How to get Apple photos to recognize Pets?
Photos will not recognize my horse as a pet and will not allow me to name it and add it to the people and pets
[Re-Titled by Moderator]
iPhone 15 Pro Max
Question marked as
The only pat recognized as pets are currently cats and dogs - it is the same on a Mac or an Phone. See this page in the user guide:
Identify people and pets in photos on iPhone – Apple Support (UK)
The Photos app 
recognizes people, dogs, and cats in your photos and sorts them in the People & Pets album (or the People album if no dogs or cats are identified).
Find and identify photos of people and pets in Photos on Mac – Apple Support (UK)
"When you first open Photos, it scans your library to recognise people, dogs and cats in your photos. After the scan is done, you can open the People album, view photos organised by the faces in them and assign names to them. If you name a dog or cat, the People album changes its name to People & Pets. As you import new photos, Photos matches any people or pets in them to the people and pets you’ve identified."
If you have a Mac as well, you can tag the face of the horse manually and name it. The name will sync with iCloud Photos to your iPhone. On your iPhone you can add the name of the horse to the caption of the photo. Then a search for it will find it.