Clinical and Parasitological Evaluation of Ivermectin and Ivermectin + Pyrantel Against Oxyuris Equi in Equines.

The equine pinworm could become an increasingly common problem, as there are reports of failure in the control of this parasite. The aim of this study was to evaluate the effects of ivermectin (IVM) and IVM combined with pyrantel pamoate (PYR). Thirteen parasitological positive equines were treated with oral IVM (200 µg/kg) and therapeutic efficacy, clinical recovery and the egg reappearance period (ERP) were evaluated. In cases for which ERP was shorter than the pre-patent period (PPP), a second treatment was performed with IVM (200 µg/kg) + PYR (6.6 mg/kg), followed by the same evaluation criteria described above. Therapeutic efficacy was 100% with IVM + PYR and 53.84% with IVM. The mean ERP was shorter than the PPP with both formulations, 77.55 days with IVM + PYR and 50 days with IVM. The presence of egg mass was always associated with a least one clinical sign. The reduction in the number of clinical signs per animal from Day 0 to Day 30 was greater in equines treated with IVM + PYR compared to those treated with IVM alone. The animals treated with IVM were 4.5-fold more likely to present clinical signs 30 days after treatment than those treated with IVM+PYR. A negative correlation was found between ERP and the number of clinical signs at 30 days in the animals treated with IVM. This clinical and parasitological evaluation demonstrated that the combination of IVM+PYR was more effective than IVM alone to control Oxyuris equi.

Coenzyme Q10 and melatonin protect cryopreserved equine sperm against lipoperoxidation.

The objective of the experiment was to evaluate the effect of the addition of different concentrations of the antioxidants Coenzyme Q10 (CoQ10) and melatonin to equine semen freezing diluent, alone or in combination, during the cryopreservation process. Twenty ejaculates (n = 5 stallions) were divided in groups: Control (C, without the addition of antioxidants), melatonin 0.75 mM (MEL1), melatonin 1.5 mM (MEL2), CoQ10 40 µg/mL (Q1), CoQ10 200 µg/mL (Q2), and CoQ10 40 µg/mL+ 0.75 mM melatonin (Q1 +MEL1). Q1 and Q2 groups demonstrated intact plasma membrane and high mitochondrial membrane potential after 30 (M-30) and 60 (M-60) min of incubation compared with the control group (Q1: 64.8 % ± 9.9 %, Q2: 65.2 % ± 10.5 %, C: 55.1 % ± 10.0 %; M-30 and Q1: 63.3 % ± 10.4 %, Q2: 64.6 % ± 10.8 %, C: 53.1 ± 10.6 %; M-60; P < 0.05). Melatonin conferred greater membrane stability at all evaluated times compared with the control group (MEL1: 42.1 % ± 6.0 %; MEL2: 44.0 % ± 6.7 %, C: 35.9 % ± 5.9 %; M-0; MEL1: 40.8 % ± 5.6 %; MEL2: 42.6 % ± 7.2 %, C: 33.1 % ± 6.6 %; M-30 and MEL1: 37.5 % ± 7.4 %; MEL2: 39.1 % ± 7.2 %; C: 31.3 % ± 6.5 %; M-60; P < 0.05). The use of antioxidants alone or in combination resulted in lower levels of lipoperoxidation at all times evaluated compared with in the control group (P < 0.05). In conclusion, CoQ10 and melatonin were effective in the cryopreservation of equine semen by decreasing lipoperoxidation and promoting a higher percentage of spermatozoa with a high mitochondrial potential, total and progressive motility, and prevention of membrane lipid disorder.

Use Low Ozone Dosages has Positive Effects on the Cooling and Cryopreservation of Equine Semen.

