If you’ve had a dog for very long, you probably know all the basics: most dogs need to be taken on walks at least once per day and they should visit a vet or animal hospital once per year for an annual checkup.

But what about when there’s something wrong with your pet demanding medical attention? Would you know what to look out for?

There are many reasons why dogs are good pets. But as human-like as they often seem, dogs can’t tell us when they aren’t feeling well. We have to be observant enough to notice when they seem under the weather and prepared to know what to do when sickness or injury occurs.

To help you better care for your canine friend, the following are seven warning signs that you should take your dog to the vet.

1. Sudden Weight Loss

If your dog loses weight very suddenly or faster than normal, you should take them to the vet. This goes for dogs at any weight, even if your dog tends to be overweight. When an animal loses weight suddenly and unexpectedly, it could be a sign of a serious health condition. If your dog loses 10% of its body weight, you should tell your vet (in small dogs, this could be as little as one pound).

2. Dragging or Scooting Rear

While it can look amusing when your dog starts to drag its rear around, it’s no laughing matter. It could be a sign that your dog has worms, diarrhea, blocked or infected anal glands, or a urinary tract infection. In any case, you should take your dog to your vet clinic if you notice this kind of behavior.

3. Acting Tired or Sluggish

If your dog suddenly seems lethargic and tired all the time, there may be something bothering them. If your dog is usually at least somewhat active, but they’re suddenly uninterested in playing, taking walks, or doing other activities they used to enjoy, take note. Fatigue and sore muscles are normal after a lot of activity or during high temperatures, but if your dog’s condition persists for more than two days, you should take them to the vet.

4. Unusual Eating Habits

It’s not unusual for dogs to occasionally skip a meal, especially if the weather is hot. However, if your dog refuses to eat for two days, this is a definite red flag that something isn’t right. In these cases, you should take your dog in for an examination.

Certain diseases cause dogs to develop unusual eating habits. If your usually well-behaved pet suddenly begins routinely raiding the pantry or garage for snacks, they may have a problem.

5. Dry or Rough Fur

A healthy dog’s coat should be shiny, soft, and thick. If your dog’s coat becomes dull, dry, or rough, or if it develops bald patches, there’s most likely something wrong. The solution could be as simple as changing dog food brands, or as complicated as getting treated for a disease. Either way, a trip to the vet is a must for these symptoms.

6. Vomiting

As disturbing as it may seem to us, occasional vomiting is not unusual for dogs and other animals. Often they just need to get rid of something that didn’t sit well with them. However, if your dog starts vomiting frequently or several times in a row, vomits blood, or has a fever and vomits, you should call your vet immediately. Severe vomiting could go on to cause diarrhea or severe dehydration, so don’t wait to seek treatment.

7. Red or Cloudy Eyes

If your dog’s eyes become red or cloudy, this could be a result of an infection or injury. Squinting or excessive discharge coming from your dog’s eyes are also details that should concern you. In any of these cases, you should take your dog in for a checkup as soon as possible. Diseases that affect the eyes can progress very quickly and some can cause blindness. Medication can often cure these types of conditions.

By keeping a watchful eye on your pet and knowing what to look out for, you can expect to enjoy many happy years of companionship with them.