Veterinary Services

 
Deaths due to chronic copper poisoning were confirmed on two farms in the Dumfries area.  In one case three rams died in a group fed cattle cake.  Postmortem findings of jaundice, orange livers, black kidneys and haemoglobinuria were consistent with copper poisoning and this was confirmed on analysis of liver and kidney copper content.  The highest liver copper result of 32,100umol/kg, (normal range 314 – 7850 umol/kg), triggered a report to the Food Standards Agency (Scotland).

Parasitic diseases

Chronic fasciolosis due to the liver fluke Fasciola hepatica continued to cause losses, with a total of 34 outbreaks.  However, no cases of acute fasciolosis were recorded. SAC C VS considered this possibly reflected the adverse effect of very cold weather on the overwintered snail population (Galba truncatula). 

Generalised and systemic conditions

Septicaemic listeriosis was diagnosed in a ten-day-old lamb submitted to Aberdeen.  A single death was reported in a group of six housed ewes and lambs. The ewes were being fed baled silage, suspected to be the source of the Listeria organism.

Black disease due to Clostridium novyi was diagnosed in a two-year-old crossbred gimmer, one of seven animals to die in a group of 80 over a period of two months.  Flukicide treatment was given later than normal and adult liver flukes were evident in hepatic lesions.  A review of clostridial vaccination policy was recommended.

Reproductive tract conditions

Abortion enquiries dominated submissions and a range of pathogens were identified.  Abortion due to Toxoplasma gondii was the most common diagnosis, being confirmed on 48 separate units, while abortion due to Chlamydophila abortus, the next most common, was confirmed on 40 different occasions.

Abortion due to infection with Salmonella species was diagnosed in four flocks, all of which were in the Aberdeen area.  Salmonella Montevideo infection was confirmed in material received from four aborting ewes and gimmers from one flock.  The sheep were reported to be otherwise healthy.  Salmonella Montevideo was confirmed in this flock in previous lambing seasons.  A profuse growth of Salmonella Brandenburg was isolated on culture of a placenta submitted from another flock.  On this occasion the affected ewes were reportedly sick for several days around the time of abortion.  On a separate unit scouring, abortions and deaths in periparturient ewes were due to infection with Salmonella Typhimurium phage type 120.  Abortion due to Salmonella Derby was suspected in an upland crossbred flock. 

Abortion due to Listeria monocytogenes was diagnosed in five flocks. A total of 13 abortions occurred in a group of 300 Suffolk and Scottish mule ewes in an Ayrshire flock approximately one week prior to lambing.  Some of the flock received prophylactic antibiotic, as C. abortus was demonstrated previously in abortion material.  Toxoplasma antibodies were also detected in foetal fluid, and blood samples from aborted ewes were requested to clarify the relative importance of the various abortefacients.

An abortion storm was attributed to tick borne fever in a flock in Inverness-shire.  Pregnant ewes were purchased two weeks previously and subsequently developed severe pyrexia, malaise and abortion.  All the foetuses submitted for examination had fibrinous pleuritis and peritonitis, congested livers and pulmonary hemorrhages (figure 4 - see top right-hand side).  There were no ewe deaths, but a blood smear from a live ewe was positive for tick borne fever.  This case was consistent with tick activity resuming during the brief period of milder weather.  The bought–in sheep came from two different sources and it was noted that only sheep from one source aborted. The sheep sourced from a known tick area did not abort and SAC C VS suggested they had some degree of immunity as a result.