Sometimes dogs and cats do things that seem pretty strange to us humans (and vice-versa). But while we find them weird, many of those behaviors are perfectly healthy for our pets. Others, however, could be a sign that something’s going on with your fur buddy that requires medical attention. Read on to learn about 6 odd dog and cat behaviors, and whether they mean it’s time for a visit to your veterinarian. 1) Why do dogs chase their tails? Watching your dog run in a tight circle is generally hilarious — but is it healthy? Maybe, but maybe not. According to Dr. Lynn Buzhardt, DVM, it could just mean that your dog is bored and looking to burn off some energy. But if your dog manages to catch his tail and starts biting and chewing, it could be a sign of pruritus or itchy skin. That could be caused by a number of things, including allergies, fleas, and infection. It could also be an obsessive-compulsive behavior resulting from separation anxiety. That’s why it’s important to keep an eye on your dog’s tail chasing, and if it results in biting or chewing, find a vet and visit them as soon as possible. 2) Why are cats such finicky eaters? If you grew up in the 70s and 80s, you no doubt remember a certain orange tabby named Morris who may have been the original foodie. Compared to the average dog who will eat just about anything, cats have a reputation for having rather discriminating palates. According to an article published last year in the journal Royal Society Open Science, there seems to be a scientific reason behind that pickiness. Apparently, cats need a diet that contains a 1 to 0.4 ratio of protein to fat, and somehow — researchers have yet to figure it out — cats are able to detect whether the food they’re being fed fits the bill. But according to Pets.WebMD, if your cat is refusing to eat, it could be a sign of a serious illness such as an infection, kidney failure, pancreatitis and even cancer. That’s why if your cat suddenly stops eating it’s important to call your veterinarian right away. 3) Why do dogs cock their heads? If there’s one dog behavior that’s a sure-fire heart-melter, it’s the head tilt. When our dogs turn their heads to one side in response to an unusual noise, it’s almost impossible to prevent an “awwww” from escaping our lips. But why do they do it? Some behaviorists think it’s as simple as trying to get an ear closer to what they’re hearing so they can figure out what it means. They could also be trying to figure out where the sound is coming from. One psychologist even thinks they could be tilting their heads to get a better look at our faces when we’re speaking to them. But when dogs tilt their heads for no apparent reason, shake them, or cock them and scratch their ears, it could be the sign of a medical issue — which means it’s time to find a vet. 4) Why do cats vomit? Compared to dogs, cats seem to — well — throw up a lot. But while some of that vomiting is normal, if it becomes too frequent, it could be a sign of a serious medical issue. As you may have noticed, cats spend a lot of time grooming themselves. Since the lack of opposable thumbs makes it difficult for them to handle a comb or brush, they rely on their tongues to do the preening. Consequently, they end up swallowing a lot of indigestible hair, which comes back up in the form of icky hairballs — usually on the rug or furniture (Thanks, Fluffy!). However, according to Dr. Elise Robertson, DVM, a specialist in feline medicine, frequent vomiting could be a sign of a serious illness. So if your cat is throwing up more than an occasional hairball, give your veterinarian a call ASAP. 5) Why do dogs eat feces? As we’ve already established, dogs will eat just about anything. And I mean aaanything. Unfortunately, one of those things is … poop. Their own poop, other dogs’ poop, cat poop — you get the picture. This habit, called coprophagia, is — without a doubt — totally and completely disgusting. But why do they find poop so delectable? There are a number of reasons why some dogs eat feces. Some observed their mothers doing it when they were tiny puppies, which is actually natural behavior. Mother dogs eat their puppies’ stool because of a primitive instinct to keep their living area clean so the scent won’t attract predators. Others developed the habit as puppies out of boredom, stress or excessive hunger. And still, others do it for no apparent reason at all. Poop-eating can, however, be a sign of a medical problem. According to PetMD, coprophagia can result from a nutritional deficiency or disease — especially in adult dogs who develop the behavior seemingly out of the clear blue sky. In that case, you need to see your vet. Keep in mind that no matter what the reason, coprophagia can put your dog at serious risk of illness, especially if the feces contains parasites or traces of medication the other animal was taking. That’s why it’s important to keep the yard clean and use positive techniques to try to modify the unwanted behavior. 6) Why does my cat attack me for no apparent reason? Unlike the average dog, cats are known for being rather unpredictable creatures. It’s not at all uncommon to be petting a purring cat when, seemingly out of nowhere, it goes into full attack mode, clawing and biting the hand that literally feeds it. According to the ASPCA, this seemingly illogical behavior can actually have very logical reasons behind it. For example, some behaviorists think that repetitive contact, like petting and stroking, can quickly become unpleasant for some cats. In fact, it can cause excitement, pain and even static electricity in their fur. Like people, some cats are more sensitive than others, which explains why they exhibit this type of petting-induced aggression while others don’t. However, if your cat suddenly develops this behavior out of nowhere, it could be pain-induced and a symptom of an underlying medical problem. In this case — once again — you need to find a vet to schedule an appointment with as soon as possible. Yep, our pets can act pretty strange sometimes. And while much of that behavior has logical explanations, in some cases, it could be a sign that your dog or cat has a medical issue in need of speedy attention. That’s why the best rule of thumb is when in doubt, call your vet!