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.

[Methods of analgesia and euthanasia in backyard poultry]

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 pets». 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.

[Survey on the use of antibiotics in exotic pets among Swiss veterinarians]

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.

Theory of medical scoring systems and a practical method to evaluate Asian elephant (Elephas maximus) foot health in European zoos

Several established models in human and veterinary medicine exist to evaluate an individual health or disease status. Many of these seem unsuitable for further epidemiological research aimed at discovering underlying influential factors. As a case example for score development and choice, the present study analyses different approaches to scoring the foot health of Asian elephants (Elephas maximus) living in European facilities. Sum scores with varying degree of detail, and without or with a weighting method, were compared using descriptive statistics, ie kurtosis, skewness, Shannon entropy, total redundancy, their maximum and their actual ranges. With increasing score complexity, a higher level of differentiation was reached. In parallel, the distribution of score frequencies in the population shifted systematically: with the least complex scoring model the pattern indicated a severely unhealthy population with an opposite skew to a hypothetically healthy population, whereas the most complex scoring model indicated a mildly affected population with a skew corresponding to that expected for a healthy population. We propose the latter, in the form of the Particularised Severity Score (ParSev), which accounts for every nail and pad individually and weights the sub-scores by squaring, as the most relevant score for further investigations, either in assessing changes within an elephant population over time, or correlating foot health in epidemiological studies to potentially influencing factors. Our results emphasise the relevance of choosing appropriate scoring models for welfare-associated evaluations, due to implications for the applicability as well as the perceived welfare status of the test population.

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.

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.

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.

Unilateral evisceration of an eye following cornea and lens perforation in a sulfur-crested cockatoo (Cacatua galerita)

A 24-year old male sulfur-crested Cockatoo (Cacatua galerita) was presented with a subacute perforation of the cornea without involvement of the lens. The bird was treated conservatively and the eye remained quiescent up to a second traumatic corneal perforation associated with a lens capsule rupture 15 months later. Due to the second perforating trauma of an already blind eye involving the lens, evisceration of the eye was performed. Two months after surgery the cosmetic result was excellent. Treatment options for perforating ocular traumas in captive birds are discussed in detail.

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.

[Dermatological diseases in reptiles]

Reptiles are presented in increasing numbers in the small animal practice. The most important cause for dermatopathies is inadequate management, especially species inappropriate temperature and humidity. This aspect has to be considered in the treatment. Infectious skin diseases in reptiles are frequently caused by mites, as well as by bacteria and fungi. The special importance of the fungal disease caused by Chrysosporium Anamorph of Nannizziopsis vriesii (CANV) in lizards is emphasized. Viral skin diseases are less frequently diagnosed. Shell necrosis in chelonians is an important bacterial disease. Frequent causes of non-infectious dermatopathies are dysecdysis and trauma. Hypovitaminosis A is the most common metabolic disease. Physical examination, diagnostic tests and therapy in reptile skin diseases are comparable to mammals, however, scientific data in reptiles are still scarce.

Collection and analysis of breath and breath condensate exhaled by feral pigeons (Columba livia) and chickens (Gallus domesticus)

Samples of exhaled breath and breath condensate were collected from 20 feral pigeons (Columba livia) while they were anaesthetised and intubated, and when they were kept unanaesthetised in an acrylic box. Samples were also collected from six chickens (Gallus domesticus) while they were kept in an acrylic box. The samples were analysed for pH, nitric oxide (NO), hydrogen peroxide and leukotriene B4. The volume of condensate collected from the pigeons was independent of bodyweight and significantly more (1.66 [0.64] ml/kg) was obtained while they were in the acrylic box than when they were intubated (0.87 [0.32] ml/kg). The mean volume collected from the chickens was 0.15 (0.06) ml/kg. Cooled samples had higher concentrations of NO than uncooled samples. The pH of the samples of condensate collected from birds in the acrylic box were significantly higher (7.9 [0.3]) than those from the intubated birds (5.3 [0.1]), and samples from the chickens had significantly higher pH values than samples from the pigeons (8.2 [0.2] v 7.9 [0.3]).

