Analysis of complications in 97 periprosthetic Vancouver B2 fractures treated either by internal fixation or revision arthroplasty.

INTRODUCTION: The treatment of Vancouver B2 periprosthetic fractures after hip arthroplasty is still a matter of debate. Revision Arthroplasty (RA) was long thought to be the treatment of choice, however several recent papers suggested that Open Reduction and Internal Fixation (ORIF) is a viable option for selected B2 fractures. Complication rates of 14-26% have been reported following surgical treatment of B2 fractures. No significant difference between RA and ORIF in the complication rates nor in the functional outcome was observed. METHOD: We conducted a retrospective analysis of 97 consecutive Vancouver B2 fractures treated according to the algorithm at our institution from 2007 to 2020 and recorded complications and patient specific data. RESULT: From the 97 patient, 45 fractures were treated with RA while 52 fractures were treated with ORIF. Thirteen patients in the RA group had a complication that needed revision (28%) and 11 patients in the ORIF group needed revision (21%). There was no significant difference between complication rates. The reason for failure in the 13 RA patients were infection (n = 4), stem subsidence (n = 1), refracture after a new fall (n = 3), secondary dislocation of the greater trochanter (n = 1) and dislocation (n = 4). The reason for failure in the 11 ORIF patients that were revised were infection (n = 5), persistent symptomatic stem loosening (n = 3) and refracture (n = 3) after a new fall. CONCLUSION: ORIF can be used to revise cemented and non-cemented shafts in more than half of Vancouver B2 fractures with no difference in complication rates when compared to RA. A periprosthetic fracture around the hip has a 21-28% risk of a re-operation after revision surgery with infection and re-fracture after a new fall being the most frequent cause of re-operation.

Management of acute periprosthetic knee infection: a comparison of arthroscopic and open debridement.

INTRODUCTION: In acute periprosthetic knee infections, debridement and implant retention (DAIR) is the preferred treatment prior to one- and two-stage revisions. The aim of this study is to compare the outcomes of arthroscopic and open debridement of infected primary total knee arthroplasties (TKA). MATERIAL AND METHODS: We analyzed clinical, laboratory, and antibiotic treatment data, collected in patients with periprosthetic knee infection treated with DAIR at a Swiss Level 1 orthopedic and trauma center over a 10-year period between January 2005 and May 2015. Inclusion criteria were primary total knee arthroplasty and early postoperative or acute hematogenous periprosthetic joint infection (PJI). The primary endpoint was the need for further revision surgery due to persistent infection. The secondary endpoint was the prosthesis salvage in further infection surgeries. RESULTS: Forty-two patients with 44 acute or hematogenous periprosthetic knee infections were included. We recorded 20 recurrent infections (45%) in our study population: 10 (77%) out of 13 in the arthroscopic DAIR group and 10 (32%) out of 31 in the open DAIR group. Two-stage revision, meaning complete removal of the TKA, insertion of a spacer and replantation at a second stage, had to be performed in three patients treated initially arthroscopically (23%) and in six patients treated initially with an open surgical procedure (21%). CONCLUSIONS: Open debridement for acute periprosthetic knee infection shows clear benefits in terms of infection eradication and prosthesis salvage compared to arthroscopic DAIR.

The mammalian brain under domestication: Discovering patterns after a century of old and new analyses.

Comparisons of wild and domestic populations have established brain reduction as one of the most consistent patterns correlated with domestication. Over a century of scholarly work has been devoted to this subject, and yet, new data continue to foster its debate. Current arguments, both for and against the validity of brain reduction occurring in domestic taxa, have repeatedly cited a small set of reviews on this subject. The original works, their sampling, methodological details, and nuances of results that would be key to establishing validity, particularly in light of new data, have not been investigated. To facilitate and encourage a more informed discussion, we present a comprehensive review of original brain reduction literature for four mammalian clades: Artiodactyla, Perissodactyla, Carnivora, and Glires. Among these are studies that generated the most cited brain reduction values in modern domestication literature. In doing so, we provide a fairer stage for the critique of traits associated with domestication. We conclude that while brain reduction magnitudes may contain error, empirical data collectively support the reduction in brain size and cranial capacity for domestic forms.

