There are several things that could help. Here are two for your consideration.
One of the easiest is to crop in a bit to minimize the busy background.
One other idea you can look into, depending upon you post processing software, is to add just a bit of sparkle to the eyes. There are many PDF and Video tutorials on eye retouching on the web. Most folks don't realize that what works for human portraiture eye retouching can often be used with some discretion on any eyes to enhance the appearance and add a livelier look.
I'd agree with Frank here that there is too much background. The picture looks a tad out of focus though and so cropping could emphasise this. Don't know what camera you're using or lens for that matter but I'm assuming it's hand held and so I'd suggest your shutter speed was a little slow on this one. Any idea what your camera settings were here ?
It was handheld and the shutter speed was only 1/125 which I didn't realise so that probably needs to be made faster. I'm using a canon 500D but don't know which lens I was using sadly. I think the ISO was on auto and it was at f5.6 which I have seen. Think it was my 18-55mm lens. Thanks for the processing tips though on the eyes.
Paul, the EXIF data shows 1/125 sec, ISO 100. F5.6 with a Focal Length of 80mm if that is any help.
You could apply some sharpening to just Arthur if you have the software to do so, otherwise, it is certainly worth reshooting if you can. If you do reshoot, try for a lower camera position - more at Arthur's height position if possible.