Veterinary Services

Nutritional and metabolic disorders

Severe copper, selenium and cobalt deficiencies were identified in a flock in northern Scotland managed under organic principles and where routine supplementation was not practised. In some samples serum copper and vitamin B12 activity was below the test limits and GSH-Px activity was less than 5 U/ml RBC (reference range > 42 U/ml RBC).

Toxic conditions

A bluefaced Leicester hogg that had aborted ten days before it died was submitted to Dumfries for postmortem examination. The owner reported one other death and another two ill hoggs. Examination revealed an orange liver, brown kidneys and haemoglobinuria. The diagnosis of copper poisoning was confirmed by analysis of liver and kidney copper, which were 24,100umol/kg and 3,100umol/kg respectively (reference ranges 314 - 7,850umol/kg and <787umol/kg.) On subsequent investigation the lambing flock including the hoggs, had been given copper needles one month earlier and that they had been housed and fed concentrates for the entire winter. Analysis of the concentrate showed that the copper content was 15mg /kg DM. Subsequent testing of an aborted foetus indicated liver copper of 13,800umol/kg suggesting that the trace element had also crossed the placenta. The owner was advised that neither the ewes nor surviving lambs should receive any additional copper supplementation and that copper needles should not be given to sheep that were to be housed for long periods.

Copper poisoning was diagnosed at Ayr in two adult ewes that were part of a group of 15 that had been housed since January and fed a proprietary sheep cake. Six animals died in the space of one week after the supply of cake was finished and the animals were given a diet of draff, treacle and straw. The diagnosis was confirmed on liver copper analysis. The SAC VS suspected that the copper accumulated while the ewes were receiving the cake, with the final haemolytic crisis precipitated by the change of diet.

Parasitic diseases

Haemonchosis was diagnosed as the cause of death in two, ill thriven gimmers from a unit in Caithness. The group of 60 in which these homebred gimmers were managed had been treated with anthelmintic in October 2006, but recently about 20 had failed to thrive. After a further suitable treatment the appetite and demeanour of the affected animals were said to have improved significantly.

Generalised and systemic conditions

Type D botulism was diagnosed on a farm in the Dumfries area where approximately 100 ewes died after being turned-out on to pasture that had been spread with poultry litter some 72 hours before. A visit confirmed the presence of multiple chicken carcases over the field. Early in the course of the outbreak ewes were found dead or died within 12-24 hours. Later cases involved a progression of clinical signs from sternal to lateral recumbency. When five live ewes were submitted for examination, four were in lateral recumbency. All had ruminal stasis and two had a copious nasal discharge of ruminal fluid. Three showed abdominal breathing only and there were varying levels of resistance to manipulation of the limbs and strength of pedal withdrawal reflexes. Type D botulism was confirmed following the detection of botulinum toxin within intestinal and ruminal contents, and in faeces.

Around the same time a neighbouring farm also spread poultry litter that was composted for ten weeks. Two weeks after the original outbreak, this second farm lost five rams that had been running in a field adjacent to where the initial problem occurred. Again type D botulism was confirmed. The SAC VS does not know whether carcase material had been transported onto this land by birds, wind or wildlife, or whether the composted litter was responsible.

Septic polyarthritis, meningitis and colisepticaemia were confirmed in a three-day-old lamb from a unit in Aberdeenshire. Pure heavy growths of E. coli were isolated from the internal organs, cerebrospinal fluid and joints. The problem was exacerbated by a complete failure of colostral antibody absorption indicated by a serum zinc sulphate turbidity value of 2 units (normal reference range > 14).

Systemic pasteurellosis due to infection with Pasteurella trehalosi was confirmed in a bought-in ewe that died after a short period of recumbency. Three of 230 ewes had died in the flock.

Clostridial enterotoxaemia type D (pulpy kidney) was diagnosed in a housed ten-month-old Blackface hogg, one of seven animals to die suddenly over one week. The same diagnosis was made in a Texel ram lamb aged four weeks. In both cases alpha and epsilon clostridial toxins were detected in the intestinal contents.

Alimentary tract disorders

Significant numbers of Cryptosporidium parvum oocysts were detected in the faeces of three, one-week-old lambs from an Ayrshire farm. Unusually the flock concerned had just started lambing. Investigation revealed that the shed in which the lambing was conducted had housed calves with cryptosporidiosis some three months earlier.

Respiratory tract conditions

Pneumonic pasteurellosis due to infection with Pasteurella trehalosi was confirmed in a two-year-old Shetland cross cheviot ewe. Twin lamb disease had been suspected after seven ewes died with a history of salivation and ataxia.

Cardiovascular diseases

A six-week-old Suffolk ram lamb, which had been in poorer condition than others in the group, was found dead. At necropsy the carcase was pale and oedematous, with both ascites and an increased quantity of pericardial fluid. The heart was dilated, especially on the right side and the foramen ovale was patent. Two other lambs from this farm were also necropsied: one with intestine incarcerated in a scrotal hernia and the other with a malformed intestine.

Reproductive tract conditions

A Beltex gimmer died shortly after an assisted lambing, which produced a dead lamb with a ruptured liver. Postmortem examination of the gimmer revealed a large tear in the diaphragm, through which half the jejunum and colon had displaced into the thorax, leading to pulmonary collapse.

During the investigation of an abortion outbreak on the Southern Isles, Abiotrophia species was isolated from foetal stomach contents. The Abiotrophia were previously known as nutritionally variable Streptococci and have been implicated in human infection. In two cases of abortion one in Perthshire and one in Ross-shire, neuropathology revealed lesions suggestive of a problem in myelination, such as seen in border disease. Foetal fluids were however negative for BDV antibodies, and in the Perthshire case a screening of 20 aborted and barren ewes similarly failed to identify any evidence of infection.

Musculo-Skeletal conditions

Three lambs were submitted to Ayr with a history of recumbency affecting animals from a few days old to three weeks old. Polyarthritis and spinal abscesses associated with Streptococcus dysgalactiae subsp. dysgalactiae were identified in the submitted lambs.

Nervous system disorders

Listerial encephalitis was diagnosed in a Texel cross hogg submitted alive in lateral recumbency and showing opisthotonus. The group from a holding in Nairnshire had a recent history of ill thrift and scour. Parasitic gastro-enteritis was diagnosed as the cause of ill thrift, and listeriosis was thought to be due to ingestion of soil associated with the feeding of turnips.

Renal diseases

A four-year-old male goat from Ross-Shire died after a period of hindquarter paralysis, nervous signs and inappetence. Urolithiasis was diagnosed in this case, with severe cystitis, fibrinous peritonitis, haemorrhagic urethritis and balanoposthitis. There were many hard crystals present in the bladder.

Skin diseases

Caseous lymphadenitis (CLA) was diagnosed in two flocks in the Thurso area. In one case a group of young rams was tested serologically after a clinical case of CLA was detected. A further six cases were found as a result of this blood testing.