Intensive human contact correlates with smaller brains: differential brain size reduction in cattle types.

Cattle are one of the most intensively bred domestic animals, providing humans with a multitude of products and uses. Using data from the fossil record, we test if their domestication, as for other taxa, has resulted in a reduction of their brain size. We not only conclude that Bos taurus (domestic cattle) have smaller brains than their wild ancestor, Bos primigenius (aurochs), but that brain size varies significantly by breed, with some having much smaller brains than others. Differences in husbandry practices between several breed categories align with a range of human engagement, which also aligns with the degree of selection for docility. Sampling 317 domestics from 71 breeds, we investigate if differences in brain size correlate with the intensity of human contact. A clear pattern emerges whereby a brain reduction gradient parallels a gradient in behavioural selection. Bullfighting cattle, which are bred for fighting and aggressive temperament, have much larger brains than dairy breeds, which are intensively selected for docility. Our results add to a fundamental aspect of animal domestication theory: the interplay between basic features of the domestic environment-selection for docility, absence of predators and human provision of resources-seems to explain differences in brain size.

Accuracy of methane emissions predicted from milk mid-infrared spectra and measured by laser methane detectors in Brown Swiss dairy cows.

Since heritability of CH4 emissions in ruminants was demonstrated, various attempts to generate large individual animal CH4 data sets have been initiated. Predicting individual CH4 emissions based on equations using milk mid-infrared (MIR) spectra is currently considered promising as a low-cost proxy. However, the CH4 emission predicted by MIR in individuals still has to be confirmed by measurements. In addition, it remains unclear how low CH4 emitting cows differ in intake, digestion, and efficiency from high CH4 emitters. In the current study, putatively low and putatively high CH4 emitting Brown Swiss cows were selected from the entire Swiss herdbook population (176,611 cows), using an MIR-based prediction equation. Eventually, 15 low and 15 high CH4 emitters from 29 different farms were chosen for a respiration chamber (RC) experiment in which all cows were fed the same forage-based diet. Several traits related to intake, digestion, and efficiency were quantified over 8 d, and CH4 emission was measured in 4 open circuit RC. Daily CH4 emissions were also estimated using data from 2 laser CH4 detectors (LMD). The MIR-predicted CH4 production (g/d) was quite constant in low and high emission categories, in individuals across sites (home farm, experimental station), and within equations (first available and refined versions). The variation of the MIR-predicted values was substantially lower using the refined equation. However, the predicted low and high emitting cows (n = 28) did not differ on average in daily CH4 emissions measured either with RC or estimated using LMD, and no correlation was found between CH4 predictions (MIR) and CH4 emissions measured in RC. When individuals were recategorized based on CH4 yield measured in RC, differences between categories of 10 low and 10 high CH4 emitters were about 20%. Low CH4 emitting cows had a higher feed intake, milk yield, and residual feed intake, but they differed only weakly in eating pattern and digesta mean retention times. Low CH4 emitters were characterized by lower acetate and higher propionate proportions of total ruminal volatile fatty acids. We concluded that the current MIR-based CH4 predictions are not accurate enough to be implemented in breeding programs for cows fed forage-based diets. In addition, low CH4 emitting cows have to be characterized in more detail using mechanistic studies to clarify in more detail the properties that explain the functional differences found in comparison with other cows.

A comparative meta-analysis on the relationship of faecal calcium and phosphorus excretion in mammals.

