Endoscope-assisted three-wire technique for extensive nasal septum resection in horses.

OBJECTIVE: To describe a 3-wire method with endoscopic guidance for extensive nasal septum resection. STUDY DESIGN: Retrospective study. SAMPLE POPULATION: Thirteen horses with nasal septum diseases. METHODS: In anesthetized horses in left lateral recumbency, endoscopic guidance was used to place obstetrical wires for the ventral and caudal incisions in the nasal septum and a trephine opening was used to place the dorsal wire. The rostral aspect of the septum was incised with a scalpel, followed by incisions with the preplaced wires, and the nasal passages were packed with gauze. Horses were recovered with a temporary tracheotomy. RESULTS: Conversion to intraoral placement of wires was required in two horses, one to correct entangled wires and the other because hemorrhage obscured the endoscopic view. Exercise tolerance was improved postoperatively, abnormal respiratory noise was decreased or eliminated by surgery in all horses, and all owners were satisfied. One Thoroughbred racehorse performed with modest success. CONCLUSIONS: Modification of the 3-wire method was effective and safe for extensive nasal septum removal. Technical complications of the procedure include entangling of wires and intraoperative hemorrhage. CLINICAL SIGNIFICANCE: Endoscopic guidance can be used to place obstetrical wires for nasal septum resection in small horses and precludes use of a large tracheotomy for anesthetic delivery. Reasons for athletic failures were difficult to establish retrospectively, although assessment of postoperative noise at speed might be more relevant to recovery of athletic potential than assessment at slower gaits.

Nonsteroidal antiinflammatory drugs reduce anion secretion and increase apoptosis in equine colonic mucosa ex vivo.

OBJECTIVE: Right dorsal colitis causes chronic colic associated with long-term treatment with nonsteroidal antiinflammatory drugs (NSAIDs). This study was designed to determine if NSAIDs could inhibit anion transporters that protect against intestinal mucosal injury in other species. ANIMALS: 20 healthy horses. METHODS: The effects of indomethacin (INDO) and firocoxib (FIR), on short-circuit current (Isc) in mucosa from the right dorsal colon (RDC) and right ventral colon (RVC) were measured in Ussing chambers by standard electrophysiological techniques. Immunohistochemical methods were used to detect apoptosis (caspase-3) with these NSAIDs and phenylbutazone (PBZ) and to locate the NKCC1 transporter. RESULTS: The Isc in RDC and RVC incubated with INDO or FIR was increased almost 3-fold (P < .0001) by prostaglandin E2 (PGE2) through a system inhibited by loop diuretics (P < .0001). Although these findings and anion replacement studies were consistent with anion secretion, the RDC also displayed an Isc response suggestive of a unique transporter apparently absent in RVC or NSAID-free solutions. In RDC, FIR, INDO, and PBZ induced apoptosis in the lower half of crypts. However, significant differences in apoptotic index were recorded in the RDC between NSAID-treated and control tissues (no NSAID). CLINICAL RELEVANCE: The effects of NSAIDs on Isc were consistent with reduced anion secretion, which could represent the pharmacological equivalent of the transport failure responsible for Cystic Fibrosis (CF) in other species. Failure of anion secretion could interfere with buffering acid from intraluminal fermentation, which could suggest a treatment target for right dorsal colitis.

Multicenter study of uterine tears and other reproductive complications in periparturient goats presented to veterinary teaching hospitals.

BACKGROUND: Goats are increasingly popular as both production animals and pets. The frequency of and factors associated with periparturient reproductive complications in goats are largely unreported. OBJECTIVES: (1) To report the frequency of periparturient reproductive complications in does presented to university veterinary hospitals and (2) to identify factors associated with uterine tears in the study population. ANIMALS: A total of 198 periparturient does presented to 9 university veterinary hospitals from October 2021 to June 2022. METHODS: Multicenter, cross-sectional study, with data collected from questionnaires completed by attending veterinarians. Logistic regression was used to identify factors associated with diagnosis of uterine tears. RESULTS: Ninety-three (47%) does had at least 1 periparturient reproductive complication. Periparturient complications included retained fetal membranes (n = 38, 26%), vaginal or perineal trauma (n = 33, 19%), uterine tears (n = 32, 18%), metritis (n = 22, 13%), uterine or vaginal hemorrhage (n = 8, 5%), Cesarean section complications (n = 8, 8%), and uterine prolapse (n = 1, 0.5%). A positive interaction effect was found between small breeds (Nigerian Dwarf and Pygmy) and manipulation on the farm by a layperson upon diagnosis of uterine tears (odd ratios [OR], 5.48; 95% confidence interval [CI], 1.41, 21.25; P = .01). CONCLUSIONS AND CLINICAL IMPORTANCE: Periparturient reproductive complications were common. Small breed combined with manipulation on the farm by layperson was associated with diagnosis of uterine tears. Clients should be educated that in the event of dystocia, small breed does are at greater risk of uterine tears and prompt veterinary intervention is critical.

