Ask the Vet

Ask the vet (with Rosie Booth, as before)

Q. When a vet talks about doing diagnostic work for an outbreak of pneumonia, what does that mean, and is it worth it?

Certainly knowing what you are up against, with any disease, is worthwhile.  Pneumonia is also a very good example of a disease that can be caused by a wide range of bacteria and viruses, which means it can be very difficult to diagnose simply by examining the animal.  And, of course, correct diagnosis will help decide on the best treatment regime, as well as how to prevent the disease from occurring again.

Recent work published in the veterinary press has found that in a group of calves which suffered an outbreak of respiratory disease, Pasteurella* was the most commonly found bacteria.  These tests were done both on the lungs of animals which died and also on nasal swabs; it was found in 90% of the lung samples, and 85% of the nasal swabs.

More often than not, pneumonia will involve bacteria (such as Pasteurella) and a virus (RSV, PI3 or IBR, for example).  In cattle throughout the UK, Pasteurella and RSV most commonly cause disease in younger calves, while IBR often affects slightly older animals.  PI3 is a common viral component of pneumonia in calves of any age.  There remains only one combined viral and bacterial vaccine on the market – Bovilis^® Bovipast RSP, which can be administered from as early as two weeks of age.  This can then be followed up with Bovilis^® IBR vaccine, in at-risk herds, or in herds with a history of IBR outbreaks.  Of course it is also worth remembering that antibiotics act only on bacteria; they have no effect on a viral infection.

Q. Assuming that the cause is identified, is vaccination the only option and can its cost be justified?

No, vaccination is not the only option, nor should it be considered the 100% secure way of preventing pneumonia on a unit.  Respiratory disease is a multi-factorial condition which means that the chances of it occurring are influenced by many things ranging from ages of stock, building design, moving and mixing animals and also whether calves are housed near older animals or the milking herd.  Everything must work together with vaccination to reduce the risk; vaccination should certainly not be viewed as a ‘cover’ for poor housing or management.

In terms of cost, a typical course of two doses of pneumonia vaccine costs less than £10/head.  Independent vet studies have shown that the losses associated with an outbreak of pneumonia are £43/dairy calf and £82/beef calf.  No-one can manage a business with regular losses like this, so prevention is critical.

*Pasteurella, also known as Mannheimia (Pasteurella) haemolytica