Equine mammary gland disease with a focus on botryomycosis: A review and case study

Mammary gland problems occur incidentally in horses and one of the rarer conditions is botryomycosis (bacterial pseudomycosis, bacterial granuloma, staphylococcal pseudomycetoma). This article includes a short review of equine mammary gland problems inappropriate lactation, mastitis and neoplasia and botryomycosis, and additionally 2 clinical cases of botryomycosis of the udder resulting from Staphyloccocus aureus infection will be discussed. Both cases involved nonpregnant, nonlactating mares referred for chronic mammary inflammation with draining abcessation. In both mares, botryomycosis caused by S. aureus was confirmed by histopathology and a bacterial culture. Both mares recovered fully after surgical hemimastectomy under general anaesthesia.     

Prevalence and duration of insensibility following electrical stunning in calves

Sixty-one calves were electrically stunned with 100-250 V currents (103-1806 mA) and the prevalence and duration of insensibility was assessed from their physical behaviour, the presence of epileptiform activity in their electrocorticograms, and the absence of visual evoked responses in their electrocorticograms. A current applied at 100 V across the head for 3 s failed to induce insensibility in all cases. Currents at 150-250 V induced insensibility in all calves and the shortest duration of insensibility was 44 s. It is recommended that a 150-200 V current would be appropriate for commercial use.     

Effect of oxytocin infusion on luteal blood flow and progesterone secretion in dairy cattle

The objective of this study was to investigate the effects of oxytocin infusion on corpus luteum (CL) function during early to mid-diestrus by measuring luteal size (LS) and luteal blood flow (LBF) along with plasma levels of progesterone (P4) and prostaglandin metabolites (13,14-dihydro-15-keto-prostaglandin F_2α, PGFM). On day (D) 7 of the estrus cycle (D1 = ovulation), seven cows received 100 IU of oxytocin (OXY) or placebo (PL) following a Latin square design. LS and LBF increased in both groups over time and no differences were observed between the groups. PGFM did not differ either within the groups over time or between the groups at any time point. P4 of the OXY group was higher compared to that of the the PL group 360 min after the infusion (p = 0.01) and tended to be higher at the time points 450 min, 48 h, and 72 h (all p = 0.08). Results from this study support the hypothesis that OXY is not directly involved in the mechanism(s) governing blood flow of the CL and has no remarkable effects either on luteal size or P4 and PGFM plasma levels. Further investigation is needed to elucidate the role of OXY in CL blood flow during early and late luteal phases.     

Effects of limited concentrate feeding on growth and blood and serum variables, and on nutrient digestibility and gene expression of hepatic gluconeogenic enzymes in dairy calves

This study elucidated the effects of limited concentrate feeding on growth, nutrient digestibility, blood profile and gene expression of gluconeogenic enzymes in the liver of dairy calves. The study utilized 36 German Holstein dairy calves (5-7 days of age) divided into two groups of 18 calves each for 150 days. Control group calves received 2 kg/(calf × day) of concentrate, whereas calves in the restricted group received only 1 kg/(calf × day). Good quality forage (mixture of maize and grass silages) was available for ad libitum consumption to both groups. The intake of milk replacer before weaning, and of concentrate were recorded daily per calf; however, the consumption of forages was quantified as daily average of the group. Body weights (BW) were recorded at start and on days 35, 70, 112 and 150. Blood and serum samples and spot urinary and faecal samples were also collected at similar time points. On days 70 and 150, liver biopsies were collected from seven animals in each group. The BW was not different between the groups at all times. Total BW gain in the control group was 124 kg as opposed to 111 kg in restricted group that led to average BW gain of 827 g/day and 739 g/day in respective groups, and the differences were significant (p = 0.018). As planned, the control group had higher concentrate and lower forage intake than the restricted group. The blood haemoglobin, haematocrit and serum variables (glucose, total protein, albumin and urea) were within the normal range in both groups, but serum glucose was higher (p < 0.05) in control than in restricted group at 70 days. There was no difference between groups in organic matter (OM) digestibility which declined (p < 0.001) with increasing age in both groups. Microbial crude protein (MCP) synthesis estimated from urinary allantoin excretion increased (p < 0.001) in both groups with increasing age but was not different between groups. The mRNA expressions for the gluconeogenic enzymes, cytosolic and mitochondrial phosphoenol pyruvate carboxykinase (EC 4.1.1.32) and pyruvate carboxylase (EC 6.4.1.1) measured by quantitative real-time PCR in liver biopsies showed no differences between groups. Overall, restricting concentrate moderately reduced the growth intensity without affecting the normal serum and blood indices, and MCP synthesis and OM digestibility showed no differences between groups, indicating that both concentrate feeding schemes can be successfully applied.     

