Teeth issues significant cause of thin ewes

Teeth issues may be responsible for a greater number of ewes being in a thin state of body condition than previously thought. This was one of the findings from the recent Thin Ewe Scheme or study carried out by the Department of Agriculture Regional Veterinary Laboratories (RVL) and Teagasc.

The results of the study were presented by Seamus Fagan, Athlone RVL at last week’s Teagasc lowland sheep conferences held in Galway and Meath.

Seamus presented the findings detailed in Table 1 which showed teeth issues to be the primary cause of poor condition in 17% of ewes assessed.

The teeth issues are not the common problems we expect in sheep with broken mouths, ewes missing teeth etc.

They are concerned with the back teeth with two main areas – back teeth protruding to one side and causing pain and discomfort and abscesses creating similar challenges.

In explaining how teeth issues can be so serious in sheep, Seamus said that sheep can commonly graze / chew for upwards of 10 hours a day and anything that causes pain has the potential to disrupt normal grazing habits leaving ewes contending with a nutrient deficiency.

It is hard to diagnose such issues as farmers typically do not notice if sheep are not grazing for long periods.

Seamus says that the effect that teeth issues can have on body condition and performance is an area he has found has been under-diagnosed for quite some time.

He encouraged farmers at the event to start to pay more heed in exploring if teeth issues are a problem where ewes are losing condition for no apparent reason or possibly throwing up their cud.

This can be completed by rubbing your hand along the jawline and feeling for teeth protruding.

A check for the presence of abscesses can generally be completed by rubbing the area under the jawline and feeling for any swelling.

This is demonstrated in photo two which shows significant swelling on one jawline.

There is no real options for treating such issues.

Anti-inflammatory medicines or antibiotics can possibly mask over problems for a while but it is questionable if sheep will recover.

The advice where there are doubts if teeth issues are responsible for problems is to give them priority feeding for a month or so and if sheep do not gain condition then irrespective of the cause of the problem they should be identified for culling.

Getting back to the aim of the study, the Thin Ewe Scheme was carried out to provide information on the cause or origin of disease processes causing chronic ill thrift in ewes in Irish sheep flocks where thin ewes were perceived to be a substantial problem. In particular there was a focus on establishing the prevalence of so-called Iceberg diseases and their contribution to routine conditions relative to dentition and parasites.

This information would then be used to inform discussions among stakeholders and help address questions such as if voluntary led control programmes were required.

Maedi visna was highlighted as one such Iceberg disease of note.

Seamus said that the RVLs are still happy that maedi visna has not made any major inroads in Ireland.

He said there were some issues in a small number of flocks including milking flocks, but highlighted that control programmes have seen these issues addressed with biosecurity an important factor in preventing disease.

Four other Iceberg diseases were investigated – Caseous Lymphadenitis or CLA; Ovine Pulmonary Adenomatosis (OPA) or ‘Jaagsiekte’; Pseudotuberculosis (Johnes Disease) and Border Disease.

The prevalence of the first three at a rate ranging from 3.8% to 6.7% denotes that these diseases are established in the Irish flock but at a relatively low level.

Farmers should be mindful that they do contribute to poor performance and send any fallen animals for post mortem analysis or carry out flock inspections where issues are suspected.

The greatest cause of ill thrift in ewes in the study was linked to parasitic problems. A relatively new disease to Ireland which has been causing a spike in problems over the last three years is haemonchus contortus or what is commonly known as barbers pole worm. Cases have been most prevalent in the south of the country due to higher temperatures but problems have also been encountered elsewhere.

The worm species has a highly efficient reproductive system with the potential to multiply rapidly. Problems are often first suspected when faecal egg counts spiral to upwards of 5,000 epg in a relatively short period. The presence of such a high number of parasites can have detrimental consequences in a very short period of time with adults sucking 0.5ml of blood per day.

Clinical signs are ewes quickly losing body condition and demonstrating similar classical symptoms to liver fluke. It can be treated by active ingredients present in flukicides such as closantel. Seamus is encouraging farmers that are experiencing problems with ewes losing flesh and possible cases of mortality to keep the threat of haemonchus in mind.

Excellent flock health management goes down to the individual animal. Condition scoring is a valuable tool in monitoring performance. Ewes continually in poor condition can act as a resevoir for disease and should be culled if they fail to respond to priority feeding.

In short