Comparison of oxidative stress status in dogs undergoing laparoscopic and open ovariectomy

Assessment of Oxidative Stress Markers in Cats Undergoing Ovariohysterectomy by a Midline or Flank Approach

OBJECTIVES

The main goal of this study was to assess oxidative stress markers in cats that were having an ovariohysterectomy (OVH) using either a midline (MAG) or flank (FAG) method.

METHODS

Twelve entire female cats were randomly assigned into two groups and ovariohysterectomized by a midline (MAG) or flank approach (FAG). Clinical evaluation was performed and haematological and biomarkers of oxidative status were evaluated at baseline (before surgery), one, and 24 h after endotracheal extubation.

RESULTS

Concerning cardiorespiratory parameters, there were no differences in heart rate (HR), respiratory rate (RR), rectal temperature (RT), peripheral capillary oxygen saturation (SpO2 saturation), and End-tidal CO2 (ETCO2) values between groups or measured time during surgery. No significant differences were observed for the concentration of malondialdehyde (MDA), total antioxidant capacity (TAC), activities of erythrocyte glucose-6-phosphate dehydrogenase (G6PD), glutathione peroxidase (GPx) and superoxide dismutase (SOD) between the two groups. There were also no significant differences between different sampling times in each group.

CONCLUSIONS AND RELEVANCE

Results of the present study showed that ovariohysterectomy (OVH), either by midline or flank approaches, was not associated with oxidative stress and lipid peroxidation in the studied cats up to 24 h after surgery.

The protective role of melatonin and agomelatine against oxidative stress following laparoscopic ovariectomy in dogs

BACKGROUND

The present study was carried out to compare biomarkers of oxidative stress and antioxidant activity of agomelatine and melatonin in bitches undergoing laparoscopic ovariectomy. Twenty-four healthy female dogs were randomly divided into four groups: Control (C), laparoscopic ovariectomy (LO), agomelatine + laparoscopic ovariectomy (ALO), and melatonin + laparoscopic ovariectomy (MLO) consisting of 6 animals each. Melatonin and agomelatine were administered to the MLO group (0.3 mg/kg/day, p.o) and the ALO group (0.3 mg/kg/day, p.o) consequently one day before LO to 7 days post-intervention. Blood sampling was performed on days - 1, 0 (immediately after surgery), 3, and 8 of the study. Total oxidant status (TOS), total antioxidant capacity (TAC), and malondialdehyde (MDA) in sera and superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) in hemolyzed red blood cells (RBCs) were measured.

RESULTS

Among all indices analyzed over time, only the MDA index in the ALO group showed a significant difference, being significantly lower on day 3 post-surgery compared to days - 1 and 0 (p = 0.023). Significant differences were observed between groups in terms of TOS, TAC, GPx, and SOD levels. The LO group exhibited a significant increase in the TOS index on day 3 compared to all other groups (p = 0.008). The TAC index experienced the most significant increase in the MLO group on day 0 compared to other groups (p = 0.005), and this trend continued significantly until day 3, only in comparison to the LO and C groups (p = 0.024). Agomelatine significantly increased SOD levels in the ALO group on postoperative day 3 compared to groups C and LO (p = 0.009). GPx levels were significantly elevated in ALO and MLO groups on day 8 compared to groups C and LO (p = 0.003).

CONCLUSION

The results of this study demonstrate that melatonin, by increasing total antioxidant capacity, and agomelatine, through enzymatic antioxidant pathways, contributed to the reduction of free radical levels in dogs. The present study revealed that administering agomelatine (0.3 mg/kg/day, p.o) could decrease MDA levels significantly after laparoscopic ovariectomy up to day 3.

Optimized Two-Port Laparoscopic-Assisted Ovariohysterectomy for Hydrometra and Pyometra in Small-Sized Dogs

The clinical outcomes of laparoscopic-assisted ovariohysterectomy for the treatment of hydrometra or pyometra in small-sized dogs have not been reported. This study aimed to retrospectively investigate the clinical outcomes of two-port laparoscopic-assisted ovariohysterectomy in small-sized dogs weighing < 6 kg with mild to moderate hydrometra or pyometra. Laparoscopic ports were placed at the umbilicus on the midline, as well as at the midpoint between the umbilicus and pelvic brim. While the uterine horn was externally retracted, the cervical region was ligated and transected. A total of 77 dogs were included, with a median age of 8.8 years (range: 10 months to 16.1 years) and a median weight of 3 (range: 1.26-6.0) kg. Clinical signs included lethargy, anorexia, polydipsia, and polyuria; 51 dogs (66%) were asymptomatic, with an enlarged uterus incidentally detected during health checkups. Histopathological analysis revealed hydrometra and pyometra in 51 and 26 dogs, respectively. The median operative time was 32 (range: 15-83) minutes, and the median hospital stay was 0 (range: 0-3) days. No intraoperative complications occurred, although 18 dogs experienced anorexia postoperatively, and 3 showed signs of incision site infection. All sutures were removed 7-10 days postoperatively, and all dogs were clinically healthy at the two-week follow-up. The findings indicate that two-port laparoscopic-assisted ovariohysterectomy is a safe and effective treatment option for managing mild to moderate hydrometra and pyometra in small-sized dogs.

