Milk or Water – What’s Best for Cats? The Surprising Truth


This article provides an overview of cats’ hydration needs and whether they should drink milk or water. The goal is to help cat owners understand the importance of proper hydration for their feline companions and determine the best hydration sources. We’ll cover why cats need adequate water, signs of dehydration, whether milk is recommended, and tips for ensuring cats stay hydrated.

Milk vs. Water

While milk may seem like a natural drink of choice for cats, the reality is that felines do not need dairy as part of their diet. Cow’s milk in particular can cause digestive upset in cats. As cats mature, most become lactose intolerant, meaning they lose the ability to digest lactose, the natural sugar found in milk (PetMD). For kittens, milk provides important hydration and nutrition, but adult cats do better drinking water.

Water is the healthiest drink for cats, providing pure hydration without extra ingredients or calories. Cats get most of their hydration from their food, but still need fresh water available at all times. Water supports every organ system in a cat’s body and aids kidney function, digestion, circulation, and more. Unlike milk, water is calorie-free and contains no lactose to upset a cat’s stomach. Providing ample clean water for cats to drink throughout the day is essential for overall health and hydration.


Kittens have special hydration needs because they cannot properly digest milk sugars (lactose) after weaning. According to PetMD, kittens should only drink their mother’s milk or a kitten milk replacer formula until about 8-12 weeks of age. After weaning, kittens lose the ability to properly digest lactose, and cow’s milk may cause diarrhea. The best hydration sources for kittens are kitten milk replacer formula, plain water, or wet kitten food. It’s important not to give cow’s milk to kittens as it can upset their stomachs.

Lactose Intolerance

Lactose intolerance is common in adult cats. According to Pet Honesty, over 50% of adult cats are lactose intolerant. This means they lack the enzyme lactase which is needed to properly digest lactose, the sugar found in milk. When cats consume milk, the undigested lactose travels to the large intestine where it ferments, causing gas, diarrhea, vomiting, and other gastrointestinal issues.

Kittens are not lactose intolerant because they produce lactase to digest their mother’s milk. However, lactase production decreases after weaning. By 6-12 months of age, most cats have become lactose intolerant. Some cats may retain some lactase activity into adulthood, but the majority do not and will have trouble digesting milk.

Certain cat breeds like Siamese and Burmese are more prone to lactose intolerance. However, the prevalence across breeds is high. Quora notes that most domestic cats, regardless of breed, are lactose intolerant. So milk should be avoided for adult cats.

Raw vs. Pasteurized Milk

There are some key differences between raw and pasteurized milk when it comes to cats. Pasteurization is a process that heats milk to high temperatures to kill potentially harmful bacteria. However, this process also destroys many of the natural enzymes and antibodies found in raw milk that make it more digestible for cats.

According to one source, raw milk contains the necessary enzymes to help cats properly digest it, while the pasteurization process damages these enzymes making it harder for cats to digest [1]. The pasteurization process can also reduce vitamin content in milk.

Additionally, some sources note that cats fed a diet of raw meat and raw milk historically tended to be healthier than cats fed processed foods [2].

That said, raw milk also carries a higher risk of transmitting dangerous bacteria like salmonella or E. coli if not handled properly. Pasteurized milk is considered safer from a bacterial standpoint. Cat owners should weigh the risks and benefits when deciding between raw and pasteurized milk.

Milk Alternatives

While dairy milk is not ideal for cats, there are some non-dairy milk options that may be safer alternatives. Many plant-based milks like almond, coconut, soy, oat, and rice milk are naturally lactose-free. These milks are typically lower in fat and calories than cow’s milk, although coconut milk tends to be higher in fat.

Some cat owners have had success using small amounts of unsweetened almond or coconut milk as a treat. However, plant-based milks lack some of the nutrients cats need, so they should not make up a significant portion of your cat’s diet.

There are also a few commercial non-dairy “cat milk” products, like CatSip. These are designed to be lactose-free and contain added vitamins and minerals to make them more nutritionally balanced for cats. But even these should be fed sparingly, according to your vet’s guidance.

Goat’s milk is another option you may consider because it contains less lactose than cow’s milk. But again, use caution and consult your vet first, as goat’s milk is not lactose-free and some cats may still have trouble digesting it.

The bottom line is dairy-free milks won’t provide complete nutrition for cats, but small amounts may be an acceptable occasional treat. Focus on a balanced cat food diet and always get your vet’s advice about milk substitutes.


Water is extremely important for cats’ health. Cats’ bodies contain about 70% water, so they need to maintain proper hydration in order to support kidney function, regulate body temperature, move nutrients, and eliminate waste. According to PetMD, most veterinarians recommend that a normal healthy cat drink about 4 ounces (about 1/2 cup) of water per 5 pounds of body weight per day1.

However, many cats do not drink enough water on their own. Here are some tips to encourage your cat to drink more:

  • Provide fresh, clean water daily in bowls throughout your home.
  • Use a cat water fountain, which makes water more enticing.
  • Offer wet or canned food, which has high water content.
  • Add a bit of tuna juice or low-sodium broth to the water to increase flavor.
  • Keep water bowls away from food bowls and litter boxes.
  • Use wide, shallow bowls so whiskers don’t touch the edges.

Monitoring your cat’s water intake and watching for signs of dehydration like lethargy, dry mouth, and loss of skin elasticity can help ensure they stay properly hydrated. Consult your veterinarian if you have any concerns.

Hydration Tips

There are several creative ways to keep your cat hydrated. Here are some tips:

Add water to your cat’s wet food. This boosts the water content and helps hydrate your cat as they eat (PetMD).

Use a pet drinking fountain. The moving water encourages cats to drink more. Place fountains in multiple rooms so water is always accessible (Brook Farm Veterinary Center).

Offer ice cubes or frozen broth cubes as treats. As they melt, it provides extra hydration.

Add extra water bowls around the house. Having water easily available at all times is key.

Use flavored waters like tuna water or bone broth to entice your cat to drink.

Try cat hydration gels that are designed to supplement hydration.

Monitor intake and adjust based on weather. Cats need more hydration in hot temperatures.

Make water easily accessible in multiple clean bowls around the house.

Signs of Dehydration

Dehydration can be dangerous for cats if left untreated. According to WebMD, some symptoms of dehydration in cats include:

  • Lethargy and weakness
  • Sunken eyes
  • Dry gums and nose
  • Skin tenting – when you pinch the skin, it stays tented rather than snapping back
  • Fast breathing and heart rate
  • Not eating or drinking
  • Fever
  • Vomiting and diarrhea

As noted by PetMD, gently lifting your cat’s lip and touching their gums is one way to check for dehydration. Healthy gums should be wet and slimy. If they are sticky, dry or tacky, it could be a sign your cat is dehydrated and needs veterinary attention (PetMD).

Some other symptoms outlined by PetMD include lethargy, weakness, and loss of appetite. Cats can become dehydrated relatively quickly, so be alert for signs they may need fluids.


In summary, both water and milk play important roles in a cat’s diet. Kittens need milk from their mother to survive, but adult cats should not drink cow’s milk regularly due to lactose intolerance. While milk can be an occasional treat, water is essential for hydration and should be readily available at all times.

Cats have a low thirst drive, so pet owners need to take steps to encourage drinking. Providing multiple water bowls, flavored waters, cat fountains, and wet food can all help increase feline water consumption. Watch for signs of dehydration like lethargy and dry gums. Consult your veterinarian if you are concerned your cat is not getting enough fluids.

With proper hydration care and access to clean, fresh water, cats can thrive on a balanced diet tailored to their unique nutritional needs.

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