Prevalence of Bartonella species,Rickettsia felis,haemoplasmas and the Ehrlichia group in the blood of cats and fleas in eastern Australia

Objectives To define the prevalence of Bartonella spp., Rickettsia felis, Mycoplasma haemofelis, ‘Candidatus Mycoplasma haemominutum’ (Mhm) and ‘Candidatus Mycoplasma turicensis’ (Mtc) in cats and their fleas in eastern Australia. Design and procedure Conventional PCR assays that detect Bartonella spp., M. haemofelis, Mhm, Mtc, Rickettsia spp., Ehrlichia spp., Anaplasma spp. and Neorickettsia spp. were performed on DNA extracted from blood and fleas collected from 111 cats. Cat sera were assayed by ELISA for IgG of Bartonella spp. Results DNA of M. haemofelis, Mtc and Mhm was amplified from 1 (0.9%), 1 (0.9%) and 17 cats (15.3%), respectively. Only DNA of Mhm was amplified from the 62 of 111 pooled flea samples (flea sets; 55.9%). Overall, the prevalence rates for Bartonella spp. DNA in the cats and the flea sets was 16.2% (18 cats) and 28.8% (32 flea sets), respectively. Bartonella spp. IgG was detected in 42 cats (37.8%), of which 11 (26.2%) were positive for Bartonella spp. DNA in their blood. R. felis DNA was amplified from 22 flea sets (19.8%), but not from cats. Overall, DNA of one or more of the organisms was amplified from 27% (30) of cats and 67.6% (75) of the flea sets. Conclusions This is the first Australian study to determine the prevalence of R. felis and B. clarridgeiae in both fleas and the cats from which they were collected. Flea-associated infectious agents are common in cats and fleas in eastern Australia and support the recommendation that stringent flea control be maintained on cats.     

Benign cranial mediastinal lesions in three cats

Cranial mediastinal lesions were detected in three cats, associated with respiratory impairment (case one), spontaneous pneumothorax (case two) and myasthenia gravis (case three), respectively. On gross and histological examination, the first case was considered either a lymphangioma or a branchial cystic mass of the thymic region of the mediastinum; a cystic lesion was suggested by sonographic detection of multiple anechoic cavitations within a circumscribed mass, while fine needle aspiration cytology excluded lymphosarcoma. The second case was diagnosed histologically as a cystic thymoma, but the third case was not examined microscopically. The masses were amenable to surgical excision in the first two cats, while this proved unnecessary in the third case because of resolution following treatment with dexamethasone. Corticosteroid responsiveness was unhelpful in distinguishing between these benign lesions and lymphosarcoma, as in two cases there was a partial or complete response to dosing with prednisolone or dexamethasone. These cases are presented to emphasise that conditions other than lymphosarcoma can produce cranial mediastinal lesions in cats, and that the prognosis for surgical treatment of lymphangiomas, multilocular thymic cysts and cystic thymomas can be excellent.     

Assessment of Humeral Length in Dogs After Repair of Salter–Harris Type IV Fracture of the Lateral Part of the Humeral Condyle

Objective— To evaluate the effect of fracture and subsequent repair on future bone growth of the humerus after Salter–Harris type IV fracture of the lateral part of the humeral condyle (LPHC).
Study Design— Prospective study.
Animals— Dogs (n=11).
Methods— Dogs that had LPHC fracture and an open distal humeral physis repaired (1992–2006) were re-examined and radiographed at ≥12 months of age and humeral length was measured.
Result— Measurements from 11 dogs showed a significant ( P =.02) increase in length of the humeral diaphysis of the affected leg compared with that of the intact limb (median, 1.2%; range, 1.3–3.4%). Condylar deformity secondary to growth disturbance was not observed.
Conclusion— Shortening or growth deformity was not observed after fracture and repair even if a transcondylar screw was placed through the distal humeral growth plate. A mild overgrowth of the humeral diaphysis was observed, although likely considered clinically unimportant.
Clinical Relevance— Fracture of the LPHC and subsequent repair in dogs >3 months of age do not impair growth of the humeral diaphysis. A transcondylar humeral screw placed through the humeral physis will not result in shortening of the humeral diaphysis. Implant removal to allow for further growth is therefore not indicated.     