Serum total antioxidant status in dogs: Reference intervals and influence of multiple biological and analytical factors

BACKGROUND

Total antioxidant status (TAS) is one of the most widely used oxidative stress biomarkers, but the lack of canine RI and the influence of analytical factors hinder its application in clinical practice.

OBJECTIVES

The aims of this study were to establish canine assay-specific RI for TAS and evaluate the sources of biological variation and the association between TAS and multiple hematologic and biochemical variables.

METHODS

Blood samples from 190 clinically healthy dogs were collected, encompassing pet dogs (82), police dogs (56), and shelter dogs (52). After hematologic and biochemical analysis, serum TAS was determined by means of a commercial 2,2'-azinobis (3-ethylbenzthiazolin-6-sulfonic acid) (ABTS) test. The American Society for Veterinary Clinical Pathology guidelines were followed to establish the RI, employing nonparametric methods. Univariate analysis and multivariate analysis were conducted to assess the influence of biological and analytical variables, yielding a final regression model.

RESULTS

The final reference population comprised 143 dogs, for which the RI was established (1.41-2.27 mmol/L). Partitioning was applied to the three study groups. The regression model revealed that police dogs had significantly higher TAS values than pet dogs. Furthermore, significant associations between four biochemical variables (albumin, globulins, cholesterol, and aspartate aminotransferase) and serum TAS were found.

CONCLUSIONS

This is the first study to establish RI for serum TAS in a large and heterogeneous canine population and provide data on its relationship with analytical variables. These findings could potentially improve the interpretation of TAS in clinical environments.

Postoperative pain in dogs undergoing either laparoscopic or open ovariectomy

A prospective, quasi-experimental, clinical trial was performed to assess acute postoperative pain in healthy female dogs following elective ovariectomy by either laparoscopy (n=13) or laparotomy (n=14). Pain was assessed by both a veterinarian at the hospital, and by the owner once the patient was discharged. The Spanish version of the short form of the Glasgow Composite Measuring Pain Scale (CMPS-SF) was used. Pain scores were assessed by the veterinarian preoperatively and at 1, 2, 4, and 6 h after extubation, whilst owner-assessed scores were performed preoperatively and at postoperative days 0, 1, 2, 3, 5 and 7. Data were compared with Mann-Whitney-U test. Veterinarian-assessed CMPS-SF scores were different between both groups at all postoperative times but not at baseline, being below 6/24 in all dogs in the laparoscopy group, but equal to or greater than 6/24 in the laparotomy group at 1 h (n=12), and 4 h (n=4) (P<0.001 and P=0.029, respectively). There were also differences in pain scores between both groups at 2 h (P=0.012) and 6 h (P=0.007), being below 6/24 in all of them. However, there were no differences in owner assessments between groups. In conclusion, ovariectomy performed by laparoscopy induced lower pain scores that were below the pain threshold set by the CMPS-SF during the first 6 h postoperatively. After discharge, and up to one week later, ongoing owner-assessed scores suggest no pain was induced with neither of the techniques. Owners were proactive allowing real-time pain assessment to be reported. The development and validation of instruments for acute pain assessment by owners is warranted, as these tools are currently lacking.

Effects of Medetomidine-Butorphanol and Medetomidine-Buprenorphine on Oxidative Stress and Vital Parameters in Dogs Undergoing Ovariohysterectomy

Oxidative stress (OS) is caused by an imbalance between the production of oxygen-containing free radicals and their elimination. General anesthesia increases the production of reactive oxygen species (ROS) and therefore causes oxidative stress. Our objective was to determine the effects of medetomidine-butorphanol (MEDBUT) and medetomidine-buprenorphine (MEDBUP) on oxidative stress and cardiorespiratory parameters in dogs undergoing ovariohysterectomy (OHE). Ten healthy female dogs were randomly assigned to two groups: the MEDBUT group (n = 5) received medetomidine and butorphanol, while the MEDBUP group (n = 5) received medetomidine and buprenorphine. OS was evaluated by measuring total antioxidant status (TAS), total oxidant status (TOS), and oxidative stress index (OSI) during five different time points (from the administration of anesthetic drugs to 2 h after surgery). The observed vital cardiorespiratory parameters included heart rate (HR), respiratory rate (fR), noninvasive systolic (SAP) and diastolic (DAP) arterial blood pressures, oxygen saturation (SpO2), end-tidal CO2 (EtCO2), and body temperature (BT). Cardiorespiratory parameters were altered at a significantly greater degree in animals sedated with MEDBUT (p < 0.05). The administration of medetomidine-butorphanol was more likely to increase OS parameters, while medetomidine-buprenorphine showed decreased levels of oxidative stress throughout the study.

