I’m sorry to hear about your rabbit’s passing. Binky free bun.

This may be sore hocks, though not in the “traditional” location: https://wabbitwiki.com/wiki/Sore_hocks

Unlike other animals, rabbit feet have no padding or extra cushioning aside from their fur, therefore improper flooring, improper nail length, being overweight, being sedentary, etc. are all factors that can contribute to the development of sore hocks. Some rabbit breeds, like Rexes, are more prone to sore hocks since their fur is short, providing less cushioning.

If it is sore hocks, this does not look too bad at this point, but I’d consider reviewing if you can make improvements in any factors listed in the Wabbitwiki link and check the sore each day to see how it progresses. If it increases in redness, size, or bursts, veterinary assessment would be wise.

One of my buns got a small abscess on her foot from where she may have gotten poked by hay or something similar. It did need some vet attention (they cleaned it up and wrapped it), but it healed well.

Since it seems swollen and is a squishy lump, I’m sorry to say I would probably take him to the vet.

It doesn’t look like it is an emergency… but I agree with Dana that this may need to be addressed by a vet. If there is a lump there, that would suggest it isn’t a simple case of a sore hock. Wick is correct though, pressure sores can develop on the front feet.