A comparison of commercially available feeds for rabbits, guinea pigs, chinchillas and degus with evidence of their diet and feeding behaviour in natural habitats.

INTRODUCTION: A large variety of pet feeds is commercially available for pet herbivores; these feeds may differ in nutrient composition from the natural diet, and may trigger different feeding behaviours than observed in natural habitats. Here, we surveyed literature on the natural diet and activity budget of rabbits (Oryctolagus cuniculus), guinea pigs (Cavia porcellus), chinchilla (Chinchilla lanigera) and degus (Octodon degus), as well as 260 compound feeds commercially available for these species between 1982 and 2020. The species are classified as herbivores, with available data on natural diets suggesting a crude fibre (CF) level of approximately 250 g/kg dry matter (DM), natural feeding activity at a magnitude of 4-7 h per day, with distinctively shorter feeding when fed on compound pet feeds. Only for a minority of feeds did the first 5 listed ingredients not include a starchy ingredient, or only ingredients not considered suitable for human consumption. The percentage of feeds whose CF level was less than 150 g/kg DM was 22 % for production rabbits, 18 % for pet rabbits, 26 % for guinea pigs, 18 % for chinchillas and 14 % for degus; in other words, a majority of currently marketed products have CF levels in accord with published recommendations, even if that means a discrepancy to natural diets. Screening the producers' feeding instructions suggests they should generally not be followed uncritically. No temporal trends in the CF levels of these diets was evident. There is no consensus whether only products resembling natural diet items should be included in pet feeds, or whether vegetable byproducts not edible by humans should also be included. The observed practice of pet feed composition largely did not follow either concept, questioning the general rationale of pet feed composition. Whole forage like hay is recommended as the main diet component for these species, and 76 % of pet feed products noted that hay should be fed in the feeding instructions.

INTRODUCTION: Une grande variété d'aliments pour animaux de compagnie est disponible dans le commerce pour les herbivores de compagnie; ces aliments peuvent différer du régime naturel dans leur composition en nutriments et peuvent déclencher des comportements alimentaires différents de ceux observés dans les habitats naturels. Nous avons étudié la littérature sur le régime alimentaire naturel et le budget d'activité des lapins (Oryctolagus cuniculus), des cochons d'Inde (Cavia porcellus), des chinchillas (Chinchilla lanigera) et des dégus (Octodon degus), ainsi que 260 aliments composés disponibles dans le commerce pour ces espèces entre 1982 et 2020. Les espèces sont classées comme herbivores et les données disponibles sur leurs régimes alimentaires naturels suggèrent une teneur en fibres brutes (FB) d'environ 250 g/kg de matière sèche (MS), une activité alimentaire naturelle de l'ordre de 4 à 7 heures par jour, avec une durée d'alimentation nettement plus courte lorsque l'animal est nourri avec des aliments composés pour animaux de compagnie. Ce n'est que pour une minorité d'aliments que les cinq premiers ingrédients énumérés ne comprenaient pas d'ingrédient amylacé, ou seulement des ingrédients considérés comme impropres à la consommation humaine. Le pourcentage d'aliments dont la teneur en FB était inférieure à 150 g/kg MS était de 22 % pour les lapins de production, 18 % pour les lapins de compagnie, 26 % pour les cochons d'Inde, 18 % pour les chinchillas et 14 % pour les dégus ; en d'autres termes, la majorité des produits actuellement commercialisés ont des teneurs en FB conformes aux recommandations publiées, même si cela signifie une divergence par rapport aux régimes naturels. L'examen des instructions d'alimentation des producteurs suggère qu'elles ne doivent généralement pas être suivies sans discernement. Aucune évolution temporelle dans les teneurs en FB de ces régimes n'a été mise en évidence. Il n'y a pas de consensus sur la question de savoir si seuls les produits ressemblant à des aliments naturels doivent être inclus dans les aliments pour animaux de compagnie ou si des sous-produits végétaux non comestibles pour l'homme doivent également être inclus. La pratique observée en matière de composition des aliments pour animaux de compagnie n'a en grande partie respecté aucun de ces deux concepts, ce qui remet en question la logique générale de la composition de ces aliments. Les fourrages entiers, comme le foin, sont recommandés comme principale composante de l'alimentation de ces espèces et 76 % des produits alimentaires pour animaux de compagnie indiquent, dans les instructions d'alimentation, que du foin doit être donné.

