Evaluation of a rebound tonometer (Tonovet®) in clinically normal cat eyes

Objective  To determine the accuracy of and to establish reference values for a rebound tonometer (Tonovet^®) in normal feline eyes, to compare it with an applanation tonometer (Tonopen Vet^®) and to evaluate the effect of topical anesthesia on rebound tonometry.
Procedures  Six enucleated eyes were used to compare both tonometers with direct manometry. Intraocular pressure (IOP) was measured in 100 cats to establish reference values for rebound tonometry. Of these, 22 cats were used to compare rebound tonometry with and without topical anesthesia and 33 cats to compare the rebound and applanation tonometers. All evaluated eyes were free of ocular disease.
Results  Both tonometers correlated well with direct manometry. The best agreement with the rebound tonometer was achieved between 25–50 mmHg. The applanation tonometer was accurate at pressures between 0 and 30 mmHg. The mean IOP in clinically normal cats was 20.74 mmHg with the rebound tonometer and 18.4 mmHg with the applanation tonometer. Topical anesthesia did not significantly affect rebound tonometry.
Conclusions  As the rebound tonometer correlated well with direct manometry in the clinically important pressure range and was well tolerated by cats, it appears suitable for glaucoma diagnosis. The mean IOP obtained with the rebound tonometer was 2–3 mmHg higher than that measured with the applanation tonometer. This difference is within clinically acceptable limits, but indicates that the same type of tonometer should be used in follow-up examinations in a given cat.     

An In Vitro Evaluation of Biochemical Processes Involved in Lead‐Induced Changes on Ram Spermatozoa

Lead (Pb²⁺) is a toxic heavy metal which interferes with several physiological processes regulated by Ca²⁺, including those characterized by changes of the membrane stability and the motility of spermatozoa necessary for the fertilization of the oocyte. In this study, ejaculated sperm from six rams (Ovis aries) have been incubated in vitro with or without 50 ng Pb²⁺/ml during 30 min and in the presence or absence of three different potential modulators of the effects of Pb²⁺ on changes in the sperm membrane before fertilization: charybdotoxin, quinacrine and staurosporine. Sperm samples incubated with Pb²⁺ have shown significant reductions in acrosome integrity and sperm viability and an increase in progressive movement. None of the studied potential modulators had a protective effect against Pb²⁺ action. On the contrary, Pb²⁺‐incubated sperm in the presence of staurosporine had lower acrosome integrity, and lower sperm viability was observed when spermatozoa were incubated with Pb²⁺ + charybdotoxin. Quinacrine was the only tested substance capable of increasing the concentration of Pb²⁺ in spermatozoa; thus, the enhancement of Pb²⁺ effects produced by staurosporine and charybdotoxin was not produced by an increased uptake of Pb²⁺ by spermatozoa. However, the increase of intracellular Pb²⁺ in those spermatozoa incubated with quinacrine did not result in an adverse effect on sperm motility or viability although the acrosome integrity was negatively affected.     

Evaluation of Functional Outcome After BFX® Total Hip Replacement Using a Pressure Sensitive Walkway

Objective— To evaluate stance phase limb use after cementless (BFX^®) total hip replacement (THR) in dogs and to relate postoperative radiographic variables to static bodyweight distribution after surgery.
Study Design— Prospective clinical study.
Animals— Dogs (n=35) that had THR.
Methods— THR was performed using the BFX^® THR technique. Postoperative pain management regimens were similar for all dogs. Standing bodyweight distribution (%BW_distrib) was measured using a pressure sensitive walkway and radiographs made before surgery and at 3, 6, and 12 months after surgery. Repeated measures models (with backwards-stepping to obtain the final model) were used for statistical analysis.
Results— Temporally, %BW_distrib to the operated limb increased ( P <.0001; normal by 3 months) and decreased to the unoperated limb ( P =.0001) and also increased to the pelvic limbs and decreased to the thoracic limbs. %BW_distrib to the unoperated limb was significantly less than the operated limb at 3, 6, and 12 months after surgery. Postoperative canal fill and femur flare were significantly negatively correlated with change in %BW_distrib (estimate=−0.24, P =.0413).
Conclusion— BFX^® THR results in normal %BW_distrib to the operated limb by 3 months after surgery. A greater fill of the proximal femur may be associated with a suboptimal outcome.
Clinical Relevance— BFX^® THR normalizes standing bodyweight distribution dogs with hip osteoarthritis. Objective evaluation of THR outcome and radiographic features may reveal factors that could be improved through changes in prosthesis design or surgical technique.     

