October 2005

Current Findings in the Regional Veterinary Laboratories
October 2005
All regional laboratories reported a sharp increase in the number of bovine foetal submissions, with
Salmonella dublin and Neospora caninum being the most commonly identified abortefacients.
Kilkenny diagnosed enterotoxigenic colibacillosis in a one-day old calf. A one-month old calf
submitted to Cork was found to have lung congestion, ulcerative colitis and gross lesions of
septicaemia. Rhodococcus equi was isolated from the lungs.
Parasitic bronchopneumonia was diagnosed by Dublin in a six-month old Friesian heifer calf that
died suddenly after being moved between farms. Athlone reported patent hoose pneumonia with
bullae and interstitial emphysema in a 10-month old heifer. There was a very severe gross
infestation of airways with the parasites.
Kilkenny diagnosed blackleg in two eight-month old weanlings. They were from a group of twenty,
five of which had been found dead on the same day.
Athlone reported choke in an 18-month old bullock, the third to die from a group of forty cattle.
The cattle were on a diet of fodder beet and pulp (figure 1). Limerick examined an 18-month old
bullock with a history of weakness and ataxia. A large abscess was found in the neck region that
involved the atlanto-occipital joint and had extended into the meninges and brain stem. Lesions in
the pharynx suggested that the problem began with foreign body penetration of the pharyngeal wall.
Arcanobacterium pyogenes was isolated on culture.
Athlone reported chronic pericarditis and epicarditis in a five-year old bull that had died after
showing illness for only a few days. Histopathological examination of the cardiac muscle showed
myopathy, myocarditis, fibrosis and haemorrhage. Athlone reported suspected aflatoxicosis in a sixyear old Charolais cow that had shown chronic ill-thrift over a period of months before death. Gross
examination showed an enlarged, pale, fibrotic liver. The diagnosis of aflatoxicosis was reached
following liver histopathology.
Athlone reported rumenal acidosis in a group of 400 six-month old lambs. One lamb of a number
that had died was presented for post-mortem examination. The rumen was engorged with grain, the
pH of the contents was found to be 4.2, and zero protozoan motility was noted on microscopic
examination of a rumenal fluid sample.
Limerick diagnosed enterotoxigenic colibacillosis in a group of four-day old piglets. There was
ninety per cent mortality in the litter involved. The Escherichia coli isolated was typed as O147.
Weaner pigs with a history of pneumonia were submitted to Kilkenny. Pasteurella multocida was
isolated from the lungs of one, and Actinobacillus pleuropneumoniae was isolated from four others.
Cork isolated several bacterial pathogens from weaner pigs from one premises experiencing high
mortality rates. Haemolytic Escherichia coli G205, Salmonella typhimurium and Salmonella london
were isolated.
Cork isolated Enterococcus faecalis (previously known as Streptococcus faecalis) from broiler
breeder hens that had septicaemia and liver necrosis. Deaths ceased following medication with
Avian tuberculosis was identified by Cork in a small “back-yard” free-range flock.
Other Species
Euthanasia had been undertaken on an eight-month old foal that had presented clinically with severe
colic. The foal was submitted to Cork where caecal torsion was found (Figure 2).
An adult greyhound bitch with a history of dyspnoea was submitted to Limerick. The examination
showed haemothorax as a result of a fracture to the proximal third of the 8th rib. A bone fragment
had penetrated a blood vessel and the costal pleura. In the monthly report of September 2005,
Kilkenny reported on a case of megaoesophagus in a seven-week old greyhound, one of four
showing poor-thrive in a litter of eight. Another of the pups was presented this month, at nine weeks
of age. Megaoesophagus was obvious again but in this case it was associated with persistent right
aortic arch (figure 3). Salmonella dublin was also isolated on routine culture. In the former case, the
whole of the thoracic oesophagus was dilated, in the latter only the oesophagus anterior to the heart
was affected. Athlone reported high mortality in two litters of border collie pups. Viral enteritis
was diagnosed with parvovirus being the most likely cause. In total, out of two litters of four, only
one pup survived.
A mute swan submitted to Cork had lesions consistent with a septicaemic condition. Erysipelothrix
rhusopathiae was isolated from all organs cultured. Another mute swan examined by Cork had
apparently died as a result of haemorrhage from a spontaneous liver rupture. There were no external
signs of trauma. An African Grey parrot examined by Cork had aspergillosis, with pneumonic
lesions predominant.
Two coursing club hares submitted to Cork had died of yersiniosis.
Figure 1 “Foreign body causing choke in an 18-month old bullock – photo John Fagan”
Figure 2 “Caecal torsion in an eight-month old foal – photo Pat Sheehan”
Figure 3 “Megaoesophagus and persistent right aortic arch in a nine-week old greyhound pup –
photo Donal Toolan”