Veterinary Services

Copper poisoning was diagnosed on analysis of blood and liver samples from a four-year-old Zwartble ewe from a holding near Edinburgh.  This was the second sudden death on the premises. The ewes were fed concentrate feed and had access to a general purpose sheep and cattle mineral.  Blood copper was 30.4 umol/l (reference range <22 umol/l) and liver copper 22,300 umol/kg (reference range <7,859 umol/kg). Testing of the rest of the group was advised to assess the extent of the problem.

Parasitic diseases

Nematodirosis was confirmed on 52 different premises. This compared to 29 in June  2007.  In one case in Aberdeenshire three-month-old lambs were affected.  One or two lambs had died each week and there was scour in the group. No anthelmintic treatment had been given. At necropsy there was gross evidence of a secondary nephrosis in a submitted lamb carcase.

Parasitic gastro-enteritis and nematodirosis were also diagnosed in a six-week-old lamb from Inverness-shire and a two-month-old lamb from Ross-shire. In both cases the history indicated diarrhoea and ill thrift, and in the latter case a significant burden of Eimeria ovinoidalis coccidia was also present.

Three, six-week-old Texel lambs died on a farm in Ayrshire with a history of ill thrift despite anthelmintic treatment two weeks earlier.  Severe haemorrhagic typhlitis and colitis were noted. Large numbers of coccidial oocysts were demonstrated on a smear from the caecal wall and in the caecal contents.  Histopathology of the caecum confirmed extensive, severe mucosal necrosis and inflammation with bacterial invasion and occasional coccidial forms. Coccidiosis with secondary bacterial invasion was diagnosed.

Generalised and systemic conditions

Five sudden deaths overnight occurred in a group of 200 suckled lambs on a farm in Ayrshire.  Necropsy of a two-month-old Texel ram lamb revealed enlarged and haemorrhagic carcase lymph nodes.  Haemorrhages were evident on the lungs and pleura.  In addition, there was a small abscess proximal to the left hind coronary band.  Mannheimia haemolytica was recovered in systemic distribution and Staphylococcus aureus was isolated from the abscess.  Ayr considered that the abscess could be the result of a tick bite with tick-borne fever a predisposing factor to the mannheimiosis.

Septicaemic pasteurellosis due to infection with M. haemolytica was also diagnosed in a three-week-old lamb in an Aberdeenshire flock. Twelve deaths of young lambs were reported over the preceding ten days.

Alimentary tract disorders

Four of 200 eight-week-old lambs were found dead over a short period of time.  Two were necropsied on farm; the first had an intestinal torsion while the second had a severely inflamed intestine without a visible torsion.  A third lamb was necropsied at Dumfries. The entire small and large intestine with the exception of the proximal duodenum was found to be red and congested, with blood stained contents.  The mesenteric lymph nodes were very large but no torsion was evident.  No evidence of clostridial disease was found. Histopathology confirmed that changes in the intestine were consistent with a resolved torsion.  The rumen content was fibrous, there had been no recent change of diet, and the underlying cause of the problem was not known.

Reproductive tract conditions

On a farm in Dumfriesshire four lambs were reported to be stillborn with signs of goitre. No increase in neonatal mortality was recorded and there were fewer barren ewes than usual.  Three lambs were examined. The thyroids weighed 40.5, 136 and 36 g with iodine contents of 24, 288 and 258 mg/kg DM respectively (reference range >1,200 mg/kg DM).  Blood samples collected from six ewes for analysis of inorganic iodine gave a mean of 21 ug/l (reference range 30-40 ug/l).   The lowest result of 6 ug/l was seen in a ewe that gave birth to a lamb with goitre.

Renal diseases

Nephrosis was diagnosed on two farms in Dumfriesshire.  In one case this was in association with parasitic gastroenteritis and in the other with enteritis due to coccidiosis.  On both occasions spongy change was present in the brain white matter consistent with a renal encephalopathy. 

Skin diseases

Corynebacterium pseudotuberculosis was isolated from three of four samples of purulent discharge submitted from shearling tups on an Aberdeenshire holding. Affected sheep had lumps at the base of the ear and angle of the jaw.  This confirmed a diagnosis of caseous lymphadenitis.

Trichophyton verrucosum was isolated on culture of skin scrapes from lambs with crusting lesions around their eyes.  This is the most common cause of ringworm in sheep.