Polar bear encephalitis: establishment of a comprehensive next-generation pathogen analysis pipeline for captive and free-living wildlife.

This report describes three possibly related incidences of encephalitis, two of them lethal, in captive polar bears (Ursus maritimus). Standard diagnostic methods failed to identify pathogens in any of these cases. A comprehensive, three-stage diagnostic 'pipeline' employing both standard serological methods and new DNA microarray and next generation sequencing-based diagnostics was developed, in part as a consequence of this initial failure. This pipeline approach illustrates the strengths, weaknesses and limitations of these tools in determining pathogen caused deaths in non-model organisms such as wildlife species and why the use of a limited number of diagnostic tools may fail to uncover important wildlife pathogens.

Investigations on hormonal changes around parturition in the dog and the occurrence of pregnancy-specific non conjugated oestrogens.

Concentrations of progesterone and estradiol-17 beta were determined throughout pregnancy in 6 to 10 bitches (exp. 1); in experiment 2 peripartal changes of estradiol-17 beta, estrone, progesterone, cortisol, prolactin and growth hormone were determined in 5 bitches; in experiment 3 total unconjugated oestrogens were determined by radioimmunoassay and radioreceptorassay in placental tissue from 25, 53, 60 and 64 days pregnant bitches. No pregnancy specific increase of estradiol-17 beta could be observed; estradiol-17 beta levels decreased prior to parturition concomitant with the decrease of progesterone, suggesting a likewise luteal origin of estradiol-17 beta in the pregnant and non pregnant dog. Cortisol and growth hormone concentrations were elevated at the time of parturition, prolactin concentrations remained unchanged but were higher in pregnant than in non pregnant dogs. No hints in respect to a specific placental oestrogen production were obtained when examining placental tissue. The hypothesis is put forward that the high sensitivity of the haematopoietic system of the dog to oestrogen was an important factor in respect to evolution of endocrine control of pregnancy and parturition in this species which-in respect to placental oestrogen production-seems to be different from most other domestic animal species.

Ovarian and pituitary function in dogs after hysterectomy.

In studies of five hysterectomized and five control dogs, hysterectomy shortened the anoestrous interval (96.6 +/- 28.0 versus 149.4 +/- 50.9 days, P < 0.05). No differences in hormone concentrations (progesterone, oestradiol, prolactin and growth hormone) were observed between the control and hysterectomized dogs except for a brief fall in progesterone concentrations over 8 days immediately after surgery, between days 35 and 40 after onset of pro-oestrous bleeding; only these animals developed symptoms of overt pseudopregnancy. It is concluded that, in dogs, luteal regression occurs independently of a uterine luteolysin, but that the uterus may play a role in control of duration of anoestrus. Pseudopregnancy seems to be initiated by a fall in progesterone concentrations rather than by other hormonal changes.