Using complete blood count-derived inflammatory markers to compare postoperative inflammation in dogs undergoing open or laparoscopic ovariectomy

BACKGROUND

The inflammatory response triggered in dogs after laparoscopic ovariectomy (LapOV) or ovariectomy through mini-celiotomy (COV) has never been compared using the neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR) and systemic inflammatory index (SII).

METHODS

Bitches underwent LapOV (n = 25) or COV (n = 25). NLR, PLR and SII were calculated 1 hour before ovariectomy (T0) and 2-3, 6-8 and 20-24 hours (T1-T3) after surgery.

RESULTS

Surgical time was longer in the LapOV group. Changes over time were observed in the NLR, PLR and SII in both groups (p < 0.001). PLR at baseline and T1 (p = 0.03 and 0.01) and NLR, PLR and SII at T2 (p = 0.01, 0.01 and 0.009) were higher in the LapOV group than in the COV group, but they did not differ at T3.

LIMITATIONS

The overrepresentation of Greyhounds in the LapOV group and the short-term follow-up are the study's main limitations.

CONCLUSION

Although an inflammatory peak was observed 6-8 hours after COV or LapOV, it was higher after the laparoscopy. However, there was no difference in the bitches' inflammatory status 24 hours after surgery.

Effect of direct therapeutic ultrasound exposure of ovaries on histopathology, inflammatory response, and oxidative stress in dogs

BACKGROUND

This research was designed to evaluate the effects of therapeutic ultrasound waves on ovarian germinal tissue and inflammatory cytokines (interleukin-6 (IL-6), IL1β, tumor necrosis factor-α (TNF-α)), acute phase proteins (serum amyloid A (SAA), C reactive protein (CRP)) and oxidative stress (total antioxidant capacity (TAC), and malondialdehyde (MDA)) in dogs. Twenty-six clinically healthy adult mix-breed female dogs were aligned into three groups. Laparotomy was performed in control (n = 6) and treatment (T5, n = 10; T10, n = 10) groups. The ultrasonic exposure of ovaries in treatment groups was performed during laparotomy by round motions of the therapeutic ultrasonic transducer on both ovaries (1 MHz frequency, 1.5 W⁄cm2) for 5 min in the T5 group and for 10 min in the T10 group. Blood samples were collected from the jugular vein into a plain glass tube on days 0 (before laparotomy), 3, 6, and 9 after surgery. All control and treatment groups' dogs were ovariectomized for histological evaluation on day 60 after laparotomy or laparotomy + ultrasound exposure.

RESULTS

Direct exposure of ovaries with therapeutic ultrasound waves induced inflammation and oxidative stress comparison with the control group. Histopathological evaluation of treated ovaries with ultrasound waves indicated a decreased number of primordial follicles (ovarian reserve) and oocyte preservation scores compared with ovaries in the control group.

CONCLUSIONS

These changes may cause subfertility in the long term. It seems that inflammatory response and oxidative stress are factors in the permanent damage of ovarian tissue.

Effect of calcium lactate in standard diet on selected markers of oxidative stress and inflammation in ovariectomized rats

The effectiveness of calcium depends on its source, i.e., salt it is supplied with. This study aimed to determine the effects of calcium lactate in diet on inflammation and oxidative stress markers in ovariectomized rats. A total of 40 female Wistar rats were included in this study, which were divided into four groups. The control group was fed a standard diet, whereas the remaining three groups were ovariectomized and provided a standard diet containing calcium carbonate (OVX), a calcium-deficient diet (OVX_DEF), or a diet containing calcium lactate (OVX_CaL). The nutritional intervention lasted for 12 weeks, and then, the rats were sacrificed. Tissue and blood samples were taken and evaluated for cyclooxygenase 1 (COX-1), cyclooxygenase 2, and thiobarbituric acid reactive substance contents in the liver and serum, and total antioxidant status and lipoxygenase 1 contents only in the serum using enzyme-linked immunosorbent assay. Differences were observed in the effects of calcium carbonate and calcium lactate on the COX-1 content in the serum of ovariectomized rats: a lower COX-1 concentration was observed in the case of the calcium lactate diet. No significant differences were observed for the other parameters.

