Veterinary Services

Nutritional and metabolic disorders

Pregnancy toxaemia was suspected in a six-year-old South Down ewe on an Aberdeenshire unit that died following a period of depression and nervous signs, progressing to recumbency. Previous blood sampling of three similarly affected ewes from the same group revealed consistently elevated serum beta-hydroxybutyrate concentrations. All ewes were described as being in ‘good-to-fat’ body condition.

St Boswells diagnosed hypocalcaemia in recumbent greyface ewes due to lamb in five weeks. This group was outside with access to hay and energy blocks. Serum calcium levels in four affected ewes ranged from 0.8 to 1.1 mmol/l (reference range 2.0 – 3.0).

Generalised and systemic conditions

A Suffolk lamb from a holding in Ayrshire was observed by the owner lying in lateral recumbency and died shortly afterwards. Postmortem lesions included enlargement of the body lymph nodes and spleen, epicardial haemorrhages, and soft kidneys with areas of necrosis and petechiae in the cortex. Glucose and protein were present in urine collected from the bladder, and epsilon clostridial toxin was detected in bowel filtrate. These finding confirm the diagnosis of pulpy kidney disease.

Alimentary tract disorders

A farmer in Dumfriesshire reported losing four adult Scottish blackface ewes within a week. Beet pulp and concentrates had been introduced in the previous two weeks. On postmortem examination the oesophagus was distended with a solid column of beet pulp, none of which was found in the rumen.

A two-year-old Cheviot wether died suddenly in flock of 35 sheep on a holding in Inverness-shire. The lungs were dark red and congested and there was white froth in the trachea, which had a dark red mucosal surface. The mediastinal lymph nodes were enlarged and there was some reddish, turbid fluid in the abdomen. There were some petechial and ecchymotic haemorrhages on the serosal surface of the rumen. Both the abomasum and large intestine were hyperaemic. Escherichia fergusonii was isolated as a profuse growth from the abomasum, and as a moderate growth from the lung and the liver. On histopathology there was a severe abomasitis and hepatic necrosis with terminal bacteraemia. Gram negative bacilli were evident in the liver, in the blood vessels of the lung and in smaller numbers in the abomasum. The main organism in the abomasum resembled Fusobacterium necrophorum. It was commented that this might have been a secondary invader exacerbating the damage. Escherichia fergusonii is a rare pathogen but has been implicated before in cases involving sheep and cattle that clinically resembled salmonellosis.

Respiratory tract conditions

Laryngeal chondritis was detected on postmortem examination of a two-year-old, Texel gimmer from the Edinburgh area. This was the third from a group of 100 to show respiratory distress apparently due to laryngeal obstruction. At necropsy the larynx was very swollen and distorted with an abscess in the right arytenoid cartilage.

Reproductive tract conditions

Salmonella Schwarzengrund was recovered from the foetal stomach contents, lung, liver and placenta of a set of aborted twins from a farm in Ayrshire where eight ewes had aborted, four of which subsequently died. On a different farm Salmonella Agona was recovered from the foetal stomach contents, lung, liver and placenta of aborted lambs from two ewes. Three abortions had occurred in the group of 125 ewes over a few days, and affected ewes looked dull.

Two abortions occurred within 24 hours in a small flock of 17 ewes that were due to lamb in ten days time. When two sets of twins were submitted for examination white spots were seen on the lungs of one lamb. Mannheimia haemolytica was isolated from the placentae and stomach contents of three out of the four lambs.

Edinburgh reported on a case of abortion and ewe deaths on a local holding. The aborted lambs were very autolytic, with gassy change. E. coli was isolated in profusion from the stomach content and placenta. Routine testing failed to identify any other potentially pathogenic organisms and no placentitis was evident on histology. Certain strains of E. coli have been linked to abortion and ewe death so the isolate was sent a reference laboratory for further identification. This revealed that it was a vero-toxin producing strain, E. coli O38:K+, a category three pathogen. E. coli 038 is a common inhabitant of sheep intestines but a very uncommon cause of abortion and death in ewes. It was possible that some other factor was involved causing delayed parturition allowing the E. coli to gain entry through the open cervix.

Nervous system disorders

An adult female goat had a 10-day history of ataxia progressing to recumbency. It was described as appearing to be drunk. It continued to eat but could only sit up with assistance and was euthanased. A 2.5 x 1 cm yellowish, spongy mass was found at necropsy in the right side of the spinal canal attached to the spinal cord above the vertebral body of C3 (see figure 4 at top right). Histopathology suggested that this was a slow growing subdural tumour located outside the spinal cord and exerting pressure upon it. The cells were of lymphoid origin with an identical aggregate found in the choroid plexus. A prolymphocytic lymphosarcoma was diagnosed.

Listerial encephalitis was confirmed on histopathological examination of the brain of a six-year-old Texel cross ewe from a farm in Aberdeenshire. Four animals in a group of 130 lambing ewes were described as showing nervous signs post-lambing, becoming ataxic and progressing to recumbency. There was a history of access to baled silage.

A single Texel lamb died about an hour after being born into a flock of 100 ewes in Inverness-shire. On neuropathology there were chromatolytic neurons in the medulla consistent with a diagnosis of swayback.

A nine-month-old, blackface tup lamb was submitted to Edinburgh in lateral recumbency and paddling. It was the second to present in this way since the batch arrived five weeks previously. On examination the lamb was unable to rise and became agitated when stimulated. At necropsy the lamb was small and in poor bodily condition with no internal fat reserves. Histopathological examination of the brain showed a moderate to severe, generalised non-suppurative meningoencephalitis consistent with a protozoal infection such as sarcocystosis.

Skin diseases

Four hundred Scottish blackface ewes were reported to be in poor condition and itchy on a farm in Dumfriesshire. Wool samples had been submitted previously but no diagnosis had been reached. Most of the ewes had been treated with a cypermethrin pour-on three weeks earlier with little improvement. An untreated ewe submitted for necropsy showed wool loss along both flanks with yellow crusts within the fleece, although the skin itself looked normal. There were huge numbers of lice present with more than ten seen at each parting of the wool. The lack of response in the treated sheep can be explained by the fact that it can take some time for pour-on treatments to spread over the whole body in fully fleeced sheep. It is also possible that pyrethroid resistant lice were present.

Corynebacterium pseudotuberculosis, the cause of CLA, was isolated from pus aspirated from a mass on the chin of a two-year-old Blackface ewe. The flock in Ross-shire has previously had cases of CLA.