Post-mortems help tackle pneumonia
FARMERS experiencing more than the odd one-off pneumonia fatality in cattle are advised to ask their vet for an on-farm post-mortem on the next one to help identify measures to prevent them in the future.
Pfizer vet Dan Griffiths gave this advice to northern England vets attending a refresher course on post-mortem techniques. He said a seasonal upturn in cattle pneumonia during the housing period could be expected following just a day or two of fluctuating ambient temperatures or humidity.
At Penrith AHVLA Centre, led by veterinary investigation officers Rebecca Mearns and Andy Holliman, vets were reminded right lungs are often more severely pneumonic than left. “So if you only look at one, make sure it’s the right,” said Mr Holliman. “Ideally, inspect both.”
According to Dan Griffiths, respiratory disease is one of the main avoidable sources of loss in growing cattle. “Minimising it requires a combination of measures,” he said.
Feed costs alone for those extra days would be in the region of £10 to £20 per head
“These include plenty of high quality colostrum for new-born calves; housing that is dry, well-ventilated and draught-free; vaccination where respiratory viruses RSV, PI3 and IBR, and the immunosuppressive BVD are known risk factors and when clinical cases do occur, prompt antibiotic therapy under veterinary direction with an appropriate high efficacy treatment, such as tulathromycin for example.”
In both beef and dairy cattle, Mr Griffiths said the impact of pneumonia on lifetime performance could be profound.
He said a large-scale study, reported in the Journal of Veterinary Medicine Association in 1995, found 78 per cent of animals treated for pneumonia had lung damage at post-mortem examination.
Among group-mates that had shown no signs of disease and were untreated, Dr Griffiths said 68 per cent had damaged lungs when examined, indicating the presence of sub-clinical disease at some time.
“This study, involving 469 cattle, also found six per cent slower growth associated with lung damage,” he added.
“So if sub-clinical disease was present for six months before sale or bulling, for example, affected but apparently healthy animals would take 11 days longer than genuinely healthy ones to reach the same liveweight.
“Feed costs alone for those extra days would be in the region of £10 to £20 per head on most farms.
“Vets who perform farmyard post-mortems report they can be very helpful in making changes for the better on farms where pneumonia disease continues to impair animal and financial performance.”