Preservation of canine and feline corneoscleral tissue in Optisol® GS

Objective The objective of the research was to determine whether preservation of corneal tissue of dogs and cats in Optisol^® GS (OGS, Bausch & Lomb Surgical, Irvine, CA, USA) is feasible for subsequent use in penetrating keratoplasty. Animals The study subjects were 33 dogs and 31 cats with no gross corneal pathology, which had been euthanised by pentobarbital overdose for reasons unrelated to this project. Procedure One cornea of each pair was evaluated immediately and the other was evaluated after storage in Optisol^® GS for either 5, 10, 15 or 20 days. The most important criterion was the preservation of the endothelial cell layer. Results Corneoscleral tissue of cats survived longer, when preserved in Optisol^® GS at 4 °C, than that of dogs. Light and scanning electron microscopy revealed good preservation of the endothelial cell layer for up to 10 days in dogs and up to 15 days in cats.     

Evaluation of the Perkins® handheld applanation tonometer in the measurement of intraocular pressure in dogs and cats

Objective  To evaluate and to validate the accuracy of the Perkins^® handheld applanation tonometer in the measurement of IOP in dogs and cats.
Animals  Twenty eyes from 10 dogs and 10 cats immediately after sacrifice were used for the postmortem study and 20 eyes from 10 clinically normal and anesthetized dogs and cats were used for the in vivo study. Both eyes of 20 conscious dogs and cats were also evaluated.
Procedure  Readings of IOP postmortem and in vivo were taken using manometry (measured with a mercury column manometer) and tonometry (measured with a Perkins^® handheld applanation tonometer). The IOP measurement with Perkins^® tonometer in anesthetized and conscious dogs and cats was accomplished by instillation of proxymetacaine 0.5% and of 1% fluorescein eye drops.
Results  The correlation coefficient ( r ²) between the manometry and the Perkins^® tonometer were 0.982 (dogs) and 0.988 (cats), and the corresponding linear regression equation were y  = 0.0893 x  + 0.1105 (dogs) and y  = 0.0899 x  + 0.1145 (cats) in the postmortem study. The mean IOP readings with the Perkins^® tonometer after calibration curve correction were 14.9 ± 1.6 mmHg (range 12.2–17.2 mmHg) in conscious dogs, and were 15.1 ± 1.7 mmHg (range 12.1–18.7 mmHg) in conscious cats.
Conclusion  There was an excellent correlation between the IOP values obtained from direct ocular manometry and the Perkins^® tonometer in dogs and cats. The Perkins^® handheld tonometer could be in the future a new alternative for the diagnosis of glaucoma in veterinary ophthalmology.     

Detection, quantifications and pharmacokinetics of toltrazuril sulfone (Ponazuril®) in cattle

Toltrazuril sulfone (Ponazuril^®) is a triazine-based anti-protozoal agent with highly specific actions against apicomplexan group of organisms, which are undergoing intensive investigation. Toltrazuril sulfone may have clinical application in the treatment of Neospora. caninum and other protozoal infections in cattle. To evaluate absorption, distribution, and elimination characteristics of toltrazuril sulfone in cattle, a sensitive validated quantitative high-pressure liquid chromatography method for toltrazuril sulfone in bovine biological fluids was developed. After a single oral dose of toltrazuril sulfone at 5 mg/kg (as 150 mg/g of Marquis^®; Bayer HealthCare, Shawnee Mission, KS, USA), samples from six cows showed good plasma concentrations of toltrazuril sulfone, which peaked at 4821 ng/mL ± 916 (SD) at 48 h postadministration. Thereafter, plasma concentration declined to 1950 ng/mL ± 184 (SD) at 192 h after administration with an average plasma elimination half-life of ∼58 h. Following oral dose of toltrazuril sulfone, the observed peak plasma concentrations were in relatively close agreement ranging from the lowest 3925 ng/mL to the highest of 6285 ng/mL with the mean peak plasma concentration being 4821 ng/mL. This study shows that toltrazuril sulfone is relatively well absorbed after oral dose in cattle. These results are therefore entirely consistent with and support the reported clinical efficacy of toltrazuril sulfone in the treatment of experimentally induced clinical cases of N. caninum and other protozoal-mediated bovine diseases.     