[Methods of analgesia and euthanasia in backyard poultry]. / Methoden der Analgesie und Euthanasie in der Hobby-Hühnerhaltung.

INTRODUCTION: The keeping of chickens in the backyard is growing in popularity in urban and suburban areas, numbers of animals are increasing and as a result small animal practitioners are more and more frequently faced with chickens as patient. Clinical conditions in backyard poultry often require the treatment of pain. The challenges regarding the adequate use of analgesics include: 1. Recognition and assessment of pain, which necessitates good knowledge of chicken behaviour, 2. Selection of the adequate drug and dosage based on evidence that is often not available for chickens, but spread over different species of birds, and 3. Implementation of food safety regulations, which result from the dual use of backyard poultry as «food producing pets¼. Analgesics used in chickens include opiates, nonsteroidal anti-inflammatory drugs and local analgesics. The opiate butorphanol has been shown to have an analgesic effect of approximately two hours in chickens. Tramadol and methadone show some promise as analgesics, but more evidence is needed especially regarding bioavailability. The nonsteroidal anti-inflammatory drugs meloxicam and carprofen appear to have an analgesic effect. Variable metabolism between breeds of chickens and the risk of accumulation, especially when used for periods exceeding five consecutive days, need to be taken into account regarding dosage. Lidocaine and bupivacaine have successfully been used in chickens for nerve blocks and spinal anaesthesia and should be included as part of multimodal analgesia especially during surgery. In cases, where termination of life is necessary the preferred method consists of an injectable anaesthesia followed by intravenous application of a barbiturate.

INTRODUCTION: L'élevage de volailles de basse-cour est de plus en plus populaire dans les zones urbaines et suburbaines, le nombre d'animaux augmente et les praticiens pour petits animaux sont, par conséquent, de plus en plus souvent confrontés à ces animaux en tant que patients. Les conditions cliniques des volailles de basse-cour nécessitent souvent le traitement de la douleur. Les défis liés à l'utilisation adéquate des analgésiques sont les suivants 1. La reconnaissance et l'évaluation de la douleur, qui nécessitent une bonne connaissance du comportement des volailles, 2. la sélection du médicament et du dosage adéquats sur la base de preuves qui ne sont souvent pas disponibles pour les volailles mais sont réparties entre différentes espèces d'oiseaux, et 3. la mise en œuvre des réglementations en matière de sécurité alimentaire, qui résultent de la double utilisation des volailles de basse-cour en tant qu'«animaux de compagnie producteurs de denrées alimentaires¼. Les analgésiques utilisés chez les poulets comprennent les opiacés, les anti-inflammatoires non stéroïdiens et les analgésiques locaux. Il a été démontré que l'opiacé butorphanol a un effet analgésique chez les poulets, d'une durée d'environ deux heures. Le Tramadol et la méthadone sont des analgésiques prometteurs, mais des preuves supplémentaires sont nécessaires, notamment en ce qui concerne leur biodisponibilité. Les anti-inflammatoires non stéroïdiens Meloxicam et Carprofen semblent avoir un effet analgésique. En ce qui concerne la posologie, il convient de tenir compte du métabolisme variable selon les races de poules et du risque d'accumulation, en particulier en cas d'utilisation pendant des périodes supérieures à cinq jours consécutifs. La lidocaïne et la bupivacaïne ont été utilisées avec succès chez les poules pour les blocs nerveux ainsi que pour l'anesthésie spinale et devraient être incluses dans l'analgésie multimodale, en particulier pendant la chirurgie. Dans les cas où il est nécessaire de mettre fin à la vie de l'animal, la méthode de choix consiste en une anesthésie injectable suivie d'une application intraveineuse d'un barbiturique.

[Survey on the use of antibiotics in exotic pets among Swiss veterinarians]. / Umfrage bei Schweizer Tierärzte/-innen über den Einsatz von Antibiotika bei exotischen Heimtieren.

