Dogs don’t suffer from anorexia in the human way. They don’t have to fit into skinny jeans or deal with unrealistic Hollywood ideals. But sometimes they don’t eat—and it’s stressful for the people in their lives! If your pup loses his appetite there could be a number of explanations, from illness to depression. In this post we’ll explore them all.

Problems that Affect Your Dog’s Appetite

Gastrointestinal diseases—which affect the esophagus or stomach—can make eating uncomfortable. Causes include parasites, like roundworms, hookworms, and giardiasis; viruses, such as parvo; bacterial or fungal infections; ulcers; and food allergies. Look for the following symptoms: salivation, vomiting, diarrhea and general sluggishness.

Liver diseases cause the body to back up with waste and toxins, which ultimately affects the brain and dulls hunger. Common diseases include chronic hepatitis, liver cancer, cirrhosis (scarring of the liver), and portosystemic shunt (a blood circulation issue). Symptoms include constipation, vomiting, diarrhea, lethargy, swollen belly, orange urine, increased drinking and urinating, yellowed skin, seizures, and occasionally, bleeding problems.

Kidney diseases affect your dog’s ability to filter out body wastes and regulate blood pressure. Loss of appetite is the main symptoms. Others include excessive drinking, frequent urinating (and maybe even urine leakage), vomiting, muscle weakness, and overall listlessness.

Pancreatic diseases decrease the production of digestive enzymes—juices that dissolve food into small pieces the intestine can absorb. If the pancreas is inflamed, those enzymes may actually digest the surrounding organs. This causes great discomfort, not to mention vomiting and lethargy. Pancreatic problems include pancreatitis (inflammation of the pancreas), pancreatic tumors, diseases of the exocrine portion of the pancreas (related to the digestive enzymes), or diseases of the endocrine portion (related to the control of blood glucose).

Blood diseases, including leukemia (cancer of the blood), leukemia-related anemia, blood loss due to ulcers, and polycythemia (excessive red blood cells) can cause reduced appetite. Other symptoms include weakness and even occasional collapsing.

Dental problems, like periodontal disease can make chewing painful. If you notice your dog chewing on one side of his mouth only, that’s a sure sign. Other symptoms include bad breath, bleeding gums, irritability, and even vomiting or diarrhea.

Psychological issues may also affect your dog’s appetite. If you’ve recently moved somewhere new, introduced another pet into your home, or even switched your dog’s food, he may react by snubbing food for a while.

If It Seems Like a Simple Problem

If you don’t notice a string of alarming symptoms, don’t panic just yet! There are a few things you can do right away to encourage him to eat.

• Do a little research. Maybe someone is sneaking him extra treats during the day spoiling his appetite for meals.
• Empty out yesterday’s dish if he doesn’t empty it and replace it with fresh food. This way he’ll be more apt to dig in.
• Make sure you aren’t feeding him expired food, or try a different brand that might be more appealing.

If You Notice Serious Symptoms

If you suspect a serious problem may be the root of your dog’s decreased appetite, schedule an appointment with your vet. He’ll recommend:

• A specific treatment, like antibiotics, to address an underlying cause
• A supportive treatment, like fluid therapy, hand feeding, or appetite-stimulating drugs, to stimulate his appetite