Do Cows Really Have Multiple Stomachs?

Q:
 My teacher told us that cows have four stomachs. Is this true?
Why do they need so many?
Q: My teacher told us that cows have four stomachs. Is this true? Why do they need so many?

A: It all depends on how you look at it, but actually cows have only one stomach. It’s just very large and it has 4 distinct compartments or sections. These compartments are named the reticulum, the omasum, the rumen and the abomasum. The reticulum, omasum and rumen contain large populations of special microorganisms (bacteria and protozoa) that help to break down grass and other roughage that cows eat. Without these “bugs,” cows couldn’t digest the hay or other forage in their diet. The rumen is the biggest of all these compartments. It helps store large amounts of swallowed food before a cow digests it.

Cows and other ruminant animals (goats, sheep and deer) are able to eat extremely coarse grass and hay because of this special digestive tract. When they rest, they lie down and ruminate, a digestive process where they chew their cud. As they ruminate, their stomach actually brings up small amounts of swallowed food and they chew it a second time, breaking it into smaller pieces for better digestion. (My parents used to tell me that whenever they had to make a difficult decision, they would ruminate on it … work it over a few times just the way a cow does its food.) It might sound odd, but ruminating is actually very relaxing for a cow. If you watch her chewing her cud, her eyes will tell you she feels content.

The abomasum is the final compartment and it contains acid, very similar to what’s in our own stomach. It finishes processing food that has been already broken down in the other three sections. After that, cows have the same small and large intestines found in other animals.

Four compartments in just one stomach – that’s what makes cows and other ruminants very special animals.

Q: I heard that walnuts are dangerous if a dog eats them. Is this true?

A: Actually, walnuts off the ground are dangerous for several reasons. First, swallowed shells can cause impaction or other damage to the intestines. But worse yet, there’s a mold that sometimes forms in the husks of walnuts on the ground, and it can be very toxic. That black material can cause nasty seizures and other central nervous system problems.

Even fresh walnuts out of the shell aren’t a good idea for dogs. Walnut meat is high in fat and can lead to extra weight gain and even pancreatitis. As far as many vets are concerned, walnuts and dogs are a bad combination. Don’t let your pooch eat these nuts.

Q: We’ve adopted a 2-year-old greyhound that is a wonderful pet, but I think we have a real problem. The other day I took her on a hike and she took off running after a small deer. She caught it and took it down before I could catch up to her. She didn’t even hear me calling her name. It was just a flash of instinctive chase, I guess. But now we’re worried that she might be a true hunter at heart. If so, could she chase and hurt other “prey.” Should I worry about other small animals and even children?

A: This is a very important question because this incident shows how rapidly instincts can take over the mind of a dog. It’s important to realize that she might, indeed, instinctively chase other “prey.” And yes, it’s possible she could mistake a small animal or even a child as her victim. Dogs can also act out misplaced aggression, where their chase starts out after one target, but suddenly turns to something or someone else (usually an innocent bystander). Here’s an example.

There was a small child injured while walking with her grandmother and the family dog in a forest near Monterey. The dog chased after a squirrel, and suddenly, in its excitement, attacked the little girl, severely injuring her. Ordinarily, this was a loving dog that enjoyed playing with this little girl. But in the excitement of the chase, this dog lost all sense of reality and seriously injured an innocent family member.

I think you’ll always have to be careful with your adopted friend. I strongly recommend that you take her to obedience classes and work with her every day to develop a better working relationship with her. This will help her better focus on your voice when you try to call her attention. But in the end, you’ll always want to avoid situations where she might show aggression.