2022 – This year it’s time to get a handle on watery mouth

By Eilidh Corr, Animal Health and Welfare Specialist at QMS

It seems likely that the green and white bottles which are still familiar in some lambing sheds will not be making an appearance this year.  Recently it has become apparent that the only oral antibiotic licensed to prevent watery mouth in lambs has faced supply issues, and the product may not be available for the upcoming lambing season.

It is now widely accepted that it is inappropriate to use this medication “just in case” or to prevent watery mouth, and in recognition of this many farmers have moved away from using it.  And while it may still be of value in outbreak situations, in a well-managed flock there is no evidence to demonstrate better outcomes in lambs that are treated prophylactically at birth compared to those which do not receive the drug, so in most cases it is an unnecessary expense. 

Driving these changes in antibiotic usage was a concern about antimicrobial resistance developing – this is when the bacteria on your farm evolve to survive treatments, making medication ineffective.  SRUC data from 2016 found that a third of E. coli samples from young lambs were resistant to spectinomycin, the active ingredient in this medication.  On those farms, the drug is likely to have been of no benefit at all – a waste of time and money.

‘Is there any good news to be had?’ you might well ask at this point.  The answer is definitely “yes”.  For those who do not routinely use oral antibiotics in their lambs, this acts as a reminder to continue maintaining high standards of husbandry and management.  And for anyone who is now worried about how they might cope this lambing season, there is still time to implement measures to prevent the disease from rearing its head in the first place.

There are three main areas to focus on: nutrition, hygiene and colostrum.  Nothing new there!  But some simple steps can make an enormous difference in the level of risk your lambs will face, and for best results, you need to start these preparations during pregnancy.

• Nutrition: the lambs most at risk for watery mouth will be those which are less vigorous, perhaps multiples, and those whose dam is not producing good quality colostrum.  All of these factors can be addressed by getting nutrition right – you are aiming for lambs that jump up and suck by themselves, minimising your workload.  While condition scoring is absolutely essential, also consider having your vet carry out some metabolic profiling: blood sampling 10 twin or triplet-bearing ewes, around a month before lambing, is a great way of checking you’re on the right track with protein and energy, helping avoid diseases such as twin lamb and milk fever.  Sample them before, or more than four hours after, feeding.
• Hygiene: ensure your lambing shed is as dry as possible.  Consider things like leaky gutters, spilt water buckets and the like.  Dispose of bedding from pens after each use, preferably disinfecting too – you can put powdered lime on the ground before replacing with fresh straw.  All hygiene measures need to be tightened as lambing progresses, because the bugs which cause disease will accumulate in the shed over time.  Don’t forget to wash or sanitise your hands between jobs, and sterilise equipment such as stomach tubes after each use.
• Colostrum: have a plan in place for when things go wrong.  Powdered replacements are convenient and far better than no colostrum, but their benefits are limited.  Suitable only for emergency use, they will be far less effective at protecting your lambs from watery mouth than the real thing.  Think about whether you could store spare colostrum from milky ewes with singles – using clean hands, milk it into a zip-lock bag (breast milk storage bags are ideal) and it can be safely stored in the fridge for several days, or frozen flat.  Warmed up gently in a pocket or a cup of warm water (never defrosted in a microwave or heated harshly – it is a living substance), it is much better at protecting lambs from disease than any antibiotic.

Getting a plan thought out in detail now will make any changes easier to implement once things get hectic in the spring.  I would encourage you to get in touch with your vet sooner rather than later, particularly if you’ve had problems with watery mouth in the past.  They are familiar with your buildings, understand disease and parasite issues specific to your flock, and can give you bespoke advice.  And, finally, if the worst happens and you do see cases of the condition, they will be able to help with alternative treatments.  However, with good planning and attention to detail, that is a conversation you can hopefully avoid altogether.