To investigate the relationship between faecal calcium (Ca) and phosphorus (P) excretion in different mammalian species, a meta-analysis on digestibility data derived from the literature was conducted. Seventy-three studies on carnivores, omnivores, large and small hindgut fermenters, ruminants and hippos (a total of 21 mammalian species, precondition for inclusion dietary Ca/P ratio 1.5/1 - 3.0/1) were analysed for Ca and P digestibility. Dietary Ca/P ratios were lower than faecal Ca/P ratios in carnivores, omnivores, ruminants and hippos. In hindgut fermenters, dietary Ca/P ratios were higher than faecal Ca/P ratios, indicating higher intestinal Ca absorption in these species. In all species investigated, there was a significant positive relationship between Ca intake and faecal Ca excretion and between P intake and faecal P excretion. In the biologically relevant range, these equations predicted lower faecal Ca losses in hindgut fermenters than ruminants, for faecal P vice versa. In all species, faecal Ca and P excretion correlated significantly. In carnivores, this highly linear correlation was exceptionally strong (R² = .92). Yet, the linearity of the correlation was questionable in omnivores and ruminants. Possibly, the strong linear correlation of faecal Ca and P excretion in carnivores is due to the formation of insoluble Ca/P complexes in their relatively short and simple gastrointestinal tract. Another hypothesis is that in carnivores, Ca homeostasis relies on modifying bone turnover to a higher degree than on changes in intestinal Ca absorption. For the formation of bone matrix, a constant ratio of Ca and P absorption is of advantage.

Kinetics of solutes and particles of different size in the digestive tract of cattle of 0.5-10 years of age, and relationships with methane production.

The digestive physiology of cattle is characterised by comparatively long digesta mean retention times (MRTs), a particle sorting mechanism (difference in MRTs of large vs. small particles) and a distinct digesta washing (difference in MRTs between particles and fluids) in the reticulorumen (RR). How these processes mature during ontogeny, and how they link to other digestion characteristics and methane production, is largely unknown. We used a set of passage markers (Co-EDTA for fluids and hay particles of 2, 5 and 8 mm length mordanted with Cr, La and Ce, respectively) to measure MRTs in 12 heifers (0.5-2.1 years; hay only) and two groups of 15 lactating cows (2.4-10.0 years; forage-only vs. forage-concentrate diet). The MRTs differed between markers (Co < Cr < La < Ce) and were longer in heifers than cows, consistent with the lower feed intake in heifers. MRTs were mostly similar between cow groups and increased with age. Digesta washing was not affected by group, age, feed intake and number of chews per unit of feed. The degree of digesta washing was not related to CH4 measures. Particle sorting was more prominent in cows than heifers but did not differ between cow groups or change with age in cows. This could be the consequence of the abrupt increase in intake from heifers to cows at a time when gut capacity is not yet fully developed; particle sorting might then clear smaller particles from the RR sooner allowing a higher intake. Surprisingly, CH4 yield per ingested feed did not correlate with MRTs, and CH4 yield per unit of digested fibre decreased with increasing MRTs and with increasing fibre digestibility. As this pattern occurred in heifers and both cow groups, it appeared independent of age, indicating a mechanism that has not been described in the literature so far and requires further investigation.

Comparative selective retention of particle size classes in the gastrointestinal tract of ponies and goats.

There is a discrepancy in the literature on potential digesta separation mechanisms in horses, with both a selective retention of fine and of large particles postulated in different publications. To assess the net effect of such mechanisms, we fed ponies on a hay-only diet a pulse dose of whole (unchopped) marked hay together with a solute marker, collected faeces on a regular basis, measured marker concentrations in whole faeces and in their large (2.0-16 mm), medium (0.5-1.0 mm) and small (0.063-0.25 mm) particle fraction, and calculated the corresponding mean retention times (MRTs). For comparison, the same experiment was performed in goats. In goats, as expected, MRTsolute (35 hr) was significantly shorter than MRTparticle (51 hr); only a very small fraction of particle marker was excreted as large particles (2%); and the MRT of these large particles was significantly shorter than that of small particles (with a relevant difference of 8.6 hr), indicating that those few large particles that escape the rumen do so mostly soon after ingestion. In ponies, MRTsolute (24 hr) did not differ from MRTparticle (24 hr); a higher fraction of particle marker was excreted as large particles (5%); and the MRT of these large particles was longer than that of small particles (but with a non-relevant difference of less than 1 hr). These results indicate that no relevant net separation of digesta phases occurs in horses and that selective particle retention mechanisms in the large intestine are unlikely to represent important characteristics of the horse's digestive physiology.

How does dietary particle size affect carnivore gastrointestinal transit: A dog model.