The aim of this study was to determine an ozone dosage capable of inducing pro-oxidation, and to verify its action on sperm cells during the process of cooling and cryopreservation of equine semen. In this study, we evaluated the ozone concentrations of 2µg/mL,15µg/mL, 30µg/mL e 60 µg/mL added in equine semen cooling and freezing extenders. Samples were evaluated for sperm kinetics patterns, function of sperm structures and lipid peroxidation. In the experiment, the concentration of 15 µg/mL showed higher total and progressive motility when comparing to control (60.3±3 and 40.7±3.4 vs. 54.9±4 e 35.0±4.4, respectively, P < .05) at M24 of cooling; The concentration of 2 µg/mL showed higher percentage of intact plasma and acrosomal membrane when comparing to control at M24 (51.1±3.6 vs. 46.1±3.9, P < .05), M24 after 30 minutes of incubation (43.4±3.1 versus 32.4±2.6, P <.05). The concentration of 2 µg/mL showed higher percentage of intact plasma and acrosomal membrane (P <.05) comparing to control at moments M0 (43.5±5.0 vs. 36.3±3.5), M30 (41.0±3,7 vs. 35.3±2,9) e M60 (39.0±7.0 vs. 31.4±5.4). Thus, it can be concluded that low doses of ozone can lead to a positive response in the sperm kinetics patterns and sperm structures after sperm storage at low temperatures. Higher concentrations (30 and 60 µg/mL) were harmful in the cooling and cryopreservation of equine semen.

Dexmedetomidine and Bupivacaine Association in Caudal Epidural Injection in Mares.

The objective of the study was to compare the effects of caudal epidural bupivacaine and dexmedetomidine (DEX) combination, with bupivacaine or DEX plain for perineal analgesia in mares. Six healthy saddle mares weighing 330-370 kg and aged 10-15 years were used in this study. Each mare was assigned to receive three treatments: 0.04 mg/kg 0.25% bupivacaine (BP), 2 µg/kg DEX (DX), or 0.02 mg/kg bupivacaine and 1 µg/kg DEX (BPDX). The order of treatments was randomized. All drugs were injected into the caudal epidural space (Co1-Co2) through a 16-G Tuohy epidural needle. After the epidural injections, heart rate, respiratory rate, arterial blood pressures (systolic, diastolic, and mean), and rectal temperature were measured at 5, 10, 15, 30, 60, 90, and 120 minutes, and after this time, every 60 minutes until the end of the experiments. A subjective score system was used to assess analgesia, behavioral and motor blockade at the same time points. The BPDX treatment produced analgesic action with twice the duration (200 minutes) of the BP treatment (97 minutes), but with an analgesic duration shorter than the DX treatment (240 minutes) in the regions of the tail, perineum, and upper hind limbs in mares. All treatments showed mild motor blockade. No behavioral changes were observed in any of the animals. There was hemodynamic stability without significant changes in respiratory rate for all treatments. Epidural analgesia using DEX alone or the combination of DEX and bupivacaine may be an option for painful obstetric and gynecological procedures in mares.

The gynecological examination in Pantaneiro mares.

Gynecological examination is essential to assess the reproductive tract of mares and can provide important information about the uterine environment. It includes physical, vaginal, and rectal examination, ultrasound, cytology, culture, and endometrial biopsy. The present study aimed to perform gynecological examination and fertility to assess the fertility prognosis of Pantaneiro mares that have not been reproductively active and to determine their reproductive ability. Eight mares underwent ultrasound and gynecological examination and artificial insemination. Ultrasound revealed changes only in one mare. Histopathological findings were mild, such as periglandular and perivascular inflammatory cell infiltrates, fibrotic areas, glandular dilation, glandular island formation, and edema due to the phase of the estrous cycle. One animal was classified in category I and the others in category IIA. Cytological changes were found in only one mare. Endometrial culture from five mares resulted in isolation of Pseudomonas sp., Bacillus sp., Escherichia coli and Candida sp. Only four mares resulted pregnant through artificial insemination, using the same stallion with fresh semen, which has been proving fertility. Thus, mares with better uterine conditions will not always become pregnant and those with mild changes will not always be barren.