Q.I have a four-year-old Lab/chow mix. About a month ago I noticed that she would run from one spot to another and check behind herself. She would also sit down and lift her left hind leg during walks. I took her to the vet and he checked her anal sacks and did a physical exam to check the mobility of her legs. He actually did what I thought was a thorough and rigorous exam. During the course of the exam she did not seem in pain or show any weakness. The only thing the vet told me to do was lower her calorie intake because she was about ten pounds overweight. I put her on [a light food] and noticed that she did not have any episodes after a couple of weeks. However she recently suffered what looked like a muscle spasm in her left hind leg. They are not frequent like the last time but it is unnerving because I have no idea what is happening.

 

A.It would be very difficult for me to definitively diagnose the problem via this column, but the most common thing I have witnessed that causes signs/symptoms such as these is, believe it or not, good old fleas. The distribution pattern for the medical condition known as flea allergy dermatitis is invariably around the base of the tail and down the back surfaces of the rear legs. Bites in these areas can cause the symptoms you are describing. Remember too, that fleas live most of their time off the animal so you don’t necessarily have to see them. By definition, this is an allergy to flea saliva. High carbohydrate diets are not only “unnatural”, but can precipitate or worsen allergy conditions. This could be why the dietary change made some difference. If fleas are truly your dog’s problem, there are many products on the market to address the allergy and help naturally repel the fleas.