Introduction
While people often think of cats lapping up a saucer of milk, many cat owners wonder if our feline companions should really be drinking milk at all. This is an important question for cat owners, as milk and dairy products may actually be harmful to cats. Knowing the facts can help keep your cat healthy and avoid digestive issues.
Milk Composition and Digestion
Milk contains a sugar called lactose that requires an enzyme called lactase to be digested properly (1). Lactase breaks down lactose into simpler sugars that can be absorbed by the body. However, most adult mammals, including cats, naturally stop producing lactase after weaning (2).
This means that once cats mature past the kitten stage, they become lactose intolerant. Their bodies no longer produce enough lactase to properly digest the lactose in dairy products like milk or cream (3). When cats drink milk, the undigested lactose travels to the large intestine where it ferments, causing digestive upset and gas.
Sources:
(1) https://www.zoetispetcare.com/blog/article/are-cats-lactose-intolerant
(2) https://www.ctvsh.com/services/cats/blog/why-cats-and-cows-milk-dont-mix
(3) https://www.four-paws.org/our-stories/publications-guides/milk-is-not-good-for-cats
Kittens vs Adult Cats
Kittens are actually able to digest milk because their bodies produce an enzyme called lactase that breaks down lactose in milk. Lactase allows kittens to digest the lactose in their mother’s milk during nursing. However, as kittens grow and mature into adult cats, their bodies begin producing less lactase. This results in most adult cats being lactose intolerant.
According to PetMD, kittens have a high need for the nutrients in milk like protein and fat for proper growth and development. But as they mature, usually around 6-12 months old, milk no longer provides nutritional benefits and can cause digestive issues instead.
So while kittens can drink milk thanks to lactase production, adult cats lose this ability over time. This makes cow’s milk unsuitable for most adult felines.
Signs of Lactose Intolerance
The most common signs that a cat is lactose intolerant and unable to properly digest milk and dairy products include:
Diarrhea – Within 8-12 hours of ingesting milk or cream, an intolerant cat will develop loose, watery stool and diarrhea. This occurs as undigested lactose passes through the digestive tract, drawing water into the colon through osmosis. According to [cite]vcahospitals.com/know-your-pet/adverse-reactions-to-food-in-cats[/cite], diarrhea is a key symptom of dietary indiscretion and lactose intolerance in cats.
Vomiting – In addition to diarrhea, cats unable to digest lactose may vomit within hours of drinking milk. As mentioned by [cite]ctvsh.com/services/cats/blog/why-cats-and-cows-milk-dont-mix[/cite], vomiting is a common symptom and sign of lactose intolerance.
Gas – The undigested lactose in the colon can also lead to increased gas production and flatulence in lactose intolerant cats.
Abdominal pain – The intestinal distress caused by undigested milk can lead to cramping, bloating, and general abdominal discomfort in cats.
Risks of Milk
Giving milk to cats carries several health risks. One of the most common is an upset stomach, which can lead to vomiting or diarrhea. Milk contains lactose, a sugar that is difficult for many adult cats to digest due to a lack of lactase enzymes. When undigested lactose reaches the colon, it can cause gas, abdominal discomfort, and loose stools.
Diarrhea from milk can potentially lead to dehydration if it persists for too long. According to PetMD, severe diarrhea leads to ‘significant fluid and electrolyte losses’ in cats [1]. Dehydration requires veterinary treatment with IV fluids and electrolyte replacement to restore hydration and proper body functioning.
Cow’s milk also poses an obesity risk for cats due to its high calorie and fat content. Just 1 cup of whole milk contains around 150 calories and 8 grams of fat [2]. The calories can quickly add up if a cat drinks milk regularly, leading to unnecessary weight gain. Obesity predisposes cats to diabetes, arthritis, heart disease, and other chronic illnesses.
Better Alternatives
Instead of regular dairy milk, there are better options to provide moisture and nutrients for cats.