Laparoscopic versus Open Ovariectomy in Bitches: Changes in Cardiorespiratory Values, Blood Parameters, and Sevoflurane Requirements Associated with the Surgical Technique

The aim of this study was to examine the cardiorespiratory and blood changes associated with pneumoperitoneum (PNP) in laparoscopic ovariectomy (LAP Ove), as well as sevoflurane requirements, comparing them to those determined in open surgery (LPT Ove). The study was performed in 16 bitches submitted to LAP or LPT Ove. The cardiorespiratory and end-tidal sevoflurane concentration values were recorded as follows: at the beginning of surgery (T1), after the right ovary resection (T2), after the left ovary resection (T3), and after surgical closure (T4). Blood samples were taken before and after PNP. Among the cardiorespiratory parameters, no differences were observed in the values of end-tidal CO2, minute volume, and heart rate. In the LAP Ove group, a significant increase in inspiratory pressures and a decreased compliance were identified at T2 and T3. Significant higher arterial pressure values were observed in both groups at T2 and T3, with this increase especially marked at T2 in the LPT Ove group. Sevoflurane requirements were significantly higher in the LPT group during ovarian resection. Finally, in terms of the hematochemical parameters, statistical differences were recorded between pre- and post-operative assessments, but not between both surgical groups. The pathophysiological effects associated with PNP seemed to be transient and well-tolerated by healthy dogs.

Novel surgical approach to neoplastic lesions in the distal part of the urethra: A pilot cadaver study comparing open and hybrid techniques

Tumours of the distal urethra in female dogs are often difficult to treat, and the surgical methods described thus far have technical limitations. This study aimed to present a novel approach to the surgical treatment of distal urethral tumours. This study used dog cadavers to evaluate the technical feasibility of surgically removing neoplastic lesions in the distal urethra and compared surgical outcomes of open surgery with those of hybrid surgery (combination of laparoscopy and open surgery). Open intact, open spayed, hybrid intact, and hybrid spayed dog cadaver groups underwent surgery (n = 6 per group). The novel surgical method was based on vulvovaginectomy (ovariohysterectomy in intact dogs), resection of the distal part of the urethra, and pre-pubic urethrostomy. Outcomes of interest included technical feasibility of each procedure, using both surgical techniques, wound length, time required to complete the procedure, and the incidence of intraoperative ureter and rectum injuries. Surgical technique and reproductive status affected operating time. Technique choice affected wound length; the surgical wound was longer in the open group than in the hybrid group. Macroscopic evaluation of the rectum did not reveal any damage to the wall. There was no evidence of ureter leakage or obstruction in any case. The present findings suggest that both open and hybrid surgery can be used to treat distal urethral tumours.

Effects of short-term administration of melatonin before gonadectomy on oxidative stress, cortisol and sex hormones in male dogs

The aim of this study was to investigate gonadectomy stress, steroid hormones and serotonin in male dogs treated with melatonin before gonadectomy. Twenty-five mixed breed adult dogs were divided into five equal groups. The melatonin and melatonin + gonadectomized groups received melatonin treatment (3 mg/10 Kg, PO, TID) the day before gonadectomy; the gonadectomized and anaesthesia groups did not receive melatonin; and the control group just received the melatonin vehicle. Blood sampling was performed before melatonin administration (day -1) and on days 0 (gonadectomy), 1, 3 and 6 after gonadectomy. Superoxide dismutase and glutathione peroxidase concentrations decreased significantly in gonadectomized dogs compared with dogs treated with melatonin before gonadectomy and intact dogs. Gonadectomy led to a significant decrease in catalase concentration in gonadectomized dogs compared with other study groups. Malondialdehyde levels increased significantly in gonadectomized dogs compared with other groups. Melatonin administration before gonadectomy led to decreased malondialdehyde concentration in gonadectomized and intact dogs compared to the control group. Cortisol concentration increased significantly in gonadectomized dogs compared to the control dogs. Serotonin levels decreased in gonadectomized dogs, but melatonin treatment increased serotonin concentration in gonadectomized and intact dogs. Melatonin treatment before gonadectomy suppressed oxidative stress and the cortisol but increased serotonin level.

A Comparison of Times Taken for the Placement of the First Portal and Complication Rates between the Veress Needle Technique and the Modified Hasson Technique in Canine Ovariectomy Laparoscopic Surgery

