Friday, 22 February 2019

Dealing with lameness at lambing time

In this month’s blog, qualified vet, Liz Nabb tackles the topic of dealing with lameness at lambing time.

Housing ewes prior to lambing can bring problems when it comes to infectious lameness, especially when they are housed for a long time.

Although frequent bedding-up helps to maintain a dry lying surface, the warm and damp conditions beneath create a perfect environment for bacteria to grow. With the ewes so close to each other, it makes conditions ideal for the rapid spread of scald/footrot and Contagious Ovine Digital Dermatitus (CODD).

So how can we ensure that we do the best for our flock, avoid spreading disease and use this time to your advantage to gain control of infectious lameness?

Stop the spread

Perhaps unsurprisingly, catching ewes for early treatment and segregation of affected ewes is easier to do when they’re housed than when they’re in a field.

One tip that will help is to try to separate lame ewes at the point of housing, with lame ewes being placed in a separate pen until they are fully recovered.

A lame ewe among a large group will likely have a reduced feed intake, especially if concentrates are trough fed. This puts her at risk of twin lamb disease and other problems. Separation also has the added advantage of allowing you to make sure that they are getting their full ration.

It is also important not to turn ewes and their lambs out until they are sound. Healthy feet means less pasture contamination, reducing the risk of spread and leading to fewer problems in both ewes and lambs later in the spring.

Appropriate treatment

Any ewes that you think might be lame should be caught and checked as soon as you notice them. Make sure you take the time to watch the ewes closely as it can be hard to spot early signs of lameness at a high stocking density and on bedding. Sometimes the sign can be as subtle as a change in their behaviour. If you are worried about tipping up a heavily pregnant ewe to check her feet then simply pick each foot up individually instead - do whatever causes the least stress for both of you.

If the ewe has infectious lameness, treat it with an injectable antibiotic and use an antibiotic spray on all four feet. Don’t be tempted to delay treatment because of the pregnancy. The most commonly used antibiotics carry little risk for pregnant ewes and a sheep in pain will be under far more stress than one which is promptly caught and treated.

Don’t be afraid to use injectable antibiotics either. Individual treatments are justified for reasons of both welfare and for the prevention of further cases in the long run. This includes scald, which has been shown to be highly infectious and can shed more bacteria than footrot cases. Whole flock treatments, including antibiotic footbaths, however, cannot be justified in this era of responsible antibiotic use.

Recognising the cause of the lameness is key for treatment selection, in particular for CODD, which can have a disappointing response to the antibiotic oxytetracycline. 

Lameness in lambs

The main cause of lameness in young lambs is joint ill. Sometimes lambs can appear to be weak and unable to stand before joint swelling develops. This leads farmers to mistakenly assume selenium deficiency instead. A correct diagnosis is vital because joint ill needs to be treated quickly for there to be any chance of a full recovery.

Joint ill in young lambs (less than three weeks old) is caused by bacteria which are almost always non-responsive to oxytetracycline. It also requires lengthy treatment to achieve full recovery, often between seven and 10 days. Ask your vet for an anti-inflammatory too, as a lamb in pain is less inclined to suckle.

If your lambs are still lame after a course of antibiotics they should be euthanised as joint damage sadly means they will be in pain for the rest of their life.

Other infectious causes of lameness rarely tend to affect lambs until they are a little older. The odd case of scald can be managed with antibiotic spray. 

Put the foot trimmers away

It is good practice to examine the feet of every ewe as soon as you get the chance. However, don’t be tempted to have a snip – a bit of hoof overgrowth is to be expected following housing on soft bedding and the horn will soon wear away after turnout. Foot trimmers are also an easy way to accidentally spread infection from ewe to ewe and, at worst, can lead to lasting damage.

Finally, if you have a board for recording births, etc., make a note of the ewes which have been treated for lameness. This will make it easier for you to track repeat offenders and to make culling decisions later on.

Liz is currently researching strain specific vaccinations for footrot and is funded by AHDB. Her project will complete in autumn 2021.

For more information see the BRP manual Reducing Lameness for Better Returns and watch the podcast recording ' Lameness, the five point plan and top tips'