The influence of dietary tannin supplementation on digestive performance in captive black rhinoceros (Diceros bicornis)

Free-ranging browsers such as the black rhinoceros (Diceros bicornis) consume a diet that contains tannins, whereas the diets offered to them in captivity consist mostly of items known to contain hardly any such secondary plant compounds. Tannins could have potentially beneficial effects, including the chelation of dietary iron (iron storage disease is a common problem in black rhinos). Here, we tested the acceptance, and the consequences on digestion variables, of a low-dose tannin supplementation in captive animals. Eight black rhinoceroses from three zoological institutions were used. Faecal output was quantified by total faecal collection. Diets fed were regular zoo diets supplemented with either tannic acid (T, hydrolysable tannin) or quebracho (Q, condensed tannins); overall tannin source intake increased at 5-15 g/kg dry matter (DM) in relation to regular zoo diets. Adaptation periods to the new diets were >2 months. Additional data were taken from one hitherto unpublished study. Data were compared to measurements in the same animals on their regular zoo diets. All animals accepted the new diets without hesitation. There was no influence of tannin supplementation on digestion coefficients of DM and its constituents, or faecal concentrations of short-chain fatty acids or lactate. Water intake did not increase during tannin supplementation. Should the inclusion of dietary tannin sources be an objective in the development of diets for captive rhinoceroses, moderate doses such as used in this study are unlikely to cause relevant depressions of digestive efficiency and will not interfere with bacterial fermentation in a relevant way.

Quantification of Enterobacteriaceae in faeces of captive black rhinoceros (Diceros bicornis) in relation to dietary tannin supplementation

Free-ranging browsing herbivores ingest a range of secondary plant compounds, such as tannins, with their natural diet. As many of these substances have been shown to have antibacterial properties, it could be speculated that a lack of such compounds in captive zoo diets could favour the growth of potentially pathogenic intestinal bacteria. The effect of a supplementation of a conventional diet (N, consisting mainly of grass hay and/or lucerne hay and pelleted compound feeds) fed to eight captive black rhinoceroses (Diceros bicornis) from three zoological institutions with either tannic acid (T), a source of hydrolysable tannins, or quebracho (Q), a source of condensed tannins, was investigated. The number of faecal colony forming units (CFU) of Enterobactericeae was determined by colony count of dilution series from fresh faeces applied to MacConkey agar plates. Tannins were added to the diets at approximately 5-15 g/kg dry matter, depending on the varying intake of roughage and compound feeds by the animals. There was no difference in the number of CFU between diets N (95.0 x 10(5) +/- 225.3 x 10(5)/g fresh faeces) and T (164.3 x 10(5) +/- 225.1 x 10(5)/g fresh faeces); in contrast, diet Q led to a significant reduction in CFU (4.3 x 10(5) +/- 6.5 x 10(5)/g fresh faeces) compared with the other diets. These findings suggest that condensed tannins could have the potential to reduce the number of potentially pathogenic intestinal bacteria, and that the deliberate inclusion of tannin sources in the diets of captive wild animals should be further investigated. The fact that tannic acid, shown to have antibacterial effects in various in vitro studies, did not have an effect in this study, emphasizes that the relevance of tannin supplementation for intestinal health must be verified in vivo.

Ante mortem diagnosis of mycobacterial infection by liver biopsy in a budgerigar (Melopsittacus undulatus)

Avian mycobacteriosis is an important disease which affects exotic, wild and domestic birds. The disease is most commonly caused by the ubiquitous soil and water organisms Mycobacterium avium sp. avium and Mycobacterium genavense. Mycobacteriosis should be considered in the differential diagnosis of any pet bird with chronic disease characterized by weight loss, an inflammatory leukogram and abdominal enlargement. Ante mortem diagnosis of avian mycobacteriosis in birds remains difficult. The present case report describes that even in very small species such as a budgerigar the investigating of a biopsy sample is an efficient way to rule out or confirm the disease in cases where other methods fail to be conclusive.