Minimally invasive surgery is increasingly being used in veterinary medicine. Laparoscopic procedures have several advantages compared with open surgery. These include the magnification of the field of surgery, reduced post-surgical pain and associated stress, reduced post-operative infection rates, and decreased hospitalization time. The establishment of a pneumoperitoneum is a critical step; however, this procedure can prolong the operation time, and most of the complications associated with laparoscopic surgery have been attributed to the insertion of devices into the abdominal cavity. Two main techniques have been employed to create pneumoperitoneum: the closed-entry method using the Veress needle and the open Hasson technique. The first portal is necessary to start insufflation and, subsequently, to realize the operative channel to insert the laparoscopic instruments into the abdomen. Many authors have compared the time necessary to create the first portal using different techniques in human medicine, but studies on this topic in veterinary medicine are lacking. In the veterinary medicine literature, complications associated with the creation of a pneumoperitoneum and the placement of ports include spleen, bowel, or bladder injuries; pneumothorax; and subcutaneous emphysema. The aim of the present study was to compare the times required for the placement of the first portal and the creation of pneumoperitoneum, and the rates of intraoperative complications using the Veress needle technique (VNT) and the open modified Hasson technique (MHT). The sample population comprised 30 female dogs who underwent laparoscopic ovariectomies. The dogs were randomly organized into two groups and two different entry techniques were used: Veress needle (VNT = group A) and the modified Hasson technique (MHT = group B). Complications related to abdominal entry were classified as major, in cases of organ perforation, and minor, in cases of subcutaneous emphysema and gas leakage. The VNT and MHT required 374.0 s and 242.9 s, respectively, for the placement of the first portal and for establishing pneumoperitoneum (p < 0.05). Their major complications rates were 20% and 0%, respectively (p < 0.05). Their minor complications rates were 20% and 35%, respectively (p < 0.05). No surgical procedures required laparotomy. The MHT was associated with a lower major complication rate and required less time to create the first portal, compared with the Veress needle technique.

Spectrophotometric assays for evaluation of Reactive Oxygen Species (ROS) in serum: general concepts and applications in dogs and humans

Reactive oxygen species (ROS) are reactive compounds derived from oxygen. In biological systems, an excessive amount of ROS can cause oxidative damage to biological macromolecules being involved in different diseases. Several assays have been developed in the last 30 years for ROS evaluation. The objective of this article will be to provide an update about the spectrophotometric methods currently used in the assessment of ROS in serum. The chemical basis of four different techniques will be reviewed, and examples of their possible applications will be provided. A particular emphasis about the practical applications of these assays in the dog will be made, but selected information about their use in humans will also be presented for comparative purposes, following a One-Health approach. The information about the spectrophotometric assays presented in this paper should be interpreted with caution once limited information about them is available yet, and further studies should be performed to clarify what they measure and their clinical application. Ideally, when applied to evaluate a sample's oxidative status, they should be incorporated in a panel of analytes where other oxidants, antioxidants, and biomarkers of inflammation were also included.

The effects of melatonin treatment on oxidative stress induced by ovariohysterectomy in dogs

BACKGROUND

As one of the most common surgeries performed in veterinary medicine, ovariohysterectomy (OHE) can induce oxidative stress in dogs. The antioxidant properties of melatonin have been confirmed in various studies. This study aimed to investigate the effects of melatonin administration on oxidative stress in dogs before and after OHE. In this study, 25 mature female intact dogs were selected and randomly divided into five equal groups: Melatonin (melatonin, no surgery), OHE (no melatonin, surgery), OHE + melatonin (melatonin, surgery), anesthesia+melatonin (melatonin, sham surgery), and control (no melatonin, no surgery) groups. Melatonin (0.3 mg/Kg/day, p.o.) was administrated to the dogs in the melatonin, OHE + melatonin, and anesthesia+melatonin groups on days - 1, 0, 1, 2, and 3 (day 0 = OHE). Blood sampling was performed on days - 1, 1, 3, and 5 of the study. Blood samples were immediately transferred to the laboratory and sera were separated and stored at - 20 °C. Superoxide dismutase (SOD), glutathione peroxidase (GPX), catalase (CAT) and malondialdehyde (MDA) concentrations were measured with commercial kits.

RESULTS

The levels of SOD, GPX and CAT were significantly higher in the melatonin and anesthesia+melatonin groups compared to those of the control group at days 3 and 5. The level of antioxidant enzymes significantly decreased in the OHE group compared to that of other groups at days 3 and 5. The administration of melatonin increased the level of antioxidant enzymes in ovariohysterectomized dogs. Ovariohysterectomy significantly increased the concentration of MDA in comparison to that of other groups at day 3. Melatonin administration significantly decreased the level of MDA in melatonin, anesthetized, and ovariohysterectomized dogs at day 3.

CONCLUSIONS

Administration of melatonin on day - 1, 0, 1, 2 and 3 modulate the oxidative stress induced by OHE in dogs by increasing antioxidant enzymes concentration and decreasing MDA levels.

Effects of Ovariohysterectomy and Hyperbaric Oxygen Therapy on Systemic Inflammation and Oxidation in Dogs

Introduction: Hyperbaric oxygen therapy (HBOT) involves breathing 100% oxygen in a specialized compression chamber leading to hyperoxia. This treatment modality is associated with anti-inflammatory, antioxidant, and healing properties in people and laboratory animals. However, there are relatively few reports that evaluate the effects of HBOT in companion animals. The goal of this study was to investigate the physiological effects of HBOT on surgically induced systemic inflammation and oxidation in dogs.

