Endometrial Tissue Concentrations of Enrofloxacin after Intrauterine Administration to Mares

Endometritis in mares is a common cause of infertility. Conventional treatments of the disease have mostly been unsuccessful, so new therapeutic alternatives need to be investigated. This study evaluated the uterine disposition and plasma pharmacokinetic behaviour of a commercial formulation of enrofloxacin (EFX) given by the intrauterine (i.u.) route (2.5 mg/kg) in healthy mares. In order to evaluate the uterine inflammatory response, an initial histopathological study assessing polymorphonuclear cell infiltration was carried out in 20 mares over a 14-day period after treatment. In a second study, 6 healthy adult mares were used for the pharmacokinetic study. Samples of uterine tissue and plasma were collected from 0 to 24 h after the i.u. treatment with 5% EFX solution. Samples were analysed by conventional microbiological assay using an EFX-sensitive strain of Escherichia coli (ATCC 25922). There was a moderate but statistically nonsignificant inflammatory response following i.u. administration of either the formulation or the vehicle alone. Pharmacokinetic analysis of the uterine concentrations of EFX showed a slow and sustained depletion, with EFX remaining at concentrations above the MIC for 24 h after treatment. The area under the concentration–time curve obtained for the uterus suggested that EFX and its metabolites are specifically retained in the uterus, which is the target tissue for bacterial colonization. Neither study provided any evidence of EFX toxicity. In conclusion, these results are encouraging and suggest that EFX may be a useful local treatment in mares with bacterial endometritis.     

Effect of Administration of Oxytocin During Diestrus on Corpus Luteum Function and Endometrial Oxytocin Receptor Concentration in Cycling Mares

The objectives of this study were to (1) compare the effect of twice versus once daily administration of oxytocin on days 7-14 after ovulation on the duration of corpus luteum (CL) function and (2) determine the effect of oxytocin treatment on endometrial oxytocin receptor concentration in mares. In experiment 1, mares were randomly assigned to three groups on day 7: (1) untreated control group (n = 7), (2) twice daily oxytocin treatment group (n = 7), and (3) once daily oxytocin treatment group (n = 8). Oxytocin-treated mares received 60 U of oxytocin intramuscularly (IM) the respective number of times each day on days 7 through 14. One of seven control mares (14%), five of seven (71%) twice daily oxytocin-treated mares, and five of eight (63%) once daily oxytocin-treated mares had prolonged CL function. There was no significant difference in the proportion of mares with prolonged CL function between the two oxytocin-treated groups, and collectively, oxytocin treatment increased (P < .05) the proportion of mares with prolonged CL function compared with no treatment. In experiment 2, mares were randomly assigned to two groups (n = 5/group): (1) saline-treated control mares, and (2) oxytocin-treated mares. Beginning on day 7, control mares received 3 mL of sterile saline IM twice daily, and oxytocin-treated mares received 60 U of oxytocin IM twice daily through day 14. On day 15, endometrial oxytocin-binding capacity was determined (as a measure of oxytocin receptor concentration), and there was no difference (P > .1) between control and oxytocin-treated mares (1,465.7 ± 108 and 1,382.8 ± 108 fmol/mg protein [mean ± standard error of mean], respectively).     

Equine Piroplasmosis

Equine piroplasmosis (EP) is a tick-borne protozoal disease of horses, mules, donkeys, and zebras that is characterized by acute hemolytic anemia. The etiologic agents are two hemoprotozoan parasites, Theileria equi (Laveran, 1901) and Babesia caballi (Nutall and Strickland, 1910) that are transmitted primarily by ixodid ticks. Equine piroplasmosis is found globally where tick vectors are present and is endemic in tropical, subtropical, and some temperate regions. Horses infected with B. equi remain seropositive for life; horses infected with B. caballi are seropositive for several years to life. Economic losses associated with EP are significant and include the cost of treatment, especially in acutely infected horses; abortions; loss of performance; death; and restrictions in meeting international requirements related to exportation or participation in equestrian sporting events. Equine babesiosis–free countries limit the entrance of Babesia-seropositive horses into their countries. In the United States a few sporadic outbreaks have occurred in recent years but have been limited due to implementation of stringent control methods. The cELISA for both T. equi and B. caballi is currently the recommended test for international horse transport. Different therapies for control and sterilization of the parasites are discussed.     

