Pharmacokinetics of amikacin after intravenous, intra-articular, and combined intravenous and intra-articular administration in healthy neonatal foals.

BACKGROUND: Pharmacokinetics of amikacin administered IV to neonatal foals are described, but little data are available regarding the plasma concentrations contributed by concurrent intra-articular (IA) administration. HYPOTHESIS/OBJECTIVES: Compare the pharmacokinetics of amikacin when the total dose is administered IV compared to being divided between IV and IA routes of administration in neonatal foals and predict the plasma concentrations from various combined IV and IA dosing regimens. ANIMALS: Eight healthy neonatal foals. METHODS: Foals received 3 amikacin treatment protocols: (1) IV-only (25 mg/kg q24h IV), (2) concurrent IV and IA (16.7 mg/kg q24h IV and 8.3 mg/kg q24h into 1 tarsocrural joint), and (3) IA-only (8.3 mg/kg q24h into 1 tarsocrural joint). Protocols were administered for 3 days beginning at 7, 14, and 21 days of age. Plasma concentrations ≥53 µg/mL at 30 minutes were considered therapeutic for isolates with intermediate susceptibility. RESULTS: Foal age was a significant variable. The IV-only protocol met or exceeded the 30-minute plasma concentrations considered therapeutic (mean µg/mL [95% confidence interval, CI]) in 7- to 9-day-old (54.0 [52.2-56.9]), 14- to 16-day-old (58.1 [55.2-61.0]), and 21- to 23-day-old (66.6 [63.7-69.6]) foals. Concurrent IV and IA protocol did not reach the 30-minute concentration considered therapeutic in 7- to 9-day-old foals (46.5 [43.6-49.4]) but did in 14- to 16-day-old (62.9 [60.0-65.8]) and 21-to 23-day-old (62.6 [59.7-65.6]) foals. CONCLUSIONS AND CLINICAL IMPORTANCE: Concurrent IV and IA administration of amikacin produces 30-minute plasma concentrations considered therapeutic in foals 14 to 23 days old, but concentrations observed in younger foals might be below those considered therapeutic for isolates with intermediate susceptibility to amikacin.

Effects of intra-articular injection of an acellular equine liquid amniotic allograft in healthy equine joints.

OBJECTIVE: Evaluate effects of acellular equine liquid amnion allograft (ELAA) injected into healthy equine joints. STUDY DESIGN: Randomized, blinded, controlled experiment. ANIMALS: Eight healthy adult horses. METHODS: One intercarpal joint (ICJ) of each horse was randomly assigned to be injected with 1.5 ml of ELAA (treatment) while the contralateral ICJ was injected with 1.5 ml of 0.9% NaCl (control). Subjective lameness evaluation, force plate analysis, and synovial fluid analysis, including interleukin-1 receptor antagonist (IL-1ra) analysis, were performed before (day 0) and at days 1, 3, 5, and 10. Synovial fluid analysis was also performed on days 20 and 30. RESULTS: No difference in subjective lameness (P = .75) and no decrease in peak vertical force or vertical impulse were seen in any limb on any day. Total nucleated cell count (TNCC) was increased in treatment joints on days 1 (P = .0007; T: 6039 cells/µl, C: 240 cells/µl) and 3 (P < .0001; T: 1119 cells/µl, C: 240 cells/µl). Log-10 transformed values for IL-1ra were higher in treated joints on days 1 (P = .0005; T: 3553.7 pg/ml, C: 1890.1 pg/ml) and 3 (P = .01; T: 2283.2 pg/ml, C: 1250.7 pg/ml). CONCLUSION: Injection of ELAA into the ICJ caused an increase in synovial fluid TNCC in comparison with saline control but no lameness was observed. There was increased IL-1ra on days 1 and 3 after ELAA injection. CLINICAL SIGNIFICANCE: Intra-articular injection of ELAA into healthy equine joints results in no significant safety concerns. The observed increase in IL-1ra may provide beneficial effects in inflamed joints.

Retained energy in lactating beef cows; effects on maintenance energy requirement and voluntary feed intake.

