Short Answer
Yes, It is totally safe for your kitty to eat watermelon. While not a normal part of their natural diet in the wild, there are no ingredients in the watermelon itself that are harmful to your cat. I don’t know of many cats that enjoy watermelon, but if your kitty is one of the unique few that enjoy the occasional piece of fruit, then it is okay to feed your cat watermelon.
Are there any Benefits?
Watermelon is mostly water, 92% water to be exact, so there isn’t much nutritional value that will benefit your cat. They might be attracted to the additional water.
Fun Fact!
Cat's don't have taste buds to determine sweet or savory flavors
While they may not be able to taste the sweet watermelon, there are some additional things in the watermelon that can be of benefit to your cat and if your cat isn’t drinking enough water, then this might be a good occasional treat to fancy their appetite.
Lycopene
Lycopene is a phytonutrient, which is a naturally occurring compound in fruits and vegetables that reacts with the cat's body to trigger healthy reactions. It is also the red pigment that gives watermelons, tomatoes, red grapefruits, and guavas their color.
Lycopene has been linked with heart health and bone health. It's also a powerful antioxidant thought to have anti-inflammatory properties.
Antioxidants
The body's normal antioxidant defenses provide some protection against free radicals that cause damage to cell membranes. Cat food rich in antioxidants, including vitamins E and C, beta-carotene and selenium, provide support for your cat's natural defenses.
Amino Acids
Citrulline is a valuable amino acid that converts to the amino acid arginine. These amino acids promote blood flow, leading to cardiovascular health, improved circulation
Fiber
The watermelon contains fiber, which encourages a healthy digestive tract and helps keep your cat regular. Fiber is an important part of all cat's diets.
How often can you feed it to them?
Watermelon doesn’t post any significant health risks to your cat, but there are a lot of alternative options if you want to give your cat water enriched with vitamins and anti-oxidants.
You should sparingly feed watermelon to your cat as a treat and on a selective basis. While it won’t hurt your cat to eat it, I wouldn’t recommend adding it to their diet on a daily basis. If you’re having watermelon and you want to give some to your cat as a treat, that makes sense.
Most veterinarians recommend that you stick to your cat's normal approved diet 90% of the time and offer treats only as an occasional snack or alternative to their normal diet.
Any Concerns?
Watermelon Seeds
There are some myths floating around the internet that watermelon seeds contain cyanide. This isn’t true, but I wouldn’t recommend giving your cat watermelon seeds. They have very little nutritional value and only serve as a potential item that your cat has to pass through their digestive tract.
Cats With Diabetes
Watermelon, like many fruits, contains a lot of sugar. If your cat is already diagnosed with diabetes, then you certainly should not be feeding them watermelon as the sugar won’t be good for them.
It’s also good to note that sugar, while a large part of our diets, isn’t really something that cats need in their diet. Giving your cat to much sugar can put them at risk for developing diabetes. Moderation is very important when giving your cat unorthodox foods.
The Rind
The rind of a watermelon isn’t something that most people particularly like, so it’s probably not something that I would feed my cat. It contains little to no nutritional value and is probably something that’s too much for your cat to really chew on. You have to remember that your cat’s natural diet largely consists of rodents, birds and other small creatures. Their teeth aren’t exactly designed to chew the hard outer skin of fruits.
Final Words
While cats can eat watermelon, it should be noted that it’s not really a part of their normal diet. There is no real harm in giving your cat watermelon as a treat when you’re having your family bbq of if they happen to be around while you are preparing your favorite treat. Just keep in mind that cats are only 10-15lb animals and while they might enjoy it, they shouldn’t be given anywhere nears as much as you might consume.