The effect of dietary particle size on gastrointestinal transit in carnivores has not been studied and might offer more insight into their digestive physiology. This study evaluated the effect of two dietary particle sizes (fine = 7.8 mm vs. coarse = 13 mm) of chunked day-old chicks on transit parameters in dogs. Six beagle dogs were fed both dietary treatments in a crossover design of 7 days with transit testing on the fifth day. Transit parameters were assessed using two markers, that is a wireless motility capsule (IntelliCap® ) and titanium oxide (TiO2 ). Dietary particle size did not affect gastric emptying time (GRT), small bowel transit time (SBTT), colonic transit time (CTT) and total transit time (aTTT) of the capsule (p > .05). There was no effect of dietary particle size on TiO2 mean retention time (MRT) (p > .05). The time of last TiO2 excretion (MaxRT) differed (p = .013) between diets, being later for the coarse diet. Both MRT (R = 0.617, p = .032) and MaxRT (R = 0.814; p = .001) were positively correlated to aTTT. The ratio MRT/aTTT tended towards a difference between diets (p = .059) with the coarse diet exceeding fine diet values. Results show that the difference between capsule measurements and TiO2 is larger for the fine than the coarse diet suggesting that the capsule becomes more accurate when dietary particle size approaches marker size. Dietary particle size might have affected transit parameters but differences are too small to claim major physiological consequences.

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.

Dry matter and digesta particle size gradients along the goat digestive tract on grass and browse diets.

Physical properties of the digesta vary along the ruminant digestive tract. They also vary within the forestomach, leading to varying degrees of rumen contents stratification in 'moose-type' (browsing) and 'cattle-type' (intermediate and grazing) ruminants. We investigated the dry matter concentration (DM) and the mean digesta particle size (MPS) within the forestomach and along the digestive tract in 10 goats fed grass hay or dried browse after a standardized 12-h fast, euthanasia and freezing in the natural position. In all animals, irrespective of diet, DM showed a peak in the omasum and an increase from caecum via colon towards the faeces and a decrease in MPS between the reticulum and the omasum. Both patterns are typical for ruminants in general. In the forestomach, there was little systematic difference between more cranial and more caudal locations ('horizontal stratification'), with the possible exception of large particle segregation in the dorsal rumen blindsac on the grass diet. In contrast, the typical (vertical) contents stratification was evident for DM (with drier contents dorsally) and, to a lower degree, for MPS (with larger particles dorsally). Although evident in both groups, this stratification was more pronounced on the grass diet. The results support the interpretation that differences in rumen contents stratification between ruminants are mainly an effect of species-specific physiology, but can be enhanced due to the diet consumed.

Little differences in digestive efficiency for protein and fat in mammals of different trophic guilds and digestive strategies: data constraints or fundamental functional similarity?

Carnivores do not vary markedly in their digestive efficiency for protein and fat, but whether they resemble other trophic guilds (omnivores and herbivores) in this respect has not been evaluated. We collated data on apparent crude protein (CP) and crude fat (ether extracts, EE) digestibility in 157 mammal species, applying the Lucas principle of regressing digestible nutrient content against nutrient content, where the slope of the regression equation represents the true digestibility and the intercept the metabolic losses per unit dry matter intake. The data collection is marked by the evident uneven distribution of dietary nutrient contents across trophic guilds and differences in the nutrient range by which different species have been evaluated, making statistical interpretation difficult. Results indicate a lower true digestibility of CP in herbivores compared to carnivores, most likely due to a lower digestibility of fibre-bound protein in herbivore diets. Metabolic CP losses did not appear to differ between trophic guilds, but herbivores had higher metabolic EE losses, compatible with the hypothesis that a higher proportion of metabolic CP losses were bound in microbes that also contain lipids in herbivores. Among herbivores, no clear pattern was evident that would indicate a difference in metabolic losses associated with microbes between digestive strategies (coprophagy, foregut/hindgut fermentation). Foregut fermenters had a lower true EE digestibility, possibly linked to the hydrogenation of lipids in their forestomach prior to digestion. The results do not demonstrate clear differences in digestive efficiency and metabolic losses for protein and fat between mammalian trophic guilds and digestive strategies, leading to the hypothesis that the process of CP and EE digestion is not physiologically challenging and hence does not lead to a noticeable differentiation between species or species groups.