The objectives of these experiments were to determine the relationship between maintenance requirements and energy partitioned to maternal tissue or milk production in limit-fed Angus cows and to determine the relationship between retained energy during the lactation period to dry-period voluntary forage intake (VDMI). Twenty-four mature fall-calving Angus cows were used in a 79-d study during late lactation to establish daily metabolizable energy required for maintenance (MEm). Cows were individually fed daily a mixed diet (2.62 Mcal MEl/kg, 18.2% crude protein) to meet energy and protein requirements of 505 kg beef cows producing 8.2 kg milk daily. If cow BW changed by ±9 kg from initial BW, daily feed intake was adjusted to slow BW loss or reduce BW gain. Milk yield and composition were determined on 3 occasions throughout the study. Maintenance was computed as metabolizable energy intake minus retained energy assigned to average daily maternal tissue energy change, average daily milk energy yield, and average daily energy required for pregnancy. After calves were weaned, cows were fed a low-quality grass hay diet (8.2% crude protein, 65% NDF) and VDMI was measured for 21 days. Lactation maintenance energy was 83% the default value recommended by NASEM (2016. Nutrient Requirements of Beef Cattle: Eighth Revised Edition.) for lactating Angus cows. Increasing lactation-period retained energy (decreasing BW loss and increasing milk energy yield) was associated with lower maintenance energy requirements (P < 0.01; R 2 = 0.92). Increased residual daily gain during lactation was associated with lower lactation maintenance energy requirements (P = 0.05; R 2 = 0.17). Post-weaning VDMI was not related to late-lactation milk energy production, although sensitive to lactation period BCS and BW loss. These results contradict previous reports, suggesting that maintenance requirements increase with increasing milk yield.

Impact of local mask mandates upon COVID-19 case rates in Oklahoma.

Use of face coverings has been shown to reduce transmission of SARS-CoV-2. Despite encouragements from the CDC and other public health entities, resistance to usage of masks remains, forcing government entities to create mandates to compel use. The state of Oklahoma did not create a state-wide mask mandate, but numerous municipalities within the state did. This study compares case rates in communities with mandates to those without mandates, at the same time and in the same state (thus keeping other mitigation approaches similar). Diagnosed cases of COVID-19 were extracted from the Oklahoma State Department of Health reportable disease database. Daily case rates were established based upon listed city of residence. The daily case rate difference between each locality with a mask mandate were compared to rates for the portions of the state without a mandate. All differences were then set to a d0 point of reference (date of mandate implementation). Piecewise linear regression analysis of the difference in SARS-CoV-2 infection rates between mandated and non-mandated populations before and after adoption of mask mandates was then done. Prior to adopting mask mandates, those municipalities that eventually adopted mandates had higher transmission rates than the rest of the state, with the mean case rate difference per 100,000 people increasing by 0.32 cases per day (slope of difference = 0.32; 95% CI 0.13 to 0.51). For the post-mandate time period, the differences are decreasing (slope of -0.24; 95% CI -0.32 to -0.15). The pre- and post- mandate slopes differed significantly (p<0.001). The change in slope direction (-0.59; 95% CI -0.80 to -0.37) shows a move toward reconvergence in new case diagnoses between the two populations. Compared to rates in communities without mask mandates, transmission rates of SARS-CoV-2 slowed notably in those communities that adopted a mask mandate. This study suggests that government mandates may play a role in reducing transmission of SARS-CoV-2, and other infectious respiratory conditions.

Evaluation of the 4-point regional nerve block using 2% lidocaine in sheep.

PURPOSE: To determine whether a single 4-point regional nerve block using 2% lidocaine administered distal to the fetlock of sheep with a single distal limb lameness will result in analgesia of the digits. ANIMALS: Eighteen adult ewes with a single limb lameness originating from distal to the metacarpo/metatarsophalangeal joint were enrolled in the study. PROCEDURES: Digital lameness was confirmed and scored based on clinical examination. Pain associated with digital lesions was assessed in triplicate using a pressure algometer to quantify mechanical nociceptive threshold. The same procedure was repeated on the contralateral limb as a control, and maximum force and time to response recorded. A 4-point regional nerve block was performed using 8 mL of 2% lidocaine. Mechanical nociception was again applied in triplicate to both limbs as described above, by a blinded investigator. Following appropriate medical treatment, the ewe was released and lameness scoring repeated.Median values for pressure and time to withdrawal were determined for affected and control limbs, and differences between pre- and post-lidocaine block measures were compared using Friedman's ANOVA test. The Wilcoxon Signed-Rank test was used to compare lameness score pre- and post-block. Statistical significance was set at α = 0.05. MAIN FINDINGS: Application of the 4-point block resulted in a change in pressure required to elicit withdrawal (F-value 17.7; P < 0.0001) as well as time to withdrawal (F-value 20.4; P < 0.0001), for the affected limb as compared to the control limb. Lameness scores decreased following the block (Signed-rank statistic 85.5; P < 0.0001). PRINCIPAL CONCLUSION: The 4-point nerve block resulted in anesthesia of the distal limb in sheep in this clinical model.

