Evaluation of Single-Incision Laparoscopic Ovariectomy in Standing Mares

Our objective was to compare the invasiveness of single-incision laparoscopic surgery (SILS) and multiport laparoscopic surgery (MLS) for ovariectomy in 5 standing healthy adult Thoroughbred mares. First, laparoscopic ovariectomy was performed by SILS or by MLS on the right paralumbar fossa region in a standing mare. One month after surgery, ovariectomy by the other method was performed on the left side. For surgery evaluation, the surgical time, length of incision, and amount of lidocaine used were recorded and compared between SILS and MLS. Physical examination (body temperature, heart rate, and respiration rate) and hematology (number of leukocytes and hematocrit) were performed before surgery and every day for 7 days after surgery. Similarly, the degrees of swelling, heat, pain, and incisional wound healing were evaluated (grades1-4). The length of incision and amount of local anesthetic for SILS were significantly less than those for MLS. Moreover, the scores for swelling, heat, and pain in the SILS group tended to be lower than those in the MLS group for several days after surgery. We concluded that SILS was less invasive than MLS and is therefore useful for ovariectomy in mares.     

Evidence of Spontaneous Recovery of Granulosa‐Theca Cell Tumour in a Heifer: A Retrospective Report

A 14‐month‐old Japanese Black heifer was evaluated on Day 0 (D 0) for enlargement of the right ovary (RO). Transrectal ultrasonography (TRUS) revealed that the RO was markedly enlarged and multicystic, while the left ovary (LO) was small and inactive. The presumptive diagnosis was granulosa‐theca cell tumour (GTCT), which was confirmed by markedly elevated plasma anti‐Müllerian hormone (AMH) of 4.42 ng/ml. Therefore, ovariectomy of the RO was the treatment of choice. The heifer was checked by TRUS and blood sampling on D 42, D 63 and immediately before ovariectomy on D 85. On D 42, TRUS did not show marked changes in either ovary in comparison with D 0. However, on D 63, the RO had transformed into a single cyst, and on D 85, the LO had resumed cyclic activity. The RO was extracted on D 85 by hand‐assisted laparoscopic ovariectomy to allow better control. Unexpectedly, histopathology revealed the lesion to be a fluid‐filled cystic structure, with no neoplastic proliferation of follicular epithelium that would indicate GTCT. The wall of the cystic structure consisted of collagen fibres and a few degenerated granulosa cells. The retrospective hormonal analysis revealed that the AMH concentrations had markedly dropped on D 63 and 85, which coincided with resumption of cyclicity in the LO. These findings suggest that the GTCT had self‐cured and transformed into a cyst‐like structure. The heifer then received an oestrous synchronization regime on D 105, was artificially inseminated on D 115 and became pregnant.     

Laparoscopic Ovariectomy in Standing Mule Mares

Mules are hybrids bred from the mating of a jack donkey and a horse mare, known for their strength and resistance and still used to work in agriculture. Although they have been for long considered sterile, evidence of estrus cycle has been demonstrated together with abnormal behavior related to ovarian activity. In this study, a bilateral standing laparoscopic ovariectomy technique using the LigaSure technology was applied in 10 mare mules for treating unwanted behavioral patterns. The technique was effectively performed on these animals avoiding the risk of general anesthesia, and the use of the LigaSure technology allowed good hemostasis and reduced surgical time. Owners declared to be satisfied with the resolution of the behavior.     

Standing Laparoscopic Ovariectomy Technique with Intraabdominal Dissection for Removal of Large Pathologic Ovaries in Mares

Objective: To describe a standing laparoscopic ovariectomy technique with intraabdominal ovarian dissection inside a specimen retrieval bag for removal of large pathologic ovaries through small incisions. Study Design: Case series. Animals: Mares (n=43) aged 2–21 years and weighing 380–680 kg. Methods: Unilateral laparoscopic ovariectomy was performed on 43 standing sedated mares. Ovaries were approached via 3 portal sites, 2 in the paralumbar fossa and a 3rd between the 17th and 18th ribs on the ipsilateral side. Ovaries were dissected free using either a LiNA Tripol‐bipolar laparoscopic forceps or a Ligasure™ Vessel Sealing Device and removed by enlarging the proximal portal site ventrally using a grid technique. Use of a plastic specimen retrieval bag and cannula suction device facilitated intraabdominal dissection of very large ovaries into 2 or more pieces, before removal through small incisions. Results: Regardless of size, all ovaries were removed successfully through small incisions (range, 5–10 cm), with no major complications and an excellent cosmetic result. All sport horses returned to previous levels of work or higher, with 93% of breeding mares successfully bred in the 1st season after surgery. Conclusions: Large pathologic ovaries can be easily and safely removed by standing laparoscopic ovariectomy on the mare. Clinical Relevance: Standing laparoscopic ovariectomy combined with a small flank incision is a safe and highly effective technique for removal of large pathologic ovaries in the mare, negating the requirement for general anesthesia or large incisions.     