Mineral absorption in the black rhinoceros (Diceros bicornis) as compared with the domestic horse

To test whether mineral recommendations for horses are likely to guarantee adequate mineral provision for black rhinoceroses (Diceros bicornis), we investigated the apparent absorption (aA) of macro- and microminerals in eight black rhinoceroses from three zoological institutions in a total of 32 feeding trials with total faecal collection, with additional data from three unpublished studies (18 feeding trials). Feeds and faeces were analysed for Ca, P, Mg, Na, K, Fe, Mn, Cu, Zn and Co. The resulting aA coefficients, and the linear relationships of apparently absorbable dietary mineral content to total dietary mineral content [per 100 g dry matter (DM)], were compared with data for domestic horses. Rhinoceroses had significantly higher aA coefficients for Ca and Mg (because of a higher calculated 'true' absorption), and lower ones for Na and K (because of calculated higher endogenous faecal losses). High absorption efficiency for divalent cations is hypothesized to be an adaptation to a natural diet of particularly high Ca:P ratio (approximately 14:1); an effective removal of Ca from the ingesta guarantees sufficient P availability at the fermentation site in the hindgut. Higher faecal losses of Na and K are hypothesized to be linked to a higher faecal bulk per DM intake in black rhinoceroses as compared with horses because of a generally lower digestive efficiency. There were no relevant differences in the absorption patterns of microminerals. In particular, there were no discernable differences in Fe absorption within the rhinoceroses for diets with and without tannin supplementation. Several of the zoo diets assessed in this study were deficient in Cu, Mn or Zn, and most contained excessive levels of Fe when compared with horse requirements. The findings of this study indicate that differences in mineral absorption between occur even between species of similar digestive anatomy; that in particular, Ca absorption might vary between hindgut fermenters with Ca:P ratio in their natural diet; that Na might be a particularly limiting factor in the ecology of free-ranging rhinoceroses; that moderate doses of tannins do not seem to markedly influence mineral absorption; and that diets for captive animals should contain adequate, but not excessive mineral levels.

Clinical application of an external fixator in the repair of bone fractures in 28 birds

The repair of seven tibiotarsal fractures, three humeral fractures, three tarsometatarsal fractures, two femoral fractures and 13 radial and ulnar fractures with a tubular external fixator system was evaluated prospectively in 10 common pigeons (Columba livia), 11 psittacine birds, six birds of prey and one Bali starling (Leucopsar rothschildii). The fixations included type 1, type 2 and intramedullary tie-in methods, and the fractures healed in all but three cases. A comparison of the weight of different connecting bars showed that the external fixation system and polymethylmethacrylate are the lightest available systems and that there was no clinically relevant difference between them.

Differences in Bone Mineral Content and Density between Male and Female Budgerigars (Melopsittacus undulatus) during the Non-reproductive Season

It is known that female birds increase medullary mineral stores in long bones shortly before egg laying. Here, we present results from two groups of budgerigars, in both of which females had significantly higher bone mineral contents and densities, as measured by peripheral quantitative computed tomography of the tibiotarsus, during a reproductively dormant period. The results could indicate that female birds can accumulate mineral stores outside of the breeding season.

Clinical approach to renal neoplasia in budgerigars (Melopsittacus undulatus)

Renal neoplasia in budgerigars (Melopsittacus undulatus) is seen regularly in general practice and is of interest to many practicing veterinary surgeons. This review article provides an overview of the current knowledge and the most recent reports in avian literature regarding renal tumours in budgerigars, with the emphasis on clinical diagnosis and treatment. The high prevalence of renal neoplasia in budgerigar is discussed, with notes on the most commonly diagnosed tumours, possibility of metastases, sex and age predisposition. The possibility of ultrasonography and radiography in the diagnosis of this pathological condition are compared as well as the possible role of blood and urine analyses. Two studies are described, both of which investigate the possible involvement of a retrovirus as the aetiological agent.

Collection of exhaled breath and exhaled breath condensate in veterinary medicine. A review

Collection of exhaled breath (EB) and exhaled breath condensate (EBC) is a noninvasive method for obtaining samples from the lower airways. While this technique has been well established for the diagnosis of lower respiratory tract diseases in human medicine, only a few studies have been performed in veterinary medicine. This article critically reviews the collection methods and parameter values measured in various animal species published to date and points out directions for further research.

Effects of two diets on the haematology, plasma chemistry and intestinal flora of budgerigars (Melopsittacus undulatus )

Two groups of 22 budgerigars (Melopsittacus undulatus) were housed for 12 months under identical conditions. One group was fed a commercial seed mixture plus carrots and a mineral supplement, and the other group was fed a commercially formulated diet plus carrots. Samples of blood and faeces were collected initially and after three, six, nine and 12 months. There were no significant differences between the haematological values of the two groups. The group fed the seed mixture had significantly higher concentrations of glucose, albumin, triglycerides and uric acid, and higher activity of aspartate aminotransferase, but the values were within the published reference ranges for normal birds. There were no significant differences between the faecal samples from the two groups, except that the fungus Macrorhabdus ornithogaster was identified in 48.3 per cent of the samples from the group fed the commercially formulated diet but from only 3.4 per cent of the samples from the group fed the seed mixture.