Improvement of the Culture Conditions for In Vitro Production of Cattle Embryos in a Portable CO2 Incubator

The effects of different concentrations of growth hormone (GH) on in vitro maturation (IVM), fertilization (IVF) and culture (IVC) of bovine oocyte/embryos in CR1aa or CR2aa media using a simple CO₂ incubator were investigated. The IVM/IVF/IVC of oocytes were carried out in the presence of 0, 50, 100 and 200 ng/ml GH in the medium. The proportion of metaphase II oocytes was significantly higher (p < 0.05) in 200 ng/ml compared with 0 ng/ml GH in CR1aa medium (59 versus 85%, respectively), but this effect was not observed under CR2aa. Higher concentrations of GH yielded lower rates of unfertilized ova and thus superior cleavage rates (36.5 ± 0.2 and 63.5 ± 2.0% versus 17.5 ± 0.2 and 82.5 ± 1.5% or 40.4 ± 0.6 and 59.6 ± 1.4% versus 16.6 ± 1.2 and 83.4 ± 6.2% for 0 and 200 ng/ml GH in portable or ordinary incubator, respectively) in CR1aa. This dose‐dependent effect was also observed in the percentages of transferable embryos, although not statistically different (17.2 ± 1.7 versus 27.3 ± 1.8% and 16.6 ± 3.1 versus 26.0 ± 1.4%, for 0 versus 200 ng/ml GH in portable and ordinary incubator, respectively). In contrast to the CR1aa, different concentrations of GH in CR2aa medium did not increase either fertilization or cleavage rates. In fact, higher concentrations of GH in this medium negatively affected the rate of transferable embryos. Hence, percentages of transferable embryos obtained in the portable incubator under 0 or 50 ng/ml GH were higher (p < 0.05) compared with those obtained in 100 or 200 ng/ml GH (35.4 ± 5.7 or 40.5 ± 5.4% versus 22.4 ± 2.4 or 15.5 ± 2.1%, respectively). There was however, no significant difference in the rate of transferable embryos in an ordinary incubator employing CR2aa medium, but the trend was more or less similar to that observed in the portable incubator. Despite the fact that relatively fewer oocytes were employed for the culture in the ordinary incubator, overall results observed employing the simple portable CO₂ incubator were within the range of those obtained in an ordinary incubator; implying that the simple portable incubator can effectively be employed for the in vitro production of bovine embryos under field conditions.     

Potential benefit from using the αs1-casein genotype information in a selection scheme for dairy goats

A stochastic approach is proposed to predict responses to selection when using α_s1‐casein genotype information in a selection scheme of a Spanish breed of dairy goats. Two independent selection objectives were considered: protein yield (PY), where the major additive gene CSN1S1, which codes for α_s1‐casein, has a small effect, and protein content (P%), where this gene has a large effect on performances. Significant differences in response between using and ignoring information on the major gene were observed only when the major gene has a large effect. The main result was in the case of P%, the total genetic gain obtained in the early generations of selection was maintained in the long‐term. Taking account of genotype information either in the evaluation model or in the selection criteria leads to a faster fixation of the favourable allele and a reduction of the total genetic variance over generations. The inbreeding rates varied across generations, the highest rates observed in later generations of selection and when the major gene has a large effect and its genotype was included in the genetic evaluation procedure. It is concluded that inclusion of the casein genotype as an additional selection criteria will improve gains for protein traits, in particular P%. Recommendations are also given in order to optimize the use of this molecular information in dairy goat selection programs.     

