Not doing a registry/gifts

Hi everyone! So my fiancé and I have decided that we don’t want to do a registry and we don’t want any wedding gifts. Instead we would rather have our guests make a donation to our local 24hr emergency animal hospital, our local animal shelter called Vintage which takes in older pets as permanent residence that are too sick or whose owners have gotten sick or passed away, or an organization in Rhode Island that helps pet owners who can’t afford vet bills. This is something that my fiancé and I hold dear to our hearts and it is what we care about the most. When we initially talked about our wedding we felt very strange about a wedding registry and bridal shower and gifts because we’ve been together for 10 years and we have everything we need. I understand that people want to give us things becauseWe’re getting married but I’m just curious how others will respond to this request that we have. Also how on earth would I put this on our wedding invitations? I haven’t discussed this part with my wedding planner yet but how do I kindly and politely ask my guests to refrain from getting us gifts and to make a donation to one of the above organizations?? Any thoughts opinions both positive and negative are all welcome.My mom doesn’t like the idea because she said that not all peopleFeel the same we do about animals and they might just want to focus more on me and my fiancé. I obviously disagree with this but feel free to share any and all opinions on this. thank you