Veterinary Services

Nematodiriasis is occasionally diagnosed in the autumn. Perth diagnosed the disease in a five-month-old Lleyn cross lamb from a group of several hundred.  Many were in poor bodily condition with faecal staining and several had died despite treatment with moxidectin in the previous month. The intestinal contents were fluid and 62,000 Nematodirus battus worms were recovered from the small intestine.  Moxidectin has no persistent effect against Nematodirus battus.  In addition both glutathione peroxidise (GSH-Px) and vitamin B12 levels were low at 13.4u/ml RBC (reference range > 50 u/ml RBC) and 111pmol/l (reference range >295 pmol/l) respectively. This may have been as a consequence of parasitism and SAC C VS advised that blood samples were collected from further lambs in the group.

Ayr, Dumfries and Edinburgh diagnosed subacute fasciolosis as the cause of death in ewes.  In one case a ewe was submitted from a group where 22 died over a period of four weeks.  A large blood clot was found on the surface of the liver and many immature and mature fluke were detected.  In another case, a four-year-old Texel ewe was presented for artificial insemination as an embryo donor.  Severe ascites was noted on laparoscopy and the ewe died 30 minutes later.  At necropsy the abdomen was found to contain over 15 litres of fluid and the liver was enlarged, soft, pale and covered in fibrin.  No fluke were seen on gross examination of the liver but immatures were seen with necrotic, haemorrhagic tracts on histopathology.

Generalised and systemic conditions

Border disease viraemia was confirmed in a 6 month old Lleyn lamb that was in poor bodily condition with chronic orf-like lesions around the nares and on the lips. Forty of the group of 330 fattening lambs were in poor condition. Seven had died in the previous month. At necropsy the animal weighed only 13.5 kg.  The prescapular lymph nodes were greatly enlarged and a severe pyothorax was found with multiple abscesses throughout the lung field.  Border disease virus RNA was detected by tissue PCR.

Alimentary tract disorders

Duodenal ulceration and perforation with secondary peritonitis was diagnosed by Aberdeen following submission of a bluefaced Leicester shearling ram.  The recently purchased animal became anorexic and bloated a few days after arrival and died shortly afterwards. At necropsy the duodenum was found to be perforated 15cm distal to the pylorus and adhesions had formed to the adjacent omentum.  The abdomen contained brown fluid and fibrin strands.  SAC C VS could find no evidence of a foreign body or intestinal obstruction and suggested that dietary change and stress predisposed the animal to this condition.

Inverness isolated Escherichia fergusonii from faeces of a lamb with profuse diarrhoea. Other affected lambs were febrile and dehydrated.  Two animals died and the rest suffered a severe loss in condition.  Salmonella species were not detected. Histopathology revealed a severe, diffuse and chronic atrophic enteritis with no convincing evidence of parasite damage. The original aetiology was not apparent from the histopathology findings but the clinical picture of a febrile digestive disease in the absence of infection with a Salmonella species suggested that the E. fergusonii was significant. It was previously reported to cause salmonellosis-like signs in sheep (Vet Record, 1999, 144, 511, Bain and Green).
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Musculo-Skeletal conditions

The owner of two pet goats noticed that one had started to lactate from one quarter only. Both goats had crepitus of the carpal joints.   One goat was sero-positive for caprine arthritis encephalitis (CAE) in the agar gel immune-diffusion test while the other goat tested negative. SAC C VS advised testing this goat using the more sensitive CAE ELISA test and culling the seropositive goat.

Nervous system disorders

A six-month-old lamb was found in lateral recumbency and unable to rise.  When supported it attempted to circle to the left.  Proprioception was poor particularly in the forelegs and there was an exaggerated withdrawal reflex in the hind legs.  The panniculus reflex was intact.  A tremor affecting the head and forequarters developed when the lamb was handled.  Pus was found within the atlanto-occipital joint at necropsy at Dumfries.   Trueperella (Arcanobacterium) pyogenes and Fusobacterium necrophorum were isolated on culture.  The source of the infection was unknown.

Skin diseases

 
St. Boswells detected forage mites (Pyemotes species) in samples from pruritic sheep on two occasions.  No other agents were identified. SAC C VS notes that forage mites do not feed on sheep and are not truly parasitic but they do cause pruritus.