Jean-Michel Hatt

Zusammenfassung: Die Enzephalitozoonose ist eine bei Kaninchen weit verbreitete Krankheit, die zudem als potenzielle Zoonose von Bedeutung ist. Ziel der Untersuchung war die Analyse der Encephalitozoonose in Bezug auf die Diagnose und Behandlung anhand einer retrospektiven Auswertung von Patientendaten. 107 Fälle von Kaninchen mit Verdachtsdiagnose Encephalitozoonose, die zwischen 2013 und 2022 in einer universitären Klinik vorgestellt wurden, wurden retrospektiv ausgewertet. Die Aufarbeitung der Fälle erfolgte bezüglich Form der Encephalitozoonose, Haltung, Fütterung, Diagnostik, Therapie und Outcome. Die Haltungsformen – Innenhaltung versus Außenhaltung, Einzelhaltung versus Gruppenhaltung – sowie die kürzlich erfolgte Integration eines Tiers in den Bestand ergaben keinen statistischen Effekt als prädisponierende Faktoren. Klinisch manifestierte sich die Encephalitozoonose bei 63,6% (n=68) der Fälle im zentralen Nervensystem. Das Durchschnittsalter der Tiere mit okulärer Form war mit 23,7 Monaten signifikant niedriger (p1:5120 bei den verstorbenen beziehungsweise euthanasierten Kaninchen mit 50,0% (n=6) deutlich häufiger stark erhöht. Die vorliegende Untersuchung ergab keinen Einfluss von Haltungsparametern auf die Encephalitozoonose. Es bestand ein Zusammenhang zwischen Alter und Krankheitsform. Der Nachweis von Antikörpern spielte in der Diagnostik eine zentrale Rolle, ließ jedoch nur eine Verdachtsdiagnose zu. Therapeutisch kamen Fendendazol, Analgesie, Entzündungshemmer sowie unterstützende Maßnahmen zum Einsatz. Solche Maßnahmen umfassten bei der zentralnervösen Form eine ruhige und stressfreie Haltung sowie Physiotherapie und bei der renalen Form das Sicherstellen der Hydratation. In rund 70% der Fälle wurde eine Besserung oder Stabilisierung des Zustandes erreicht.

The fovea is an area of increased cone density in the avian retina and provides a high level of visual acuity. Damage to the fovea may negatively impact su

Vertebrate reproduction is controlled by 2 pituitary gonadotropin hormones (GtHs), FSH and LH, binding to gonadotropin hormone receptors (GtHRs) in gonadal tissues. All gnathostome vertebrates have been confirmed to possess at least 1 receptor for each GtH [LH receptor (LHR) and FSH receptor (FSHR)], except for species of the reptilian (nonavian sauropsidan) orders, such as lepidosauria, testudines, and crocodylia, which showed inexplicable reactions to heterologous amphibian, avian, and mammalian GtHs in early endocrinological studies. This study investigated the number and function of reptilian GtHRs. Genomic and transcriptomic analyses of selected tetrapod species now strongly suggest the inactivation of the LHR in all nonavian sauropsidans. This gene inactivation likely occurred independently in 3 branches of the sauropdisan clade, sparing only the avian class. Bioassays served to investigate the binding specificity of squamate, chelonian, crocodilian, avian, and mammalian GtHRs with their homologous and heterologous GtHs. The FSHR of a squamate lizard proved completely promiscuous to both its homologous GtHs, while the chelonian FSHR responded slightly stronger to the homologous LH than FSH, and the crocodylian FSHR was only stimulated by the homologous LH but not FSH. We therefore propose a modified paradigm with a neuroendocrine control of nonavian reptilian reproduction by a single GtHR and either 1 GtH in crocodylians or 2 GtHs in chelonians and squamate reptiles. Finally, we discuss hypotheses of tightly regulated temporal and spatial expression of the remaining FSHR in different gonadal somatic cells and temperature-dependent functions of the single nonavian reptilian GtHR.