INTRODUCTION: Monitoring programs and guidelines on the use of antibiotics and antibiotic resistance in human and veterinary medicine have been developed worldwide to promote the prudent use of antibiotics in recent years. However, such information on the use of antibiotics in exotic pets is absent. This fact must be taken into account, since the number of exotic pet patients is constantly increasing and the administration of antibiotics is particular challenging due to the diversity of species and the differences in physiology. The present study reports the results of a survey of frequently used antibiotics and the criteria of antibiotic usage in exotic pets (rabbits, rodents, birds and reptiles) among Swiss veterinarians. These data should form the basis for the development of antibiotic usage guidelines in exotic pets. A total of 61 veterinarians returned the questionnaire. The most important decision-making criteria for antibiotic treatment and antibiotic selection were clinical symptoms (55/59, 93% for antibiotic treatment and 40/59, 68% for antibiotic selection), experience (41/59, 69% and 36/59, 61%, respectively) and textbooks (39/59, 66% and 40/59, 68%). The most important decision-making criteria for dosage and duration of therapy were textbooks (59/59, 100%) and experience (31/59, 53%). The use of a microbial culture was used as a decision criterion for both antibiotic treatment and antibiotic selection by 39% of the participants, sensitivity testing was chosen as a decision criterion by 37% for antibiotic treatment and by 46% for antibiotic selection. Fluoroquinolones were used most frequently, 46/56 (82% of the participants) for rabbits, 49/57 (86%) for rodents, 36/37 (97%) for reptiles and 38/46 (83%) for birds. The vast majority of veterinarians (57/58, 98%) would consult a guide for the use of antibiotics. The frequent use of critical antibiotics in exotic pets underscores the need for a guide to the prudent use of antibiotics. The positive influence of such guidelines has already been proven in dogs and cats.

INTRODUCTION: Pour promouvoir une utilisation prudente des antibiotiques, des programmes de surveillance et des lignes directrices sur l'utilisation des antibiotiques et la résistance aux antibiotiques en médecine humaine et vétérinaire ont été élaborés dans le monde entier ces dernières années. Cependant, il n'existe actuellement aucune information de ce type en ce qui concerne les nouveaux animaux de compagnie ainsi que des informations exhaustives sur l'utilisation d'antibiotiques dans la pratique vétérinaire. Ce fait doit être pris en compte, d'autant plus que le nombre d'nouveaux animaux de compagnie est en constante augmentation dans la patientèle et que l'administration d'antibiotiques est un défi particulier en raison de la diversité des espèces et des différences de physiologie. Dans la présente étude, une enquête a été menée pour avoir un aperçu des antibiotiques fréquemment utilisés et de leurs critères d'utilisation chez les nouveaux animaux de compagnie (lapins, rongeurs, oiseaux et reptiles) auprès de vétérinaires suisses. Ces données sont destinées à servir de base à l'élaboration d'un guide sur les antibiotiques pour les animaux exotiques. Au total 61 vétérinaires ont répondu au questionnaire. Les critères de décision les plus importants pour le traitement antibiotique et la sélection d'un antibiotique étaient les symptômes (55/59, 93% pour le traitement antibiotique et 40/59, 68% pour la sélection de l'antibiotique), l'expérience (41/59, 69% et 36/59, 61%, respectivement) et la littérature spécialisée (39/59, 66% et 40/59, 68%). Les critères de décision les plus importants pour e dosage et la durée du traitement étaient la littérature spécialisée (59/59, 100%) et l'expérience (31/59, 53%). L'utilisation d'une culture bactériologique a été donnée par 39% des participants comme critère de décision à la fois pour le traitement antibiotique et le choix de l'antibiotique et un antibiogramme a été choisi par 37% comme critère de décision pour le traitement antibiotique et 46% pour le choix de l'antibiotique. Il a été constaté que les fluoroquinolones sont utilisées le plus fréquemment, chez 46/56 (82% des participants) pour les lapins, 49/57 (86%) pour les rongeurs, 36/37 (97%) pour les reptiles et 38/46 (83%) pour les oiseaux. La grande majorité des vétérinaires (57/58, 98%) a déclaré qu'ils consulteraient un guide pour l'utilisation des antibiotiques. L'utilisation fréquente d'antibiotiques critiques chez les nouveaux animaux de compagnie souligne la nécessité d'un guide sur l'utilisation prudente des antibiotiques. L'influence positive de ces recommandations a déjà été prouvée pour les chiens et les chats.