Biological effect of tyrosine kinase inhibitors on three canine mast cell tumor cell lines with various KIT statuses

Tyrosine kinase inhibitors (TKIs) can be important in the treatment of canine mast cell tumor (cMCT). Meanwhile, some TKIs have been identified as substrates for ABCB1. The inhibitory effect of four TKIs (axitinib, imatinib, masitinib, and vatalanib) for proliferation and phosphorylation of c-Kit receptor as well as the expression and function of ABCB1 were investigated in three cMCT cell lines (HRMC, VIMC1, and CMMC1). The IC(50) values of the TKIs in HRMC, the only cell line with wild-type KIT, were clearly higher than those in CMMC1 and VIMC1. In HRMC and CMMC1, both the growth and phosphorylation of c-Kit receptor were suppressed proportionally by the TKIs. VIMC1 required higher concentrations for the inhibition of c-Kit receptor phosphorylation than those in cell growth. The treatment with cyclosporine increased the effects of the TKIs on VIMC1 since ABCB1 was expressed in VIMC1. The results indicated that cMCT cell lines harboring wild-type KIT had lower sensitivity to TKIs. The growth of VIMC1 was seemingly reduced by TKIs through the inhibition of other tyrosine kinases than c-Kit receptor. There was little influence of ABCB1 on TKI effects to the proliferation of VIMC1. These results will be helpful to understand the different sensitivity to TKIs in cMCT patients.     

Isolation of Leptospira noguchii from sheep

The main goal of this study was to obtain new isolates of Leptospira spp. from sheep. A total of 10 kidney samples and 44 blood samples were collected from sheep slaughtered in Pelotas, Southern Brazil. One isolate was obtained which was identified by 16S rRNA gene sequencing and serogrouping to be Leptospira noguchii serogroup Autumnalis. Microscopic agglutination test (MAT) evaluation revealed that 4.5% of the sheep sera reacted against the Autumnalis serogroup. This is the first report of isolation of L. noguchii from sheep. Together these findings indicate that L. noguchii infections may be a potentially important veterinary problem in this domestic animal species.     

Association between floor type and behaviour, skin lesions, and claw dimensions in group-housed fattening bulls

Rubber mats covering concrete slatted flooring are a developing market in dairy barns but remain rare in beef cattle facilities. The aim of this study was to investigate the effects of covering slatted concrete floor with perforated rubber mats on behaviour and occurrence of skin and claw lesions in fattening bulls. The groups of six bulls each with a total average age of 9.8 months were kept over 1 year on either slatted concrete (CONCRETE PEN) or on slatted concrete covered completely (RUBBER PEN) or partially (CHOICE PEN) with perforated rubber mats. Every quarter-year, behaviour (preference of flooring, lying, aggression, mounting) was recorded. In two-weekly intervals the incidence of skin lesions was examined. At 12 and 18 months of age the rising time of the bulls was measured. At the beginning of the study and after slaughter claw dimensions were recorded. Bulls in the CHOICE PEN preferred (P<0.01) the rubber coated area throughout the experiment. Animals in the RUBBER and the CHOICE PENS showed more lying periods (P<0.01) and had a lesser incidence of skin lesions (P<0.01) compared to bulls in the CONCRETE PEN. Bulls in the CHOICE PEN needed less time for rising (2.7+/-0.3s) than bulls in the CONCRETE PEN (4.4+/-0.5s, P<0.01). Net claw growth differed significantly between all pens (RUBBER>CHOICE>CONCRETE; P<0.05). In conclusion, the results of this study indicate that rubber coated slatted flooring has a positive influence on the housing conditions of beef cattle.     

High prevalence of methicillin resistant Staphylococcus aureus in pigs

Recently methicillin resistant Staphylococcus aureus (MRSA) was isolated from pigs and pig farmers in The Netherlands. In order to assess the dissemination of MRSA in the Dutch pig population, we screened 540 pigs in 9 slaughterhouses, where a representative portion of Dutch pigs (63%) was slaughtered in 2005. We found 209 (39%) of the pigs to carry MRSA in their nares. Forty-four of 54 groups of 10 consecutive pigs (81%), each group from a different farm, and all slaughterhouses were affected. All MRSA isolates belonged to 1 clonal group, showing Multi-Locus Sequence Type 398 and closely related spa types (mainly t011, t108 and t1254). Three types of the Staphylococcal Chromosome Cassette (SCCmec) were found: III (3%), IVa (39%) and V (57%). All 44 tested isolates (1 isolate per group) were resistant to tetracycline, reflecting the high and predominant use of tetracyclines in pig husbandry. Twenty-three percent of the isolates were resistant to both erythromycin and clindamycin and 36% to kanamycin, gentamicin and tobramycin but only a single isolate was resistant to co-trimoxazole and none to ciprofloxacin and several other antibiotics. The percentage of MRSA positive pigs was significantly different among slaughterhouses and among groups within slaughterhouses, indicating a high prevalence of MRSA in pigs delivered from the farms as well as cross contamination in the slaughterhouses.