Mediastinitis in Dogs
An inflammation of the mid-chest area is usually caused by a bacterial infection or a fungus. It’s rare in dogs, but in severe cases it may be life-threatening. It is also likely to spread, infecting the bloodstream. Abscesses sometimes develop, and the short vein (called the cranial vena cava in animals) that carries deoxygenated blood from the upper half of the body to the heart's right atrium may become infected. These abscesses can cut off the flow of blood to the heart, resulting in death.
Symptoms
- Gagging
- Drooling
- Difficulty swallowing
- Vomiting
- Lethargy
- Swelling of the head, neck, and front legs
- Difficulty breathing
- Fever
Causes
Dogs often try to eat and swallow inedible things, often causing blockage in the esophagus. This is followed by drooling, gagging, difficulty swallowing, and vomiting -- the usual signals for blockage. These and other signals may be depend on the location of the foreign object, the degree to which the esophagus is obstructed and the length of time of the blockage.
A partial obstruction, for instance, may allow fluids to pass, but not food. If the obstruction has been there for an extended period of time, the dog may refuse to eat, lose weight and/or become more tired. The foreign object may puncture the esophagus, resulting in an abscess, inflammation of the chest cavity, pneumonia, or abnormal breathing. Even after the foreign object has been removed or regurgitated, pneumonia may develop.
Another possible cause of mediastinitis is a blow to the neck or chest, or a wound to those areas.
Diagnosis
Tests of various kinds will be conducted to rule out a range of possible causes for the symptoms; among these:
- Respiratory tests
- Examination of the digestive system
- Blood tests will determine whether there is an infection and what that infection is
- X-rays are used to identify any foreign bodies
- A scope of the esophagus with contrast dye may also be necessary
Treatment
If your dog has a severe infection, it will require hospitalization. A drainage tube is usually inserted into the lungs and intravenous (IV) fluids will probably be used to balance electrolytes until your dog is able to eat again. And if there is an abscess, surgery will be required.
If there is a foreign body, it will generally be removed with a flexible endoscope and forceps. If the foreign body has smooth edges, a tube with suction may work to get it out. For sharp foreign bodies such as fish hooks, a large tube may be placed over the endoscope to draw the item out without tearing up the esophagus.
If all of these methods fail, the foreign body may be pushed into the stomach where it can move through the digestive tract or be surgically removed. If the foreign object has perforated the esophagus, surgery will also be required. This is the worst possible scenario because the esophagus does not heal very well.
The veterinarian will put the dog on a regimen of antibiotics if it is determined that the infection is bacterial. If the infection is due to a fungus, the animal will be put on antifungal drugs. However, a dog will be on an antibiotics regimen for a relatively short time as compared to antifungal treatment, which may last as long as six months. Antibiotics can also be prescribed after removing the foreign object to prevent infection.
Living and Management
You will need to keep track of the dog's temperature daily. If it is hospitalized, blood tests will be conducted every two to three days, for up to a week. X-rays of the lungs will be taken every seven to ten days.
The antibiotics regimen will usually continue for a week after the blood tests and X-rays find no more infection. And for another four to six weeks if an abscess was found originally.