Roughage can be a significant source of vitamin D in herbivore diets. The vitamin D content of forages can vary considerably and depends, among others, on plant species, plant maturity and climate fluctuations. Ultraviolet B (UVB) exposure causes conversion of provitamin D to vitamin D and thus represents the most important influence. To characterise this effect, two batches of a young‐cut roughage of high hygienic and nutritional quality were exposed to constant artificial UVB‐irradiation up to 192 h and were sampled at regular intervals. In previous studies, both ergocalciferol (vitamin D₂), cholecalciferol (vitamin D₃) and/or their metabolites have been detected in plants. Therefore, the present roughage was analysed for both D₂ and D₃. Whereas cholecalciferol never exceeded the detection limit of 0.25 µg/100 g, ergocalciferol increased from 2.22 µg to 19.15 µg/100 g dry matter in a time‐dependent manner. Additionally, the values indicate an interplay with other factors not investigated in this study, for example, leaf‐stem‐ratio in the different samples. The high amounts of ergocalciferol in the experimental roughage after UVB‐exposure confirm the value of hay as a vitamin D source for managed herbivores. The quick rise with time cautions against neglecting UVB‐irradiation's effect on feed, both in practical as well as in experimental settings.

Many different animal species are susceptible to SARS-CoV-2, including a few Canidae (domestic dog and raccoon dog). So far, only experimental evidence is available concerning SARS-CoV-2 infections in red foxes (Vulpes vulpes). This is the first report of SARS-CoV-2 RNA detection in a sample from a red fox. The RT-qPCR-positive fox was zoo-kept together with another fox and two bears in the Swiss Canton of Zurich. Combined material from a conjunctival and nasal swab collected for canine distemper virus diagnostics tested positive for SARS-CoV-2 RNA with Ct values of 36.9 (E gene assay) and 35.7 (RdRp gene assay). The sample was analysed for SARS-CoV-2 within a research project testing residual routine diagnostic samples from different animal species submitted between spring 2020 and December 2022 to improve knowledge on SARS-CoV-2 infections within different animal species and investigate their potential role in a One Health context. Within this project, 246 samples from 153 different animals from Swiss zoos and other wild animal species all tested SARS-CoV-2 RT-qPCR and/or serologically negative so far, except for the reported fox. The source of SARS-CoV-2 in the fox is unknown. The fox disappeared within the naturally structured enclosure, and the cadaver was not found. No further control measures were undertaken.

Hindgut fermenting herbivores from different vertebrate taxa, including tortoises, and among mammals some afrotheria, perissodactyla incl. equids, several rodents as well as lagomorphs absorb more calcium (Ca) from the digesta than they require, and excrete the surplus via urine. Both proximate and ultimate causes are elusive. It was suggested that this mechanism might ensure phosphorus availability for the hindgut microbiome by removing potentially complex‐building Ca from the digesta. Here we use Ussing chamber experiments to show that rabbits (Oryctolagus cuniculus) maintained on four different diets (six animals/diet) increase active Ca absorption at increasing Ca levels. This contradicts the common assumption that at higher dietary levels, where passive uptake should be more prevalent, active transport can relax and hence supports the deliberate removal hypothesis. In the rabbits, this absorption was distinctively higher in the caecum than in the duodenum, which is unexpected in mammals. Additional quantification of the presence of two proteins involved in active Ca absorption (calbindin‐D9K CB; vitamin D receptor, VDR) showed higher presence with higher dietary Ca. However, their detailed distribution across the intestinal tract and the diet groups suggests that other factors not investigated in this study must play major roles in Ca absorption in rabbits. Investigating strategies of herbivores to mitigate potential negative effects of Ca in the digesta on microbial activity and growth might represent a promising area of future research.

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 & DLANGBRAC;food producing pets & drangbrac;.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.

