Infestation of sheep with the stored product mite Sancassania berlesei (Acaridae)

A sheep reared outdoors in Victoria was found to be heavily infested with a stored product mite, Sancassania berlesei (Acaridae), apparently subsequent to an earlier flystrike. Laboratory observation revealed the infestation to be self-sustaining. Shearing rapidly resolved the infestation but treatment with diazinon was ineffective. The infestation could be transferred to other sheep only in the presence of moisture; once established it caused an extensive skin lesion with considerable fluid loss, apparently contributing to the death of one animal. This lesion was extremely attractive to blowflies. Animals infested with mites showed few signs of irritation.     

Temporal pattern of locomotor activity recuperation after administration of propofol in Japanese quail (Coturnix coturnix japonica)

The present study evaluates the organization and complexity of the temporal pattern of locomotion after an acute administration of propofol in Japanese quail by using traditional and fractal analysis. Birds were administered with propofol 0, 10, 20, 40 or 80 mg/kg. Ten min after administration, they were placed in an open-field apparatus and their locomotor activity was recorded during 45 min at a resolution of 0.5 s. A significant dose dependant increase in the latency to initiate ambulation was observed for doses of 20, 40 and 80 mg/kg when compared to the control group. A rapid recuperation of normal locomotor activity was observed after sedation with 20 mg/kg. Birds administered with propofol 40 mg/kg showed signs of recuperation of normal locomotion after 30 and 40 min (males and females, respectively) of propofol administration, that was not observed in quail treated with propofol 80 mg/kg. Our results suggest that depending on the dose, propofol administration in quail may allow full locomotor recovery of a sedative/anesthetic dose as early as 30 min post-administration.     

Expression of inducible nitric oxide synthase in macrophages inversely correlates with parasitism of lymphoid tissues in dogs with visceral leishmaniasis

Background

There are only a few studies reporting the role of nitric oxide metabolites for controlling macrophage intracellular parasitism, and these are controversial. Therefore, the present study aimed to evaluate the expression of inducible nitric oxide synthase (iNOS) in the lymph nodes and spleen of dogs affected by visceral leishmaniasis through immunohistochemistry and to determine its correlation with tissue parasite burden and serum interferon (IFN)-γ levels. Twenty-eight dogs were selected and assigned to one of two groups, symptomatic (n = 18) and asymptomatic (n = 10), according to clinical status and laboratory evaluation. A negative control group (n = 6) from a non-endemic region for visceral leishmaniasis was included as well.

Results

Parasite density (amastigotes/mm²) was similar between clinical groups in the lymph nodes (P = 0.2401) and spleen (P = 0.8869). The density of iNOS⁺ cells was higher in infected dogs compared to controls (P < 0.05), without a significant difference in lymph node (P = 0.3257) and spleen (P = 0.5940) densities between symptomatic and asymptomatic dogs. A positive correlation was found between the number of iNOS⁺ cells in lymph nodes and interferon-γ levels (r = 0.3776; P = 0.0303), and there was a negative correlation between parasites and iNOS⁺ cell densities both in lymph nodes (r = −0.5341; P = 0.0034) and spleen (r = −0.4669; P = 0.0329).

Conclusion

The negative correlation observed between tissue parasitism and the expression of iNOS may be a reflection of NO acting on the control of parasites.     

Transmission of Lawsonia intracellularis to weanling foals using feces from experimentally infected rabbits

The aim of this study was to investigate whether feces from rabbits experimentally infected with Lawsonia intracellularis were infectious to foals. Two rabbits were infected with L. intracellularis, while two rabbits served as controls. Eight foals received daily feces from either the infected or the control rabbits. All rabbits and foals were monitored daily for clinical signs for the entire study period (21 days for rabbits, 42 days for foals). Feces and blood were collected for the PCR detection of L. intracellularis and serologic analysis, respectively. None of the infected rabbits or foals developed clinical signs compatible with proliferative enteropathy. All infected rabbits and foals shed L. intracellularis in their feces and all seroconverted. The results support the role of rabbits as asymptomatic amplifiers of L. intracellularis and their role as sources of infection for susceptible foals.     

Antibody response to an anti-rabies vaccine in a dog population under field conditions in Bolivia

Rabies remains an important public health issue in Bolivia, South America. Public concern and fears are most focussed on dogs as the source of rabies. The objective of the present study was to assess immunity of an inactivated suckling mouse brain vaccine against canine rabies used for the official vaccination campaigns under field conditions in an endemic area of rabies in Bolivia. A total of 236 vaccinated and 44 unvaccinated dogs in Santa Cruz de la Sierra, selected using stratified random sampling, were investigated in order to obtain owned dog characteristics and antibody titres against rabies in April 2007. The proportion of vaccinated dogs with an antibody titre exceeded the protection threshold value of 0.5 EU/ml was 58% [95% confidence intervals (CI): 52-65], indicating that vaccination is likely to elicit an antibody response (odds ratio 6.3, 95% CI: 1.2-11.5). The range of geometric mean of antibody titre for vaccinated dogs (0.89 EU/ml; 95% CI: 0.75-1.04) was considered to meet the minimal acceptable level indicating an adequate immune response to the vaccine. However, the titre level was not satisfactory in comparison with the results from other field investigations with inactivated tissue culture vaccines. It is recommended for public health authorities to (1) consider modernizing their vaccine manufacturing method because the level of immunity induced by the current vaccine is comparably low, (2) conduct frequent vaccination campaigns to maintain high levels of vaccination coverage, and (3) actively manage the domestic dog population in the study area, which is largely responsible for rabies maintenance.     

Survey of potato spindle tuber viroid in seed potato growing areas of the United States

Fourteen United States (U.S.) seed potato certification agencies surveyed all U.S. seed potato growing areas for presence of the potato spindle tuber viroid (PSTVd). The survey included general surveillance, which involved searching for the occurrence of PSTVd in state seed potato certification records from 1990 through 2000, and a field survey, which involved testing selected crops for PSTVd infection by nucleic acid dot blot hybridization during 1999 through 2001. No PSTVd incident was documented in any of the state certification records, nor was PSTVd detected in the field surveys. All U.S. seed-growing areas were determined to be free of PSTVd. It is concluded that PSTVd has been eradicated and freedom from potato spindle tuber viroid has been successfully maintained in all of the seed potato growing areas in the United States.