Microanatomy of the digestive tract, hooves and some visceral organs of addax antelope (Addax nasomaculatus) following a concentrate or forage feeding regime.

Subacute ruminal acidosis is a common disease in captive non-domesticated ruminants and is mainly diagnosed by rumen fluid pH and rumen histology. Furthermore, differences in ruminant gastrointestinal histology have been hypothesized to correlate with the browser-grazer continuum. Twelve surplus addax antelope (Addax nasomaculatus) were divided into two groups, fed either their usual diet, consisting of a concentrate feed with a limited amount of hay, or a diet of unlimited hay only, for 3 months. After culling, descriptive and morphometric histology and pH measurements were compared between groups. Significant variations in cellular subpopulations were noted between groups, with roughage-fed individuals presenting primarily with balloon cells of the Stratum corneum and living layer cell vacuolization, whereas parakeratosis and intermediate-type cells were more frequent in the concentrate-fed group. Lesions typical of subacute ruminal acidosis were significantly more pronounced in concentrate-fed individuals. Ruminal pH measurements did not differ significantly, but were more consistent in forage-fed individuals, indicating a more stable reticuloruminal environment. The results indicate that ruminal histology may be more appropriate in assessing ruminal health compared to a single post-mortem pH measurement. It is proposed that Stratum corneum balloon cells may indicate cell maturation and not, as previously assumed, hyperfunction. Concentrate-fed individuals scored higher on the presence of inflammatory cells on hoof corium histology. The study further emphasizes the adaptability of ruminant digestive tract microanatomy in adult animals even after a short period of time and the positive effects an increased roughage diet may have in populations of captive grazing ruminants.

Gross Measurements of the Digestive Tract and Visceral Organs of Addax Antelope (Addax nasomaculatus) Following a Concentrate or Forage Feeding Regime.

Differences in macroscopic measurements of the gastrointestinal tract have been hypothesized to correlate with the browser-grazer continuum in the natural diet of ruminants. However, to what extent these characteristics represent species-specific traits, or respond to the actually ingested diet, remains to be investigated. Twelve surplus addax antelope (Addax nasomaculatus) were divided into two groups and fed, for 3 months, either their usual diet, consisting of a concentrate feed with a limited amount of hay, or a diet of unlimited hay only. After culling, macroscopic measurements were compared between groups. The macroscopic anatomy of the addax showed many characteristics considered typical for grazing or 'cattle-type' ruminants. While both diet groups had mesenteric, pericardial and perirenal adipose tissue, these depots were subjectively more pronounced in concentrate-fed animals. Hay-fed animals had significantly heavier filled forestomach compartments, with corresponding significantly longer linear measurements. Masseter muscles and the surface of first-order omasal leaves were significantly more prominent in hay-fed animals, reflecting possible adaptations to overcome resistance of grass forage and to reabsorb fluid from increased rumination, but differences were not as distinct as reported between 'cattle-type' and 'moose-type' ruminants. Some measurements such as reticular crests and empty foregut mass remained stable between groups, indicating possibly genetically pre-defined characteristics less prone to change in adult life. The results emphasize the adaptability of ruminant digestive tract anatomy in adult animals even after a short period of time, but also suggest limits to this adaptability that reveals a species-specific anatomy regardless of the diet actually consumed.

Guinea pig (Cavia porcellus) drinking preferences: do nipple drinkers compensate for behaviourally deficient diets?