Acute Oropharyngeal and Esophageal Stick Injury in Forty‐One Dogs

Objective— To report clinical findings, treatment, and outcome in dogs with acute (<7 days) oropharyngeal or esophageal stick injury. Study Design— Retrospective study. Animals— Dogs (n=41) with acute oropharyngeal or esophageal injury. Methods— Dogs had clinical and radiographic examination, and frequently, cervical surgical exploration. The decision to operate was based on radiographic findings of cervical emphysema. Outcome was determined by owner or veterinarian interview. Results— Of 41 dogs, 27 had oropharyngeal injury and 14 had esophageal injury. Five dogs with esophageal injury died. All dogs with radiographic evidence of cervical emphysema (n=34) had ventral median cervical exploration or necropsy; 11 had wood fragment(s) retrieved. In 7 dogs without radiographic signs of cervical emphysema, wounds involving the pharynx or soft palate were treated by local debridement and lavage using an oral approach. Mean follow‐up time was 36.4 months. All wounds healed without complication; however, 1 dog that was not surgically explored had a piece of wood surgically retrieved 3 months later. Conclusions— Radiographic evidence of cervical emphysema is a frequent finding in dogs with acute penetrating oropharyngeal or esophageal injury and indicates trauma to the deeper cervical tissues. Acute penetrating injury of the oropharyngeal region, when treated appropriately, has a better prognosis than acute esophageal penetration. Clinical Relevance— Ventral median cervical surgical exploration is recommended in dogs with acute penetrating injury of the oropharynx or esophagus if there is radiographic evidence of tissue emphysema.     

Predictors of beef calf temperament at weaning and its impact on temperament at breeding and reproductive performance

Two experiments were conducted to determine (i) factors influencing calf temperament at weaning, (ii) association between heifer–calf temperament at weaning and temperament at breeding and (iii) effect of heifer–calf temperament on pregnancy rate per artificial insemination (P/AI). In experiment 1, beef cows and their calves (n = 285) from three farms were used. Sire docility estimated progeny difference (EPD) score, birth type (normal or assisted), calf gender, calf behaviour (during 1st 4 weeks) and calf health status (until weaning) were recorded. Cows and calves were assigned a temperament score (0—calm; 1—excitable), and all cows were given a body condition score (BCS, 1–9; 1—emaciated; 9—obese) at weaning. Calf's illness (p < .05), low sire docility EPD score (p < .05), altered gait (p < .05), altered resting behaviour (p < .01), reduced/no play behaviour (p < .05) and cow excitable temperament (p < .001) increased calf excitable temperament at weaning. In experiment 2, replacement heifer–calves (n = 758) from 12 farms were assigned a temperament score at weaning and later at breeding. Blood from 40 calves at weaning and 31 heifers at initiation of synchronization (same animals) was collected by coccygeal venipuncture for determination of circulating cortisol and substance P concentrations. Heifers were assigned a BCS and reproductive tract score (RTS, 1–5; 1—immature, acyclic; 5—mature, cyclic), synchronized for fixed time AI, observed for oestrus and were artificially inseminated. Cortisol concentrations were increased in excitable heifer–calves compared to calm heifer–calves at weaning (p < .05), and substance P was increased in excitable compared to calm females both at weaning and breeding (p < .05). Low sire EPD docility score (p < .01), heifer–calf excitable temperament at weaning increased excitable temperament at breeding (p < .01). Controlling for BCS categories (p < .01), oestrous expression (p < .0001) and temperament at breeding by oestrous expression (p < .05), the calf's excitable temperament at weaning (p < .001) reduced P/AI (Calm, 62.7 (244/389) vs. Excitable, 53.4% (197/369); p < .01). In conclusion, selection of docile cows and sires with greater docility EPD score should be given consideration to reduce calf excitement. Temperament in beef female can be detected earlier in their life and could be used as a tool in the selection process and to improve their performances.     

Bone Morphogenetic Protein‐6 (BMP‐6) Stimulates the Antrum Formation by the Regulation of its Signalling Pathway in Caprine Pre‐antral Follicles Cultured In Vitro

