Effects of a challenge dose of Salmonella Typhimurium or Salmonella Yoruba on the patterns of excretion and antibody responses of pigs

The epidemiology of a feed-associated Salmonella serotype (Salmonella Yoruba) was compared with that of a 'classical' serotype (Salmonella Typhimurium) by inoculating pigs aged 10 weeks with 0.65 x 10(3), 0.65 x 10(6) or 0.65 x 10(9) colony-forming units (cfu) of either serotype. The pigs were then monitored for eight weeks with respect to the faecal excretion of Salmonella species and the presence of serum antibodies. Only minor differences were observed between the two serotypes but the dose inoculated had significant effects. The pigs inoculated with 0.65 x 10(9) cfu shed Salmonella species in faeces constantly for four weeks, and intermittently during the subsequent four weeks; the pigs inoculated with 0.65 x 10(6) cfu shed Salmonella species intermittently for four weeks, but not for longer, and the pigs inoculated with 0.65 x 10(3) cfu generally did not excrete Salmonella species. The pigs inoculated with 0.65 x 10(9) cfu S Typhimurium seroconverted at a high titre within two weeks, the pigs inoculated with 0.65 x 10(6) cfu seroconverted later and with lower titres of antibodies, and the pigs inoculated with 0.65 x 10(3) cfu did not seroconvert. A similar pattern was observed with S Yoruba, but the responses were slower and at lower titres.     

Low levels of haptoglobin and putative amino acid sequence in Taiwanese Lanyu miniature pigs

Porcine haptoglobin (Hp) is an acute phase protein. Its plasma level increases significantly during inflammation and infection. One of the main functions of Hp is to bind free hemoglobin (Hb) and inhibit its oxidative activity. In the present report, we studied the Hp phenotype of Taiwanese Lanyu miniature pigs (TLY minipigs; n=43) and found their Hp structure to be a homodimer (beta-alpha-alpha-beta) similar to human Hp 1-1. Interestingly, Western blot and high performance liquid chromatographic (HPLC) analysis showed that 25% of the TLY minipigs possessed low or no plasma Hp level (<0.05 mg/ml). The Hp cDNA of these TLY minipigs was then cloned, and the translated amino acid sequence was analyzed. No sequences were found to be deficient; they showed a 99.7% identity with domestic pigs (NP_999165). The mean overall Hp level of the TLY minipigs (0.21 +/- 0.25 mg/ml; n=43) determined by enzyme-linked immunosorbent assay (ELISA) was markedly lower than that of domestic pigs (0.78 +/- 0.45 mg/ml; p<0.001), while 25% of the TLY minipigs had an Hp level that was extremely low (<0.05 mg/ml). In addition, the initial recovery rate (first 40 min) in the circulation of infused fluorescein isothiocyanate (FITC)-Hb was significantly higher in the TLY minipigs with extremely low Hp levels than those with high levels. This data suggests that the low concentration of Hp-Hb complex is responsible for the higher recovery rate of Hb in the circulation. TLY minipigs have been used as an experimental model for cardiovascular diseases; whether they can be used as a model for inflammatory diseases, with Hp as a marker, remains a topic of interest. However, since the Hp level varies significantly among individual TLY minipigs, it is necessary to prescreen the Hp levels of the animals to minimize variation in the experimental baseline. The present study may provide a reference value for future use of the TLY minipig as an animal model for inflammation-associated diseases.     

Seroepidemiology of infection with Toxoplasma gondii in waste pickers and waste workers in Durango, Mexico

Municipal waste is a potential source of infection for Toxoplasma gondii as it may contain contaminated meat with parasite tissue cysts and cat excrement with parasite oocysts. Therefore, we sought to determine the prevalence of T. gondii infection and associated characteristics in two populations exposed to municipal solid waste in Durango, Mexico. Ninety waste pickers and 83 waste workers of Durango City, Mexico were examined for T. gondii infection. They were tested for anti-T. gondii IgG and IgM antibodies using enzyme-linked immunoassays. In addition, socio-demographic and behavioural characteristics from each participant were obtained. Nineteen (21.1%) of the 90 waste pickers and seven (8.4%) of the 83 waste workers were positive for anti-T. gondii IgG antibodies. The difference in prevalence among the groups was statistically significant (P =0.03). Waste pickers aged 31-50 years showed a significantly higher prevalence (40.9%) than waste workers of the same age group (2.9%, P < 0.001). Anti-T. gondii IgM antibodies were found in two (2.2%) of the waste pickers but in none of the waste workers. The seroprevalence of T. gondii was significantly higher in workers of the waste transfer station (25.0%) than in drivers or helpers of waste vehicles (2.5%) (P =0.03). Multivariate analysis showed that T. gondii infection was associated with consuming food found in the garbage [adjusted odds ratio (OR) = 4.4; 95% confidence interval (CI) 1.6-11.8] and with lack of education (adjusted OR = 3.2; 95% CI 1.1-8.8). From this study, we conclude: (i) waste pickers may represent a risk group for T. gondii infection; (ii) lack of education might be a contributing factor for T. gondii infection; (iii) the higher the exposure to garbage, the higher the seroprevalence of T. gondii infection; (iv) Eating food products from the garbage may represent an important route for T. gondii infection.     

Malignant mediastinal extra-adrenal paraganglioma with spinal cord invasion in a dog.

