There are many risks associated with rawhide, some of these include:
Hazard of choking
Risk of salmonella- contamination has been known to cause serious vomiting and diarrhoea. Allergic reactions to the additives can also cause inflammatory reactions.
Once swallowed can begin to swell in your pets stomach - reaching upto 4x its size, causing life threatening blockage
If swallow in chunks it will not be digested
Rawhide bones are not considered as a food item so are not covered by any content or processing laws.
Colouring used to enhance the rawhide leather is also treated with chemicals such as arsenic, bleach, ethoxyquin and hydrogen peroxide. These chemicals can be toxic and traces of these tend to remain on the chews and irritate the dogs system.