Parasite disease update November 2024 – South West Scotland

It is always interesting and challenging to predict the seasonal variations in parasite disease risk. This year is no exception and the often used phase ‘test and don’t guess’ is particularly relevant.

Liver fluke: At the end of this week we have seen acute and sub-acute fasciolosis cases in the PM room in Dumfries for the first time in a few years. Discussions with practitioners would suggest that there have been sporadic cases seen in practice as well. 

Looking at the fluke recovered from this week’s cases it would suggest infection in late August and September. The subacute fasciolosis case was interesting with the pathology suggesting that the ewe had survived a significant acute infection, but it then presented as thin, hypoproteinaemic with a marked bottle jaw prior to death. 

Best advice remains to examine any sudden deaths and ill thriven sheep to assess fluke risk. Also to use liver fluke serology in lambs and coproantigen testing in ewes to provide early indications of a problem and monitor the efficacy of treatments given as we get further into the ‘season’.

Late grazing cattle: In some situations the warm and dry autumn weather in recent weeks has allowed youngstock to graze for longer with a reluctance to house in such warm and at times humid conditions. Housing may have been delayed beyond the persistent period of any wormers given allowing the opportunity for reinfection with either gut or lungworm. 

For example, it is not unusual for us to see respiratory disease outbreaks in housed cattle which have a bacterial/viral cause, but initiated and complicated by a concurrent lungworm infection.

The key message for farmers is to consider what if any products have been used this autumn, what persistent activity they have had and what might the risk of reinfection have been to ensure that the housing dose is as effective as it can be.

We are happy to discuss cases with you to consider the best way to investigate and manage things. 

Posted by SRUC Veterinary Services on 21/11/2024