Laparoscopic Removal of a Large Abdominal Testicular Teratoma in a Standing Horse

Objective— To describe laparoscopic removal of a large testicular teratoma in a standing horse.
Study Design— Clinical report.
Animals— Thoroughbred horse (11 months) with a testicular teratoma.
Methods— A unilateral cryptorchid testicle could not be removed by an inguinal approach under general anesthesia because of it s large size. After recovery from general anesthesia, ultrasound evaluation revealed a 24 × 19 cm fluid-filled testicular mass. The mass was removed by paralumbar fossa laparoscopy with the horse in a standing position. After fluid aspiration of the mass, the mesorchium and ductus deferens were ligated with extracorporeal knots and the mass retrieved inside a laparoscopic specimen pouch. Morphologic features were consistent with a teratoma.
Results— Laparoscopic-guided aspiration of fluid from the teratoma decreased mass size and increased ease of manipulation and retrieval. Retrieval of the teratoma in a laparoscopic specimen pouch prevented loss of abdominal insufflation, helped reduce fluid leakage, and potential seeding of neoplastic cells.
Conclusion— Use of laparoscopy for removal of neoplastic cryptorchid testicles offers many advantages including minimal invasiveness and increased safety associated with good visibility of structures.
Clinical Relevance— Standing laparoscopic surgery should be considered for removal of testicular neoplasms in horses.     

A Retrospective Analysis of 2,253 Cases Submitted for Endocrine Diagnosis of Possible Granulosa Cell Tumors in Mares

Endocrine diagnoses of granulosa cell tumors (GCTs) in the mare are frequently based upon determination of serum concentrations of inhibin, testosterone, and progesterone (GCT panel). In the present study, we examined results from 2,253 samples submitted for determination of GCT panel. In an additional subset of samples (n = 75), diagnosis of GCT was confirmed based upon surgery or necropsy. The objective of the current study was to examine the agreement between serum inhibin and testosterone concentrations in mares with serum progesterone concentrations less than or ≥1 ng/mL. Across all samples, elevations in serum inhibin or testosterone were noted in 15.2% or 17.3% of samples, respectively. For samples with progesterone <1 ng/mL, more (P = .001) samples had elevated inhibin than elevated testosterone, whereas for samples with progesterone ≥1 ng/mL, more (P < .0001) samples had elevated testosterone than elevated inhibin. For samples with progesterone <1 ng/mL, the agreement between elevated inhibin and testosterone was greater than that for samples with progesterone ≥1 ng/mL. In a subset of 53 samples with progesterone ≥1 ng/mL, 28 samples had endocrine evidence of a granulosa cell tumors based upon elevations of serum anti-Müllerian hormone, and 4 of these samples had endocrine evidence of pregnancy based upon estrone sulfate concentrations. For samples from mares with confirmed GCTs, 85% and 55% had elevated inhibin or testosterone, respectively. Based upon endocrine diagnosis, GCTs occur in mares with elevated progesterone and/or estrone sulfate, albeit at a low rate.     

Pulse‐Administered Toceranib Phosphate Plus Lomustine for Treatment of Unresectable Mast Cell Tumors in Dogs

Background

Nonresectable mast cell tumors (MCT) in dogs remain a therapeutic challenge, and investigation of novel combination therapies is warranted. Intermittent administration of tyrosine kinase inhibitors (TKI) combined with cytotoxic chemotherapy may effectively chemosensitize canine MCT while decreasing cost and adverse effects associated with either agent administered as monotherapy.

Hypothesis/Objectives

The primary study objectives were to (1) identify the maximally tolerated dose (MTD), (2) determine the objective response rate (ORR) and (3) describe the adverse event profile of pulse‐administered toceranib phosphate (TOC) combined with lomustine.

Animals

Forty‐seven client‐owned dogs with measurable MCT.

Methods

Toceranib phosphate was given PO on days 1, 3 and 5 of a 21‐day cycle at a target dosage of 2.75 mg/kg. Lomustine was given PO on day 3 of each cycle at a starting dosage of 50 mg/m². All dogs were concurrently treated with diphenhydramine, omeprazole, and prednisone.

Results

The MTD of lomustine was established at 50 mg/m² when combined with pulse‐administered TOC; the dose‐limiting toxicity was neutropenia. Forty‐one dogs treated at the MTD were evaluable for outcome assessment. The ORR was 46% (4 complete response, 15 partial response) and the overall median progression‐free survival (PFS) was 53 days (1 to >752 days). On multivariate analysis, variables significantly associated with improved PFS included response to treatment, absence of metastasis, and no previous chemotherapy.

Conclusions and clinical importance

Combined treatment with pulse‐administered TOC and lomustine generally is well tolerated and may be a reasonable treatment option for dogs with unresectable or metastatic MCT.     