Digestion coefficients achieved by the black rhinoceros (Diceros bicornis), a large browsing hindgut fermenter

In contrast to the grazing white (C. simum) and Indian (R. unicornis) rhinoceros, the black rhinoceros (D. bicornis) is an exclusive browser. Due to the particular fermentation characteristics of browse, one would expect browsers to display both shorter ingesta retention times and lower digestion coefficients on comparable diets than grazers. In order to generate a database to test this hypothesis, we performed digestibility studies in eight black rhinoceroses (D. bicornis) from three zoological institutions, using total faecal collection for the quantification of faecal output. One to three regularly fed zoo rations of roughage, concentrates and varying proportions of browse material were used per animal. Additional data was taken from three hitherto unpublished studies as well as several published sources. When compared with horses on similar rations, black rhinoceroses achieved lower digestion coefficients for organic matter and CF. In general, an increase in dietary CF content led to a steeper decrease in organic matter and GE digestibility in black rhinoceroses than in horses. When comparing available data for rhinoceroses, browsing species showed a steeper decrease in organic matter digestibility than grazing species with increasing dietary cell wall content. Endogenous losses as determined by linear regression analysis were within the range reported for horses and Indian rhinoceroses. The results suggest that the horse is not a useful model animal for evaluating diets for black rhinoceroses energetically. In general, diets fed to captive black rhinoceroses seem to include higher proportions of concentrates than diets for other rhinoceros species, and an increase in browse or roughage would reduce digestion coefficients to levels observed in animals fed natural forage.

Antioxidant Status of Faeces of Captive Black Rhinoceros (Diceros bicornis) in Relation to Dietary Tannin Supplementation

In context with the frequent observations of excessive iron (Fe) storage in captive black rhinoceroses (Diceros bicornis), it has been suggested that both an excessive dietary Fe content and a lack of dietary Fe-chelating substances, such as tannins, is the underlying cause. Therefore, studies on the effects of tannin supplementation to captive diet are warranted. Six captive rhinoceroses were fed their normal zoo diet (N), and a similar diet supplemented with either tannic acid (T, hydrolysable tannin) or quebracho (Q, condensed tannins), and the total antioxidant capacity (TAC) was measured as mmol Trolox equivalents per kg fresh faeces. The TAC values on diets N (1.24 +/- 0.39 mmol/kg fresh faeces) and T (1.34 +/- 0.33 mmol/kg fresh faeces) were similar, but significantly higher on diet Q (2.32 +/- 0.61 mmol/kg fresh faeces). In contrast to expectations, faecal TAC increased with increasing faecal Fe, possibly as a result of the fact that the faecal Fe content was positively correlated to the proportion of concentrate feeds in the diet, which also contain antioxidants, such as vitamin E, in addition to Fe. Increased antioxidant status caused by the use of tannin substances could have a beneficial effect on animal health, but if tannins should be incorporated in designed diets, other tannin sources, such as grape pomace should be tested.

Chronic regurgitation in a cockatiel (Nymphicus hollandicus) with a trichobezoar

Crop disorders are very common in small psittacine birds. Psittacine birds are very curious and like chewing on different materials. Therefore, they are predisposed to ingest foreign material. In the literature only very few cases have been reported. This case report describes the clinical examination, the diagnostic workup and the ingluviotomy in a cockatiel with a bezoar in the crop.

