Oral and Poster Abstracts

2
Finnish Food Safety Authority Evira, Veterinary Bacteriology,
Kuopio, Finland
3
Finnish Food Safety Authority Evira, Veterinary Virology, Helsinki,
Finland
Objectives of the study: Sheep-associated malignant catarrhal fever
(SA-MCF) is a severe and mostly fatal disease of cattle and other
ruminants. Severe outbreaks have been described in bisons that are the
most susceptible animals. Sheep-associated MCF has been linked to
ovine herpesvirus-2 (OHV-2) infection. We describe here an outbreak
of SA-MCF with high mortality in a Finnish dairy farm.
Materials and Methods: The farm. The affected herd consisted of
appr. 40 dairy cows and heifers, calves and young cattle. All animals
were housed in the same insulated barn with shared air conditioning,
operated with forced exhaust ventilators. Free stall was used for cows,
and young cattle were raised in group pens. The farmer brought two
lambs, born in spring 2005, into the dairy barn in November 2005 and
the lambs stayed in the barn until early April 2006. Examinations:
Pathological examinations were carried out and diagnoses were
verified by OHV-2 specific PCR. Serum and EDTA blood samples
were collected from all living animals in early April 2006 for analyses
of OHV-2 (PCR) and MCF-antibodies (c-ELISA).
Results: In early January 2006 the exhaust ventilators were off for
eight hours due to a power failure. Thus the air quality in the barn was
extremely poor with high humidity and severe condensation. First signs
of MCF were seen in February and the last case was in November 2006.
The peak of the cases was at spring time. The sings including high
fever, milk drop in cows, hyperaemic oral and nasal membranes,
depression, oculo-nasal discharge and diarrhoea were seen in a total of
31 animals including cows, calves, heifers and young cattle. One cow
with typical clinical signs, high titre of specific antibodies and positive
OHV-2 PCR result recovered. The remaining 30 animals with signs of
MCF died or were euthanized. The diagnosis of MCF was based on
gross and histopathology and presence of both OHV-2 DNA and
specific antibodies. The animals were also tested for other agents of
upper respiratory tract and intestinal infections including respiratory
syncytial virus, infectious bovine rhinotracheitis, bovine coronavirus,
bovine viral diarrhoeal virus, mycoplasmas and salmonella, with
negative results.
Conclusions: The adolescent sheep between 6 and 9 months of age
have been shown to shed OHV-2 virus more often and in greater
amounts than adults. Here keeping of two adolescent sheep in a dairy
barn caused a severe outbreak of MCF in a dairy herd resulting in death
of 30 animals.
662 Evaluation of Nasopharyngeal Swabs in Sampling for
Respiratory Pathogens in Calves
T. Autio 1 , T. Pohjanvirta 2 , A. Huovilainen 3 , L. Sihvonen 3 ,
S. Pelkonen 2
1
Finnish Food Safety Authority Evira, Production Animal Health,
Kuopio, Finland
2
Finnish Food Safety Authority Evira, Veterinary Bacteriology,
Kuopio, Finland
3
Finnish Food Safety Authority Evira, Veterinary Virology, Helsinki,
Finland
Objectives of the study: The aim of this study was to compare
nasopharyngeal swab (NP) and bronchoalveolar lavage (BAL) samples
in sampling for respiratory pathogens in calves. The samples were
examined for presence of Pasteurella multocida, bovine coronavirus
(BCV) and respiratory syncytial virus (RSV), which are the most
common pathogens associated with calf respiratory disease in Finland.
The similarity of Pasteurella multocida isolates from upper and lower
respiratory tract was analysed.
Materials and Methods: NP and BAL samples were taken in parallel
from 42 calves. NP was taken with a guarded 27-cm swab and BAL
with a guarded nasal tube. The samples were examined
bacteriologically by standard laboratory methods. Pulsed-field gel
electrophoresis (SalI) was utilized for genetic typing of P. multocida
isolates. BCV and RSV were detected with RT-PCR.
Results: Five animals were negative for the studied pathogens. Both P.
multocida and BCV were detected in 14 animals. A combination of P.
multocida, RSV and BCV was found in two animals, and three were
infected with both P. multocida and RSV. A total of five animals
harboured RSV, of which two in both samples and two only in NP.
