It’s easier to write BVD rather than give this insidious and too often unacknowledged cattle disease its full name, bovine viral diarrhoea – not least because I find diarrhoea one of the trickiest words to spell, no matter how often I make the attempt.

I say unacknowledged because in spite of evidence from the SAC veterinary division that almost 40 per cent of beef herds have been exposed to the BVD virus and about 17 per cent show signs of active infection, too many farmers either don’t appreciate how much of a problem the disease is or refuse to accept the evidence.

That refusal or lack of knowledge is difficult to understand when beef herds affected by BVD can be losing an estimated £37 per animal and dairy herd losses can be up to £90 per cow.

Given what we are often told are the razor-edge finances of beef and dairy farming, any effort to prevent losses must be worthwhile. Yet as with almost anything to do with preventable animal disease, some farmers are reluctant to either learn what can be done or take action.

Nigel Miller, president of NFU Scotland and a qualified veterinary surgeon, has advocated action on a number of animal diseases since he began to make his way up the NFU leadership ladder.

So much so that it might only be coincidence that awareness of BVD as a national problem in cattle herds has increased at the same time, that is in the past 10 years. That awareness has reached the stage of a Scottish government consultation and Mr Miller’s call last week for a compulsory BVD testing scheme to be considered.

The huge animal welfare and financial implications of BVD, he said, mean that eradication by identification and culling is realistic, but only if the scheme is national with an element of compulsion after an initial voluntary phase.

He is right about the compulsion. We have seen too many times – the continued prevalence of sheep scab the best example of the worst that can happen – that voluntary schemes to eradicate animal disease do not work because a percentage of farmers that might be small, but is remarkably stubborn, refuse to take part.

That was recognised in December when new controls to deal with sheep scab were introduced. Keepers of sheep who fail to notify the authorities of scab in their flock, or fail to take action, can now be prosecuted. It’s not exactly tough action, but it’s a step forward.

Mr Miller, as NFU president, can’t say that a witless few farmers, some possibly his members, should be banned from keeping livestock of any kind. What he did say last week was that farmers who attended a series of meetings on BVD earlier this year “are well informed”. But many others are “not up to speed”.

In short, those going to the meetings tended to be the ones who were already aware of BVD while those who weren’t aware or didn’t want to know didn’t go – the age-old problem for any organisation, from parent-teacher associations to religious fanatics, of preaching to the converted.

We can only hope that compulsory testing for BVD, whether introduced in September as the Scottish government has proposed, or from the beginning of next year as NFU Scotland prefers, will bring home to every cattle farmer the need to eradicate a distressing, expensive disease.

Action to take includes blood or bulk milk testing. If persistently infected animals are diagnosed, work out an action plan with your vet – that might mean vaccinating all cattle on the farm. Have a bio-security plan to avoid the risk of buying in infected cattle, and run annual testing.

No one says it will be easy, but Mr Miller points out in a leaflet of practical advice: “Farmers must work together as an industry to successfully eradicate this nasty disease. BVD is our most significant production disease, not only because of its direct impacts on fertility, but through the suppression of immunity, allowing pneumonia and other infectious diseases to gain hold.”

As with BVD and sheep scab, so with tail docking of sheep as far as the witless, stubborn, few are concerned, except that in the case of docking – removing a sheep’s tail – we are back in the parallel universe of pedigree breeding. There, for some breeds, it is deemed that cutting off a tail to as near the spine as possible is necessary to show off breed points, rather than the normal tail-docking necessary to prevent the accumulation of faeces that can cause welfare problems with flies laying eggs there and maggots hatching out.

Such docking must leave a section of tail long enough to cover the anus of male sheep and the vulva of females. “Pedigree” docking cuts way above that and is illegal. Yet some breeders keep doing it. They have been warned, again, that if identified by animal welfare inspectors – usually when exhibiting sheep at shows, so IQ might be a factor as well as stubbornness – they can be prosecuted.