Individual tumors of multifocal EB virus-induced malignant lymphomas in tamarins arise from different B-cell clones.

Cotton-top tamarins were inoculated with sufficient Epstein-Barr virus to induce multiple tumors in each animal within 14 to 21 days. The tumors consisted of large-cell lymphomas that contained multiple copies of the Epstein-Barr virus genome and generated Epstein-Barr virus-carrying cell lines showing no detectable consistent chromosomal abnormality. Hybridization of tumor DNA with immunoglobulin gene probes revealed that each lymphoma was oligo- or monoclonal in origin and that individual tumors from the same animal arose from different B-cell clones. Thus the virus induced multiple transformation events in tamarins in vivo to cause malignant tumors resembling the Epstein-Barr virus-associated lymphomas of patients with organ transplants.

A Mössbauer spectroscopic study of the form of iron in iron overload.

There are major differences in the temperature dependence of the Mössbauer spectra of ferritin and haemosiderin extracted from the organs of humans suffering from transfusional iron overload. Iron overload can also occur in animal systems as a result of artificial treatments or dietary factors. None of the animal systems which were investigated in the present study showed evidence in their Mössbauer spectra for the presence of the haemosiderin found in transfusional iron overload in humans. This suggests that the haemosiderin which occurs in the case of human transfusional iron overload may be specific to that situation.

Adrenal myelolipoma in the cottontop tamarin (Saguinus o. oedipus).

Two cases of myelolipoma in the cottontop tamarin (Saguinus o. oedipus) were found unequivocally within the adrenal gland, supporting an earlier suggestion that the adrenal gland was the possible origin of a juxtarenal myelolipoma in the same species. In the present study a 30-mm-diameter myelolipoma was present in the adrenal gland in case 1, whereas in case 2 the myelolipoma was only detected on histological examination. In case 1, changes in the adrenal gland were considered to be of minor clinical significance, whereas in case 2 the myelolipoma was an incidental finding.

Exposure to heavy metals and infectious disease mortality in harbour porpoises from England and Wales.

We investigate whether long-term exposure to heavy metals, including immunosuppressive metals like mercury (Hg), is associated with infectious disease in a wild cetacean. Post-mortem investigations on 86 harbour porpoises, Phocoena phocoena, found dead along the coasts of England and Wales revealed that 49 of the porpoises were healthy when they died as a consequence of physical trauma (most frequently entrapment in fishing gear). In contrast, 37 porpoises died of infectious diseases caused by parasitic, bacterial, fungal and viral pathogens (most frequently pneumonia caused by lungworm and bacterial infections). We found that mean liver concentrations of Hg, selenium (Se), the Hg:Se molar ratio, and zinc (Zn) were significantly higher in the propoises that died of infectious disease compared to healthy porpoises that died from physical trauma. Liver concentrations of lead (Pb), cadmium (Cd), copper (Cu) and chromium (Cr) did not differ between the two groups. Hg, Se, and the Hg:Se molar ratio were also positively correlated with age. The association between Zn concentration and disease status may result from Zn redistribution in response to infection. Further work is required to evaluate whether chronic exposure to Hg may have presented a toxic challenge to the porpoises that succumbed to infectious disease.

Investigating potential associations between chronic exposure to polychlorinated biphenyls and infectious disease mortality in harbour porpoises from England and Wales.

Bioaccumulation of immunosuppressive organochlorines like polychlorinated biphenyls (PCBs) may pose a threat to the health and viability of cetacean populations. To investigate possible associations between chronic exposure to PCBs and infectious disease mortality in harbour porpoises Phocoena phocoena in UK waters, blubber concentrations of 25 individual chlorobiphenyl (CB) congeners in 34 healthy harbour porpoises that died due to physical trauma (mainly by-catch) were compared with CB concentrations in 33 animals that died due to infectious disease. The infectious disease group had significantly greater total 25 CBs (sigma 25CBs) concentrations than the physical trauma group (P < 0.001). The mean sigma 25CBs concentration in animals that died due to physical trauma was 13.6 mg kg-1 extractable lipid whereas the mean concentration in the infectious disease group was 31.1 mg kg-1 extractable lipid. The relationship between higher sigma 25CBs and the infectious disease group was not confounded by age, sex, nutritional status, season, location or year of stranding. In addition, adult females had significantly lower sigma 25CBs levels than adult males (P < 0.05) due to maternal transfer of CBs to offspring. These findings are consistent with the hypothesis that chronic PCB exposure predisposes harbour porpoises in UK waters to infectious disease mortality, although further research is required to test these associations more robustly.

Adenocarcinoma of the large bowel and colitis in captive cotton-top tamarins Saguinus o. oedipus.

