Buddies Forever

This is a good, energetic piece. The poses are great and capture the friendship between the two characters. Your style is consistent and unique. The linework is smooth. This piece is very well done. Composition really emphasizes the focal point and draws the viewer into the scene.
I understand that this is stylized, but there are a few glaring atomically issues that I feel must be addressed.
These are cats yet the most pressing issue is that they look very canine. The muzzle is short, but shaped like a dog. The proportions are more canine than feline. Cats are longer than they are tall. They have long bodies and short legs. The legs are too long in comparison to their body length.
Fireheart's back legs are off. The metatarsals are too long and the tibia and fibula need to be longer. Basically, the foot is too long and the ankle needs to be lower. Here is a skeletal chart as a reference.
facinatingamazinganimals.files…
Graystripe's back legs are hidden but the same applies. Graystripe's leap is very canine like as well. Cat's have very flexible spines while dogs do not, you show this well in Fireheart's pose but it needs to be emphasized in Graystripe. Here are two photos of cats running to help you.
www.warrenphotographic.co.uk/0…
The ears shouldn't originate from the top of the head either.
This is tricky to describe, but if you look at a cat skull you'll see behind the zygomatic arch and below the parietal bone at the back and bottom of the skull there is a 'hole', this is the Meatus caustics externus, I call it the earhole. <img src="e.deviantart.net/emoticons/b/b…" width="15" height="15" alt="" data-embed-type="emoticon" data-embed-id="402" title=" (Blank Stare)"/> Heres a cat skull to show you.
www.skullsunlimited.com/record…
That's where the ear truly 'beings', or where sounds goes into so the brain can process it. The ear stars more at the side of the head than the top. Here is a picture of a sphinx head profile to show you.
www.kimballstock.com/results.a…
Try to define joints a little more, the front legs look like one unit, the elbow is missing, as are most of the forearm muscles. Also, dewclaw is missing. And the pisiform pad is too low, it needs to be closer to the wrist. The shoulder is coming above the spin which is definitely cat like, but its too high and too pointy.
Overall, great job.
Sorry for the long winded critique...O.O The simple but elegant background really helps ground the characters without distracting from the focal point, the characters. Great work!