Évaluation du bloc nerveux régional en quatre points avec de la lidocaïne à 2 % chez le mouton. OBJECTIF: Déterminer si un seul bloc nerveux régional en quatre points utilisant de la lidocaïne à 2 % administrée distalement du boulet d'un mouton présentant une boiterie d'un seul membre distal entraînera une analgésie des doigts. ANIMAUX: Dix-huit brebis adultes avec une boiterie d'un seul membre provenant de la partie distale de l'articulation métacarpo/métatarsophalangienne ont été incluses dans l'étude. PROCÉDURES: La boiterie digitale a été confirmée et notée sur la base d'un examen clinique. La douleur associée aux lésions digitales a été évaluée en triple à l'aide d'un algomètre à pression pour quantifier le seuil nociceptif mécanique. La même procédure a été répétée sur le membre controlatéral en tant que témoin, et la force maximale et le temps de réponse ont été enregistrés. Un bloc nerveux régional en quatre points a été réalisé avec 8 ml de lidocaïne à 2 %. La nociception mécanique a de nouveau été appliquée en triple exemplaire aux deux membres comme décrit ci-dessus, par un chercheur en aveugle. Suite à un traitement médical approprié, la brebis a été relâchée et le score de boiterie répété.Les valeurs médianes de la pression et du temps de retrait ont été déterminées pour les membres affectés et les membres témoins, et les différences entre les mesures du bloc avant et après le bloc de lidocaïne ont été comparées à l'aide du test ANOVA de Friedman. Le test de Wilcoxon (signed-rank) a été utilisé pour comparer le score de boiterie avant et après le bloc. Le seuil de signification statistique a été fixé à α = 0,05. PRINCIPAUX RÉSULTATS: L'utilisation du bloc à quatre points a entraîné une modification de la pression requise pour déclencher le retrait (valeur F 17,7; P < 0,0001) ainsi que du temps de retrait (valeur F 20,4; P < 0,0001), pour les membres affectées par rapport au membres témoins. Les scores de boiterie ont diminué après le bloc (statistique de Signed-rank 85,5; P < 0,0001). CONCLUSION PRINCIPALE: Le bloc nerveux en quatre points a entraîné une anesthésie du membre distal chez le mouton dans ce modèle clinique.(Traduit par Dr Serge Messier).

Characterization of short- and long-term morbidity and mortality of goat kids born to does with pregnancy toxemia.

BACKGROUND: Pregnancy toxemia is a common metabolic disease of periparturient small ruminants. Information on its effects on metabolism and perinatal adaptation of newborn lambs and kids is lacking. OBJECTIVES: Evaluate differences in morbidity, mortality, and common biochemical and hematologic variables between pregnancy toxemia kids (PT) and control kids (CON). ANIMALS: Sixteen kids born to does being treated at the hospital for pregnancy toxemia (blood beta-hydroxybutyrate concentration [BHB] > 1.2 mmol/L) and 12 kids from healthy dams (dam BHB < 1.2 mmol/L) that kidded at the hospital. METHODS: In this cohort study, serial measurements of blood L-lactate, glucose, and BHB concentrations, arterial blood gases, hematocrit, total protein concentrations, nonesterified fatty acids (NEFAs) concentrations, and body weight were compared between groups over the first 72 hours of life. Long-term follow-up was performed after 3 months. RESULTS: Pregnancy toxemia kids were more likely to require tube feeding at 0 and 12 hours (relative risk 7.7 [1.13, 52.45] and 2.8 [1.39, 5.65]). Pregnancy toxemia kids were more acidemic (7.26 ± 0.069 vs 7.34 ± 0.079, P = .003) and hyperlactatemic (8.17 ± 2.57 vs 5.48 ± 2.71, P = .003) at birth than CON kids. Control kids were 1.1 [1.01, 1.77] times more likely to survive to discharge and 2.2 [1.15, 4.20] times more likely to survive to 3 months than PT kids. CONCLUSIONS AND CLINICAL IMPORTANCE: Pregnancy toxemia kids had higher short- and long-term mortality and were more likely to require perinatal intervention. Weight loss in the first few days could be a useful predictor of nonsurvival.