BMP‐6 has been found to be important to ovarian cells and oocyte, as well as to uterus. Thus, this study investigated the effect of bone morphogenetic protein (BMP‐6) and recombinant follicle‐stimulating hormone (rFSH) alone or in combination on the in vitro culture (IVC) of isolated caprine secondary follicles (Experiment 1) and the mRNA levels for BMP receptors/Smad signalling pathway (BMPR1A, BMPR2, SMAD1, SMAD4, SMAD5, SMAD6, SMAD7 and SMAD8) in vivo and in vitro using BMP‐6 (Experiment 2). Secondary follicles were cultured in αMEM⁺ alone (control medium) or supplemented with BMP‐6 at 1 or 10 ng/ml and rFSH alone or the combination of both BMP‐6 concentrations and rFSH. The results from Experiment 1 showed that the antrum formation rate was higher in the BMP‐6 at 1 ng/ml (p < 0.05) than in MEM. In Experiment 2, the mRNA expression for BMPR2, SMAD1, SMAD5 and SMAD6 was detected in non‐cultured control and after in vitro culture (MEM and 1 ng/ml BMP‐6); while the expression of SMAD7 and SMAD8 mRNA was only detected after IVC, SMAD4 was only detected in the BMP‐6 at 1 ng/ml treatment. In conclusion, the low BMP‐6 concentration positively influenced antrum formation and ensured normal mRNA expression for BMP receptor and Smads after IVC of caprine secondary follicles.     

Effects of IGF‐1 on In Vitro Culture of Bovine Preantral Follicles are Dose‐Dependent

This study aimed at assessing the effect of different concentrations of the growth factor similar to insulin 1 (IGF‐1) in the development, survival and ultrastructure of the bovine preantral follicles cultured in situ. Fragments of bovine ovarian cortical tissue were cultured during 1 and 7 days in 1 ml of α‐MEM⁺, supplemented with different concentrations of human recombinant IGF‐1 (0, 30, 70 and 100 ng/ml), in an incubator at 37°C and 5% of CO₂ in 24‐well plates with total replacement of the medium every 2 days. Non‐cultured ovarian fragments (control) and ovarian fragments cultured during 1 and 7 days were processed for classic histology, mechanical isolation and electron transmission microscopy (ETM). Parameters such as normality, viability, activation, development, diameter and ultrastructure were evaluated. All statistical analyses were carried out using sas Version 9.2. The results showed that the percentage of follicles morphologically normal in the IGF‐1 30 ng/ml treatment was similar to the fresh control (p > 0.05) both on the day 1 and on the day 7 of in vitro culture. In the viability analysis, the cultured treatments maintained the percentage of viable follicles during the entire culture period (p > 0.05). After 7 days of culture, the IGF‐1 30 ng/ml treatment showed higher percentages of developing follicles (48.33%) than those of the fresh control (22.22%) and the cultured treatments (p < 0.05). Also, after 7 days of culture, IGF‐1 30 ng/ml presented a higher follicular diameter when compared to the control and other concentrations of IGF‐1 tested. Ultrastructurally, the non‐cultured control and IGF‐1 30 ng/ml, after 7 days of culture, showed conserved oocytes, nuclei and organelles. Hence, it is concluded that IGF‐1 30 ng/ml was the most efficient concentration for the development of bovine preantral follicles cultured in vitro.     

Expression of retinoic acid‐metabolizing enzymes,ALDH1A1, ALDH1A2, ALDH1A3, CYP26A1, CYP26B1 and CYP26C1 in canine testis during post‐natal development

Mammalian spermatogenesis involves highly regulated temporal and spatial dynamics, carefully controlled by several signalling processes. Retinoic acid (RA) signalling could have a critical role in spermatogenesis by promoting spermatogonia differentiation, adhesion of germ cells to Sertoli cells, and release of mature spermatids. An optimal testicular RA concentration is maintained by retinaldehyde dehydrogenases (ALDHs), which oxidize RA precursors to produce RA, whereas the CYP26 class of enzymes catabolizes (oxidize) RA into inactive metabolites. The objective was to elucidate gene expression of these RA‐metabolizing enzymes (ALDH1A1, ALDH1A2, ALDH1A3, CYP26A1, CYP26B1 and CYP26C1) and their protein presence in testes of young, peripubertal and adult dogs. Genes encoding RA‐synthesizing isozymes ALDH1A1, ALDH1A2 and ALDH1A3 and RA‐catabolizing isomers CYP26A1, CYP26B1 and CYP26C1 were expressed in testis at varying levels during testicular development from birth to adulthood in dogs. Based on detailed analyses of mRNA expression patterns, ALDH1A2 was regarded as a primary RA‐synthesizing enzyme and CYP26B1 as a critical RA‐hydrolysing enzyme; presumably, these genes have vital roles in maintaining RA homeostasis, which is imperative to spermatogenesis and other testicular functions in post‐natal canine testis.