When offered diets with hay ad libitum, rabbits (Oryctolagus cuniculus) clearly prefer open dishes over nipple drinkers, but whether this preference also applies in guinea pigs (Cavia porcellus) is unsure. We tested the drinker preference of 10 guinea pigs when offered open dishes (OD) and nipple drinkers (ND) simultaneously and measured the amount of water consumed by each animal on four different diets (grass hay 100%, or as 10% of intake on diets of fresh parsley, seed mix or pelleted complete feed, respectively) on either of the drinking systems. All animals ingested the hay portion of the combined diets first. The amount of water consumed differed significantly between individual animals. Animals drank less water on parsley than on the other diets. Nine of 10 animals clearly preferred ND when having a choice, and eight of these drank more when on ND only. The difference between the drinking systems was not consistent across all diets: on hay, similar amounts of water were drunk when on OD or ND only. Differences in water intake were reflected in urine production. Because drinking from ND in guinea pigs involves jaw movements similar to those in chewing, the results could suggest that when motivation for oral processing behaviour is not satisfied by a diet, animals may respond in using ND beyond physiological water necessity. Whereas physiological water requirements are probably better investigated with other drinking systems due to a possible overestimation when using ND, offering ND to pet guinea pigs most likely offers a form of behavioural enrichment that at the same time may increase water intake and hence act as prophylaxis against urolithiasis.

Retention of solute and particle markers in the digestive tract of chinchillas (Chinchilla laniger).

The chinchilla (Chinchilla laniger) is a herbivorous hystricomorph South American rodent for which no mean digesta retention times have been reported so far. Six animals (mean body mass ± standard deviation: 513 ± 99 g) on a diet of grass hay and lucerne-based pellets were given a pulse dose of a solute (cobalt-EDTA) and a particle (chromium-mordanted fibre, <2 mm) marker with subsequent frequent faecal collection. Dry matter intake was 45.2 ± 8.0 g/kg(0.75) /day. Mean retention times were 22.2 ± 5.3 h for solutes and 25.4 ± 5.2 h for particles, with the difference being not significant within individuals. This indicates the presence of a 'mucus-trap' colonic separation mechanism, which is in accord with morphological descriptions of the typical colonic furrow in chinchillas. Corresponding to a strategy of colonic digesta separation and caecotroph formation, secondary marker excretion peaks indicated coprophagic events that were spaced approximately 12 h apart. Given that these retention times appear longer than measures reported for rabbits (Oryctolagus cuniculus) or guinea pigs (Cavia procellus), it would be interesting to compare the digestive efficiency of chinchillas on high levels of dietary fibre to other species.

Anatomical Atlas of the Quail's Ear (Coturnix coturnix).

This study aims to enhance the anatomical knowledge of the ear of the adult quail (Coturnix coturnix) through the creation of a scaled 3D model utilizing data from micro-CT images. In addition, 17 annotated histological sections of the quail's ear are aligned to their 3D position in the model. The resulting anatomical atlas provides an intuitive insight into the 3D anatomy and can be used for medical education. The model also allows measuring anatomical structures and can thus serve as reference for the quail's auricular anatomy and as a basis to evaluate clinical diagnostic imaging results.

Organic matter and macromineral digestibility in domestic rabbits (Oryctolagus cuniculus) as compared to other hindgut fermenters.

It is generally assumed that animal species differ in physiological characteristics of their digestive tract. Because investigating digestive processes is often labour-intensive, requiring lengthy adaptation and collection periods, comparisons are often made on the basis of data collated from different studies. We added a new data set on dietary crude fibre (CF) and macromineral (Na, K, Ca, P, Mg) composition and apparent digestibility (aD) of organic matter (OM) and macrominerals in rabbits (Oryctolagus cuniculus; a total of 180 measurements with 12 individuals and 10 different diets) to a literature data collection for rodents and domestic horses (Equus caballus). Significant negative relationships between dietary CF and aD OM were obtained, but the significant difference in digestive efficiency between rabbits and guinea pigs (Cavia porcellus) reported from studies where both species had been investigated under identical conditions were not detectable in the larger data collection. However, the 95% confidence interval of the negative slope of the CF-aD OM relationship did not overlap between domestic horses on the one hand, and rabbits and guinea pigs on the other hand, indicating a less depressing effect of CF in horses. Akaike's information criterion indicated that aD of a macromineral did not only depend on its concentration in the diet, but also on the individual and various other diet characteristics and the presence of other macrominerals, indicating complex interactions. The data indicate similar mechanisms in the absorption of macrominerals amongst rabbits, rodents and horses, with the exception of Na and K in guinea pigs and Ca in chinchillas (Chinchilla laniger) that should be further corroborated. In particular, the occurrence of high aD Ca in hindgut fermenters, regardless of whether they employ a digestive strategy of coprophagy or whether they have fossorial habits, suggests that this peculiarity might represent an adaptation to hindgut fermentation in general.