Material and Methods: Twelve healthy female beagle dogs were spayed and randomized into control and HBOT groups (n = 6). Both groups received conventional post-ovariohysterectomy therapy, and the HBOT group received two hyperbaric treatments at 2.0 atmosphere of absolute pressure and 100% oxygen for 35 min, 6 and 18 h after surgery. Blood samples were collected 3 h prior to ovariohysterectomy, 6, 18, and 30 h after surgery, prior to HBOT when applicable. Inflammatory biomarkers, including C-reactive protein, circulating cytokines, and changes in iron homeostasis were evaluated at each time point to determine the effects of surgery and HBOT on inflammation. Similarly, serum total oxidant status and total antioxidant status were measured to assess the oxidative stress. Pain and incision scores were recorded and compared between groups.

Results: Following ovariohysterectomy, all dogs had significantly increased serum concentrations of C-reactive protein, KC-like, IL-6, and increased unsaturated iron-binding capacity compared to their pre-surgical values (p < 0.02), while serum iron, total iron-binding capacity and transferrin saturation were significantly decreased after surgery (p < 0.02). There was no significant difference between the control group and the HBOT group for any of the variables. There were no overt adverse effects in the HBOT group.

Conclusion: This is the first prospective randomized controlled study to investigate the effects of HBOT on surgically induced systemic inflammation in dogs. While elective ovariohysterectomy resulted in mild inflammation, the described HBOT protocol portrayed no outward adverse effect and did not induce any detectable pro-inflammatory, anti-inflammatory, or antioxidant effects. Additional investigation is required to identify objective markers to quantify the response to HBOT and determine its role as an adjunctive therapy in dogs with more severe, complicated or chronic diseases.

Oxidative-antioxidative status and hepatic and renal factors following melatonin administration in castrated and intact dogs

Backgrounds

Melatonin has significant antioxidant and hepatoprotective effects in normal and oxidative stress conditions. The aim of the present study was to assess the effects of melatonin on antioxidant, hepatic, and renal factors in intact and castrated dogs. Twenty male mixed-breed adult dogs were aligned in an experimental randomized and controlled trial. The dogs were randomly divided into four equal groups: melatonin, castrated, castrated and melatonin, and control. They were treated with melatonin (0.3 mg/Kg, once daily, orally) immediately after the castration for 1 month and their blood samples were collected weekly from 2 days after treatment with melatonin.

Results

Treating castrated dogs with melatonin increased the level of glutathione peroxidase, superoxide dismutase, and catalase compared with that of the control and castrated groups. The malondialdehyde level increased significantly following castration. Melatonin treatment decreased malondialdehyde concentration in the castrated dogs. Castration increased the level of alkaline phosphatase, aspartate aminotransferase, and alanine aminotransferase significantly in comparison with that of the control group. Treating the castrated dogs with melatonin decreased significantly liver enzymes compared with those of the castrated dogs. Blood urea nitrogen and creatinine levels increased in the castrated dogs in comparison with that of the control group.

Conclusions

The administration of melatonin in castrated dogs increased antioxidant activity and decreased oxidation products, compared with those of the castrated and untreated dogs, without adverse effects on liver enzymes and kidney function.

Effect of oophorosalpingo-hysterectomy on serum antioxidant enzymes in female dogs

There are few studies evaluating the oxidant-antioxidant status after oophorosalpingohysterectomy (OSH) in female dogs. Here we determined the effect of OSH on antioxidant enzymes in serum, and quantified morphological changes in subcutaneous adipocytes. Lateral OSH was performed in 12 female dogs. The concentration of 17β-estradiol (17β-E₂), the activities of extracellular superoxide dismutase (SOD-ec), glutathione peroxidase (GPx), glutathione-S-transferase (GST) and glutathione reductase (GR) were determined. Glutathione (GSH), glutathione disulfide (GSSG), lipid peroxidation (LPO), total antioxidant capacity (TAC), carbonylation and vitamin C were measured in serum. Subcutaneous adipose tissue was obtained to determine morphological changes and cell number, under basal conditions and six months after OSH. The SOD-ec, GPx and GST activities increased significantly (p ≤ 0.05), LPO, carbonylation and GSSG also increased. GSH and vitamin C decreased (p = 0.03). 17β-E₂ tended to decrease six months after OSH. Hypertrophy of subcutaneous adipocytes was observed after OSH from the first month and was accentuated after six months (p = 0.001). The results suggest that 17β-E₂ decreases after OSH and alters the antioxidant enzyme activities in serum thus, redox balance is altered. These changes are associated with an increase in body weight and hypertrophy of subcutaneous adipose tissue.

A laparoscopic approach for removal of ovarian remnant tissue in 32 dogs

BACKGROUND

Surgical treatment of ovarian remnant syndrome (ORS) in dogs usually necessitates large celiotomies and considerable manipulation of organs because of the relatively deep position of ovarian remnant tissue, large patient size, and often encountered adhesions. In women, laparoscopic treatment of ORS is successful and has significant advantages over laparotomy. Since laparoscopic ovariectomy has significant advantages over open ovariectomy in dogs, including reduced surgical stress and postoperative pain and shorter convalescence period, the rationale for a laparoscopic approach of canine ORS is evident. Feasibility and efficacy of a laparoscopic approach for treatment of ORS in dogs was prospectively evaluated using a standardized protocol for diagnosis, treatment, and follow-up. Treatment success was evaluated by histology of removed tissues, postoperative hormone testing, and long-term clinical follow-up.