The gross and microscopic appearance of large bowel adenocarcinoma in two young adult, captive-born cotton-top tamarins is described. A retrospective examination of sections of colons from other animals that had died in the colony revealed a high incidence of chronic colitis. The adenocarcinomas, which resembled those reported from colonies of this species in the U.S.A., are thought to be the first seen in Great Britain.

Food consumption in relation to bodyweight in captive snakes.

The weekly food consumption of 25 captive snakes of nine species fed on freshly killed laboratory mice was measured for periods of three to eight weeks. Their ad libitum intake was found to vary in proportion to their initial body weight (w) raised to an exponent close to and not significantly different from 0.75 (mean [SE] 0.79 [0.064]. However, the food consumption in relation to w varied between animals, and the rates of change in bodyweight relative to w0.75 during the measurement period were highly correlated with food consumption (r = 0.801, P < 0.001). From the regression describing the relationship between these variables, the mean food requirement for maintenance was estimated at 4.2 g day-1 kg-0.75 and the mean rate of weight loss when fasting was estimated at 2.0 g day-1 kg-0.75. The mean weight gain for each gram of food eaten above maintenance level was estimated to be 0.46 g. The limits, in relation to w, within which the ad libitum food consumption of snakes can be predicted from these results with 95 per cent probability are estimated.

Variation in plasma halflife of gentamicin between species in relation to bodyweight and taxonomy.

Data on the plasma halflife of gentamicin during the elimination phase were collected from the literature for 30 species for analysis of the effects of bodyweight and taxonomy. Log halflife was significantly correlated to log bodyweight between species of birds (r = 0.784, n = 9, P less than 0.05) and mammals (r = 0.873, n = 13, P less than 0.001), but not among the poikilotherms (n = 9). The slopes of regressions of log halflife on log bodyweight for mammal and bird species did not differ significantly (0.27 +/- 0.045 and 0.32 +/- 0.095, respectively) but the elevations did (t = 2.73, P less than 0.05). The variations in halflife between species in relation to bodyweight and taxonomy were broadly consistent with variations in glomerular filtration rate. The results illustrate the value of interspecies comparisons of pharmacokinetic data for estimating appropriate dosage regimes for vertebrates for which no specific data are available.

Interspecies variation in the plasma halflife of oxytetracycline in relation to bodyweight.

The relationship between halflife (t1/2, minutes) of oxytetracycline and bodyweight (W, kg) between species of mammals and birds was examined using data collected from the literature. Linear regression of the logarithm of the halflife of the elimination phase of oxytetracycline following intravenous injection on the logarithm of bodyweight for a variety of species of mammals and birds revealed a significant correlation between species (r = 0.602, n = 13, P less than 0.05). The interspecies relationship was described by the allometric equation; t1/2 = 160 W0.20. This suggests that there is about a 14-fold variation in t1/2 across the size range of terrestrial homoeotherms, and provides a guide to dosage regime for species in which oxytetracycline kinetics have not been studied.

Some haematological data for the European kestrel (Falco tinnunculus).

The mean packed cell volume and haemoglobin concentration of blood samples taken from a colony of captive European kestrels were found to be 45.9 per cent and 17.3 g per cent respectively. No evidence of protozoal parasites was found in smears from 13 birds examined.

A survey of the aerobic bacteria in the droppings of captive birds of prey.

Fresh droppings were collected from six species of bird of prey (Falconiformes and Strigiformes). Bacteriological examination revealed that the birds' digestive systems were colonised by bacteria found widely in other species of animals. Throughout the survey no Salmonella species were isolated.

Patterns of cell proliferation and growth rate in limb bones of the domestic fowl (Gallus domesticus).

The growth rates of each extremity of the tibiotarsus (TibT) and tarsometatarsus (TMT) bones and of a phalangeal bone were measured in Rhode Island red chicks. Histological sections of the growth plates at each of these sites were made for measurements of the thickness of the flattened dividing cell layer and counts of the number of cells between its boundaries. The diameter of the mature chondrocytes in the metaphysis was also measured. The extent of the dividing cell population within the flattened cell layer and the proportion of cells in division were measured from autoradiographs prepared after labelling dividing cells in vitro or in vivo (three birds in each group) with tritiated thymidine. From the results the rate of cell production in the plane of growth at each growth plate was estimated. It varied from about six cells per day at each end of the phalanx to just over 50 cells per day at the proximal end of the TibT and TMT. The duration of the cycle time was estimated to be 13 to 21 hours at the proximal TibT and TMT and distal TibT but considerably longer at the distal TMT and at both ends of the phalanx. Variation in growth rate between extremities of the bones examined was associated largely with variation in the dividing cell populations and the thickness of the flattened cell layer, but it appears that there were also significant differences in cell cycle times between sites. The in vitro and in vivo labelling techniques gave comparable results.

Comparative cell kinetics of avian growth plates.