Effects of β-OH Butyrate on Bovine Granulosa and Theca Cell Function in Vitro

In this study, the effects of beta-OH butyrate (BHB) levels, associated with a negative energy balance, on bovine granulosa and theca cell function were investigated in vitro. Granulosa and theca cells of healthy large follicles (>8 mm), obtained from slaughterhouse ovaries, were cultured in serum free medium containing 0, 0.5, 1 or 1.5 mm BHB and 3 mm glucose, to mimic the situation in the early postpartum dairy cow. Hormone concentrations (progesterone, oestradiol-17beta and/or androstenedione) in spent medium and cell numbers were measured after 48 h of culture. No effects of BHB on theca cell numbers or on steroid production were observed. In granulosa cells, all BHB treatments evenly increased cell numbers (p < 0.05), while they reduced progesterone and oestradiol-17beta production per cell (p < 0.05). These effects may be attributed to the use of BHB as energy source which is however differently metabolized than glucose. Conclusively, in the presence of physiological glucose concentrations BHB can modulate granulosa but not theca cell function in vitro.     

Comparison of Intraoperative Behavioral and Hormonal Responses to Noxious Stimuli between Mares Sedated with Caudal Epidural Detomidine Hydrochloride or a Continuous Intravenous Infusion of Detomidine Hydrochloride for Standing Laparoscopic Ovariectomy

Objective: To compare the presence or absence of pain, pain‐related behavioral responses, and hormonal responses to noxious stimuli during standing laparoscopic ovariectomy in mares sedated with continuous intravenous (IV) detomidine infusion and caudal epidural detomidine. Study Design: A double blind prospective study. Animals: Mares (n=12) Methods: Mares were divided into 2 treatment groups; 6 were sedated using continuous IV detomidine infusion and 6 were sedated with caudal epidural detomidine. All mares received IV xylazine (0.33 mg/kg) and butorphanol tartrate (5 mg) premedication before detomidine administration. Venous blood samples were taken to assess serum cortisol levels in each mare at 4 time points: a baseline cortisol measurement after the mares' arrival to the clinic, 10 minutes before surgery, at the removal of the 2nd ovary, and 10 minutes postsurgery. Two surgeons performed bilateral ovariectomy and at 8 time points involving surgical manipulations, noted the presence or absence of pain (yes/no) and scored the patient's response on a 10 cm visual analogue scale (VAS) for pain assessment with 0 indicating no pain responses and 10 cm indicating pain so severe that the mare required additional sedation or analgesia to complete the procedure. Each mare was also assigned a VAS score by each surgeon for the overall satisfaction of analgesia during the entire procedure. Results: Serum cortisol levels between the 2 detomidine administration groups differed significantly at the baseline (precortisol) measurement but not at the 3 remaining time points. Seven of the procedures within the surgeries did not differ significantly in VAS scores between the 2 groups. The initial grasp of the left ovary (the 1st ovary) in the continuous infusion group had a significantly higher (P=.05) median VAS score compared with the caudal epidural group. Conclusions: Mares sedated with a continuous IV infusion of detomidine have similar hormonal and behavioral responses to painful stimuli during standing laparoscopic ovariectomy as mares sedated with caudal epidural detomidine. Clinical Relevance: Sedation using a continuous IV infusion of detomidine can be used for laparoscopic ovariectomy in mares.     

Evaluation of Pentobarbital as a Drug for Standing Sedation in Cattle

Pentobarbital (1.0, 1.5, and 2.0 mg/kg intravenously [IV]) was administered to four adult cows to determine a dose suitable for producing standing sedation in adult cattle, and to evaluate its effects on cardiopulmonary function and rumen motility. The response was assessed after 15, 30, 60, and 90 minutes. The 1.0 and 1.5 mg/kg doses induced mild sedation at 15 and 30 minutes, and no sedation at 60 and 90 minutes. The 2.0 mg/kg dose produced moderate sedation at 15 and 30 minutes, and mild sedation at 60 minutes. The 2.0 mg/kg dose was judged to be the most suitable. The effects of pentobarbital (2.0 mg/kg IV) on heart rate, blood pressure, respiratory rate, blood gases, and rumen motility were measured in five cows during a 90 minute period. Respiratory rate was significantly depressed at 15, 30, and 60 minutes, but there were no significant changes in the other variables. Pentobarbital (2.0 mg/kg IV) is reliable in adult cattle for standing sedation of short duration.     

