Why Would a Dog Throw Up Mucous?

A dog that throws up doesn't necessarily have a serious problem. The animal may have eaten too fast, or ingested too much water too quickly after eating. If you notice something unusual about the vomit -- if it consists solely of phlegm or mucus, occurs frequently or contains blood -- consider seeking medical attention. Only a veterinarian can provide a correct diagnosis for a dog that throws up mucus.

  1. Observation

    • Much depends on whether your dog is vomiting or regurgitating. The two sound similar but are not. Washington State University's College of Veterinary Medicine describes vomiting as expelling the contents of the stomach and intestines, while regurgitating involves the material in the esophagus. Because the esophagus produces mucus, its presence indicates your dog may actually be regurgitating. If the substance your dog throws up is a thin, yellow liquid, your dog may be vomiting bile rather than regurgitating mucus. To determine the problem, observe your dog's behavior. If the dog gags and heaves, it is probably vomiting bile. If there is little warning before your dog spits up, it may be regurgitating mucus.

    Causes

    • A wide range of causes lead to vomiting and regurgitation. Digestive diseases, poison and ulcers can lead to vomiting bile. According to "The Complete Healthy Dog Handbook," issues with the throat, such as megaesophagus, cause your dog to throw up mucus. Megaesophagus occurs when the dog's esophageal muscles don't correctly move food to the stomach. This defect is hereditary but can also result from nerve or muscle damage.

    Diagnosis

    • To determine why your dog throws up mucus, observe the animal's actions and any other symptoms it displays. Watch for issues such as fever, lethargy, diarrhea and lack of appetite. When you take your dog to the veterinarian, mention symptoms you have observed. The veterinarian will examine your dog and test a sample of its vomit. Material with a higher pH tends to be regurgitation. Other diagnostic techniques include endoscopy, x-rays and fluoroscopy.

    Treatment

    • Treatment depends on the exact cause of regurgitation or vomiting, which only a veterinarian can determine. For megaesophagus, a veterinarian may suggest modifying your dog's eating habits or surgery. If another disease or injury contributes to the megaesophagus, treating that condition may improve the esophageal muscles.