Lungworms are a group of parasites that can infest lungs and airways of a dog.
The condition usually becomes chronic over time. Infection can persist for several weeks before the first symptoms become obvious. Dry, persistent coughing, which is sometimes productive is the pre-dominant complaint in infestation with lungworms. Breathing difficulties only occur in rare cases. In the first stages of contracting lungworms, the larvae develop inside a transient host before they are contracted orally. Once they are orally ingested, they travel through the digestive system and pierce the intestinal wall during passage and travel from there via the blood stream to the lungs. It is in the lungs where the larvae become adult worms. After the worms being their adult lives in the animal’s lungs, they produce large numbers of eggs which are coughed up along with mucous, and ingested and swallowed again, as well as being subsequently shed with the feces. It is at this point where the cycle can start anew.
Infection usually occurs after the animal consumes a transient host, which is in most cases, a snail that contains the larvae. Infected dogs constantly shed the lungworms’ eggs inside their feces. Thus, new, transient hosts that come in contact with an infected animal’s feces may become infected. Lungworms in dogs is a rare condition in the UK but known to exist throughout the USA.
Parasites inside the lungs can be identified with x-rays or by an endoscopy of the lower airways. Affected dogs usually show symptoms that are similar to bronchitis. However, the symptoms do not heal when treated with antibiotics. In such a case, a lungworm infection has to be suspected. Treatment can be performed with various anti-helmintic drugs that will are administered over a period of time ranging from a number of days to a number of weeks.
In the case that you suspect that your dog may have contracted lungworms you should consult a veterinarian. If bloody coughing is present, medical attention must be provided as soon as possible. Every pet should receive a quality de-wormer at least every three months in order to protect the animal and the humans around him too.