There are a wide variety of conditions that can affect paws and claws beyond acute trauma and soft tissue injuries. Dry, cracked pads are common, and older dogs seem to be more susceptible. Causes of dry, cracked pads can include repeated exposure to chemicals, zinc deficiency, distemper, and chronic licking.
Claw diseases can also lead to paw pain and lameness. Immune-related disorders such as pemphigus and symmetric lupoid onychodystrophy (SLO) lead to a sloughing off of the nails and regrowth of soft, brittle, irregularly-shaped nails. Treatment usually includes a course of oral steroids and supplementation with Omega 3 and 6 fatty acids and immune regulators.
If you remember wearing uncomfortable shoes, you know that more than your feet hurt by the end of the day. Your whole body aches. Likewise, when a dog has painful paws it can affect the entire body. Just like humans with painful feet, dogs with painful paws tend to shift their weight to reduce the pressure and pain. As a result, there is added stress on the neck and spine, as well as on the legs bearing the extra weight.