Digestive physiology of captive giant anteaters (Myrmecophaga tridactyla): determinants of faecal dry matter content.

Giant anteaters (Myrmecophaga tridactyla) are specialized insectivores and consume mainly ants and termites in the wild. In captivity, giant anteaters are either fed a complete diet, or a combination of a domestic carnivore diet with leaf eater pellets, or a traditional gruel-type diet. Soft faeces are a frequently encountered problem with this type of feeding. In the present study, we analysed diet and faeces composition, calculated digestibility and measured mean retention time on various diets in eight giant anteaters (total of n = 64 experiments). The results suggest that the digestive physiology of giant anteaters is similar to that of domestic dogs and cats in terms of nutrient digestibility and digesta retention. When testing correlations between faecal dry matter content and other variables, no relationship with dietary crude fibre content or mean digesta retention time could be detected. However, acid insoluble ash intake was significantly and positively correlated with faecal dry matter content. The amount of acid insoluble ash excreted with the faeces was higher than that ingested with the diet offered, indicating that the giant anteaters ingested soil from their enclosure of up to 93 g per day. This finding is consistent with observation of faeces of wild giant anteaters that contain soil or sand most likely due to indiscriminate feeding. It also corresponds to reports that indigestible materials such as peat, soil, chitin or cellulose contribute to a firmer faecal consistency in various carnivore species. Therefore, offering giant anteaters the opportunity to voluntarily ingest soil from their enclosure might be beneficial.

Tooth length and incisal wear and growth in guinea pigs (Cavia porcellus) fed diets of different abrasiveness.

Dental diseases are among the most important reasons for presenting guinea pigs (Cavia porcellus) and other rodents to veterinary clinics, but the aetiopathology of this disease complex is unclear. Clinicians tend to believe that the ever-growing teeth of rabbits and rodents have a constant growth that needs to be worn down by the mastication of an appropriate diet. In this study, we tested the effect of four different pelleted diets of increasing abrasiveness [due to both internal (phytoliths) and external abrasives (sand)] or whole grass hay fed for 2 weeks each in random order to 16 guinea pigs on incisor growth and wear, and tooth length of incisors and cheek teeth. There was a positive correlation between wear and growth of incisors. Tooth lengths depended both on internal and external abrasives, but only upper incisors were additionally affected by the feeding of whole hay. Diet effects were most prominent in anterior cheek teeth, in particular M1 and m1. Cheek tooth angle did not become shallower with decreasing diet abrasiveness, suggesting that a lack of dietary abrasiveness does not cause the typical 'bridge formation' of anterior cheek teeth frequently observed in guinea pigs. The findings suggest that other factors than diet abrasiveness, such as mineral imbalances and in particular hereditary malocclusion, are more likely causes for dental problems observed in this species.

Drinking preferences in chinchillas (Chinchilla laniger), degus (Octodon degu) and guinea pigs (Cavia porcellus).

Chinchilla (Chinchilla laniger), degus (Octodon degus) and guinea pigs (Cavia porcellus) are South American rodents living in a semi-arid habitat with varying, species-specific adaptations to water deprivation. Nonetheless, several diseases have been linked to insufficient water intake when these species are kept as pets, such as urolithiasis or obstipation. This study evaluated preferences for drinking systems. Six animals of each species were given a choice between an open dish and a nipple drinker. Food intake and water intake were measured daily for 13 days. Chinchillas in this study had significantly lower water intakes than the other two species, indicating particular species-specific adaptations to aridity. All chinchillas favoured open dishes, whereas the degus and guinea pigs had variable individual preferences. Water intake of chinchillas was similar or higher in this study than in previous studies where nipple drinkers were used. The results indicate that degus and guinea pigs can meet their drinking water needs with nipple drinkers; for chinchillas, other drinking systems may be more adequate.