子宫内膜炎患牛子宫黏液内念珠菌的分离及体外溶血活性鉴定

本研究通过API20CAUX系统对从子宫内膜炎患牛子宫内黏液中分离到的183株念珠菌进行鉴定。结果显示克鲁斯念珠菌最多,为33.9%,其次是皱褶念珠菌为17.5%,乳酒念珠菌为13.1%,白色念珠菌为11.5%及热带念珠菌为8.7%。分离中不常见的有假丝酵母为5.5%,近平滑念珠菌为4.4%,吉利蒙念珠菌为3.3%,著名念珠菌为1.1%和光滑念珠菌为1.1%。此外,还对所分离到的念珠菌进行体外溶血活性检测,结果显示克鲁斯念珠菌、乳酒念珠菌、白色念珠菌、热带念珠菌、涎沫假丝念珠菌和光滑念珠菌在接种后48 h后显示α和β溶血;皱褶念珠菌、吉利蒙念珠菌、著名念珠菌只显示α溶血;在孵育72 h后,近平滑念珠菌不显示任何溶血活性。涎沫假丝酵母、白色念珠菌和乳酒念珠菌的β溶血活性比其他菌株高。本研究为临床牛真菌性子宫内膜炎的防治及发病机理的研究奠定了基础。     

Frequency of Rhodococcus equi in Feces of Mares in Central Kentucky

Rhodococcus equi (R equi) pneumonia is an important cause of disease and death in foals. Feces from mares can contain R equi, including virulent R equi, and thus may act as a source of the bacteria at horse breeding farms. A previous report documented that every mare at a farm in central Kentucky shed virulent R equi in at least one of four fecal samples collected serially during the periparturient period. The objective of this study was to assess the extent to which this high prevalence of fecal shedding could be replicated at other horse breeding farms. The frequency of detection of R equi and virulent R equi in fecal samples was studied among 131 mares from 24 farms in central Kentucky. The proportions of fecal samples from mares containing R equi and virulent R equi were 95% and 76%, respectively. These findings indicate that R equi and virulent R equi may be isolated with high frequency from feces of mares at breeding farms in central Kentucky, and that mares are a source of virulent R equi for the environment of their foals.     

Equine hyperimmune serum protects mice against Clostridium difficile spore challenge

Clostridium (C.) difficile is a common cause of nosocomial diarrhea in horses. Vancomycin and metronidazole have been used as standard treatments but are only moderately effective, which highlights the need for a novel alternative therapy. In the current study, we prepared antiserum of equine origin against both C. difficile toxins A and B as well as whole-cell bacteria. The toxin-neutralizing activities of the antibodies were evaluated in vitro and the prophylactic effects of in vivo passive immunotherapy were demonstrated using a conventional mouse model. The data demonstrated that immunized horses generated antibodies against both toxins A and B that possessed toxin-neutralizing activity. Additionally, mice treated with the antiserum lost less weight without any sign of illness and regained weight back to a normal range more rapidly compared to the control group when challenged orally with 10⁷ C. difficile spores 1 day after serum injection. These results indicate that intravenous delivery of hyperimmune serum can protect animals from C. difficile challenge in a dose-dependent manner. Hence, immunotherapy may be a promising prophylactic strategy for preventing C. difficile infection in horses.     

Isolation of Nicoletella semolina from Equine Tracheal Washes

The aim of the present study was to describe the prevalence of Nicoletella semolina in equine airways and its relationships with cytological evaluation of tracheal wash (TW). Samples were collected in the framework of routine bacteriological diagnostics of equine TW between May 2010 and June 2011. N semolina has been isolated, along with either common pathogens or contaminants, from 19 (1.8%) of the 1,054 TW samples. Median TW neutrophil counts (87.0%) in specimens from N semolina-positive horses were significantly different from those from N semolina-“negative” horses (52.0%). The data presented in this report may suggest considering such bacteria in horses clinically suffering from airway inflammation.     

Equine Proliferative Enteropathy Caused by Lawsonia intracellularis in a Foal in Brazil

An 8-month-old foal in Brazil presented with fever, colic, diarrhea, hypoproteinemia (especially hypoalbuminemia), leukocytosis, and hyperfibrinogenemia and became lethargic and anorexic with a poor body score. A diagnosis of Lawsonia intracellularis proliferative enteropathy was confirmed by fecal polymerase chain reaction and serologic testing, and the foal was successfully treated with oxytetracycline followed by azithromycin.     

Epidemiological Survey of Equine Pythiosis in the Brazilian Pantanal and Nearby Areas: Results of 76 Cases

