Veterinary Services

Nutritional and metabolic conditions

A Luing cow was found dead and a second was recumbent three days after being moved to a field of kale for out-wintering.  Magnesium licks were removed one week earlier. The recumbent cow had a serum calcium of 1.3 mmol/l, (reference range 2.2 - 2.6 mmol/l), and magnesium of 0.2 mmol/l, (reference range 0.8 – 1 mmol/l).  These results confirmed hypocalcaemia and hypomagnesaemia.

Generalised and systemic conditions

The number of outbreaks of disease due to bovine virus diarrhoea (BVD) virus from 1998 to 2008 is shown in figure 1 (see top right-hand side). The introduction of BVD vaccine in 1996 coincided with the initial decline in the number of cases of acute infection or viraemia and of mucosal disease. However, in spite of the widespread uptake of BVD virus vaccines, the number of outbreaks where acute or persistent infections or mucosal disease have been diagnosed has remained at a fairly static level over the last seven years. This could be due partly to the increased awareness of BVD virus as a result of promotion by pharmaceutical companies and the interest in cattle health schemes. The number of cases of foetopathy or congenital disease due to BVD virus has remained at a reasonably constant level following peaks in 2000 and 2001.  The BVD statistics from the cattle health schemes are not included in the chart figures.  

A ten-month-old Charolais-cross steer was submitted to Ayr for postmortem examination. One month previously it reacted inconclusively to the single intradermal comparative tuberculin test. More recently it became inappetant and recumbent with profuse salivation and submandibular oedema and was euthanased. The retropharyngeal, submandibular and mediastinal lymph nodes were enlarged. A large solid mass containing white nodules (figure 2 - see top right-hand side) was present adjacent to the trachea, in the distal cervical area. The thymus was also enlarged with white nodules present, and white foci were evident on the liver and kidneys. Multiple lymph node samples were submitted to screen for bovine tuberculosis and results are awaited. However, histopathology findings suggested the sporadic form of bovine lymphoma.

Ayr recovered Salmonella Dublin from samples from nine farms. Scour was the main clinical presentation on six of these farms. Abortions occurred on the other three.  On one affected dairy farm three heifers out of a batch of 12 aborted in one week. Two foetuses and placentae were submitted and a heavy pure growth of Salmonella Dublin was recovered in septicaemic distribution from both cases.

Alimentary tract disorders

A faeces sample was submitted from a one-month-old dairy calf with a history of sudden onset of diarrhoea with blood in six calves. Microscopic examination of the sample found a coccidial oocyst count of 753,000 oocysts per gram, 95 per cent  Eimeria zurnii, five per cent  Eimeria bovis. Both species are regarded as pathogenic in cattle.

A faeces sample was submitted from an 18-month-old beef heifer identified with faecal staining of the perineum with some blood at the anus. A count of 71,500 coccidial oocysts of pathogenic species was made. Although more commonly a disease of animals aged less than 12 months, coccidiosis is occasionally seen in older cattle. The heifer was also found to be bovine virus diarrhoea (BVD) antibody negative and antigen positive. SAC postulated that the BVD viraemia could have contributed to the clinical picture. 

Respiratory tract diseases

Two of 45 nine-month-old Galloway bull calves were found recumbent and kicking one week after being weaned and temporarily housed for management purposes. They were vaccinated intra-nasally against respiratory syncitial virus (RSV) and parainfluenza virus type 3 (PI3) at housing.   Postmortem examination at Dumfries revealed a severe pleurisy and pericarditis.  Mannheimia haemolytica was the only significant pathogen identified. 

A Dumfriesshire dairy farm suffered multiple cases of severe, acute pneumonias in adult cows.  Response to treatment was poor and six heifers and three cows died or were culled.  A typically affected untreated four-year-old Holstein cow was submitted for postmortem examination. The entire right lung and 80 per cent of the left lung showed consolidation and interlobular oedema.  Arcanobacterium pyogenes, Bacteroides fragilis and Mycoplasma bovis were isolated from lung tissue. 

Two dairy-cross calves aged between two and three months were submitted from a calf rearer in Perthshire. Eleven deaths were reported associated with respiratory signs in a group of 80 recently housed calves. In both calves consolidation involved around 60 per cent of the lung volume. The areas of consolidation were well-demarcated (figure 3 - see top right-hand side). A pericarditis was also present. Fluorescent antibody testing (FAT) of lung tissue from both calves found no evidence of viral involvement.  Bacterial cultures of lung tissue yielded growths of Pasteurella multocida in the first calf and Histophilus somni in the second.  Culture of caecal contents isolated Salmonella Dublin. This organism was isolated  previously  from calves on these premises.  Histopathological examination of lung tissues from both calves found a severe mixed cell exudative pneumonia with oedema and fibrinonecrosis in the interlobular septum. These changes indicate a predominantly bacterial aetiology.

Renal diseases

A beef suckler unit in Fife submitted the carcase of a nine-year-old Simmental cross cow. The animal died following a short period of illness during which it showed signs of abdominal pain.  At necropsy there was marked jaundice of the tissues. The liver showed extensive fibrosis, with thickening and calcification of the bile ducts and the presence of a number of adult fluke. There was marked distension of both kidneys, and on cross-section the pelvises were found to be enlarged and contained thick purulent material.  The cortices were extensively fibrosed and a number of small abscesses were noted in this area of both kidneys. A bacterial aetiology was suspected but cultures were overgrown by contaminant species.