BCV was detected in nine animals by both sampling techniques and in
eight and three animals only in NP or BAL, respectively. P. multocida
was detected in 33 animals. Out of these, 23 calves harboured P.
multocida both in NP and BAL. All BAL samples positive for P.
multocida were also NP positive, and 10 only in NP. Paired P.
multocida isolates obtained from 23 animals with both sampling
methods were characterized by PFGE. Majority of animals (20/23)
harboured isolates showing similar macrorestriction patterns (MRP) or
had minor differences in their MRPs.
Conclusions: Nasopharyngeal swabbing was found to be a suitable
method for sampling for BCV, RSV and P. multocida. All pathogens
were recovered more often in nasopharyngeal swab than in BAL
samples. PFGE typing indicated that in most Pasteurella cases the same
strain was isolated by both sampling methods. Thus the P. multocida
culture obtained by nasopharyngeal swabbing represents reasonable
well for the microbes in the lung.
663 First Case of Immunohistochemical Detection of Mycoplasma
bovis in Natural Cases of Calf Pneumonia in Hungary
L. Szeredi 1 , T. Labossa 2 , M. Tenk 3 , V. Pálfi 1 , D. Rigó 1 , T. Molnár 1
1 Central Agricultural Office, Budapest, Hungary
2 Veterinary Practitioner, Lajoskomárom, Hungary
3 CEVA, Budapest, Hungary
Objectives of the study: Bovine respiratory disease complex (BRDC)
is a major cause of morbidity, mortality and economic losses in cattle
production systems. The cause of this disease is rather complex
involving both managing factors and infectious agents (bacteria and
viruses). In our study, we demonstrate the primary role of Mycoplasma
(M.) bovis in a severe respiratory disease in feedlot cattle.
Materials and methods: Five feedlot cattle died after a few days of
illness without any specific symptom in a herd. Out of these 2 were
treated with antibiotics whereas 3 suddenly died without any treatment.
All the animals were imported from Poland, vaccinated previously
against infectious bovine rhinotracheitis (IBR) and bovine respiratory
syntitial virus (BRSV). After gross pathological investigation swabs
were collected for bacterial culture. From the lungs, mycoplasma
culture was also made in 1 case and virus isolation (VI) was attempted
in 4 cases. Tissue samples were collected from the lungs and
occasionally also from the trachea and the mediastinal lymph nodes for
histological examination. Immunohistochemical (IHC) method was
used to detect viruses (bovine herpesvirus 1 (BHV-1), BRSV, bovine
respiratory coronavirus, influenza A virus) and bacteria (M. bovis and
Chlamydiaceae) in formalin-fixed paraffin-embedded tissue samples.
Results: The cranioventral part or the whole lungs were affected by
dark discoloration in all cases. Histologically, fibrinopurulent
pleuropneumonia, suppurative bronchiolitis and focal to coalescing
coagulative necrosis were observed in the lungs in all cases. M. bovis
was detected in large numbers in the lung tissue samples with IHC,
mostly in the area of bronchiolitis and coagulative necrosis, and in
smaller number in the area of the fibrinopurulent inflammation. M.
bovis was isolated from one of the cases. Other pathogens were
detected only infrequently: parainfluenza 3 virus (1 case with VI), RSV
(1 case with IHC), Pasteurella multocida (2 cases with culture),
Mannheimia haemolytica (1 case with culture).
Conclusions: M. bovis was the most important pathogenic agent that
induced a severe respiratory disease in the feedlot cattle examined in
this study. Other bacteria and viruses were detected only in a few cases.
In spite of the sudden death in 3 cases, the lung lesions were not acute
in any of the cases.
664 Short-duration Antimicrobial Treatment of Bovine
Respiratory Disease with Enrofloxacin, Florfenicol and
Cefquinome
R. Froyman 1 , C. Boda 2 , C. Rizet 3 , A. Valognes 4 , N. Brunner 1 ,
P. Liege 2 , H. Navetat 3
1 Bayer HealthCare, Animal Health Division, 51368 Leverkusen,
Germany
2 Anisteme Biosciences, Animal Health Division, 34400 Saint-
Christol, France
3 Centre d’Information Veterinaire Clinique, 03130 Le Donjon,
France
4 LDV03, 03017 Moulins, France
Mannheimia haemolytica (Mh) is the most prevalent causative
bacterium in bovine respiratory disease (BRD) but Mycoplasma bovis
Infectious and Zoonotic Deseases (Public Health) 91