Evaluation of the accuracy of an electronic point-of-care analyzer to quantify blood creatinine concentration in goats.

BACKGROUND: There are no commercially available handheld blood creatinine analyzers validated in goats. OBJECTIVES: The objective of the study was to validate the accuracy of a handheld point-of-care (POC) analyzer (Nova StatSensor) for quantifying blood creatinine concentration in goats. A secondary objective was to compare this POC against a chemistry analyzer to classify goats as normal or having mild or moderate azotemia. ANIMALS: Sixty-three goats admitted to a referral hospital. METHODS: Cross-sectional study. Venous blood was obtained, and creatinine concentration was measured by the POC in duplicate. Plasma was submitted for creatinine determination via the chemistry analyzer (gold standard). RESULTS: A total of 101 blood samples were collected from 63 goats. There was high repeatability for creatinine concentrations obtained by the POC (adjusted R2 = .97, P < .0001). Correlation of POC concentrations with those reported by the chemistry analyzer was moderate (adjusted R2 = .57, P < .0001). When correctly categorizing goats with mild azotemia, the POC demonstrated a sensitivity of 73.3% and a specificity of 88.3%. For moderate to severe azotemia, the POC had a sensitivity of 75.0% and specificity of 97.5%. CONCLUSION AND CLINICAL IMPORTANCE: The Nova StatSensor POC provided above average accuracy for measuring blood creatinine concentration in goats compared with the gold standard test.

Efficacy of orally administered gabapentin in horses with chronic thoracic limb lameness.

OBJECTIVE: To evaluate the analgesic effects of orally administered gabapentin on horses with chronic thoracic limb lameness. STUDY DESIGN: Randomized, crossover design. ANIMALS: A total of 14 adult horses with chronic thoracic limb lameness. METHODS: Following baseline measurement of lameness, horses were administered each of four treatments orally in grain: treatment G, gabapentin (20 mg kg-1) twice daily for 13 doses; treatment F, firocoxib (171 mg once, then 57 mg once daily for six doses); treatment GF, gabapentin and firocoxib at previously stated doses and frequencies; or treatment C, grain only as a control. Treatments were administered in a randomized, crossover design, separated by 2 weeks. Subjective lameness score (SLS), inertial sensor vector sum (VS) calculations, peak vertical ground reaction force (PVGRF) measurements and vertical impulse (VI) calculations were determined immediately prior to each initial treatment dose and 2-4 hours after the final treatment dose for each treatment. Mean change in SLS, VS, PVGRF and VI for each treatment were compared among treatments. RESULTS: The rank change in SLS of treatment GF was significantly greater than that of treatments C (p = 0.01) and G (p = 0.01) but not of treatment F (p = 0.08). No differences in VS (p = 0.4), PVGRF (p = 0.4) or VI (p = 0.1) were observed among treatments. CONCLUSIONS AND CLINICAL RELEVANCE: Gabapentin, as administered here, did not improve subjective or objective measures of lameness in horses with chronic thoracic limb musculoskeletal pain. Although subjective evaluation identified an improvement in lameness with treatment GF, it was not different from that observed with treatment F. Higher oral dosing and longer treatment regimens of gabapentin may be indicated for the treatment of chronic musculoskeletal pain in horses.

Frontal sinusitis in adult beef bulls: 18 cases (1999-2014).