Studies on the Intracellular Ca2+ Concentration of Frozen–Thawed Dog Spermatozoa: Influence of Equex from Different Sources, Two Thawing Diluents and Post-thaw Incubation in Capacitating Conditions

The addition of 0.5% (v/v) of Equex STM Paste (Nova Chemical Sales, Scituate Inc., MA, USA), whose active ingredient is sodium dodecyl sulphate (SDS), to a Tris–egg yolk extender was demonstrated to improve the longevity of frozen–thawed dog spermatozoa during in vitro incubation at 38°C. The aim of the first experiment was to compare the effects of two SDS‐containing compounds, Equex STM Paste and Equex Pasta (Minitüb, Tiefenbach, Germany), when added to a Tris–egg yolk based extender, on the post‐thaw longevity of dog spermatozoa, as well as on the intracellular Ca²⁺ concentration of spermatozoa, during post‐thaw incubation at 38°C. The post‐thaw sperm survival and longevity, as well as the quality of the sperm movement, were significantly better when using Equex STM Paste. Such prolonged sperm longevity, however, was associated to a higher intracellular Ca²⁺ concentration in a large subpopulation of the live spermatozoa. A second experiment was aimed to evaluate the effects of sperm dilution immediately post‐thaw with a Tris buffer containing glucose or fructose. The two Tris buffers were no different for any of the sperm parameters studied. The aim of a third experiment was to evaluate the sperm longevity, motility patterns and intracellular Ca²⁺ concentration of cryopreserved dog spermatozoa during post‐thaw incubation in capacitating conditions [canine capacitating medium (CCM) with or without 5 μg/ml of heparin]. Heparin had no significant effects on any of the sperm parameters evaluated. During the first 8 h of incubation, the majority of the live spermatozoa had a high intracellular Ca²⁺ content. However, after 8–10 h of incubation, it had significantly declined. The highest proportion of fast motile sperm, and the highest curvilinear velocity, average path velocity and amplitude of lateral head displacement for the total motile sperm were observed during the 2–4‐h incubation period. It was concluded that: (a) the addition of 0.5% (v/v) of Equex STM Paste to a Tris–egg yolk based extender significantly improved the post‐thaw longevity of dog spermatozoa, but the same concentration of Equex Pasta had no significant beneficial effects; (b) sperm dilution after thawing with a Tris buffer containing glucose or fructose made no difference in post‐thaw sperm longevity; (c) the addition of 5 μg/ml of heparin to CCM had no significant capacitating effects on frozen–thawed dog spermatozoa.     

Thermal antinociceptive pharmacodynamics of 0.1 mg kg−1 hydromorphone administered intramuscularly in cats and effect of concurrent butorphanol administration