Wound Retractor Laparoscopic Port System for Standing Laparoscopic Cryptorchidectomy in the Horse: A Case Report

Cryptorchidectomy is the most commonly performed laparoscopic procedure in horses. However, its use for the extraction of an abdominal testis has disadvantages such as loss of a resected testis from grasp and fragmentation of the specimen because of the excessive tension required for extraction through a thick body wall. The ring wound retractor laparoscopic port system was recently used in human and small animal surgery to perform laparoscopic-assisted procedures and retrieve large specimens from the abdomen. In the present case, the wound retractor was placed as the ventral port in the right flank through a minilaparotomy. Thereafter, the cap with the gas inlet and instrument port was connected. The other two ports were placed dorsally using 10-mm stainless steel cannulas. Grasping forcep was introduced through the ventral port, and the laparoscope and vessel-sealing devices were introduced through the dorsal ports. After the testis was resected, it was retrieved from the abdomen through the retractor without the grasping forceps jaw being released. This is the first case report describing the use of the wound retractor laparoscopic port system for standing cryptorchidectomy in a horse. This system can be a feasible and safe option for flank laparoscopy in horses, and it facilitates specimen retrieval from the abdominal cavity, but further studies should confirm this preliminary report.     

Laparoscopic Closure of the Renosplenic Space in Standing Horses

OBJECTIVE: To report a technique for laparoscopic ablation of the renosplenic space in standing horses. STUDY DESIGN: Development of a technique to perform laparoscopic renosplenic space ablation in standing horses. ANIMALS: Five healthy horses, aged 3 to 13 years, weighing 380 to 520 kg. METHODS: Horses were restrained in standing stocks and sedated with detomidine (0.01 mg/kg intravenously [IV]) and butorphanol (0.01 mg/kg IV). Portal sites in the left paralumbar fossa were infiltrated with 2% mepivacaine. A laparoscopic portal was placed between the 17th and the 18th ribs. Two instrument portals were located caudal to the 18th rib. Closure of the renosplenic space was accomplished by apposing the dorsomedial splenic capsule to the dorsal portion of the renosplenic ligament with 1 polyglactin 910 in a continuous pattern. All horses had repeat laparoscopy 3 weeks after initial surgery. RESULTS: Laparoscopic closure of the renosplenic space required 35 minutes (range, 20-65 minutes) and was successful without intraoperative or postoperative complications. On laparoscopic re-examination at 3 weeks, there was smooth connecting fibrous-like tissue between the dorsal splenic capsule and the dorsal portion of the renosplenic ligament. CONCLUSIONS: Laparoscopic closure of the renosplenic space can be efficiently and safely performed in standing horses. CLINICAL RELEVANCE: Laparoscopic-assisted closure of the renosplenic space can be performed in standing horses and may be useful in preventing recurrent incarceration of viscera in this space.     

Treatment of Persistent Mating‐Induced Endometritis in Mares with the Non‐Steroid Anti‐Inflammatory Drug Vedaprofen

Recently, successful treatment of mares with a history of persistent mating‐induced endometritis (PMIE) with dexamethasone has been reported. As systemic treatment of horses with glucocorticoids should be handled with caution, we tested the hypothesis that treatment with the non‐steroid anti‐inflammatory drug (NSAID) vedaprofen, an inhibitor of cyclooxygenase‐2, may have comparative, positive effects on fertility. Barren mares with a history of repeated PMIE were treated with vedaprofen (n = 8; initially 2 mg/kg bodyweight followed by 1 mg/kg orally twice daily) from 1 day before the first insemination to 1 day after ovulation or left untreated (n = 9). All mares received oxytocin (20 I.E. s.c.) thrice daily. Uterine swabs were collected for bacteriology and cytology. The day after ovulation, fluid accumulation was detected in three control mares and four treated mares (n.s.). The percentage of neutrophils in uterine cytology was significantly increased in comparison to the day before ovulation irrespective of treatment. Pregnancy was confirmed in two of nine mares in the control group and seven of eight mares in the treatment group (p < 0.05). NSAIDs may positively affect fertility in mares with a history of PMIE.     

Diagonal Paramedian Approach for Removal of Ovarian Tumors in the Mare

A diagonal paramedian approach to the abdomen was used for unilateral ovariectomy in 15 mares. In each case, surgery was performed for removal of a granulosa cell tumor. All horses recovered from surgery with minimal complications. Surgical exposure of the affected ovary was adequate to allow exteriorization and ligation. Other advantages of this approach were ease of closure and lack of postsurgical complications.     

Removal of Five Canine Cardiac Tumors Using a Stapling Instrument

Cardiac tumors in five dogs, including four right atrial appendage hemangiosarcomas and one heartbase chemodectoma, were removed, and the excisional edges were closed with a thoracic-abdominal (TA) stapling instrument. All five dogs recovered from surgery and were discharged from the hospital within 4 days. The four dogs with atrial appendage hemangiosarcomas developed extensive metastasis, although no evidence of tumor recurrence was found at the surgical site in two dogs that were necropsied. The dog with a chemodectoma was alive with no clinical or radiographic evidence of recurrence or metastasis 17 months following surgery.