Veterinary professionals are urging milk producers to consider vaccinating valuable herd replacements pre-housing this autumn.
Last winter the bacterial organism M.haemolytica was by far the most commonly diagnosed cause of pneumonia in housed dairy calves.
According to AHPA data, pneumonia diagnoses attributed to this common bacterial cause were particularly prevalent in both unweaned and weaned dairy calves over the November 2019 to March 2020 period.
MSD Animal Health said it was important for farmers to understand that both viruses and bacteria can cause pneumonia.
The firm's veterinary adviser, Dr Kat Baxter-Smith said: "However, many viral and bacterial respiratory pathogens live harmlessly as part of the normal micro-organism profile of the respiratory tract of healthy cattle.
"But when a calf’s resistance is reduced as a result of significant environmental challenges – or where there is an overwhelming pathogen load – then financially damaging outbreaks of pneumonia can result."
Dr Baxter-Smith added that whilst farmers can treat calves showing signs of pneumonia – with antibiotics and non-steroidal anti-inflammatory medications (NSAIDS) – preventing performance-limiting permanent lung damage may not be possible.
Pneumonia is the most common reason for poor performance and death in growing calves, so immunity-led disease prevention should be the focus for all calf rearers, she said.
“Sound colostrum feeding practices and vaccination with a multi-valent vaccine that will deliver protection against both common viral and bacterial pathogens can play an important part here; as will effective management of the key disease risk factors."
Improving the rearing environment, reducing stock density, not mixing age groups and isolating any clinically affected animals are all measures farmers can take to reduce chance of pneumonia.