A Study on the Predilection Sites of Trichinella spiralis Muscle Larvae in Experimentally Infected Foxes (Alopex lagopus,Vulpes vulpes)

Kapel, Chr. M., Sv. Aa. Henriksen, H. H. Dietz, P. Henriksen, P. Nansen: A study on the predilection sites of Trichinella spiralis muscle larvae in experimentally infected foxes (Alopex lagopus, Vulpes vulpes). Acta vet. scand. 1994, 35, 125-132.–Studies were carried out on the predilection sites of Trichinella spiralis muscle larvae in experimentally infected arctic foxes (Alopex lagopus) and silver foxes (Vulpes vulpes) reared in cages. The highest number of larvae per gramme tissue was found in the muscles of the legs, eyes, diaphragm, and tongue. The 2 fox species showed no significant differences with regard to predilection sites.     

Activation of Zona‐Free Buffalo (Bubalus bubalis) Oocytes by Chemical or Electrical stimulation,and Subsequent Parthenogenetic Embryo Development

Parthenogenetic activation using zona‐free oocytes offers an alternative model that could be applied to develop protocols for the activation of reconstructed embryos for cloning. The aim of this study was to compare the efficacy of different methods for the activation of zona‐free buffalo oocytes in terms of their effects on the developmental competence of parthenogenetic embryos. The effects of zona removal on parthenogenetic activation and in vitro developmental competence of metaphase II oocytes were also examined. All activation methods were followed by incubation of 2 mm 6‐dimethylaminopurine (6‐DMAP) for 4 h. Out of three different pulse strengths (1.2, 2.1 or 3.3 kV/cm) used, 2.1 kV/cm resulted in the highest blastocyst rate (25.3%). On comparing different chemical agents and electric pulse, highest blastocyst rate was observed for calcium ionophore (CaI) (28.6%) followed by ethanol (25.0%), electric pulse (22.5%) and combined CaI and ethanol treatment (16.7%) although differences among them were not significant. Furthermore, a significantly reduced developmental potential was observed in zona‐free oocytes when compared to zona‐intact ones up to the blastocyst stage (44.3% vs 27.1%). In conclusion, zona‐free buffalo oocytes can be successfully activated for parthenogenetic development using chemical or electrical stimulation. Out of different agents examined, CaI followed by 6‐DMAP resulted in the highest blastocyst rate.     

Mastitis in the lactating mink female (Mustela vison S.) and the development of "greasy kits"

"Greasy kits" is the result of a multifactorial disease complex with few known definitive aetiological factors. Mastitis has been hypothesized as a triggering factor although classical clinical signs of mastitis (rubor, tumor, dolor, calor) are rarely seen in lactating Danish mink females. In this study we sacrificed 2 groups of lactating mink females with a total of 78 mammary glands at day 19-30 after giving birth. The first group had raised normal mink kits while the other group had suffered severe attacks of greasy kits. We found no clinical or histopathological evidence of mastitis but isolated streptococci and staphylococci from 2 mammary glands in females raising greasy kits. These glands showed no clinical or histological signs of inflammation attributable to bacteria and we conclude that mastitis is not necessary for the generation of greasy kits.     

Oocyte viability and cortical activation under different salt solutions in Prochilodus lineatus (Teleostei: Prochilodontidae)

This study aimed to evaluate the effect of five salt solutions in the maintenance of morphological features of cortical alveolus, hydration and fertilization capacity of Prochilodus lineatus oocytes. For this purpose, five saline solutions were tested: Ringer's solution, Ringer's lactate solution, Hank's balanced salt solution (HBSS), Hank's balanced salt solution without calcium (HBSS without calcium) and solution for salmonid eggs. Oocytes were maintained for 2 hr in saline solution with controlled temperature subsequently evaluated for hydration, cortical activation and fertilization ability. In the evaluation of the fertilization ability, two controls were used: C1—fertilized oocytes after extrusion—and C2—oocytes kept in ovarian fluid and fertilized after 2 hr. There was a significant reduction in the viability of oocytes C2 (28.8% ± 12.9%) compared to C1 (65.3% ± 26.7%), and no significant differences were found between treatments HBSS and HBSS without calcium and C2. Only HBSS and HBSS without calcium maintained the non‐activated state of the gametes, with a fertilization rate of 16.4% ± 6.7% and 5.6% ± 2.3%, respectively; however, they did not extend the viability of oocytes, such that they continued to undergo degradation during the storage period, similar to oocytes retained only in ovarian fluid.     

Prevalence and intensity of intestinal helminths found in free-ranging golden lion tamarins (Leontopithecus rosalia, Primates, Callitrichidae) from Brazilian Atlantic forest

Helminth identification and egg counts were performed in 316 fecal samples during 4 years in 199 golden lion tamarins (GLTs), Leontopithecus rosalia, from two Brazilian conservation units. Tamarin sex and age, area of occurrence and helminth co-infection were tested as potential factors that could affect helminth prevalence and egg shedding in host individuals. Three nematodes species were found at low prevalences but not in both conservation units: Ancylostomatidae (12%), Ascarididae (1%) and Tripanoxyuris minutus, an Oxyuridae (4%). Three other species had high prevalences and were found in both conservation units: one acanthocephalan, Oncicola sp. (30%), and two nematodes, Spiruridae (24%), and Trichostrongylidae (31%). These three latter helminths had distinct prevalences between the conservation units, probably due to differences in availability of helminth infective stages in each area. Prevalences were greater in females for all helminth species; this was especially the case for Oncicola sp. Sex and age differences in helminth prevalence may be associated with changes in sexual steroid levels that accompany age and reproductive status. Frequency of simultaneous infections by the two helminths considered most pathogenic (Oncicola and Trichostrongylidae) were statistically lower than expected; this may be related to: (i) higher tamarin death rate caused by the association; (ii) differences in exposure to helminth infective stages in the various areas of occurrence; (iii) and competition between these helminth species. All helminth species followed a negative binomial distribution, with stronger clumping occurring in Trichostrongylidae and in female GLTs. Distinct transmission strategies of Oncicola sp. and Spiruridae, in contrast with Trichostrongylidae, may partially explain the different clumping levels of these helminths in GLTs. Mean fecal egg counts of all helminths were not different between GLT sexes, ages or areas of occurrence. The three most common helminth species may be a threat to isolated or dense GLT populations.