Hydromorphone (HY) has not been objectively assessed as an analgesic in cats. It has been suggested that butorphanol (B) can have a synergistic action with pure μ‐agonists. The aim of this study was to assess the antinociceptive activity of a single dose of HY, and to examine the effect of concurrent B administration on the thermal threshold (TT). Thermal thresholds were measured following IM administration of HY, B, a combination of B and HY (HY‐B), or saline (S). Six cats (four spayed females, two castrated males, 4.75–6.8 kg) were used. Each cat received HY (0.1 mg kg^?1), B (0.4 mg kg^?1), HY (0.1 mg kg^?1), and B (0.4 mg kg^?1) (HY‐B), or S (0.05 mL kg^?1) in a randomized, blinded, cross‐over study design. Each cat received each treatment, with at least 12 days interval between the treatments. All injections were IM randomized to left or right quadriceps using a 24 SWG needle. Twenty‐four hours prior to each study, the thorax of each of the cats was shaved. On the day of the study, TT was measured using a thorax‐mounted thermal threshold‐testing device specifically developed for cats. Skin temperature was recorded before each test and then the heater was activated. When the cat responded by flinching, turning, or jumping, the stimulus was terminated and the threshold temperature was recorded. Three baseline thresholds were recorded over 1 hour before IM injection of test drug. Thermal threshold cut‐off was 55.5 °C. TT was measured at 5 and 15 minutes, every 15 to 360 minutes, every 30 minutes to 8 hours, every hour to 12 hours, and at 24 hours post‐injection. Threshold data were analyzed using an anova with a repeat factor of time. Behavioral adverse effects (dysphoria) were associated with B administration, but not with HY or HY‐B administration (these produced calm euphoria). The control group was stable over time (p = 0.22) (mean threshold 40.15 °C). Overall, there was no period effect, no significant effect of administering B, but a significant effect (raised TT) of administering HY or HY‐B. If the mean value of one of the experimental groups differed from the control group (40.075 °C) by more than 2.355 °C (>42.425 °C), that mean was significantly different from control at p < 0.05 (Bonferroni's t‐tests). This occurred between 15 and 165 minutes for B, from 15 to 345 minutes for HY, and between 15 and 540 minutes for HY‐B. In this model, HY provided up to 5.75 hours of antinociception at 0.1 mg kg^?1, and concurrent administration of butorphanol (0.4 mg kg^?1) decreased the intensity of antinociception over the first 2 hours, but extended the duration of significant antinociception to about 9 hours.     

Safety and tolerability of 3-week and 6-month dosing of Deramaxx® (Deracoxib) chewable tablets in dogs

Although non-steroidal anti-inflammatory drugs (NSAIDs) are effective in reducing pain and inflammation, these agents have adverse effects. Selective inhibitors of COX-2 are an alternative to traditional NSAIDs. Deramaxx^® [Novartis Animal Health US, Inc. (NAH), Greensboro, NC, USA] contains the selective COX-2 inhibitor, deracoxib, and is approved for the relief of pain and inflammation associated with orthopedic surgery and osteoarthritis in dogs. The safety of Deramaxx was evaluated in two target animal safety studies: 40 dogs (four dogs/sex/group) received 0, 4, 6, 8, or 10 mg/kg/day deracoxib once daily for 21 days; and 60 dogs (five dogs/sex/group) received 0, 2, 4, 6, 8, or 10 mg/kg/day deracoxib once daily for 6 months. There was a dose-dependent trend towards increased blood urea nitrogen (BUN) in treated dogs, however mean BUN values remained within the reference range at the labeled doses. In both trials, histopathology revealed focal renal tubular degeneration/regeneration in some dogs receiving ≥6 mg/kg/day deracoxib. Focal renal papillary necrosis was seen in one dog treated with 8 mg/kg/day and in three dogs receiving 10 mg/kg/day deracoxib on the 6-month study. No other parameters of renal function were adversely affected for either study. Results show that Deramaxx is safe and well-tolerated in dogs when administered as directed.     

Comparison of the pharmacokinetics and thermal antinociceptive pharmacodynamics of 20 µg kg−1 buprenorphine administered sublingually or intravenously in cats