A 1.5-year-old castrated, male, mixed-breed dog was evaluated because of a 2-week history of lethargy, stiffness, and progressive paraparesis. Spinal radiographs, myelography, and computed tomography of the region showed a locally invasive mass involving the thoracic wall. Upon necropsy, an encapsulated, fluctuant mass was noted attached to the right dorsal body wall in the region of the fifth to seventh thoracic vertebra. Churukian-Schenk staining revealed positive granules within the neoplastic cell cytoplasm and immunohistochemistry was positive for expression for cytoplasmic neuron-specific enolase and synaptophysin. Chromogranin A and S100 expression were found to be negative. Immunohistochemistry and silver staining did not allow further differentiation of the tumor, and the diagnosis remains consistent with either a chromaffin paraganglioma or a nonchromaffin paraganglioma (chemodectoma) with some production of catecholamines. Extra-adrenal paragangliomas are rare neoplasms in dogs but should be considered as a possible differential diagnosis for a primary paraspinal thoracic mass.     

Pathological fractures secondary to metaphyseal osteopathy in a dog.

A four-month-old German Shepherd Dog (GSD) was admitted with bilateral non-weight bearing hindlimb lameness and pyrexia. A diagnosis of bilateral distal femoral fractures secondary to metaphyseal osteopathy was made on the basis of clinical signs, radiography and biopsy. The dog returned to normal function following conservative management. As far as the authors are aware there are no previous reports of pathological fractures secondary to this condition.     

Diagnostic exercise: papulovesicular dermatitis in rhesus macaques (Macaca mulatta)

Eleven rhesus monkeys developed multifocal erythematous and a vesicular rash. Most recovered spontaneously, but a 21-year-old female became moribund and was euthanized. Findings were of vesicular dermatitis and widespread multifocal hemorrhagic necrosis of the lungs and other viscera, with intralesional intranuclear inclusions. Simian varicella virus was identified as the cause by polymerase chain reaction analysis and serologic testing.     

Interaction between the effects of evaporation rate and amount of simulated rainfall on development of the free-living stages of Haemonchus contortus

A factorial experiment (3 x 4 x 2 x 3) was conducted in programmable incubators to investigate interaction between the effects of rainfall amount, rainfall distribution and evaporation rate on development of Haemonchus contortus to L3. Sheep faeces containing H. contortus eggs were incubated on sterilised soil under variable temperatures typical of summer in the Northern Tablelands of NSW, Australia. Simulated rainfall was applied in 1 of 3 amounts (12, 24 or 32 mm) and 4 distributions (a single event on the day after deposition, or the same total amount split in 2, 3 or 4 equal events over 2, 3 or 4 days, respectively). Samples were incubated at either a Low or High rate of evaporation (Low: 2.1-3.4 mm/day and High: 3.8-6.1 mm/day), and faeces and soil were destructively sampled at 4, 7 and 14 days post-deposition. Recovery of L3 from the soil (extra-pellet L3) increased over time (up to 0.52% at day 14) and with each increment of rainfall (12 mm: <0.01%; 24 mm: 0.10%; 32 mm: 0.45%) but was reduced under the High evaporation rate (0.01%) compared with the Low evaporation rate (0.31%). All rainfall amounts yielded significantly different recoveries of L3 under Low evaporation rates but there was no difference between the 12 and 24 mm treatments under the High evaporation rate. The distribution of simulated rainfall did not significantly affect recovery of infective larvae. Faecal moisture content was positively associated with L3 recovery, as was the ratio of cumulative precipitation and cumulative evaporation (P/E), particularly when measured in the first 4 days post-deposition. The results show that evaporation rate plays a significant role in regulating the influence of rainfall amount on the success of L3 transmission.     

Relationships between demographic variables and lead toxicosis in cattle evaluated at North American veterinary teaching hospitals

OBJECTIVE: To determine associations between age, sex, breed, and month and year of admission and the diagnosis of lead toxicosis in cattle. DESIGN: Retrospective case-control study. Sample Population-Records of all cattle evaluated at North American veterinary teaching hospitals during the years 1963 to 2002, which were available through the Veterinary Medical Database. PROCEDURES: Logistic regression was used to evaluate the associations between postulated risk factors and the occurrence of lead toxicosis in cattle and predict the occurrence of the diagnosis of lead toxicosis in cattle. RESULTS: 413 cases of lead intoxication and 202,363 control cattle were identified and met the inclusion criteria. Cattle < 4 years of age were at increased risk for the diagnosis of lead intoxication relative to cattle > or = 4 years of age. Cattle > or = 2 months and < 6 months of age had the greatest risk for lead intoxication (odds ratio, 12.3). Angus cattle were at greater risk for toxicosis (odds ratio, 1.95), compared with other breeds. The risk of lead toxicosis was greater before 1985 (odds ratio, 1.94) than the risk thereafter. The risk of lead toxicosis diagnosis was greatest in the months of May, June, July, and August. CONCLUSIONS AND CLINICAL RELEVANCE: Lead toxicosis in cattle was associated with age < 4 years and the Angus breed. A seasonal pattern existed with peak occurrence in the late spring and summer. The occurrence of lead toxicosis has declined over time.     

Treatment with rhBMP-2 of extreme radial bone atrophy secondary to fracture management in an Italian Greyhound

rhBMP-2 solution on a collagen sponge was placed along the diaphysis of an atrophicradius, which had a history of recurring fractures. Two months after rhBMP-2 treatment, new mineralized bone was present, which significantly increased the diameter of the radius and allowed the removal of the external skeletal fixator (ESF). Due to carpo-metacarpal joint compromise, a pancarpal arthrodesis was performed seven months later. At follow-up evaluation two years later the dog was only very mildly lame.