First detection of Borrelia burgdorferi-antibodies in free-living birds of prey from Eastern Westphalia, Germany.

Borrelia (B.) burgdorferi sensu lato, the causative agent of Lyme disease, is the most important arthropod-borne zoonosis-pathogen in the Northern hemisphere. Besides small mammals, birds, primarily Passeriformes and sea birds, play an important role in the transmission, distribution and maintenance of this disease. Previous studies on birds have focused mainly on the detection of Borrelia-infected ticks. However, the presence or absence of an infected tick cannot be taken as an indicator of the infective status of the avian host; to date this area of research has not been explored. In this study, serological analyses of blood collected from free-living birds of prey (n = 29) at the rehabilitation centre in Eastern Westphalia, Germany, highlights that birds of prey are also susceptible to B. burgdorferi and react immunologically to an infection. Increased antibody-levels could be found by using a modified Indirect Immunofluorescent-testing in two common buzzards, Buteo buteo, and two eagle owls, Bubo bubo. Further research regarding the serological diagnostics of B. burgdorferi within the avian host is required. In the future, it should be taken into account that birds of prey can be reservoirs for B. burgdorferi, as well as carriers of infected ticks; although at present their epidemiological importance is still to be confirmed.

Energy intake for maintenance in a mammal with a low basal metabolism, the giant anteater (Myrmecophaga tridactyla).

Giant anteaters (Myrmecophaga tridactyla) are among those mammals for which a particularly low metabolism has been reported. In order to verify presumably low requirements for energy, we used eight anteaters (two males, six females; aged 1-14 years; body mass between 46 and 64 kg) in a total of 64 individual trials, in which a variety of intake levels was achieved on various diets. Digestible energy (DE) intake was quantified by measuring food intake and faecal excretion and analysing representative samples for gross energy, and animals were weighed regularly. Maintenance DE requirements were calculated by regression analysis for the DE intake that corresponded to zero weight change. Differences between individuals were significant. Older anteaters (n = 3 animals aged 12-15 years in 29 trials) had lower relative requirements than younger ones (n = 5 animals aged 1-7 years in 35 trials); thus, giant anteaters resemble other mammals in which similar age-specific differences in energy requirements are known. However, estimated maintenance requirements were 347 kJ DE/kg(0.75)/day in the anteaters, which is low compared to the 460-580 kJ DE/kg(0.75)/day maintenance requirements of domestic dogs. The lack of knowledge that metabolic requirements are below the mammalian average could make species particularly susceptible to overfeeding, if amounts considered adequate for average mammals were provided. Non-scientific reports on comparatively fast growth rates and high body masses in captive giant anteaters as compared to free-ranging animals suggest that body mass development and feeding regimes in captivity should be further assessed.

Influence of diet on calcium metabolism, tissue calcification and urinary sludge in rabbits (Oryctolagus cuniculus).

Rabbits absorb more calcium (Ca) from their diet than they require, and excrete surplus via urine, which therefore contains a typical 'sludge'. This makes rabbits susceptible to Ca-containing uroliths. But given the Ca content of diets of free-ranging specimens, and the limited reports of urinary sludge and Ca contents in free-ranging lagomorphs, we can suspect that rabbits are naturally adapted to high urinary Ca loads. We fed four groups of New Zealand hybrid rabbits [n = 28, age at start 5-6 weeks) pelleted diets consisting of lucerne hay only (L, Ca 2.32% dry matter (DM)], lucerne:oats 1:1 (LG, Ca 1.36%), grass hay only (G, Ca 1.04%), or grass:oats 1:1 (GG, 0.83%) for 25 weeks, with water available ad libitum. Diets were not supplemented with Ca, phosphorus, or vitamin D. Rabbits on diets LG and GG had lower food and water intakes, lower faeces and urine output, grew faster and had higher body mass at slaughter (mainly attributable to adipose tissue). Apparent Ca digestibility decreased in the order L-LG-G/GG. Rabbits on L had larger and heavier kidneys, more urinary sediment at sonography, and a higher urinary Ca content than the other groups. No animal showed signs of urolithiasis/calcinosis at X-ray, sonography, or gross pathology. Kidney/aorta histology only sporadically indicated Ca deposits, with no systematic difference between groups. Under the conditions of the experiment, dietary Ca loads in legume hay do not appear problematic for rabbits, and other factors, such as water supply and level of activity may be important contributors to urolithiasis development in veterinary patients. However, due to the lower Ca content of grass hay, the significantly lower degree of urinary sludge formation, and the significantly higher water intake related with grass hay feeding, grass hay-dominated diets are to be recommended for rabbits in which urolithiasis prevention is an issue.

