the upset items might have been caused by a rat or some other animal with an attitude -- I've been down that road, and it isn't a pleasant trip.

The third time I entered the building, I found a dead cat on the floor. The cat had apparently entered the outbuilding to look around and hid when I came back to put my tools away. The cat was emaciated, with one paw up through its collar. For some reason, he had gotten his leg through the collar past his elbow and couldn't get it back out.

There is no doubt in my mind that this poor cat suffered almost a week without water or food and with temperatures in the building well over 100 degrees. I still get upset now, three years later, when I think of the suffering and horrible death this cat endured. I think M.D. lives in some kind of fantasy world of his own design. -- A.T.P, Keyser, W.Va.

DEAR A.T.P.: I hope your letter will convince readers who still let their cats roam free to get them used to life indoors and time outdoors only in an enclosed structure or gazebo.

There are breakaway safety collars for dogs and cats who may get out. If the collar gets caught on a branch or fence, or even another animal's paw or jaw during a fight, it can unsnap. It's also a good idea to get microchip IDs injected under the skin of your pet.

MORE RECALLS OF PET FOODS AND DOG TREATS

I have never seen such a spate of recalls:

-- Natura has expanded the recall of their Innova, Evo, California Natural and Healthwise brands of cat and dog foods because of potential salmonella bacterial contamination.

-- Barf Co. has recalled their Barf Lamb and Barf Combo patties because of possible contamination of salmonella.

-- Growth of mold on Iams Shakeables Turkey and Shakeables Lamb dog treats has lead the parent company, Proctor & Gamble, to launch a recall.

For details on the lot numbers on all the products identified for recall, visit DrFoxVet.com. While dog and cat owners may be relieved to know of these recall initiatives, in part instigated at public expense by state and federal health authorities that are now testing pet food products on a more routine basis, the fact remains that our food chain seems to be increasingly unsafe. For further insights and what you can do, check out the book on this topic that I co-authored with two other veterinarians, "Not Fit for a Dog: The Truth About Manufactured Cat and Dog Foods."

(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: I adopted two cats from a shelter in July. The vet there gave them a clean bill of health. Later, I took them to my own vet and was told the same.

Over time, I noticed that Jay's "third eyelid" showed more frequently than on any of my previous cats. I went to the Internet and saw that it was a sign of all kinds of problems. I emailed the vet's office and was told to bring her in. I have not done so yet because I don't see it as frequently and she shows no other symptoms. My concern is that she has only one good eye, so I would hate for her to lose the other.

Can I safely wait to take her in? -- S.M.Z., Poughkeepsie, N.Y.

DEAR S.M.Z.: If I read your letter correctly, you adopted a one-eyed cat from the shelter. I applaud your choice, since most people are repulsed at the sight of "defective" animals. Those who have suffered and had to have a leg amputated or eye removed surely deserve to experience the affection and security of a loving home.

It may be less traumatic for your cat to have a veterinarian come and examine her in your home. Many animal doctors do house calls.

The good eye should be examined, and your cat should be given a full physical. The eye could be affected by a condition called sympathetic opthalmia, triggered by the optic nerve stump in the empty eye socket. This may not be harmful, but an eye examination is advisable since, as you found on the Internet, extrusion of the third eyelid (or nictitating membrane) could be a signal of possible ocular disease.

DEAR DR. FOX: My son and his family have a great and mild-mannered border terrier who is about 6 years old. My son works out of the home, so, for the most part, he is with the dog most of the time.

During the day, the dog is fine. But in the evening, he becomes anxious and hyper. They try playing with him as a distraction, but it takes a while for him to settle down.

Is this something common in his breed? Any suggestions would be appreciated. This behavior began just recently. -- J.H., Silver Spring, Md.

DEAR J.H.: I appreciate your concern for your son's family dog. I know the breed -- border terriers are great! The dog's evening anxiety could have a physical or psychological cause.

He may have retinal degeneration or some similar eye problem -- the first symptom is night blindness, which could be causing his behavioral change. A veterinary examination is called for if this is suspected.

Psychological causes include the fear of being abandoned when the family goes out for the evening, some element of post-traumatic stress disorder after an upsetting event one evening during a walk or a family argument, or high-frequency sound from the TV or other entertainment unit upsetting the dog.

Some detective work and a change in the evening routine may help.

DEAR DR. FOX: I got two beautiful 4-month-old kittens in August 2011 from a Humane Society foster home (they were from different litters). About two months later, one of the cats, Brody, developed sores on the back of his legs and a swollen lower lip.

I took him to our vet, who diagnosed him as having eosinophilic granuloma. Brody was given a steroid shot to suppress the outbreak. The vet then prescribed 5 milligrams of prednisolone twice a day for two weeks with instructions to wean Brody off of it slowly. Since this is an autoimmune disorder, I was instructed to take him off store-bought food, and I switched him to Hill's Prescription Diet z/d canned and dry food, which is quite costly.

The research I've done indicates that a majority of kittens outgrow this condition, but the prognosis is poor for cats who don't outgrow it. Unfortunately, every time I try to wean Brody down to a lower dosage, the condition reappears. I know that being on a steady dose of steroids, even a low dosage, can cause other problems down the line.

Do you have any suggestions? Thanks very much. -- L.S., Kansas City, Mo.

DEAR L.S.: My first concern is that there may be some other underlying health problem such as round worms or herpes virus that is impairing your cat's immune system.

The prednisolone treatment suppresses the symptoms, but won't cure the condition. Explore with your veterinarian putting your cat on a course of doxycycline oral antibiotics, which can be of benefit in treating cats' suffering from eosinophilic granulomatosis. Your cat should be weaned off the prednisolone and given no further vaccinations. Local applications of hydrosols of frankincense, myrrh and lavender may prove beneficial thanks to the soothing, anti-inflammatory properties of these plant extracts. Adding a few drops of fish oil to his food may help promote healing and reduce inflammation.

(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.)