Little is known about the analgesic action of buprenorphine (BUP) in cats. Relative to man, the cat has a more alkaline oral pH, which may make this an effective route for administering BUP in this species. This study aimed to assess and compare the pharmacokinetics and pharmacodynamics of sublingual (S‐L) and IV administration of BUP. Thermal threshold (TT) was measured and blood samples were collected following IV or S‐L administration (20 µg kg^?1) of the injectable formulation. Six cats (five spayed females, one castrated male, 4.1–6.6 kg) were used. Each cat received both treatments in a randomized cross‐over study design with 1 month between experiments. Twenty‐four hours prior to each study, the lateral thorax of each of the cats was shaved, cephalic and jugular catheters placed, and oral pH measured. On the day of the study, TT was measured using a ‘thorax‐mounted’ thermal threshold‐testing device specifically developed for cats. The cats were free to move around. Skin temperature was recorded before each test, then the heater activated. When the cat responded by flinching, turning, or jumping, the stimulus was terminated and the threshold temperature was recorded. The thermal threshold cut‐off point was 55.5 °C. Three baseline thresholds were recorded before treatment with S‐L or IV (via cephalic catheter) BUP (20 µg kg^?1). Blood was withdrawn (jugular) at 1, 2, 4, 6, 10, 15, 30, 45, 60 minutes and at 2, 4, 6, 8, 12, and 24 hours post‐administration. TT was measured every 30 minutes?6 hours, 1–12 hours, and at 24 hours post‐administration. Plasma was immediately separated, stored at ?20.5 °C, and assayed within 4 months using a commercially available ¹²⁵I radioimmunoassay. Threshold data were analyzed using anova with a repeat factor of time. No adverse effects were noted. Pupils were dilated for up to 9 hours post‐BUP. Behavioral changes were calm euphoria. Measured oral pH was 9 in each cat. Pre‐treatment mean threshold (±SD) was 41.2 ± 0.9 °C in the S‐L group and 40.8 ± 0.85 °C in the IV group. There were no significant differences between the groups with respect to thresholds over time (p = 0.72). Thresholds were significantly increased from 30 to 360 minutes in both the groups (>44.615 °C). Peak plasma BUP (C_max) was lower (11 ± 6.7 ng mL^?1vs. 92.9 ± 107.9 ng mL^?1) and occurred later (T_max) (30 minutes vs. 1 minute) after S‐L compared to IV administration, respectively. BUP (20 µg kg^?1)‐administered S‐L or IV provided antinociception between 30 and 360 minutes after administration. Plasma levels did not correspond to TT.     

Effect of 0.1, 0.2, 0.4, and 0.8 mg kg−1 of intravenous butorphanol on thermal antinociception in cats

Many cats do not receive analgesics for treatment of perioperative pain, but when they do, the opioid agonist–antagonist butorphanol (B) is widely used. B is reported to provide long‐lasting visceral analgesia, but its somatic actions are not well documented. This study aimed to assess B by using a thermal threshold (TT) model. Six cats (four spayed females, two castrated males, 4.4–6.9 kg) participated in the study. The day before each study, the lateral thorax of each of the cats was shaved and a cephalic catheter was placed. TT was measured using a thermal threshold testing device specifically developed for cats. A heater element and temperature sensor housed in a small probe was held against the cat's thorax with an elastic band and pressure bladder to assure consistent contact. Skin temperature was recorded before each test, then the heater was activated. When the cat responded by flinching, turning, or jumping, the stimulus was terminated and the threshold temperature recorded. A cut‐out temperature was set at 55.5 °C. Three baseline measurements were recorded before IV injections of 0.1, 0.2, 0.4, or 0.8 mg kg^?1 of B. Each cat received all doses in a randomized order at least 1 week apart, and the investigator was blinded to the treatments. TT was measured at every 15 minutes for 6 hours. Data were analyzed using a three‐factor anova , and the critical mean difference was calculated. Pre‐treatment threshold was 40.8 ± 2.25 °C in all cats. There was a significant increase in threshold in all groups from 15 to 90 minutes, but no dose‐related differences were observed. Peak threshold achieved was 48.35 °C, 60 minutes after 0.4 mg kg^?1 of B was injected. Mydriasis was present in all cats after treatment, and many exhibited dysphoric behavior. In this model, B had a short duration of action and no dose–response relationship. Compared to other opioids tested under similar conditions, the intensity of the effect of B was small and of shorter duration.     