Energy and fibre intake in a group of captive giraffe (Giraffa camelopardalis) offered increasing amounts of browse

We investigated the effect of diet on intake of energy and fibre in a group of three captive adult giraffe by weighing offered diet items and leftovers for 7 days after an adaptation period of 7 days. Digestion coefficients were calculated using, as internal marker, the acid detergent lignin content of a faecal sample pooled from subsamples taken during the last 5 days of intake measurement. Two lucerne hay-only diets of differing quality (L1, L2) were fed, as well as the regular diet of lucerne hay and concentrates (L2C), and the regular diet supplemented with 3 or 6 kg of edible, fresh browse material (L2CB3, L2CB6). The proportion of roughage in the ingested diets L2CB6 (45 +/- 5% dry matter), L2CB3 (35 +/- 3%) and L2C (37 +/- 10%) did not differ significantly. Digestible energy intake was low on the hay-only diets [L1: 0.28 +/- 0.06 MJ/kg body weight (BW)0.75; L2: 0.33 +/- 0.10 MJ/kg BW0.75] and increased from L2C (0.60 +/- 0.13 MJ/kg BW0.75) to a significant increase with L2CB3 (0.72 +/- 0.17 MJ/kg BW0.75); no further increase was obvious for L2CB6 (0.63 +/- 0.15MJ/kg BW0.75). The results confirm that giraffes are unlikely to meet energy requirements on lucerne hay-only diets. In a feeding scenario where both lucerne hay and the concentrate component of the diet are fed ad libitum, the animals tended to exchange hay for browse when browse was added. Only the higher level of browse supplementation led to a potentially beneficial increase in fibre intake. Whether additional browse supplementation will lead to increased intakes in a feeding scenario with restricted concentrate provision can be suspected but remains to be demonstrated.

Overt fatal and chronic subclinical Encephalitozoon cuniculi microsporidiosis in a colony of captive emperor tamarins (Saguinus imperator)

The course of an infection with the microsporidian Encephalitozoon cuniculi in a colony of captive emperor tamarins (Saguinus imperator) is described. In two litters, the infection was associated with overt disease and death of all infants. Immunohistochemistry for E. cuniculi showed generalized infections, and histopathologic evaluation revealed systemic vasculitis and disseminated mixed inflammatory cell infiltration with and without necrosis in several organs. Serologically, some of the juvenile animals presented with high titres for Encephalitozoon, while the adults had low titres. The E. cuniculi "dog strain" was identified by molecular means for the first time in Europe. The origin of the infection appeared to be a pair of breeding adults that originated from the US. Our data suggest that the organism persisted over years in the colony, and that subclinically infected animals most likely were involved in perpetuating the infection. Efforts should be made to ascertain if this microorganism is present in other captive populations of this endangered monkey species and to prevent its further spreading.

Headspace solid-phase microextraction (SPME) and gas chromatography-mass spectrometry (GC-MS) for the determination of 5alpha-androst-2-en-17-one and -17beta-ol in the female Asian elephant: application for reproductive monitoring and prediction of parturition

Asian elephants are not self-sustaining in captivity. The main reasons for this phenomenon are a low birth rate, an aging population, and poor calf-rearing. Therefore, it is essential that reproductive rates had to be improved and there is need for rapid quantitative measures to monitor reproductive functions focussing on estrous detection and the prediction of the period of parturition. The objective of this study was to develop a method which combines headspace solid-phase microextraction (SPME) and gas chromatography-mass spectrometry (GC-MS) for analyses of 5alpha-androst-2-en-17beta-ol and -17-one to prognose estrous and to predict the period of parturition. SPME was carried out with a CTC Combi Pal system. The course of the luteal phase-specific substance 5alpha-androst-2-en-17beta-ol and -17-one followed a cyclic pattern in which the follicular and luteal phases could be clearly distinguished (mean estrous cycle length, 15+/-1.4 weeks). Based on daily urine samples, estrous prognosis might be possibly based on the initial 5alpha-androst-2-en-17beta-o1 increase at the end of the follicular phase. Parturition prognosis was performed in three elephant cows based on the 5alpha-androst-2-en-17beta-o1 drop to baseline levels 5-4 days prior parturition. Experiments revealed that 5alpha-androst-3alpha-ol-17-one and probably 5alpha-androst-3alpha-ol-17beta-ol are generated from sulfate conjugates by a thermal process.

[Anesthesia and analgesia of ornamental birds]

Pet birds are frequently viewed as difficult patients for anaesthesia. The present paper revises the current anaesthetic procedures for injectable and inhalant anaesthetics. Currently the method of choice for the anaesthesia of pet birds is the isoflurane inhalation anaesthesia. Special emphasis is given to the preanaesthetic preparations. Fasting is shorter for pet birds than for mammals. Anaesthetized birds are at special risk for hypothermia. Methods for the prevention of heat loss are given. The use of analgesics are recommended both for welfare reasons but also because of the possibility to reduce the concentration of inhalation anaesthetics and therefore the amount of possible exposure of personnel to waste gases.