The drivers of dental wear and compensatory hypselodont tooth growth are of current research interest. Expanding previous macroscopic dental wear measurements based on microtomographic scans of guinea pigs ( Cavia porcellus ) fed natural diets, we added diet groups with different predicted drivers of dental wear and analysed how measured variables relate to each other. The teeth of guinea pigs fed either pelleted diets containing external abrasives of various shapes, sizes and percentages ( n = 66) or natural whole-leaf diets ( n = 36, low-phytolith lucerne or grass or high-phytolith bamboo) were evaluated. The bamboo-fed animals showed the lowest tooth height with deep dentine basins, similar to the pellet-fed animals. Deeper dentine basins generally correlated with higher occlusal surfaces, allowing the hypothesis that changes in the pressure signal due to lower basins could initiate compensatory growth and broadening of the whole tooth surface in hypselodont teeth. Macroscopic dental wear did not categorically differ between whole-leaf or pelleted diets or between diets with internal phytoliths or with external silicate abrasives. Supporting interpretations that tooth wear should be viewed as a response to the biomechanical properties of ingested feed which may or may not be aptly summarized by broad descriptors such as ‘whole/pelleted’ or ‘natural/artificial’.

Dental wear due to ingestion of dust and grit has deleterious consequences. Herbivores that could not wash their food hence had to evolve particularly durable teeth, in parallel to the evolution of dental chewing surface complexity to increase chewing efficacy. The rumen sorting mechanism increases chewing efficacy beyond that reached by any other mammal and has been hypothesized to also offer an internal washing mechanism, which would be an outstanding example of an additional advantage by a physiological adaptation, but in vivo evidence is lacking so far. Here, we investigated four cannulated, live cows that received a diet to which sand was added. Silica in swallowed food and feces reflected experimental dietary sand contamination, whereas the regurgitate submitted to rumination remained close to the silica levels of the basal food. This helps explain how ruminants are able to tolerate high levels of dust or grit in their diet, with less high-crowned teeth than nonruminants in the same habitat. Palaeo-reconstructions based on dental morphology and dental wear traces need to take the ruminants’ wear-protection mechanism into account. The inadvertent advantage likely contributed to the ruminants’ current success in terms of species diversity.

Background: Limb fractures represent the most common orthopaedic disease in pet rabbits. However, only a few studies have evaluated therapeutic details of limb fractures. There are no data available for long‐term outcomes of limb fracture treatment. Methods: The medical records of six institutions were reviewed retrospectively to identify cases of traumatic limb bone fractures in pet rabbits between 1999 and 2020. The medical records ( n = 387) were analysed for details of fracture prevalence, aetiology, therapy protocols, treatment complications, outcome and long‐term effects. In addition to the retrospective data evaluation, 13 rabbits were re‐evaluated in person in recent clinical analyses, including orthopaedic examination, radiography and computed‐tomographic imaging. Details of long‐term effects of fracture treatment were requested over the telephone for a further 232 animals using a standardised questionnaire. Results: Long bone fractures accounted for the majority of all fractures (296/387; 76.5%). Hindlimb fractures (301/387; 77.7%) were more common than forelimb fractures (86/387; 22.2%), and tibial fractures and combined fractures of the tibia and fibula (119/387; 30.8%) were observed most frequently. Most fracture treatments were based on osteosynthesis procedures (243/328; 74.1%). Treatment complications occurred in 130 out of 328 (39.6%) cases. A high bodyweight ( p = 0.047) and an older age ( p = 0.01) were found to be significant risk factors for the emergence of therapy complications. Overall, 75.4% of animals (175/232) had a satisfactory long‐term outcome. Limb posture anomalies were evaluated in 61 cases (26.3%). Limitations: The multi‐centre approach led to the inclusion of various institutions, veterinarians, treatment protocols and rabbit populations that might have influenced the results. The medical records were reviewed retrospectively, so there were some data that were lacking or could not be collected in a standardised manner. Furthermore, rabbit owners' evaluation of long‐term outcomes might be prone to error, despite the use of a standardised interview questionnaire. Conclusion: Limb fractures are a common orthopaedic issue in pet rabbits. The patient's bodyweight and age are significant risk factors for the emergence of complications during the fracture treatment process. Long‐term orthopaedic effects, such as abnormal limb posture and permanent lameness of the affected limb, were observed regularly.