Biological implications of longevity in dairy cows: 2. Changes in methane emissions and efficiency with age.

Previous studies indicated that absolute CH4 emissions and CH4 yield might increase and that milk production efficiency might decrease with age in cattle. Both would make strategies to increase longevity in dairy cattle less attractive. These aspects were experimentally determined in Brown Swiss cattle distributed continuously across a large age range. Thirty lactating dairy cows (876-3,648 d of age) received diets consisting of hay, corn silage, and grass pellets supplemented with 0 or 5kg of concentrate per day. Twelve heifers (199-778 d of age) received hay only. Cows and heifers were members of herds subjected to the 2 different feeding regimens (with or without concentrate) for the past 10 yr. Methane emissions were measured individually for 2 d in open-circuit respiration chambers, followed by quantifying individual feed intake and milk yield over 8 d. Additional data on digestibility, rumination time, and passage time of feed of all experimental animals were available. Regression analyses were applied to evaluate effects of age and feeding regimen. Body weight, milk yield, and the hay proportion of forage dry matter intake were considered as covariates. Methane emissions per unit of intake, body weight, and milk yield were significantly related to age. Their development in the cows with age was characterized by an increase to maximum at around 2,000 d of age, followed by a decline. This response was not accompanied by corresponding age-related changes in intake, chewing activity, digesta passage time, and digestibility of organic matter, which would have explained shifts in CH4. However, fiber digestibility showed a similar change with age as methane emissions, resulting in quite stable methane emissions per unit of digestible fiber. As expected, methane emissions intensity per unit of milk produced was greater by 8% without concentrate than with concentrate, but no difference was noted in the response to age when the animals were subjected to different feeding regimens. The efficiency of milk production was only marginally influenced by age and diet, and no different response was observed for age in the 2 dietary regimens. In conclusion, life cycle analyses of milk production systems focusing on longevity should consider changing methane yields with age in addition to the variation in environmental costs for replacements of culled cows.

Biological implications of longevity in dairy cows: 1. Changes in feed intake, feeding behavior, and digestion with age.

Milk production strategies focusing on longevity and limited use of concentrate are receiving increasing attention. To evaluate such strategies, knowledge of the development with age of animal characteristics, particularly digestion, is indispensable. We therefore investigated the development of feed intake, chewing activity, and digestion in 30 lactating Brown Swiss cows (876-3,648 d old) and 12 heifers (199-778 d old). We also studied whether age effects were exhibited differently in animals selected from herds subjected for 11 yr either to a forage-only or to a forage-concentrate feeding regimen. Forages consisted of grass hay (the only feed for heifers), corn silage, and grass pellets. Measurements lasted for 8 d, where amounts and composition of feeds, feces, and milk were recorded and analyzed. Ruminal pH data and eating and rumination activity were assessed by pH sensors put into the rumen and halter-mounted noseband sensors. The mean retention time of feed particles was assessed using Cr-mordanted fiber and data were used to calculate dry matter gut fill. Data were subjected to regression analyses with age and feeding regimen as explanatory variables, and body weight, milk yield, and proportion of hay in forage as covariates. This allowed separating age-related changes of body weight and milk yield from independent age effects and correcting for differences in preference for individual forages. In cows, organic matter intake increased with age (from slightly below to above 20kg/d), as did mean retention time and gut fill. Digestibility of organic matter did not show a clear age dependency, but fiber digestibility had a maximum in cows of around 4 to 6 yr of age. Ruminal pH and absolute eating and rumination times did not vary with cow age. Young and old cows chewed regurgitated boluses more intensively (60-70 times) than middle-aged cows (about 50 times). Effects of feeding regimen were small, except for fiber intake and rumination time per unit of intake, owing to the different fiber content of the diets. No significant interactions between age and feeding regimen were found. Heifers spent more time eating and ruminating per unit of feed than cows, which resulted in a high fiber digestibility. Irrespective of the feeding regimen tested, older cows maintained intake and digestion efficiency with longer retention times and chewing rumination boluses more intensively. The results support efforts to extend the length of productive life in dairy cows.