A long life among ruminants: giraffids and other special cases.

In order to investigate differences in the relative maximum longevity and other life history parameter between ruminant species, we collated data on mean body mass, maximum longevity, gestation period and newborn mass in wild ruminant and camelid species. Among ruminants, giraffids (giraffe Giraffa camelopardalis and okapi Okapia johnstoni) have particularly high longevities, long gestation periods, and low intrauterine growth rates. A particularly high absolute and relative longevity is also achieved by the anoa (Bubalus depressicornis), a member of the bovinae (cattle-type ruminants) and an insular dwarf (inhabiting the Indonesian island of Sulawesi). The fact that some (but not all) other small ruminants also achieve surprisingly high longevities leads to the hypothesis that extreme relative longevities in this group are an indication for secondary body size reduction.

Upper respiratory tract disease in captive orangutans (Pongo sp.): prevalence in 20 European zoos and predisposing factors.

BACKGROUND: Upper respiratory tract disease (URTD) is a significant cause of morbidity in captive orangutans (Pongo abelii, Pongo pygmaeus), and the pathogenesis is often unknown. METHODS: The prevalence of respiratory disease in captive European orangutans (201 animals; 20 zoos) and possible predisposing factors were investigated. RESULTS: Bornean orangutans (P. pygmaeus) showed chronic respiratory signs significantly more often (13.8%) than Sumatran (P. abelii; 3.6%), and males (15.8%) were more often afflicted than females (3.9%). Hand-reared animals (21%) developed air sacculitis more often than parent-reared animals (5%). Diseased animals were more often genetically related to animals with respiratory diseases (93%) than to healthy animals (54%). None of the environmental conditions investigated had a significant effect on disease prevalence. CONCLUSION: Results suggest a higher importance of individual factors for the development of URTD than environmental conditions. Bornean, male and hand-reared orangutans and animals related to diseased animals need increased medical surveillance for early detection of respiratory disease.

Water intake in domestic rabbits (Oryctolagus cuniculus) from open dishes and nipple drinkers under different water and feeding regimes.

Rabbits (Oryctolagus cuniculus) are often presented suffering from urolithiasis. A high water intake is important in the prophylaxis of uroliths. We investigated the influence factors for water intake using 12 rabbits subjected to different feed and water regimes with practical relevance: Hay, fresh parsley, a seed mix and two different pelleted feed were offered in diverse combinations. Water was provided either by open dish or nipple drinker. Water was accessible ad libitum except for four treatments with 6 h or 12 h water access. Under the different feeding regimes, the drinker had no influence on water intake, but faecal dry matter content was significantly higher with nipple drinkers [60.0 ± 2.1 vs. 57.2 ± 2.1% of wet weight (mean ± 95% confidence interval), p = 0.003]. Dry food led to a higher drinking water intake but total water intake was still lower than with addition of 'fresh' food. With restricted water access, rabbits exhibited a significantly higher water intake with open dishes compared with nipple drinkers (54.9 ± 9.8 vs. 48.1 ± 8.2 g/kg(0.75) /day (mean ± 95% confidence interval), p = 0.04). High proportions of fresh parsley or hay in the diet enhanced total water intake and urine output, and led to lower urinary dry matter content and lower urinary calcium concentrations. Restricted access to drinkers led to a decreased total daily water intake and increased dry matter content of urine and faeces. For optimal water provision and urolith prophylaxis, we recommend a diet with a high 'fresh food' proportion as well as additionally hay ad libitum with free water access, offered in an open bowl.