Water should be a cat’s primary drink. Make sure clean, fresh water is always available. Cats tend to drink more when water is kept away from their food bowls.
Bone broth or meat broth can provide hydration along with vitamins and minerals. Look for low-sodium varieties. Broths should be fed in moderation, not as a complete milk replacement.
There are products designed as cat milk replacements that contain essential nutrients. The Honest Kitchen’s Cat Blend uses goat milk and probiotics. PetAg KMR is a nutrient-rich formula made for orphaned kittens. These cat milk substitutes are designed to be digestible and healthy for cats.
Small Amounts May Be OK
While milk is generally not ideal for cats, especially in large quantities, a few laps of milk as an occasional treat is likely fine for most cats. Many cats enjoy the taste of milk. As obligate carnivores, cats lack the enzyme lactase to properly digest the milk sugar lactose. However, some cats may retain a small amount of lactase into adulthood, allowing them to consume small quantities without issue.
Before offering any milk to your cat, monitor them closely for signs of lactose intolerance, including diarrhea, vomiting, gassiness, or abdominal pain after drinking milk. If your cat experiences any of these symptoms, discontinue milk immediately. But if your cat seems to tolerate a bit of milk without problems, a few laps of milk here and there is likely harmless.
It’s best to offer milk in very small amounts infrequently. Too much can overwhelm your cat’s digestive system. Monitor your cat during and after drinking milk to ensure no adverse effects. If you notice any issues, do not give your cat milk again. With observation and caution, a small treat of milk should be fine for most cats on occasion.
Cream is Worse
Cream contains a higher fat content and greater lactose concentration than regular milk, making it more difficult for cats to digest properly. According to [name of source], cream has about 2-3 times the fat content of whole milk. This increased fat and lactose content means that drinking cream is more likely to cause diarrhea and other digestive issues in cats compared to regular milk.
The high fat levels in heavy cream can overload a cat’s digestive system, resulting in vomiting, diarrhea, and even pancreatitis according to veterinarians. Most vets recommend avoiding giving cats cream or any dairy products, since the lactose and fat is too difficult for their bodies to manage.
Cats lack the enzyme lactase needed to properly digest lactose sugars. Consuming cream forces their digestive system to work overtime trying to break down the components. Often this results in diarrhea, gas, bloating, and abdominal pain. It’s best to avoid cream and stick to cat-appropriate foods and treats.
Exceptions
While most adult cats are lactose intolerant, some may actually tolerate milk in small quantities without issue. Certain cat breeds like Siamese are thought to retain more of the lactase enzyme needed to properly digest lactose into adulthood.
Studies have found the prevalence of lactose intolerance in Siamese cats may be lower compared to other breeds. One study showed over half of Siamese cats maintained lactase activity at one year of age. Another study found Siamese kittens had higher lactase levels at two months compared to other breeds.
So while milk is still not generally recommended for adult cats, some Siamese cats and other individual cats likely tolerate it better than average without digestive upset. However, pet owners should still monitor carefully for signs of intolerance. If no issues arise after consuming small amounts occasionally, some cats may continue enjoying milk as an occasional treat without problems. But cream and large quantities are still ill-advised.
Conclusion
As we’ve discussed, while milk and cream may seem like natural drinks to give cats, they are generally not recommended. Cats are lactose intolerant as adults, meaning milk and dairy products can cause digestive upset. Kittens can tolerate some milk, but they should be transitioned to solid foods and water soon after weaning.
For most cats, it’s better to avoid milk and cream altogether. Water, commercial cat foods, and cat-safe human foods like boneless meat are healthier choices. If you want to give your cat a treat, cat-safe options like tuna water, bone broth, or small amounts of plain yogurt tend to be better tolerated.
Always consult your veterinarian if you are unsure about giving your cat any new foods or have concerns about their digestive health. While an occasional lap of milk likely won’t harm them, milk and cream are not recommended parts of a cat’s diet in most cases.