OBJECTIVE: To characterize frontal sinusitis unrelated to standard dehorning procedures in adult beef bulls. ANIMALS: 18 beef bulls > 2 years of age treated for frontal sinusitis at a veterinary medical teaching hospital between May 1999 and May 2014. PROCEDURES: Medical records were reviewed. Information obtained for each bull included signalment, history, findings from physical examination and diagnostic procedures, treatment, and survival to discharge. Long-term follow-up (≥ 1 year) was obtained from owners by telephone. RESULTS: 18 bulls were included, and 17 were bucking bulls. Median age and duration of signs were 4.5 years and 23 days, respectively. The most common owner complaints were nonspecific signs (eg, separation from the herd, hypo- or anorexia, and weight loss; n = 10) and suspected horn or sinus infection (7). Only 8 bulls had nasal discharge, and only 7 of the 17 bulls for which the rectal temperature was recorded were febrile. Results of radiography indicated frontal sinusitis in 12 of 13 bulls, with increased opacity of the affected sinus (n = 11) noted most commonly. Seventeen bulls were discharged from the hospital alive. Long-term follow-up was obtained for 14 bulls, including 13 bucking bulls. All 14 bulls recovered fully, and 9 of the 13 bucking bulls performed well after treatment. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that frontal sinusitis should be considered as a differential diagnosis in beef cattle examined for nonspecific clinical signs and that, with appropriate treatment, the prognosis is good for long-term survival in affected beef cattle.

Evaluation of prognostic indicators for goats with pregnancy toxemia.

OBJECTIVE: To evaluate potential prognostic indicators for does with pregnancy toxemia (PT) and their offspring. DESIGN: Retrospective cohort study. ANIMALS: 56 does. PROCEDURES: Medical records were searched to identify does with PT. Signalment, history, clinical signs, examination findings, treatments, number of offspring present, and duration of hospitalization for does as well as outcome (death vs survival to hospital discharge) for does and their kids were recorded. Variables of interest were examined for association with outcome by contingency table analyses. RESULTS: Boer goats were overrepresented, compared with the general population of goats for the facility in the last year of the study. Most (15/36) does had appropriate body condition scores. All pregnancies involved twins (11/56), triplets (37), or quadruplets (7). Neutrophilia (26/26) and hyperglycemia (32/40) were common in does. Most (39/56) does survived to hospital discharge. Does with high BUN concentration and those with serum bicarbonate concentration < 15 mEq/L were more likely to die than does without these findings. Forty-nine does survived to delivery of offspring; survival to discharge for these does was positively associated with outcome of their offspring. Among offspring of dams that survived to their delivery, twins had a higher survival rate than quadruplets. Death was more likely for offspring delivered by cesarean section than for those delivered vaginally. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested Boers were more likely to develop PT than goats of other breeds in the population examined at the study hospital. In contrast with other studies, hyperglycemia was common in affected does. Further research is needed to confirm associations with outcome identified in this study.

Subtourniquet pressures generated by application of wide-rubber tourniquets in standing, sedated horses.

OBJECTIVE: To determine the influence of location and movement on subtourniquet pressure (STP) generated by application of a wide-rubber tourniquet (WRT) on equine limbs. STUDY DESIGN: Randomized experimental cross-over design. ANIMALS: Six standing, sedated horses. METHODS: Horses were sedated with detomidine hydrochloride (0.2 µg/kg IV), and 4 investigators applied WRTs to the antebrachium (AB), gaskin (GK), and midmetacarpus (MC) of each horse in a predetermined, randomized order. Subtourniquet pressure was consequently measured at 10-minute intervals (T0, T10, T20, T30) for 30 minutes. Indirect systolic blood pressure (SBP) was measured presedation, postsedation, and throughout the tourniquet application period. Target STP was established as SBP + 100 mm Hg. Limb movements at each location were classified as none, low, moderate, or high, on the basis of counts and magnitude. RESULTS: Mean STP did not change with time (P = .93) and exceeded SBP by 163 mm Hg (95% CI 122-205), 185 mm Hg (95% CI 156-214), and 402 mm Hg (95% CI 351-454) at the AB, GK, and MC, respectively. Mean STP at each location exceeded the target STP in 59 of 70 (81%) of the trials. Limb movements affected STP generated by tourniquets at the AB (P = .04) and MC (P < .0001) but not at the GK (P = .67). CONCLUSION: Wide-rubber tourniquets applied at the AB, GK, and MC generated STP >100 mm Hg above SBP for 30 minutes in standing, sedated horses. CLINICAL SIGNIFICANCE: Wide-rubber tourniquets as applied in this study can achieve and maintain the current recommended STP (SBP + 100 mm Hg) for equine IV regional limb perfusion. Number and magnitude of limb movement can decrease STP over time, potentially reducing the efficacy of a WRT.