RESULTS

Thirty-two client-owned predominantly medium and large breed dogs diagnosed with ORS underwent abdominal ultrasound for ovarian remnant localization prior to laparoscopic surgery for removal of ovarian remnants. Tissue dissection and excision was performed using a vessel sealing forceps. Laparoscopy subjectively enabled detailed visibility and facilitated detection and removal of suspected ovarian tissue in all cases. Histology confirmed ovarian origin of removed tissue in all dogs. Additionally, a GnRH stimulation test was performed in fourteen dogs after a median follow-up of 10.5 months, which verified absence of residual functional ovarian remnant tissue in all dogs. Median surgery duration was 97.5 min and mean total convalescence duration, subjectively scored by owners, was 1.5 ± 0.7 days. No major complications occurred. Adhesions were observed in 79% of the dogs, complicated the surgical approach, and significantly affected surgery duration (85 versus 109 min; p = 0.03). Minor hemorrhage occurred in 12% and significantly increased surgery duration (95.5 versus 128 min; p = 0.02). Trendelenburg position and lateral tilting of the patient were essential for proper access to ovarian remnants. GnRH stimulation test results and/or absence of clinical signs indicative of ORS after a median follow-up period of 22.5 months confirmed treatment efficacy in all dogs.

CONCLUSION

Laparoscopic surgery for ORS in dogs is effective with minimal complications and short convalescence and can successfully replace the conventional, more invasive open surgical procedure.

Partial (two-thirds) nephrectomy in pigs: A comparison of three surgical approaches

Partial (2/3) nephrectomy can be performed via the laparoscopic, retroperitoneal, and transperitoneal approach. Outcomes of the three approaches were compared in this study. 2/3 nephrectomy were performed in 21 healthy Bama miniature pigs (mean bodyweight 20.59±2.78kg). Pigs were divided into three groups: those that underwent 2/3 nephrectomy via laparoscopy (LN group, n=7), the retroperitoneal approach (RN group, n=7), or the transperitoneal approach (TN group, n=7). We monitored pre- and postoperative physiologic parameters, blood cell count, and stress and renal function biomarkers. Differences among groups were analyzed. 2/3 nephrectomy was successfully performed in all pigs without any complications. Mean surgical time in the LN group (60.71±7.34min) and the TN group (58.57±4.72min) was significantly longer than that in the RN group (41.14±5.33min). Warm ischemia in the LN group (38±7.57min) was significantly longer than that in the TN group (28.86±4.53min), which was significantly longer than that in the RN group (17.86±2.34min). The postoperative serum concentration of C-reactive protein in the TN group was significantly higher than that in the LN group (p<0.05). So retroperitoneal approach was best choice in case of bilateral renal lesion resulted in shortest ischemia time, and laparoscopic partial nephrectomy should be the primary choice in majority situations resulted in less body stress, smaller surgical incisions and less blood loss.

Comparison of postoperative pain and inflammation reaction in dogs undergoing preventive laparoscopic-assisted and incisional gastropexy

This study compared the effects of postoperative pain and inflammation reaction after preventive laparoscopic-assisted gastropexy (LAG) and incisional gastropexy (IG) in 10 clinically normal Beagles. Surgical time, incision length, visual analog scale (VAS) score, University of Melbourne Pain Scale (UMPS) score, and plasma C-reactive protein (CRP), plasma cortisol (COR), and serum interleukin-6 (IL-6) levels were evaluated. The VAS and UMPS scores and COR and IL-6 levels were recorded at 0.5, 1, 2, 4, 8, 12, 18 and 24 hr after surgery. CRP level was recorded at 12, 24 and 48 hr after surgery. The VAS and UMPS scores showed no significant intergroup differences. Compared to IG, LAG had significantly lower surgical time (45 ± 9.91 min vs 64 ± 5.30 min; P<0.05), incision length (46 ± 8.21 mm vs 129 ± 19.49 mm; P<0.05), CRP level (12 hr after surgery; 4.58 ± 1.58 mg/dl vs 12.4 ± 1.34 mg/dl; P<0.01), and COR level (1 hr after surgery; 10.79 ± 3.07 µg/dl vs 15.9 ± 3.77 µg/dl; P<0.05). IL-6 levels showed no significant intergroup differences at any time point. However, LAG resulted in lower IL-6 levels than did IG at all postoperative time points. Neither procedure resulted in significant surgical complications. LAG produced lower surgical stress than did IG, suggesting that LAG is a safe, minimally invasive, and highly useful technique for preventing canine gastric dilatation-volvulus. Nevertheless, since this study used experimental models, its usefulness should be evaluated in future cases.