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.

Digestive physiology, metabolism and methane production of captive Linné's two-toed sloths (Choloepus didactylus).

Sloths are renowned for their low metabolic rate, low food intake and low defecation frequency. We investigated factors of digestive physiology and energy metabolism in four captive individuals (mean body mass 10.0 ± SD 3.7 kg) of a hitherto mostly unstudied sloth species, Linné's two-toed sloth (Choloepus didactylus), in a 2-week digestion recording and 23-h respiration experiment on animals fed a standard zoo diet of vegetables and starchy components. Dry matter intake, defecation frequency and particle mean retention time (MRT) in the gastrointestinal tract (GIT) were 12 ± 3 g/(kg(0.75)  day), once every 5 days and >140 h in three individuals, but 53 g/(kg(0.75)  day), daily and 82 h in one individual that was apparently compensating for a period of weight loss prior to the experiment. In all animals, solute marker was eliminated at a faster rate than the particle marker, indicating 'digesta washing' in the sloths' GIT. The overall metabolic rate calculated from oxygen consumption matched the metabolisable energy intake in three individuals [173 ± 22 vs. 168 ± 44 kJ/(kg(0.75)  day)] but not in the fourth one [225 vs. 698 kJ/(kg(0.75)  day)], supporting the interpretation that this animal was replenishing body stores. In spite of the low food intake and the low-fibre diet (209 ± 26 g neutral detergent fibre/kg dry matter), methane production was rather high accounting for 9.4 ± 0.8% of gross energy intake (2.7% in the fourth individual), which exceeded literature data for ruminants on forage-only diets. These results corroborate literature reports on low intake, low defecation frequency, low metabolic rate and long MRT in other sloth species. The long MRT is probably responsible for the comparatively high methane production, providing more opportunity for methanogenic archaea than in other non-ruminant mammals to produce significant amounts of methane.

[Veterinary care of birds of prey: Development from 1985 to 2015]. / Tierärztliche Betreuung von Greifvögeln: Entwicklungen im Zeitraum von 1985 bis 2015.

INTRODUCTION: A retrospective study was conducted which analysed the patient histories of free-living birds of prey presented to the Clinic of Zoo Animals, Exotic Pets and Wildlife of the University of Zürich from 2009 to 2015. The data were compared with a previous study on the period from 1985 to 1994. The average number of cases presented per year increased from 55 to 109. Most cases are presented in the months of February, June and July. Surgical problems were most frequently diagnosed and occurred in 61.5% of the cases, with 66.5% of patients presenting with one or more fractures. Regarding medical cases (29.5%) the most frequent finding was unspecified weakness (47.8%). Ophthalmic pathologies were diagnosed in 9% of the patients. With respect to outcome 41.7% of the patients could be released, 47.3% and 11.0% had to be euthanized or died, respectively. In 6 of 9 of the most frequently presented species the rate of release increased significantly compared to the previous study.

INTRODUCTION: Dans le cadre d'une étude rétrospective, on a analysé des dossiers des oiseaux de proies admis entre 2009 et 2015 à la Clinique pour animaux de zoo, animaux de compagnie et animaux sauvages de l'Université de Zürich et on les a comparés avec les résultats d'une étude effectuée entre 1985 et 1994. Le nombre moyen de cas durant cette période a augmenté de 55 à 109 patients par an. C'est en février ainsi qu'en juin/juillet que sont présentés le plus grand nombre d'oiseaux. Les problèmes chirurgicaux étaient, avec 61.5% les plus fréquents; parmi ceux-ci 66.5% des oiseaux de proie présentaient une ou plusieurs fractures, la plupart au niveau de l'aile. Parmi les problèmes médicaux (29.5%), une faiblesse non-spécifique était la principale cause de consultation (47.8%). Au total 9% des patients présentaient des lésions occulaires. En ce qui concerne les suites, 41.7 % des oiseaux de proie ont pu être remis en liberté, 47.3% ont dû être euthanasiés et 11% ont péri. Une augmentation du taux de remise en liberté par rapport à l'étude antérieure a pu être constatée pour 6 des 9 espèces les plus fréquemment présentées.

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.