New data on the cell kinetics of the cartilage growth plates in the chicken, budgerigar and rhea derived from studies with tritiated thymidine labelling are given. Quantitative histological measurements on growth plates from leg bones (tibiotarsus, tarsometatarsus and a phalangeal bone) in a further five species of birds are presented. Counts of flat cells and measurements of the average diameter of hypertrophic cells were made for each growth plate. These data are compared with values for the overall growth rates of the bones. The variation in sizes of hypertrophic cells was small and it is concluded that the largest factor in determining the growth rate of an avian bone is the size of the zone of flat cells.

Pharmacokinetics of oxytetracycline in clinical cases in the red-necked wallaby (Macropus rufogriseus).

Oxytetracycline, administered at 40 mg kg-1 by intravenous injection, was used as part of the treatment of three female red-necked wallabies, Macropus rufogriseus, with suspected Fusobacterium necrophorum infections. The plasma concentrations of this drug in blood samples collected at intervals up to 24 hours after administration were measured using a biological assay. The pattern of decline in plasma oxytetracycline concentration with time was consistent with a two-compartment model. The half-life of the elimination phase was calculated to be 11.4 hours and the apparent volume of distribution was found to be 2.041 litres kg-1. These results provide a basis for devising appropriate oxytetracycline dosage regimes for the species.

Special challenges of maintaining wildlife in captivity in Europe and Asia.

In the second half of the 20th century, populations of many wild animal species have been established in captivity for various purposes (e.g. education, conservation, research, farming) and many are kept as companion animals. With continuing human pressure on the environment, captive or semi-captive management is likely to become a component in the conservation of an increasing range of species throughout Europe and Asia. The management of small and divided populations (some of which may be in zoos while some are free-ranging) requires careful control to minimise loss of genetic diversity. This, in turn, may require movements of animals or germplasm between sub-populations. A potentially serious hazard associated with these translocations is the accidental introduction of infectious agents into populations which have hitherto been geographically or ecologically isolated from these agents. When planning translocations, the state veterinary authorities of both importing and exporting countries should be contacted at an early stage for details of legal requirements in relation to animal health, welfare and conservation. Animal health legislation is mostly aimed at preventing disease in man and domestic animals, and further disease control measures may be required when translocating wild animals. In addition to the need for efforts in ensuring genetic diversity and disease control, good husbandry and welfare can often be challenging in species about which relatively little is known. A variety of organisations are involved in coordinating captive breeding programmes in Europe and Asia, and some of these organisations and the routes through which they can be identified are mentioned here.

Management of a colony of common kestrels (Falco tinnunculus) in captivity.

Management and captive breeding techniques of the kestrel are described. 5 pairs of kestrel laid 48 eggs in 1979, 27 of which were artificially incubated producing 19 hatchlings.

Factors influencing population growth of a colony of cotton-top tamarins.

43% of full-term births in a colony of Saguinus oedipus oedipus occurred during April and May. Interbirth interval was usually 12 months in females which reared live young and 7 months in those whose young died perinatally. 81% of all full-term births were of twins, the rest were singles. High mortality among neonates was seen with a group of bought-in animals which had been taken from their parents at an early age without participating in the rearing of siblings, and was attributable to parental incompetence. Colony management aiming to ensure that animals gain experience in caring for young before breeding is described. Mortality among all animals older than 7 days was very low. Marginal protein deficiency may have been involved in a chronic diarrhoea and weight loss syndrome seen in some animals. They recovered after addition of hard-boiled egg to the diet.

Rearing a second generation of cotton-top tamarins (Saguinus oedipus oedipus) in captivity.

The average age at first parturition in captive-born female cotton-top tamarins was 31 months. Only 18% of full-term young born were successfully reared by primiparous females, but success increased with parity and 71% of babies born at 4th and 5th pregnancies were raised. 15% of litters were single births, 61% were twins and 24% were triplets. There was a seasonal distribution of births, with a clear peak in the spring months. The average interbirth interval was 294 days.

Hematology of fledgling Manx shearwaters (Puffinus puffinus) with and without 'puffinosis'.

Hematological parameters were measured in 14 fledgling Manx shearwaters (Puffinus puffinus), with the disease puffinosis and in 10 birds that did not have the disease, on the Island of Skomer between 2 and 11 September 1991. The mean plasma fibrinogen concentration was significantly higher in the diseased birds and some of these had abnormally elevated monocyte counts. No other significant differences were observed.

Interventions for wildlife health, conservation and welfare.

Environmental changes induced by the activities of the increasing human population are likely, through effects on both hosts and infectious agents, to alter the patterns of incidence of diseases of wildlife. These changes may affect the conservation status or welfare of some populations. There is a need for investigations into causes of wildlife mortality incidents and for assembling information on these to assist in guiding responses to incidents in the future. Increasingly, interventions are made for the conservation or welfare of free-living wild animals and veterinary involvement in these ventures is important.