Prevention and treatment of Encephalitozoon cuniculi infection in rabbits with fenbendazole

The efficacy of fenbendazole for preventing an experimental infection of Encephalitozoon cuniculi and for eliminating the spores from the central nervous system of naturally infected rabbits was investigated. Fenbendazole (20 mg/kg bodyweight daily) was administered from seven days before until two or 21 days after rabbits had been infected orally with 10(6) spores of E. cuniculi. Both regimens were effective in preventing the establishment of the parasites, as demonstrated by negative parasitic-specific serology and by the failure to isolate the parasite from brain tissue. In naturally infected, seropositive rabbits, parasites were successfully isolated from seven of nine untreated animals, but not from the brain tissue of eight animals treated with fenbendazole-medicated pellets for four weeks.

[Dicrocoeliasis in New World camelids]

Natural infections with the lancet fluke (Dicrocoelium dendriticum) were detected in a group of seven diseased or dead/euthanized South American Camelids (five Llamas, two Alpacas) from Switzerland and Southern Germany. Clinical findings in almost all the animals revealed an acute decline of general condition followed by recumbency, decreased body temperature and a varying degree of anaemia. Concurrently, all animals showed an average to poor nutritional status. All liver enzyme activities analysed in serum biochemistry conformed to the reference values and therefore offered no diagnostic clues for this disease. Necropsy however, disclosed major alterations in the liver in the form of cirrhosis, abscesses, granulomas, and a massive infestation with D. dendriticum. The coprological investigations performed at the outset of the examinations revealed eggs of the lancet fluke in only two animals. This suggests that clinical findings alone permit at best only a provisional diagnosis. Repeated coprologic follow-ups showed that the presence of eggs of D. dendriticum can be diagnosed accurately and that clinical signs appear with an excretion rate above 1000 eggs per gram faeces (EpG). In these cases, praziquantel in a single dose of 50 mg/kg per os was given. This treatment was well tolerated and achieved a quite acceptable 90% reduction of eggs in the faeces.

Unusual case of metabolic bone disease in a common marmoset (Callithrix jacchus)

Metabolic bone disease was diagnosed in an 11-month-old female common marmoset (Callithrix jacchus). It was depressed, reluctant to move, and was cachectic and small for its age. Laboratory findings included anaemia, azotaemia and an inverse calcium to phosphorus ratio. The radiological findings showed simultaneous signs of osteomalacia and soft-tissue calcification. There was decreased bone density with lytic areas in the pelvis and femur, and severe bilateral nephrocalcinosis. Postmortem examination revealed marked focal dystrophic calcification of the epi- and myocardium. Calcium and vitamin D3 deficiency (nutritional secondary hyperparathyroidism) was the most likely cause of the osteomalacia.

[The zoo veterinarian in changing times]

During this century the field of work for zoo veterinarians has dramatically changed. Preventive medicine at herd, group or even species level has gained importance. The therapy of single animals is no longer a priority. On the basis of recent developments progress for the future can be proposed. Effective conservation requires thinking and action by a combination of different specialists. Exchange of information at an international level will be of increasing importance. The continuing specialisation in veterinary and human medicine requires interdisciplinary co-operation. The ethics of research and medical interventions on zoo animals is of concern to the public and it is necessary to publicly advance the arguments for and against. The training of specialized zoo veterinarians should be increased.

[Endocrinologic and pathologic findings in ornamental birds with polyostotic hyperostosis]

Polyostotic hyperostosis is a finding that is often seen on x-rays in companion birds. Hyperestrogenism might be a causative for polyostotic hyperostosis. The purpose of this study was to compare endocrinologic and pathologic findings in birds with polyostotic hyperostosis. Thirty-five affected and three control birds were examined. Blood samples were taken for endocrinologic statement (estrone, estradiol, testosterone and estrone sulfate) and the values were compared with the pathologic findings. In the present study the comparison of endocrinologic and pathologic findings did not reveal any significant results supporting the hypothesis that polyostotic hyperostosis was caused by hyperestrogenism.