Animal Sponsorship

I am with an animal rescue organization.  We aren't very big and this is strictly volunteer.  I am wanting to add a "sponsor an animal" page on our website and I am curious what the best/easiest way to do that is.  I would like to have a "Sponsor 'Dog Name'" then they have options such as Heartworm for a year (amount), food for 3 months (amount), and so and so.  Would also like to have a monthly donation option for each animal. 

Any help would be greatly appreciated.  Thank you!

You could potentially set up a donate button, but also you could set up a product for each animal, and set a variant that relates a price to 'Dog Name' and 'Year of Heartworm' etc.