In the last issue of Home Farm a reader noted that there could be a confusion between the 'full and plump' feeling of a well-fed lamb and the early stages of 'watery mouth'. In case other readers were wondering how one could tell the difference I thought I would add a few notes from our own experience.
Another name for 'watery mouth' is 'rattle belly', which probably sums up the difference most succinctly. A hand placed under the belly of a well-fed lamb encounters flexible resistance; the lamb feels heavy. It will wake with a start if startled and almost invariably run in to suck. A lamb sickening for 'watery mouth' is listless and unwilling to suckle. The ears often feel cold and the belly is sore and distended. If the lamb is shaken gently the contents of the belly will 'rattle'. One of the first signs seems to be a telltale shivering when the usual causes (wet or cold) are absent. And, of course, there is the wet mouth caused by an excess of saliva which usually dribbles from the corners of the mouth-sure sign of acute stomach pain. If the lamb is over 24 hours old there is often a pale lemon coloured diarrhoea (scour). This should not be confused with the loose dung of a thriving lamb which is a deep orange-yellow colour. However, 'watery mouth' in a new born lamb is usually accompanied by retention of all faeces, including the first dung or meconium.
It is obvious from all these symptoms, that colostrum is vital in the control of I 'watery mouth' in young lambs. Not only does it contain the vital antibodies but its extremely laxative action gets the whole system moving and prevents the build-up of pathogenic bacteria. It is also an important form of central heating. Chilling is almost always a contributory factor in neo-natal sickness in lambs. Even the use of an anti-E.coli vaccination programme for the ewes pre-supposes an adequate 'dose' of colostrum for the lambs.
Several years ago we had an outbreak of 'watery mouth' and lost nearly 10% of our lambs. Most died within four days of birth, some within 24 hours. This was during the transition from lambing mostly outside to indoor lambing and from having mostly singles to a high proportion of multiple births. Although we used drugs and improved hygiene the biggest single factor in the virtual eradication of 'watery mouth' has been the introduction of a group of 50 dairy ewes (mostly Friesland crosses) into our flock of over 400 commercial sheep. They have provided a colostrum 'bank' which has meant that every lamb can receive enough colostrum within the first a hour after birth to give it a good start.
The immunity provided by the colostrum seems to last about seven to ten days. After this time any vulnerable lamb, such as a triplet, weak lamb or gimmer's (shearling's) twin faces a fresh challenge; especially if it is still inside. The lamb obviously has a far better chance of recovery by now. If it is a reasonably strong lamb I would treat it by administering a glucose/electrolyte solution by stomach tube to prevent dehydration. The lamb should be isolated with its mother and sibling(s), preferably under of a heat-lamp. The truly fatal combination for young lambs is E.coli together with pneumonia. If the lamb is very sick I use the drug framomycin (framycetin sulphate) which is very easy and safe be to administer and is extremely effective (and cheap).
If an outbreak of 'watery mouth' occurs the vet will run a sensitivity test on submitted dung samples to test for drug resistance. The E.coli bacteria (and there are hundreds of strains, not all of them dangerous) is able to acquire resistance from other resistant bacteria it comes into contact with. Hence it will acquire resistance to drugs such as penicillin and terramycin, which are commonly used on farms, even though these drugs have riot been administered for 'watery mouth'. A sensitivity test saves a waste of lambs, money and effort. I can vouch for this. In the year we lost so many lambs to E.coli and before we changed vets, our bill for (largely ineffective) medicines was £400.
Hygiene is obviously extremely important. Having always used disinfectant to clean the lambing pens between patients I became unhappy with the idea of the disinfectant contaminated straw going on to our organic muckheap. So we tried ordinary builders lime (hydrated) instead. And, as they say, we have never looked back. There has been no increase in disease. While the disinfected floors were left wet the limed floors, whether earth or concrete, have a nice dry 'seal' to them. Bacteria don't like dry alkaline conditions. Lime is also extremely cheap. Each vacated pen is cleared of straw, swept and limed with a small amount spread evenly with the broom. The pen is then re-strawed. The only disadvantage is that lime is a fine, powdery dust and should be given time to settle before the next lot of lambs are moved in. Compared to the smell of disinfectant this disadvantage seems acceptable. The pens of seriously ill sheep are disinfected in the normal way and the bedding burnt. I hope the above will be of some use to other sheep owners. 'Watery mouth' is very much a disease of intensification, big numbers and prolonged lambing periods. It may never be seen in small flocks. When it does occur however, it's effects can be very distressing.