Ethologische und hygienische Untersuchungen über die Haltungsbedingungen von Raubkatzen in zoologischen Gärten.
Dr. med. vet. Dissertation
Fachbereich Veterinärmedizin, Freie Universität Berlin
Neun Zoos in Deutschland
The aim of the present study was to obtain informations which help to define guidelines to improve the environmental conditions in enclosures for cats of prey. In order to assess the animales"welfare im their environment the hygienic, ethological and breeding aspects, as well as the death rate and the occurrence of diseases were studied. During 15 months nine zoos in the Federal Republic of Germany were visited. Data of the environmental conditions in 35 enclosures, where 266 animals (21 species) were kept, were collected. During five visits, each one for a period of three days, the following data were reported: relative humidity, temperature inside and outside of every stable, C02, ammonia, lung passing dust, concentration of airborn microorganism and their compound, ventilation of the air inside of every pen, light intensity and temperature of surfaces. To decide, if cats of prey are able to cope whith their surrounding environment, the behaviour of 33 lions, 30 tigers, 31 leopards and 20 cheethas was observed for a period of 10 days per animal. For each day the time was subdivided in two hlocks of ten minutes and five blocks of one minute. The enclosures' physical characteristics were recorded. The breeding records of all cats present in the zoos and the data of pathology since 1981 were collected. There was a large variation in indoor temperature relative humidity, concentration of airborn ammonia and microorganisms during the year. In vitrines (cages with a front glas and an average volume of 31mü) the temperature was higher and the relative humidity lower than in the othersystems (p < 0,01). The data depended on the seasons and ranged between 22.2 and 25.6 øC and 33.3 to 46.6% relative humidity. In stables for only a single species with an average volume of 116mü the parameters were between 11.8 and 21.8 øC and 51,5 to 63.8 % relative humidity. The large buildings for cats of prey ( 3257mü) worked as an intermediate. In enclosures for tropical cats the data of relative humidity were not significantly higher than in the pens of the animals of the other climatic zones. In 55 to 78% of the cases the measured ammonia concentration was between 0 and 5 ppm. The area per animal, the temperature inside the stables and the amount of time, in which the animals left the houses, correlated negatively with the concentration of the disadvantage gas. The intensity of artificial light ranged on average from 18 to 1600 Ix and for daylight from 16 to 6892 Ix. In buildings reachable for visitors cages were brighter than those which were not (p e 0,01). The ascertained concentrations of airborn microorganism distinguished between the different housing systems and ranged between 7177.3 and 15834.2 KBE/mü. The concentration correlated negativly with the temperature outside of the buildings, while the amount of each compound, especially the gram positive cocci and rods, was influenced by the microclimate of the stables. The gram negative germs covered only 4.5 to 7.5%. Therefore the gram positive microorganisms were predominant. The further specification showed a wide range of different germs. Staphylococcus xylosus and lentus were the main cocci of the genus Staphyloccus. In the group of the Micrococcaceae Micrococcusa varians and luteus were dominant. 31% of the gram positve rods was classified as Rhodococcus equi. In the group of fungi members Penicillium and Aspergillusspecies were represented preferantiably. The part of the primary pathogen germs was low and amounted totaly below 1%. The analysis of the enclosures "physical characteristics showed that not all possibilities of design and construction were used in the best way. In only 48 2% of the outdoor cages the bottom was built with natural materials. In 20% of the indoor pens with concrete and tiles the ground was also covered with litter or sand. Mostly the development of the third dimension was mostly made available by boards; supplementary trees and artificial hills were insert. In only 20% of the indoorand 19% of the outdoor pens the structure of the room was assessed to be very good. In 22.5%(indoor) and 9.4% (outdoor) of the cases this rating was poor. The comparison between the ethograrms of the different species (lion, tiger, leopard, cheetha) showed a speciesspecific distribution of the observed parameters. Lions showed a longer resting period and they were more inactive than the other cats (p < 0 01 ). Cheethas and leopards did not sleep as long as the other big cats. Giving the opportunity all cats prefered higher resting places, but leopards used them more frequently (p < 0 01). This species prefered also concealments (holes, trees) for its resting period. Comparing the moving activities the males of the big cats walked for a longer period than the female ones (p < 0.05) . Leopards showed stereotypies more often than the others (63 3% of the active period) (p < 0 01), male leopards moved longer in astereotypic way than the females (male: 67 9 min; female: 34.9 min) (p < 0 05). Enclosures also influenced this behaviour. In pens below 200 mý animals showed stereotypies for longer periods than in larger ones (44 6 min /6 9 min) (p < 0 01). Most of the animals (85%) descented from breeding programs. There were no differences in successful breeding among the different species or zoos. But cats living in an area larger than 50 mý per animal gave birth to more cubs ( 8.4 cubs) than those in a smaller one (5.5 cubs) The type of building, in which he animals were kept, influenced the number of born and grown up animals. In the large buildings for cats of prey less animals were born (5.2) and grown up (3.0) than in houses for only one species (10.6 born and 7.3 juveniles) (p < 0.01). The noted data of the breeding records showed that 57% of the dead cubs were killed by their mother or father. This quota of the young animals died by occlusion comprised 24% of pathological data of the subadults. Not all the animals were available for pathological examination. Further analysis of the pathological data showed that infectious diseases were common for both groups -young and adult. Pneumonia followed by bronchopneumonia were the main respiratory problems - pulmonary diseases ranked on the third place as reason of death. In comparison with cats of the other regions cats from the tropic showed more often infections and pulmonary diseases.The ability of animals to adapt to different environmental conditions is limited. Therefore it is necessary to understand the animals" needs in order to offer good animal housing. As a kind of help to build adequate environments for cats of prey a catalogue of recommendations respectively demands for the housing were given.