Let's start with the second question. Pruritus can have a tremendous impact on our patients' quality of life, and by extension, pet owners' quality of life. What may begin as a small annoyance ("Stop licking!") may turn into a cause of sleep disruption ("No more sleeping in the bed room!") The human-animal bond suffers and there may be feelings of guilt and betrayal. I see a couple that takes shifts for weeks at a time, continuously monitoring their pruritic dog, fearing what they might find if he is left to his own devices. We've all cared for pets that have been relinquished due to their pruritus. So, even if you have yet another "itchy dog" appointment sandwiched between "bite wound" and "vomiting blood" appointments, give it your full attention. You just might be saving a life, even if a little more indirectly.

Now that I hopefully have you convinced of the importance of pruritus as a complaint, how are we going to assess it? Until fairly recently, there wasn't much in the veterinary literature about trying to quantify pruritus severity. Many studies on canine atopic dermatitis either didn't report a measure of pruritus severity, instead relying on cutaneous lesions as a measure of disease severity, or they relegated pruritus severity to a secondary outcome measure. But, what do owners of atopic dogs really want, more than anything? They want their dogs to stop scratching, biting, chewing and licking!

Stemming from my frustration with trying to design a sound study on atopic dermatitis, I became particularly interested in trying to measure pruritus severity while I was on the faculty at Oregon State. In one study (http://tinyurl.com/VetDerm-2007-18-294), I bribed veterinary students (with food) to watch a collection of videos of 16 dogs with various degrees of pruritus. Each short video was shown two times, in random order on day 1, then again one week later. Students scored the pruritus with one of two commonly used (at that time) methods: a visual analog scale (essentially a line with anchors on each end), and a numerical rating scale (0-5). From the results of this study I concluded that the mid-range scores were not as reliable as desired for a health measurement scale, and that while some students scored consistently, many did not.

In a second study (http://tinyurl.com/VetRec-2008-162-624), I expanded on some recent work by a group in the UK that tried to quantify pruritus using accelerometers, devices that measure motion and acceleration. This group had found that accelerometers could detect a difference in movement, especially at night, between normal dogs and atopic dogs. I went on to show that, in kenneled dogs, this difference was primarily 

My pal in his first ever cover shot!

attributable to pruritic behaviors (not just roaming around at night). To do this, I watched hour upon hour of video of shelter dogs fitted with the accelerometer on their collars, correlating the duration

of their pruritic behavior and the movement

recorded by the collar in 15 second increments. Picture a lot of sad shelter dogs anxious about getting left behind for the night, followed by long stretches of dogs sleeping intermixed with brief episodes of scratching, licking and head shaking. I went through a lot of coffee.

Just as I was starting a project that I hoped would produce a valid scale for measuring canine prutitus severity, another group out of the UK beat me to it. Theirs, it turns out, is simpler than what I had envisioned, and I have fully adopted it for use in my practice. I suggest that you do as well. You'll have a better sense of whether or not your patients are really improving in the owner's eyes, or not. It turns out that just asking someone to tell you if some sign (e.g. pruritus severity) has improved since a previous examination, is not as accurate as comparing a measure of the attribute on both occasions. To download a pdf of the validated onwer-assessed scale, that I call the pruritus visual analog scale (PVAS), go to www.vetrespit.com then click on Learn More. The link to the pdf is titled "Hill: A validated canine pruritus severity scale you can use in your practice." Keep track of pruritus severity for every derm case. It's probably what brought the client to you!

• Florida VMA Annual Conference (Tampa, FL, May 4-5) 
• GA-AL VMA Conference (Destin,FL, May 30 - June 2)
• PacVet Conference (San Francisco, CA, June 29-30) 
• AVMA Convention (San Diego, CA, August 4-6)  
• CVC (Kansas City, MO, August 25-27) 
• Southwest Veterinary Symposium (Dallas, TX, Sept. 21-23)