Prickly paddy melon (Cucumis myriocarpus) poisoning of cattle

Twenty-six Hereford heifers died after eating mostly ripe fruit of Cucumis myriocarpus growing in a fallowed cultivation paddock. Four affected cattle were dehydrated and apparently had abdominal pain. Necropsy of three revealed intense congestion with haemorrhage of the alimentary tract, numerous C. myriocarpus seeds in ruminal contents, pulmonary congestion and oedema and, in two, swollen livers. Midzonal swelling and vacuolation of hepatocytes occurred in these two. C. myriocarpus fruit (83% by weight ripe) were dosed to two calves at 60 g wet weight/kg live weight. Both collapsed with tachycardia and dyspnoea and died within 6 h. Their packed cell volumes just before death had increased to 0.7. They had hydropic degeneration and necrosis of the ruminal mucosa, intense congestion and oedema of the rumen, abomasum and intestines, swollen and vacuolated hepatocytes and foci of myocardial degeneration and necrosis. Two other calves were dosed daily with 20 g fruit/kg for three days, then 40 g/kg for three days. One calf received a further 40 g/kg next day. Both calves developed persistent diarrhoea and neutrophilia, and their plasma gamma glutamyltransferase and bilirubin concentrations increased. Necropsy revealed necrosis and oedema of the rumen and swollen degenerate hepatocytes.     

Key role of Chlamydophila psittaci on Belgian turkey farms in association with other respiratory pathogens

Two hundred turkey sera from eight Belgian and two French farms were tested for the presence of antibodies against avian pneumovirus (APV), Ornithobacterium rhinotracheale (ORT), Mycoplasma gallisepticum, Mycoplasma meleagridis and Chlamydophila psittaci. At slaughter, C. psittaci, APV and ORT antibodies were detected in 94, 34 and 6.5% of the turkeys, respectively. No antibodies against M. gallisepticum or M. meleagridis were present. Additionally, turkeys on three Belgian farms were examined from production onset until slaughter using both serology and antigen or gene detection. All farms experienced two C. psittaci infection waves, at 3-6 and 8-12 weeks of age. Each first infection wave was closely followed by an ORT infection starting at the age of 6-8 weeks, which was still detectable when the second C. psittaci infection waves started. Animals on farm A were not vaccinated against APV leading to an APV subtype B outbreak accompanying the first C. psittaci infection wave. Despite subtype A APV vaccination on farms B and C, the second C. psittaci infection waves were accompanied (farm B) or followed (farm C) by a subtype B APV infection. On all farms respiratory signs always appeared together with a proven C. psittaci, APV and/or ORT infection. This study suggests an association between C. psittaci, APV and ORT, and indicates the multi-factorial aetiology of respiratory infections in commercial turkeys. All three pathogens should be considered when developing prevention strategies for respiratory disease.     

Comparison of inoculation regimes for the experimental production of swine erysipelas arthritis: II Serological findings in a gel diffusion precipitin test and enzyme-linked immunosorbent assay

The serological response of pigs to Erysipelothrix rhusiopathiae inoculation was monitored by a gel diffusion precipitin test (GDPT) using a crude, serotype-specific, autoclaved antigen and an enzyme-linked immunosorbent assay (ELISA) using a heat-extracted, alcohol precipitated and molecular seived antigen previously shown to react with serum from pigs infected with serotypes 1 or 2. All pigs receiving 3 or 5 weekly intravenous inoculations of either a highly virulent (VRS 229) or a lowly virulent isolate (VRS 252) produced GDPT-reactive antibody within 3 weeks, but only 44% were still reactive at 8 to 9.5 weeks. The ELISA response was significantly higher in pigs inoculated with the highly virulent strain, and was similar in pigs receiving 3 or 5 doses of either strain. In a dose-response trial, after 3 doses of VRS 229, GDPT reactivity occurred earlier and was stronger in pigs given higher doses of E. rhusiopathiae, but the response peaked 3 to 5 weeks after the start of challenge and was short lived. GDPT reactivity correlated with dose, but not with the severity of arthritis. The ELISA demonstrated specific IgG antibody was present by 2 weeks, and persisted to at least 11 weeks. The ELISA reactivity was significantly higher in pigs with arthritis than in pigs that received low doses and were not arthritic. Within groups of pigs with arthritis a significant, dose dependent, linear ELISA response developed but did not correlate with the presence or degree of arthritis at slaughter. Non-arthritic pigs had similar low ELISA responses to uninoculated controls.     

Soil and agronomic factors associated with cadmium accumulations in kidneys of grazing sheep

SUMMARY Mean concentration of cadmium (Cd) in kidneys of hogget sheep from 67 flocks grazing in the Agricultural Region of Western Australia was tested for association with soil, pastoral, climatic and nutritional factors. Hoggets grazing pastures on acidic soils and soils with a sandy-textured surface had higher Cd concentrations in kidneys than hoggets grazing pastures on more alkaline soils or soils with a clay-textured surface. Application of more than 100 kg of phosphatic fertiliser during the past 3 years to loamy soils was also associated with greater Cd concentration in kidneys of the grazing animals.     

Swine dysentery in a sow herd

Summary

An acute outbreak of swine dysentery (Doyle) on a farrowing farm is described. Besides clinical signs of enteritis a general loss of condition was seen throughout the herd. This resulted in a decreased fertility and breeding performance among sows and an increase in piglet mortality. Several dehydrated sows aborted.

The outbreak was stopped by oral treatment with lincomycin/spectinomycin 1:1. In the course of the treatment all animals and buildings were washed and disinfected. The use of pharmacotherapeutics in treating swine dysentery is discussed with emphasis on the involuntary induction of carriers.     

Presence of Ureaplasma diversum in the Australian cattle population

In cattle, Ureaplasma diversum has been associated with decreased fertility, granular vulvovaginitis, endometritis, salpingitis and spontaneous abortion in cows and seminal vesiculitis, balanoposthitis and changes in bull sperm. The presence of U. diversum within the Australian cattle population has not been established. One of the aims of this study was to determine if U. diversum was present in Australian cattle, using culture and polymerase chain reaction (PCR), both of which are considered to be gold standards for bacterial identification. Of 100 samples collected from 66 male and 34 female cattle, 15 were positive for U. diversum. Therefore, Australia can no longer be considered free of U. diversum. Further studies should be conducted to ascertain the effects of U. diversum within Australian cattle herds and, if warranted, to investigate prevention, treatment and eradication protocols.     

Standing transcutaneous surgical excision of a sialolith in an 11-year-old Thoroughbred mare

An 11-year-old Thoroughbred mare was diagnosed with sialolithiasis of the right parotid salivary duct. A firm nonpainful subcutaneous mass was palpable in the right maxillary region adjacent to premolar 4 (tooth 108). Radiographic and ultrasonographic examinations identified a discrete mineralised ovoid mass that was hyperechoic and produced an acoustic shadow. Surgical excision of the mass was performed under standing sedation using a transcutaneous approach and the excised sialolith submitted for histopathological and mineral composition analyses. Histological examination found no evidence of a nidus at the sialolith's core. Mineral analysis of the sialolith revealed its composition to be 40% calcium phosphate (apatite) and 60% calcium carbonate. The mare recovered with no post-operative complications and was clinically unremarkable 2 years later.