Comparison of a commercially available oral nutritional supplement and intravenous fluid therapy for dehydration in dairy calves.

Calf scours is a primary cause of morbidity and mortality in the dairy industry. Effective treatments are needed to minimize death, maximize welfare, and maintain growth and productivity. The objective of this trial was to compare the efficacy of a commercially available nutritional supplement (Diaque, Boehringer-Ingelheim Vetmedica Inc., St. Joseph, MO) and i.v. lactated Ringer's solution (LRS) in rehydrating, preventing acidemia, and correcting electrolyte imbalances in an experimental model for calf scours. Twenty-four colostrum-fed suckling dairy calves were used in a modified crossover design. An osmotic diarrhea was induced by orally feeding commercial milk replacer modified with high level of sucrose to create a hypertonic milk solution, and administering oral hydrochlorothiazide and spironolactone for 48 h. The intention was to create a challenge sufficient to result in moderately dehydrated, standing calves without producing severe depression or loss of suckle. The efficacy of i.v. fluid therapy and a commercial nutritional supplement were subsequently compared for reversing the effects of the diarrheal disease. Treatment A consisted of administering the nutritional supplement according to label directions (100 g in 1.9 L of warm water, 3 times a day), and treatment B consisted of i.v. LRS (2 L, once a day). Clinical signs and laboratory results were obtained once daily by a blinded observer. The induction method was effective in creating the desired effect, as demonstrated by weight loss and subjective health and hydration scores. Both treatment groups experienced increases in body weight, base excess, and bicarbonate, and decreases in total protein and packed cell volume following treatment. Both i.v. LRS and Diaque are effective methods to correct hypovolemia and control derangements in acid-base status in calves with diarrhea and dehydration.

Retrograde catheterization of the urinary bladder in healthy male goats by use of angiographic catheters.

OBJECTIVE To identify and evaluate 3 types of angiographic catheters for retrograde urinary bladder catheterization in healthy male goats. ANIMALS 12 sexually intact yearling Alpine-cross bucks. PROCEDURES Three 5F angiographic catheters of the same length (100 cm) and diameter (0.17 cm) but differing in curvature at the tip were labeled A (straight tip), B (tip bent in 1 place), and C (tip bent in 2 places). During a single anesthetic episode, attempts were made to blindly pass each catheter into the urinary bladder of each goat. Order of catheters used was randomized, and the veterinarian passing the catheter was blinded as to catheter identity. The total number of attempts at catheter passage and the total number of successful attempts were recorded. RESULTS Catheter A was unsuccessfully passed in all 12 goats, catheter B was successfully passed in 8 goats, and catheter C was successfully passed in 4 goats. The success rate for catheter B was significantly greater than that for catheter A; however, no significant difference was identified between catheters B and C or catheters A and C. CONCLUSIONS AND CLINICAL RELEVANCE 2 angiographic catheters were identified that could be successfully, blindly advanced in a retrograde direction into the urinary bladder of healthy sexually intact male goats. Such catheters may be useful for determining urethral patency, emptying the urinary bladder, and instilling chemolysing agents in goats with clinical obstructive urolithiasis.

Efficacy of Bdellovibrio bacteriovorus 109J for the treatment of dairy calves with experimentally induced infectious bovine keratoconjunctivitis.

OBJECTIVE To determine the efficacy of Bdellovibrio bacteriovorus 109J for the treatment of calves with experimentally induced infectious bovine keratoconjunctivitis (IBK). ANIMALS 12 healthy dairy calves. PROCEDURES For each calf, a grid keratotomy was performed on both eyes immediately before inoculation with Moraxella bovis hemolytic strain Epp63-300 (n = 11 calves) or nonhemolytic strain 12040577 (1 calf). For each calf inoculated with M bovis Epp63-300, the eyes were randomly assigned to receive an artificial tear solution with (treatment group) or without (control group) lyophilized B bacteriovorus 109J. Six doses of the assigned treatment (0.2 mL/eye, topically, q 48 h) were administered to each eye. On nontreatment days, eyes were assessed and corneal swab specimens and tear samples were collected for bacterial culture. Calves were euthanized 12 days after M bovis inoculation. The eyes were harvested for gross and histologic evaluation and bacterial culture. RESULTS The calf inoculated with M bovis 12040577 did not develop corneal ulcers. Of the 22 eyes inoculated with M bovis Epp63-300, 18 developed corneal ulcers consistent with IBK within 48 hours after inoculation; 4 of those eyes developed secondary corneal ulcers that were not consistent with IBK. Corneal ulcer size and severity and the time required for ulcer healing did not differ between the treatment and control groups. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that B bacteriovorus 109J was not effective for the treatment of IBK; however, the experimental model used produced lesions that did not completely mimic naturally occurring IBK.