Intraoperative use of a reflective blanket (Sirius® rescue sheet) for temperature management in dogs less than 10 kg

O bjectives : To compare the effects of the Sirius^® rescue sheet with gel pads versus gel pads alone on intraoperative body temperature in dogs less than 10 kg.
M ethods : Forty small breed dogs undergoing elective surgical procedures were randomly assigned to two groups. One group was intraoperatively laid on warmed gel pads, and the other group was additionally wrapped in a Sirius^® rescue sheet. Oesophageal body temperature was determined every 10 minutes and compared between groups. Temperature of gel pads was measured preoperatively and postoperatively to compare heat loss of the gel pads between groups.
R esults : The body temperature of dogs wrapped with the Sirius^® rescue sheet increased intraoperatively. In dogs just lying on warmed gel pads, a decrease in mean body temperature was revealed and mean body temperatures differed between groups after 40 minutes. Extent of heat loss from the gel pads did not differ between the groups.
C linical S ignificance : The Sirius^® rescue sheet, used in addition to warmed gel pads, led to higher intraoperative body temperatures in small breed dogs undergoing surgical procedures to the extremities and the head. The cost-effectiveness and ease of handling make this a useful addition to clinical practice.     

Successful Timing of Ovulation Using Deslorelin (Ovuplant®) is Labour-saving in Mares Aimed for Single AI with Frozen Semen

To minimize the number of matings/inseminations, controlled ovulation has been practised since a long time ago. A potent short-term implant, releasing the GnRH analogue deslorelin (Ovuplant((R))) has been used in Australia and North America for several years for hastening the ovulation time in mares, but the product is not registered on the European market. This study was aimed to investigate: (1) ovulation time in mares implanted with Ovuplant when the largest follicle was 42 mm or more in size, (2) repeatability of ovulation time in successive oestruses when treated with Ovuplant, (3) pregnancy rate after single insemination with frozen-thawed semen near ovulation. This study included 11 mares, and altogether 17 timed ovulations. Follicular growth and ovulation were determined by palpation per rectum and by ultrasonography in the morning (at 7:00 hours) every second day until observation of a follicle of at least 42 mm in diameter. Then the mares were re-examined in the afternoon (at 19:00 hours), and an Ovuplant was inserted in the mucosa of the vulva. For detection of ovulation, the mares were palpated and ultrasounded repeatedly from 36-42 h after the insert. The mares were inseminated with frozen-thawed semen once at ovulation. All mares ovulated at 36-48 h after treatment and 94% at 38-42 h after treatment. The six mares that were treated at two oestruses ovulated at 39.9 and 39.7 h, respectively. Five of 11 mares (45.4%), inseminated with frozen-thawed semen at the first oestrous cycle were pregnant day 14-16 after ovulation. Using this protocol, there is no need of palpation/ultrasonography during night hours, and examination at 36 and 41 h after implantation might be enough for estimation of ovulation time.     

Cefquinome Concentrations in Endometrium after Intrauterine Treatment of Cobactan 4.5%® in Mares and Inflammatory Response of the Endometrium to this Treatment

This study was conducted to measure the concentration of cefquinome in the endometrium of mares after intrauterine treatment and to evaluate associated inflammation. Mares (n = 14) were randomly assigned to one of the following groups: (i) control (n = 4) were either not treated (n = 2) or received (n = 2) lactated Ringer's intrauterine for 1 or 3 days; (ii) treated mares (n = 10) received intrauterine cefquinome for 1 or 3 days. After at least 10 days had passed following the last treatment and ovulation, mares were given Prostaglandin F2α (PGF2α) and were randomly assigned to an alternate treatment. Endometrial biopsy samples were taken at 2, 8, 24 and 48 h, or at 4, 12 and 36 h, after the last treatment. Biopsy samples were taken at the same time points from control mares (n = 2) and lactated Ringer-treated mares (n = 2). Cefquinome concentrations were quantified using a high-performance liquid chromatography (HPLC) assay and inflammation was assessed using haematoxylin and eosin (H&E)-stained sections. Concentrations of cefquinome [559 (1 day) and 595 μg/g (3 days) at 2 h, and 403 (1 day) and 370 μg/g (3 days) at 4 h] were similar between treatment groups at 2 and 4 h after treatment (p > 0.05). At 8 h, as well as at 24 and 48 h, concentrations were greater in the 3-day group (17 vs 301 μg/g, 3 vs 80 μg/g and 0.1 vs 0.2 μg/g, respectively) (p < 0.05). No significant differences (p > 0.05) in the inflammatory response at 2–48 h after treatment were found between groups.