Anti-Müllerian hormone concentrations in female rabbits and its relation to spay status, pseudopregnancy and ovarian follicle numbers

Anti-Müllerian hormone (AMH), known for its role during fetal sexual differentiation, is secreted by the Sertoli cells in males and the granulosa cells in females during postnatal life. As serum AMH concentrations correlate with follicle numbers, AMH is utilised as a marker of ovarian reserve in many species. In dogs and cats, AMH is used as a diagnostic tool to determine spay or neuter status. In the available literature, no research regarding serum AMH levels in rabbits has been published yet. The objectives of the present study were to 1) measure serum AMH concentrations in female rabbits and investigate the value of AMH as a diagnostic tool to differentiate between spayed and intact does, and 2) relate measured AMH levels to pseudopregnancy and ovarian follicle numbers. For AMH measurement, serum samples were obtained from sexually intact (n = 64) and spayed (n = 22) female rabbits. Spayed does were of various breeds; intact rabbits were Zika hybrid rabbits. In the intact does, AMH measurement was complemented by determination of progesterone levels, gynaecological examination, and histopathologic evaluation of the uterus and ovaries, including follicle counts. Serum AMH and progesterone concentrations were measured using a human-based chemiluminescence immunoassay (CLIA) and an enzyme-linked fluorescence assay (ELFA), respectively. Depending on progesterone levels, sexually intact does were classified into follicular (n = 52) or luteal phase (n = 12). Median serum AMH levels were 1.53 ng/ml (range 0.77 - 3.36 ng/ml) in intact and 0.06 ng/ml (range ≤ 0.01 - 0.23 ng/ml) in spayed does. AMH concentrations between the intact and spayed rabbits differed significantly and did not overlap (p < 0.001). Receiver operating characteristic (ROC) curve analysis yielded a sensitivity and specificity of 100% for a cut-off level of 0.50 ng/ml. Follicular or luteal phase had no significant influence on measured AMH levels (t = 0.061, df = 62, p = 0.951). While the number of secondary follicles correlated significantly with AMH concentrations (r_s = 0.410, p = 0.001), the number of primary or antral follicles did not (r_s = 0.241, p = 0.055 and r_s = 0.137, p = 0.281, respectively). In conclusion, a single determination of serum AMH concentrations was adequate to distinguish spayed from intact female rabbits. Among sexually intact individuals, whether does were in follicular or luteal phase had no significant influence on measured serum AMH concentrations. The relationship between small growing follicles and AMH levels as described in other species could be partially confirmed, as secondary follicles correlated significantly with AMH.

Neoplasia and Tumor-Like Lesions in Pet Rabbits (Oryctolagus cuniculus): A Retrospective Analysis of Cases Between 1995 and 2019

Prevalence and age distribution of tumors is largely unknown in pet rabbits. Currently available studies focused on specific organ systems or specific tumor types and never covered a comparative examination of all tumor types. Previous studies on laboratory rabbits suggested a low tumor prevalence but were mostly limited to young adult animals. In the present study, all tumor types and several tumor-like lesions of all organ systems were analyzed retrospectively in archived pet rabbit samples of all ages. Cases included necropsy cases ( n = 2,014) or postmortem tissue samples ( n = 102) as well as surgical biopsies ( n = 854). All lesions suspicious of neoplasia were reevaluated by histopathology and, when indicated, by immunohistochemistry. Necropsy cases had a tumor prevalence of 14.4% in both sexes or 19.8% in female intact rabbits of all age groups, and up to 47.2% or 66.7%, respectively, in rabbits older than 6 years. Overall, the most common tumor types were uterine adenocarcinoma (prevalence in female intact animals: 13.1%), lymphoma (prevalence: 2.8%), and thymoma (prevalence: 2.1%). Lymphoma, the most common tumor of rabbits ≤24 months of age, were of B-cell immunophenotype in 96% of cases and most commonly located in the lymph nodes (57%), gastrointestinal tract (54%), kidneys (48%), spleen (42%), and liver (41%). Tumors accounted for 81.1% of surgical biopsies and mostly comprised cutaneous, mammary, and uterine tumors. In conclusion, tumor types and prevalence varied significantly with respect to age, revealing some differences from previous studies on laboratory rabbits.

[Urolithiasis in a pet rat (Rattus norvegicus)]

Uroliths are uncommon findings in rats. This report describes a case of a neutered male rat with dysuria due to an infectious cystitis as well as an urolith of the urinary bladder consisting of struvite and whewellit. Following cystotomy as well as treatment with antibiotics and analgetics the rat recovered rapidly.

[Microbial flora and antibiotic susceptibility of purulent tooth diseases in rabbits]

OBJECTIVE

Bacteria involved in purulent tooth disease and the most effective antibiotics were investigated.

MATERIAL AND METHODS

Swab samples were taken from 126 rabbits with facial abscesses or purulent periapical inflammation during surgical treatment. Bacteriological examination and susceptibility testing were performed.

RESULTS

A wide range of aerobic and anaerobic bacteria were detected. The most commonly isolated anaerobes were gram-negative rods (Prevotella sp., Fusobacterium sp., Bacteroides sp.) and gram-positive non-sporulating cocci (mostly Peptostreptococcus sp.). Of the aerobes, 66.7% were gram-negative (mostly Pasteurella sp., Escherichia coli, Pseudomonas sp.) while 33.3% were gram-positive (mostly Streptococcus sp., Staphylococcus sp.). Depending on the individual patients, fluoroquinolones in combination with amoxicillin-clavulanate, chloramphenicol, amoxicillin-clavulanate, tetracyclines, pradofloxacin, and fluoroquinolone-metronidazole-combinations were most effective.

CONCLUSION AND CLINICAL RELEVANCE

Because of the variability of the detected bacteria, considerable differences in antibiotic susceptibility were observed. Therefore, bacterial examination and susceptibility testing are recommended for effective postsurgical treatment of odontogenic abscesses in rabbits.

Erkrankungen der Harn- und Geschlechtsorgane bei Nagern und Kaninchen

Erkrankungen des Harn- und Geschlechtsapparates kommen bei Kleinsäugern häufig vor und müssen in vielen Fällen differenzialdiagnostisch voneinander abgegrenzt werden, insbesondere wenn anamnestisch von einer Hämaturie berichtet wird. Neben einer gründlichen klinischen Allgemeinuntersuchung kommt dabei weiterführenden diagnostischen Maßnahmen wie Harn- und Blutuntersuchungen sowie Röntgen und Ultraschall auch beim Heimtier eine zunehmende Bedeutung zu. Der Artikel beschreibt ätiologie, Diagnosestellung und Therapie der häufigsten Erkrankungen.

[Blood chemical parameters for wild raptor patients and their changes after liver biopsy]

The present paper tried to find relations between specific anamnesis of wild raptors and blood chemistry values at their day of presentation. 60 (88%) of 68 presented birds of prey showed changes in their blood values. In most birds an increase of GOT, GPT and AP was seen. Some birds showed increases of uric acid, urea and changes in the relation of Ca and P as well. A comparison between Eurasian buzzards with fractures and some without clinical signs showed a significant increase of uric acid, urea, potassium and inorganic phosphorus in the group of fractured birds. Changes of blood chemistry values after liver biopsy are investigated in the second part of the present study. Liver- and kidney values showed an increase after the biopsy. Kestrels (Falco tinnunculus) showed the maximum of the increase at the first day after biopsy while Eurasian buzzards (Buteo buteo) had the maximum at the third and Black kites (Milvus migrans) at the fifth day after biopsy.