Clinical disease and lung lesions in calves experimentally inoculated with Histophilus somni five days after metaphylactic administration of tildipirosin or tulathromycin.

OBJECTIVE: To compare clinical disease and lung lesions in calves experimentally inoculated with Histophilus somni 5 days after metaphylactic administration of tildipirosin or tulathromycin. ANIMALS Twenty-four 3-month-old Holstein and Holstein-crossbreed steers. PROCEDURES: Calves were randomly allocated to 3 groups of 8 calves. On day 0, calves in group 1 received tildipirosin (4 mg/kg, SC), calves in group 2 received tulathromycin (2.5 mg/kg, SC), and calves in group 3 received isotonic saline (0.9% NaCl) solution (1 mL/45 kg, SC; control). On day 5, calves were inoculated with 10 mL of a solution containing H somni strain 7735 (1.6 × 10(9) CFUs/mL, intrabronchially; challenge). Calves were clinically evaluated on days 5 through 8 and euthanized on day 8. The lungs were grossly evaluated for evidence of pneumonia, and bronchial secretion samples underwent bacteriologic culture. RESULTS: The mean clinical score for each group was significantly increased 12 hours after challenge, compared with that immediately before challenge, and was significantly lower for tildipirosin-treated calves on days 6, 7, and 8, compared with those for tulathromycin-treated and control calves. The mean percentage of lung consolidation for tildipirosin-treated calves was significantly lower than those for tulathromycin-treated and control calves. Histophilus somni was isolated from the bronchial secretions of some tulathromycin-treated and control calves but was not isolated from tildipirosin-treated calves. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that metaphylactic administration of tildipirosin to calves 5 days prior to H somni challenge prevented subsequent culture of the pathogen from bronchial secretions and was more effective in minimizing clinical disease and lung lesions than was metaphylactic administration of tulathromycin.

Crystal structure of tert-butyl-diphenyl-phosphine oxide.

In the structure of the title triorganophosphine oxide, C16H19OP, the P-O bond is 1.490 (1) Å. The P atom has a distorted tetrahedral geometry. The O atom inter-acts with both phenyl groups of a neighboring mol-ecule [C⋯O = 2.930 (3) and 2.928 (4) Å]. The C-O interaction directs an extended supramolecular arrangement along the a-axis.

Prevalence of Cytauxzoon felis infection in healthy cats from enzootic areas in Arkansas, Missouri, and Oklahoma.

BACKGROUND: Infection with Cytauxzoon felis in domestic cats can cause fever, lethargy, depression, inappetence, icterus, and often death. With a high mortality rate, cytauxzoonosis was historically considered a fatal disease. Within the last 15 years, cats with or without treatment have been recognized as chronically infected survivors of C. felis infection. Our objective was to determine the prevalence of C. felis in healthy domestic cats from Arkansas, Missouri, and Oklahoma. METHODS: Infection with C. felis was determined using DNA extracted from anticoagulated whole blood and PCR amplification using C. felis-specific primers. Chi-square, Fisher's exact tests, and odds ratios were used to compare proportions of cats infected with C. felis. RESULTS: Blood samples were collected from 902 healthy domestic cats between October 2008 and April 2012. DNA from Cytauxzoon felis was detected in 56 of 902 (6.2%; 95% confidence interval, 4.7-7.9) samples. The highest prevalence of C. felis infection (15.5%; 10.3-21.7) was observed in cats from Arkansas, followed by cats from Missouri (12.9%; 6.1-24.0), and cats from Oklahoma (3.4%; 2.2-5.1). Cats sampled in Arkansas and Missouri were 5.1 and 4.2, respectively, times more likely to be chronically infected with C. felis than cats from Oklahoma. CONCLUSIONS: Infection with C. felis is common in domestic cats through Arkansas, Missouri, and Oklahoma. The high prevalence of C. felis reported herein suggests that infected domestic cats are likely reservoirs of infection for naive felines. The high prevalence of C. felis substantiates the importance for the use of approved acaricides on cats to prevent cytauxzoonosis.

