Investigation of infectious reproductive pathogens of large ruminants: Are neosporosis, brucellosis, leptospirosis and BVDV of relevance in Lao PDR?

N. caninum, bovine viral diarrhoea virus, Brucella abortus and Leptospira interrogans serovar Hardjo are globally significant reproductive pathogens that cause abortion and reproductive loss in large ruminants. Prevalence information is lacking in Lao People's Democratic Republic (Laos) despite the poor reproductive performance of cattle and buffalo. Serological examination of frozen cattle (n=90) and buffalo (n=61) sera by commercially available enzyme-linked immunosorbent assays provided the first reported screening of some of these pathogens in Laos. Seroprevalence differed amongst these large ruminant species, with N. caninum, BVDV and L. interrogans serovar Hardjo antibodies found in 68.9% (95% CI±11.6), 4.9% (95% CI±5.4) and 3.3% (95% CI±4.5) of buffalo sera, respectively, and in 7.8% (95% CI±5.5), 10.0% (95% CI±6.2) and 22.2% (95% CI±8.6) of cattle sera, respectively. Buffalo sera had a significantly higher seroprevalence of N. caninum compared to cattle (p<0.001) and cattle sera had a significantly higher seroprevalence of L. interrogans serovar Hardjo compared to buffalo (p=0.003). Variability was also observed across provinces for N. caninum in buffalo (p=0.007) and for L. interrogans serovar Hardjo in cattle (p=0.071), suggesting provincial risk factors conducive to pathogen transmission. BVDV and N. caninum seropositivity were negatively associated in buffalo (p=0.018) and cattle (p=0.003). In buffalo, L. interrogans serovar Hardjo and BVDV seropositivity were associated (p=0.035, p=0.039). The identification of antibodies against three major abortifacient pathogens in Laos prompts further research to determine if infection is associated with low reproductive efficiency and the risk factors for infection. This is needed for the development of evidence based prevention strategies for improved large ruminant reproductive management among smallholders in Laos.

Prognosis after surgical excision of canine fibrous connective tissue sarcomas.

One hundred eighty seven dogs from which fibrous connective tissue sarcomas had been excised were studied until death or for at least 3 years after surgery. Dogs with a skin fibrosarcoma had a median survival time of 80 weeks, compared with 140 weeks for animals with haemangiopericytoma in similar sites, this difference being statistically significant. However, the difference in survival time between the two histologic types disappeared when tumours with a similar mitotic index were compared. Dogs with a tumour of mitotic index 9 or more had a median survival time of 49 weeks, compared with 118 weeks for those with a tumour of mitotic index less than 9, regardless of tumour morphology. Tumour recurrence rates of 62% and 25% respectively for the two groups were also significantly different.

Prognosis after surgical excision of fibrosarcomas in cats.

Forty-four cats from which fibrosarcomas had been excised were studied for a minimum of 3 years, of until death. Two factors, tumor site and mitotic index, were found to be of prognostic significance, but tumor size, duration of growth, and histologic appearance were not. Following removal of fibrosarcomas from the pinna or flank in 6 cats, none died as a result of the tumor but 24 of 35 (70%) cats with fibrosarcoma in the skin of the head, back, or limbs were euthanatized because of local recurrence, usually within 9 months of surgery. The median survival time of cats with a tumor of mitotic index 6 or more in the head, back, or limbs was 16 weeks, compared with 128 weeks when the mitotic index was less than 6. Eleven percent of cats developed pulmonary metastases.