Validation of three automated assays for total antioxidant capacity determination in canine serum samples

We performed analytical validation of 3 automated assays of the total antioxidant capacity (TAC) in canine serum and evaluated their use in dogs with inflammatory bowel disease. The assays were based on the generation of a 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) radical cation (ABTS•⁺) in aqueous media, which produces a blue-green color. The antioxidants present in the sample remove the chromogen in proportion to their concentrations. The assays differed mainly in the way in which this radical was produced. All 3 assays produced acceptable results in the analytical validation. However, only 2 of the assays were capable of detecting significantly different TAC values in healthy and diseased animals.

Spectrophotometric assays for total antioxidant capacity (TAC) in dog serum: an update

The aim of this review is to study the main spectrophotometric methods used to evaluate total antioxidant capacity (TAC) in serum samples of dogs. Total antioxidant capacity (TAC) is an analyte frequently used to assess the antioxidant status of biological samples and can evaluate the antioxidant response against the free radicals produced in a given disease. Trolox equivalent antioxidant capacity (TEAC), ferric reducing ability of plasma (FRAP), and cupric reducing antioxidant capacity (CUPRAC) are different assays described to determine TAC of a sample. This review explains the basis of each assay and their application in the determination of TAC in dogs, and also provides selected information about reports in humans for comparative purposes. It is concluded that, ideally, various different assays integrated in a panel should be used for TAC evaluation, since depending on the assay performed TAC results can be markedly different.

Validation of an automated assay for the measurement of cupric reducing antioxidant capacity in serum of dogs

BACKGROUND

The objective of the present study was to optimize and validate an automated method to assess the total antioxidant capacity (TAC) in serum of dogs using the cupric reducing antioxidant capacity (CUPRAC) methodology (TACc) with bathocuproinedisulfonic acid disodium salt as chelating agent, evaluating also possible variations due to the use of two different automated analyzers. The method is based on the reduction of Cu(2+) into Cu(1+) by the action of the non-enzymatic antioxidants that are present in the sample.

RESULTS

Imprecision was low in both apparatus utilized, and the results were linear across serial Trolox and canine serum samples dilutions. Lipids did not interfere with the assay; however, hemolysis increased the TACc concentrations. When TACc concentrations were determined in ten healthy (control) dogs and in twelve dogs with inflammatory bowel disease (IBD), dogs with IBD had lower TACc concentrations when compared with the healthy dogs.

CONCLUSIONS

The method validated in this paper is precise, simple, and fast and can be easily adapted to automated analyzers.

Biomarcadores inflamatórios e de estresse oxidativo em cadelas submetidas à ovário-histerectomia videoassistida ou convencional

RESUMO A videocirurgia é atualmente uma das principais ferramentas operatórias, com vantagens que incluem menor estresse, incisões e dor pós-operatória quando comparada aos procedimentos abertos. Objetivou-se comparar o processo inflamatório e o estresse oxidativo resultantes das técnicas de ovário-histerectomia (OVH) convencional e videoassistida, com dois portais em cadelas, por meio de hemograma, avaliação de acetilcolinesterase, butirilcolinesterase, catalase e malondialdeído séricos, imediatamente antes da operação e duas, seis, 12, 24, 48 e 72 horas após a cirurgia. Observou-se menor estresse cirúrgico nas pacientes operadas pela técnica videoassistida, e sugere-se que a técnica convencional possa implicar peroxidação lipídica, mesmo com o uso de anti-inflamatório.

Anesthesia for Endoscopy

Anesthesia for endoscopic surgery can be challenging depending on surgical manipulations and patient comorbidity. Anesthetists must understand the possible systemic changes and complications that are associated with endoscopic surgery. Pneumoperitoneum induces vasoconstriction, reduces cardiac output, and decreases functional residual capacity in the cardiopulmonary system. Both hypoventilation caused by the thoracoscopic procedure and CO2 insufflation increase Paco2. To prevent the problems associated with high Paco2, monitoring of end-tidal CO2 (ETco2) and capability of positive pressure ventilation are crucial. Sudden changes of ETco2 should be monitored closely. Endoscopic surgery should be a less invasive procedure; however, appropriate analgesia remains necessary.

Complications and Conversion from Endoscopic to Open Surgery

Endoscopic surgery is a rapidly expanding modality of diagnosis and treatment of small animal patients. The development of skills, equipment, and minimally invasive means of correcting complications may be of great importance in decreasing the incidence of conversion from endoscopic to open surgery; however, conversion to an open approach should never be seen as a failure. Conversion should be considered at any time that it is of the greatest benefit for the patient. This concept is important enough to warrant discussion with the owner before surgery and acceptance of the need to convert without further consultation during the procedure.