Bacteremia in the pedal circulation following regional intravenous perfusion of a 2% lidocaine solution in cattle with deep digital sepsis.

OBJECTIVE: To evaluate whether pedal bacteremia develops following regional IV perfusion (RIVP) of a 2% lidocaine hydrochloride solution in cattle with deep digital sepsis (DDS) and to determine which bacterial pathogens are most commonly isolated from the pedal circulation. DESIGN: Prospective observational cohort study. ANIMALS: 9 adult cattle with DDS in 10 limbs and 10 healthy adult cattle with no evidence of lameness or digital infection. PROCEDURES: Blood samples were obtained aseptically from the dorsal common digital vein immediately following tourniquet application and 30 to 60 minutes after aseptic RIVP with a 2% lidocaine solution. Aerobic and anaerobic bacterial cultures were performed on all samples collected. For cattle with DDS, clinical examination with or without debridement of digital lesions was performed after RIVP. RESULTS: Bacteria were isolated from pedal blood prior to RIVP in 1 cow with DDS and after RIVP and examination with or without debridement in that cow and 4 additional cattle with DDS. Bacteria were not isolated from any blood sample obtained from the healthy cattle. Of the 8 bacterial isolates identified, 5 were gram-positive facultative anaerobes. Cattle with DDS were significantly more likely to develop bacteremia in the pedal circulation than were healthy cattle following RIVP. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that bacteremia may be present in the pedal circulation before and following RIVP and examination with or without debridement in cattle with DDS. Thus, systemic or local antimicrobial treatment might be warranted prior to or concurrently with RIVP in cattle with DDS.

Comparison of genotypic and phenotypic characterization methods for Pasteurella multocida isolates from fatal cases of bovine respiratory disease.

Bovine respiratory disease (BRD) is the most costly disease of beef cattle in North America. Because Pasteurella multocida is a commensal of the upper respiratory tract, it is generally considered an opportunistic pathogen. However, studies in swine indicated that there may be a limited number of strains associated with disease, suggesting that some are more virulent than others. Although this may also be true of isolates from cattle, appropriate typing methods must be established before this possibility can be investigated. The purpose of this study was to compare effectiveness of polymerase chain reaction (PCR) fingerprinting to more traditional approaches for typing bovine P. multocida isolates. Isolates were obtained from 41 cases of fatal BRD and subjected to random amplified polymorphic DNA PCR (RAPD-PCR), whole cell protein (WCP) profiles, outer membrane protein (OMP) profiles, and serotyping. The discrimination index was calculated for each typing method and combinations of each using Simpson's index of diversity. Correlation coefficients were calculated to assess concordance between classification results achieved through genotypic (RAPD-PCR) and phenotypic (WCP, OMP, and serotyping) approaches. All characterization methods were capable of discriminating between isolates. However, there was poor concordance between techniques. There were also few significant associations between typing results and epidemiologic data. Random amplified polymorphic DNA PCR was validated as being a repeatable and reliable means of discriminating between P. multocida isolates obtained from cattle. Isolates obtained from fatal cases of BRD in calves in a commercial feedlot demonstrated significant diversity, justifying additional investigation into whether P. multocida is a strictly opportunistic pathogen in cattle.

The epidemiology of bovine respiratory disease: What is the evidence for predisposing factors?

Bovine respiratory disease (BRD) is the most costly disease of beef cattle in North America. It is multi-factorial, with a variety of physical and physiological stressors combining to predispose cattle to pneumonia. However, efforts to discern which factors are most important have frequently failed to establish definitive answers. Calves are at highest risk shortly after transport. Risk factors include purchasing from sale barns and commingling. It is unclear whether or not these practices increase susceptibility, increase exposure, or are proxies for poor management. Lighter-weight calves appear to be at greater risk, although this has not been consistent. Persistent infection (PI) with bovine virus diarrhea virus increases BRD occurrence, but it is unclear if PI calves affect other cattle in the feedlot. The complexity of BRD has made it difficult to define involvement of individual factors. Stressors may play a role as "necessary but not sufficient" components, requiring additive effects to cause disease.