Lung Worm

Recently we have been seeing cases of lungworm in cattle and while it is normal to see a few every year, outbreaks are certainly more common during wetter summers like the one we’ve been experiencing. Lungworm is a parasitic infestation of the bovine respiratory tract ingested from grazing contaminated pasture.

Just like gastrointestinal worms, animals become infested by eating grass contaminated with infective larvae.
However, the difference is, once ingested the larvae migrate through the bloodstream into the lungs where they develop into adults, once in the lungs they cause damage to the air sacs in the lungs and live in the bronchial tubes. Once they are adults they produce a tremendous amount of eggs, the eggs are then coughed up out of the lungs into the trachea and swallowed. These eggs become larvae and are passed in the infested animals feces. The entire cycle takes about one month.

Lungworm is typically seen in older calves from July to October. If left untreated, the disease may not be noticed until after cattle are brought home from pasture. Widespread coughing in a herd is the most notable sign but signs also include weight loss, diarrhea and laboured breathing. Death can occur in heavy infestations.

Finding these larvae in manure is one of the ways we can diagnose the condition. It is a different test than looking for the intestinal worm eggs. While it is treatable, many factors play into what we may recommend for your herd.

If you suspect this pest or have more questions give us a call!