Lungworm: Diagnosis and Prevention

A Reduced Threat This Year, But Vaccination Remains Crucial

Published on: Feb 27, 2023

Fewer Cases Due to Weather

Good news for cattle farmers! Lungworm cases have been uncommon this year, likely due to the extended dry summer followed by a mild autumn. However, a recent report from the South West of England suggests a potential decrease in the effectiveness of eprinomectin, a common lungworm treatment. This emphasizes the importance of vaccination as a preventative measure.

Signs of Lungworm Infection

• Persistent coughing throughout the herd
• Increased breathing rate
• Difficulty breathing
• Weight loss
• Reduced milk production in lactating cows
• In severe cases, cattle may become lethargic, stand with their head down and neck outstretched.

Lungworm Life Cycle

1. Cattle ingest lungworm larvae while grazing.
2. Larvae migrate to the lungs, mature, and reproduce.
3. Eggs are coughed up, swallowed, and hatch in the stomach.
4. New larvae develop and are passed in feces.
5. Larvae mature on pasture and become infectious.

Diagnosis and Treatment

• Microscopic examination of feces for larvae confirms lungworm infection.
• Early treatment is crucial, as severely affected animals may not respond.
• Dead or dying larvae can worsen symptoms by blocking airways.

Who’s Most at Risk?

• Calves in their first grazing season, especially dairy calves and autumn-born suckler calves.
• Risk factors include lack of prior exposure, wet summers, and high stocking densities.

Prevention with Vaccination

• Huskvac vaccine provides protection.
• Two 25ml oral doses, four weeks apart, are given to healthy calves over 8 weeks old.
• Vaccination should be completed two weeks before turnout.
• Immunity is typically maintained through seasonal exposure to larvae on pastures.
• If grazing practices limit exposure (e.g., extensive anthelmintic use, clean pastures), a booster dose of Huskvac is recommended before turnout.

By being aware of the signs and risk factors, and prioritizing vaccination, cattle farmers can effectively protect their herds from lungworm.