The short answer
Revelation Pets, Gingr, PetExec or Kennel Connection. All four are built for boarding, which means a calendar of pens rather than a calendar of appointments, and all four hold vaccination records, medication notes and owner accounts on the pet's profile.
Any of the four can book a cattery well. The choice is about size and about what else you run.
What a cattery booking actually is
This is why a general salon calendar does not work. A cattery booking is a date range, not a slot. It has to check whether a pen of the right type is free for every night in the range, price a stay that may be shared by two cats from one household, apply a peak rate, take a deposit, collect the vaccination record with its expiry, capture the feeding and medication notes, and get an agreement signed.
A tool that does not understand occupancy will happily double-book August. That is the whole reason to use boarding software rather than the plugin your web developer already knows.
Revelation Pets
Cloud boarding software widely used by smaller and mid-sized kennels and catteries. It covers the occupancy calendar, customer and pet records with vaccination detail, online booking requests from the website, invoicing and automated emails. It tends to be the choice for a cattery run by one or two people who want the diary, the records and the invoicing in one place without a lot of configuration.
If you run a cattery only, this is usually the shortest route from paper to online.
Gingr
Broader pet-care software covering boarding, daycare, grooming and training, with an owner-facing booking area, new-client registration with vaccination upload and signed agreements, and a customer portal. Worth looking at when the cattery sits alongside a kennel, daycare or grooming under the same roof, because one platform then carries every service and one owner account covers the household with a dog and a cat.
PetExec
Also multi-service, covering boarding, daycare, grooming and training, with owner accounts, vaccination tracking and reporting. Similar shape to Gingr in what it addresses. Catteries that are part of a larger boarding business often end up choosing between these two on the strength of their reporting and their staff-side workflow rather than on the owner-facing booking.
Kennel Connection
A long-established kennel and cattery management product with boarding, grooming and daycare modules and an online booking add-on. Common in larger established boarding businesses, and worth a look if you want deep reporting and have someone who will spend a day setting it up properly.
How to choose between them
Ask five questions.
Does it handle your pen types as distinct capacity, so it cannot overbook a type. Does online booking let an owner pick dates and see availability, rather than sending a message you have to answer. Does the pet profile carry vaccination expiry with reminders. Does it take a deposit and hold your cancellation terms. Does it embed into or link cleanly from your own website.
Then book a demo of two of them and run a real August week through each. Feature lists all look similar; the difference shows up when you try to price three cats sharing over a bank holiday.
What does not work
A contact form. A generic appointment calendar sold for salons. A phone-only diary in peak season, which is the single most expensive habit in cat boarding, because enquiries arrive in the evening when you are not answering and the owner books whoever had a calendar.
What the website has to do
Whichever you pick, the site's job is the same. A Book button on every page. A dedicated booking page carrying the embed or the link, so the widget does not slow down every other page. A separate route for new clients, who have to register a pet and upload a vaccination card before they can book. Prices on the site matching the rates in the platform. And the requirements and routine pages linked from the booking area, because an owner mid-booking is exactly who wants to reread them.
If you already use one
Keep it. All four can be made to book properly from a website, and moving platforms means moving every owner account, every pet record and every vaccination date. That is rarely worth doing as part of a website project. The exception is a cattery still running a paper diary, which should choose from this list before the site is designed, because the site is built around the booking flow rather than the other way round.
Where this sits
Online booking through one of these four is one of the must-haves on every cattery website we build, and picking the platform that matches the kind of booking is how we approach pet business websites generally. Packages are on pricing. The tool holds the pens and the records. The site gets the owner into it in one tap.