Dog's loose, broken nails may be sign of infection

6/1/2008

Dear Dr. Thompson: I have a 9-year-old shepherd mix that has been losing his nails. He doesn't appear to be chewing them off, but they seem to be coming loose and falling off at times. I had to take him into his vet four weeks ago for one nail that came off, to cut back and cauterize, only to find he actually had a second nail that needed to be done. Now I see he has one more that's fallen off and one that's loose. He is primarily indoors, doesn't dig in the yard, and is otherwise very healthy. Is there any explanation as to what may be causing this?

ANSWER: A dog breaking off the occasional nail is not unusual, but the frequency that you are describing suggests an underlying problem. Healthy nails are typically very durable and resistant to damage. However, if an infection or inflammatory process has taken hold, the toenail may become brittle and prone to falling off.

A nail-bed infection can be hard to diagnose. A scraping near the cuticle is examined microscopically to evaluate if a bacterial or yeast infection is festering. Fungal cultures may be taken. Chronic infections can take weeks to clear with oral medications and healthy new nails take months to grow, so it is important to be patient.

Some dogs can develop an immune mediated inflammatory process at the junction of the nail and tissue of the nail bed called symmetrical lupoid onchodystrophy. This mouthful of a disease results in unhealthy nails that fall off periodically. Certain breeds are more commonly affected, including Rottweilers, but any breed can be afflicted. Fortunately for many dogs, this does not appear to be a painful condition.

A definite diagnosis is tricky because a biopsy of that part of the body is not easily obtained. However, many dogs respond to fatty-acid supplements. In more extensive cases, the antibiotic tetracycline and a B-vitamin called niacinamide can reduce the inflammation, and eventually healthier nails will re-grow. For severely affected dogs, immunosuppressive drugs may be needed, but that is exceedingly rare.

Dear Dr. Thompson: I recently read that I shouldn't allow my dog to lick my face because he can carry diseases that will make me very ill. Is there any truth to that notion?

ANSWER: There are some diseases that your pets can pass along to you, called zoonotic infections. Certain parasites and some other infections may be transmitted between us, but you can take steps to ensure a happy, healthy relationship with your pet.

One of the main reasons for your dog or cat's annual check-up is to ensure that he may not be harboring any of these creatures. We also vaccinate our pets for some of the diseases that can infect people, like rabies or leptospirosis, to protect humans and pets alike.

People with weakened immune systems should have a detailed conversation with their physician and veterinarian and take steps to make sure they are extra-careful, but they can still enjoy time with their pet.

Sharing our homes with pets requires a dose of healthy prevention and common sense. Routine screening and monthly preventives help prevent parasite infections. Basic pet hygiene helps avoid many problems, and modern medicine has fortunately made many of these problems rare. The occasional smooch on the cheek is part of the joy of my job and likely the highlight of many people's day.

Questions for Dr. Thompson can be e-mailed to askthevet@theblade.com or mailed to The Blade, Attn. Ask the Vet, 541 North Superior St., Toledo, OH 43660. Dr. Thompson regrets that he cannot answer individual letters.