A clinical epidemiological study was conducted among 34 rural properties located within the Brazilian Pantanal region and nearby areas between 2007 and 2010. The diagnosis of equine pythiosis was based on antibody detection (by enzyme-linked immunosorbent assay), polymerase chain reaction, histopathological analysis, and cultures positive for Pythium insidiosum. The majority of the affected animals (85%) were in the Pantanal biome, which had a higher disease prevalence (0.9%-66.7%) than that of the Cerrado (2.7%-33.3%). The disease was more prevalent in the rainy season (January-March), with an abrupt fall in the number of cases during the drought period (April–September; correlation of R² = 0.77; P < .01). Generally, the average prevalence of equine pythiosis in both regions was 5%, with mortality and lethality rates of 1.3% and 23.1%, respectively, in the Pantanal and 2.3% and 45.5%, respectively, in the Cerrado. However, the treatment with immunotherapy may have underestimated these numbers, especially in the Pantanal. Animals older than 1 year were 8.09 times more affected by the disease than younger animals in the same environment (P < .05). A correlation between the anatomical area of the lesion and the type of skin color was also observed. Approximately 73% of the lesions were found in dark-pigmented areas, and animals with a dark coat color were affected more frequently. These findings highlight the importance of hematophagous insects in the epidemiology of pythiosis because these areas are preferred for blood feeding.     

肉仔鸡静注和内服环丙沙星(ciprofloxacin)的药物动力学

16只健康 AA肉仔鸡 ,随机分成 2组 ,每组 8只 ,按 10 mg/ kg剂量分别进行静注和内服单剂量环丙沙星药动学试验。血浆中药物浓度用高效液相色谱法测定 ,血药浓度 -时间数据用 MCPKP药动学计算机程序处理。结果表明 ,静注给药后的药时数据符合无吸收二室开放模型 ,主要动力学参数分别为 :t1 /2α为 (0 .2 34± 0 .0 49) h,t1 /2β为 (10 .118±0 .2 71) h,VB为 (1.374± 0 .12 4) L/ kg,CLB为 (0 .0 94± 0 .0 0 9) L· kg- 1 · h- 1 ,AUC为 (10 7.0 6 8± 10 .6 40 ) mg· L- 1· h。内服给药后的药时数据符合一级吸收一室开放模型 ,主要动力学参数分别为 :t1 /2 kα为 (0 .114± 0 .0 0 8) h,t1 /2 k为(7.784± 0 .5 14) h,Tp 为 (0 .70 2± 0 .0 31) h,Cmax为 (5 .736± 0 .5 15 ) m g/ L,AUC为 (6 8.6 2 2± 8.147) mg· L- 1· h,F为 (6 4.0 92± 7.6 10 ) %。肉仔鸡静注环丙沙星在其体内消除较慢 ,分布广泛 ;内服给药吸收迅速 ,消除较静注给药快。     

A Case of Equine Aspergillosis: A Novel Sampling Procedure for Diagnosis

Aspergillus spp. may induce equine respiratory infections such as fungal pneumonia, guttural pouch mycosis, and systemic infection in immunocompromised individuals. This study describes a case of probable respiratory aspergillosis in a horse presenting clinical signs of the upper airway disease different from those previously reported. Nasopharyngeal swabs and guttural pouch centesis were performed, and Aspergillus flavus was isolated and identified. Following 30 days of pharmaceutical treatment with itraconazole, clinical signs resolved. Results suggested that aspergillosis should be included in the differential diagnosis of upper airway infections, guttural pouch centesis may be useful to make a correct diagnosis, and itraconazole is efficacious in the treatment of A flavus infection.     

Perception of Equine Practitioners Regarding the Occurrence of Selected Equine Neurologic Diseases in the Northeast Over a 10-Year Period

A survey was developed to examine the perception of equine practitioners regarding the occurrence of five equine neurologic diseases in the northeastern United States over the 10-year period between June 1, 1997 and June 1, 2007. This information was then compared with trends at Cornell University's Equine Hospital during the same time span, which in general agreed with practitioners' opinions. Equine herpes virus-1 (EHV-1) neurologic disease, equine motor neuron disease (EMND), and equine protozoal myelitis (EPM) have historic and current relevance. Results showed that the frequency of EMND and EPM has remained relatively stationary or decreased somewhat, whereas the frequency of the neurologic strain of EHV-1 may have increased slightly over the last decade. Less historical information on clinical disease associated with Borrelia burgdorferi infection (Lyme disease) and Parelaphostrongylus tenuis exists; however, results suggest that P. tenuis in the equine is presently emergent. Opinions regarding the existence and rate of occurrence of clinical borreliosis in horses appear divided. A better understanding of the frequency with which these diseases occur, as well as possible associated positive risk factors, will aid the equine practitioner in making an appropriate diagnosis in cases of neurologic disease in their equine patients.     

Comparative Disposition Kinetics of Albendazole in Sheep Following Oral and Intraruminal Administration

The pharmacokinetics of albendazole was studied in sheep following single oral and intraruminal administration at nematocidal dose rates. The disposition curves of its metabolites indicated increased uptake of the drug in sheep following intraruminal as compared to oral dosing (p<0.05). The increased bioavailability of benzimidazole anthelmintics given by the intraruminal route could be exploited for optimizing the use of anthelmintic for sustained parasite control in small ruminants.