Several different ailments can cause chest congestion in dogs ranging from fairly innocuous problems to extremely serious ones. The immediate cause of congestion is usually fluid in the dog’s lungs. To treat the animal, your vet has to determine what's causing the congestion.
Race Foster, D.V.M., describes pneumonia as a serious infection or irritation that causes fluid to collect in the dog’s lungs. Causes include bacterial, viral or fungal infections, inhaling an irritant like smoke or foreign objects into the lungs or another underlying condition like congestive heart failure. (See Reference 1)
Symptoms, Diagnosis and Treatment of Pneumonia
A dog with pneumonia will have trouble breathing and probably will have bluish lips and/or gums because its tissues aren’t getting enough oxygen. If the dog has an infection, it may run a temperature of more than 104 degrees Fahrenheit. If the illness is caused by a heart problem, the animal’s temperature is more likely to be normal. If you spot any such symptoms, you should take your dog to the vet immediately.
Vets diagnose these illnesses by physical examination and chest X-rays or ultrasounds. If fluid has built up in the dog’s lungs, the vet may take a sample to find out if there’s a bacterial, viral or fungal cause for the illness. Once the vet determines the cause, he will prescribe medications to treat the dog. (See Reference 1)
Congestive Heart Failure
According to Vet Info, an informational web site, chest congestion in dogs can be a symptom of congestive heart failure, an extremely serious and sometimes fatal ailment that results from the heart not performing efficiently. As a result, fluid builds up in the dog’s lungs and, sometimes, in its belly. Congestive heart failure is the most common heart problem in dogs. (See Reference 2)
Some breeds of dogs are more prone to congestive heart failure than others, but being overweight also puts your dog at greater risk of developing the disease. Steps you can take to help minimize the chances your pet will develop this problem include keeping it active, feeding it a high protein, low sodium diet, limiting the amount of table scraps you give it, making sure it has plenty of clean water to drink and taking good care of its teeth, since dental infections can travel to the heart and damage it. (See Reference 2)
Symptoms and Treatment of Congestive Heart Failure
The most obvious sign that your dog may have congestive heart failure is a persistent, dry cough but other symptoms you can readily observe include fainting or collapsing suddenly, distress and/or agitation, a distended belly, a bluish tongue and/or gums, exceptional fatigue after even mild exertion and fast or labored breathing, including wheezing and gurgling noises.
If your vet diagnoses your dog with congestive heart failure, he probably will treat it with drugs that improve the heart’s performance, and with diuretics, which remove excess fluid from the dog’s body. (See Reference 2)
Electrical shock can damage a dog’s lungs and lead to congestion. If a dog chews an electrical wire and gets shocked, the electricity can travel to the lungs and burn them. The lungs will then fill with fluid, inhibiting the dog’s ability to breathe.
If your dog gets shocked, examine it right away to see if it’s suffered burns to its mouth. Such burns will take several days to heal, but their presence also indicates that your dog has gotten a serious shock. Watch the animal carefully for several days. If it shows any signs of respiratory distress, take it to the vet immediately. (See Reference 3)