Basic Postoperative Care of the Equine Colic Patient.

The 3 time periods around colic surgery (preoperative, operative, and postoperative) are all critical to successful outcomes. Although much focus is often paid to the first 2 time periods, the importance of sound clinical judgment and rational decision-making in the postoperative period cannot be overstated. This article will outline the basic principles of monitoring, fluid therapy, antimicrobial therapy, analgesia, nutrition, and other therapeutics routinely used in patients following colic surgery. Discussions of the economics of colic surgery and expectations for normal return to function will also be included.

Repeat Celiotomy-Current Status.

Repeat celiotomy can be lifesaving in horses with a surgically treatable postoperative obstruction, although guidelines for its use are lacking, except for uncontrollable postoperative pain. Overdiagnosis of ileus as the cause of postoperative obstruction could delay a second surgery so the disease progresses beyond a manageable level of severity. Although many horses respond favorably to repeat celiotomy, complications can be severe and life threatening, such as incisional infection and adhesions. Repeat celiotomy does not seem to exacerbate postoperative ileus, despite additional surgical manipulation. An important benefit of repeat celiotomy is termination of hopeless cases, thereby reducing cost and suffering.

Sedated cesarean sections are associated with increased kid survival compared to general anesthesia in goats: retrospective cohort of 45 cases (2011-2021).

OBJECTIVE: To determine whether anesthesia type (sedation or general anesthesia) affects kid survival to discharge in caprine cesarean sections (C-sections). ANIMALS: Retrospective cohort of 99 caprine C-sections (2011-2021). PROCEDURES: All surgeries were performed via left flank laparotomy in right lateral recumbency. The number of kids alive at presentation, surgery, and discharge was recorded. Kids that were dead on presentation or euthanized intraoperatively were excluded. Goats were classified as "healthy" (American Society of Anesthesiologists status ≤ 2) or "sick" (≥ 3). RESULTS: Kid survival was significantly higher for C-sections performed under sedation (47/52 [90%]) than for C-sections performed under general anesthesia (16/24 [66%]; P = .004). Relative risk was 1.4 and odds ratio was 4.7. CLINICAL RELEVANCE: Performing C-sections in sedated goats may improve kid survival rates over those under general anesthesia.

Surgical enlargement of the epiploic foramen in horses.

OBJECTIVE: To assess the safety and efficacy of a method for digitally enlarging the caudal aspect of the epiploic foramen (EF). STUDY DESIGN: Healthy horses and clinical cases of EF entrapment (EFE). ANIMALS: Fourteen healthy horses and three clinical cases. METHODS: Through a ventral midline celiotomy under general anesthesia, the EF was enlarged by digital separation of the caudal attachments of the caudate lobe of the liver from right dorsal colon, right kidney, gastropancreatic fold, and pancreas. Healthy horses were euthanized under anesthesia, and the enlarged EF was measured at necropsy. RESULTS: The method used for enlarging the EF did not cause clinically relevant hemorrhage, as determined by visual inspection of the EF in 14 horses at necropsy and by vital parameters under anesthesia in all horses. In clinical cases, EFE was reduced following enlargement of the EF, and no intraoperative complications were encountered. In one clinical case, necropsy at 30 days confirmed partial closure of the enlarged EF. CONCLUSION: The method proposed enlarged the EF safely and effectively. Limitations of the study include the small number of clinical cases and the lack of postoperative follow-up on the healthy horses. CLINICAL SIGNIFICANCE: Enlargement of the EF at its caudal extent should be considered in selected cases of EFE in which manual reduction is difficult or protracted. Although the procedure was safe in this study, knowledge of the anatomy, practice on cadavers, and careful selection of cases with greatest need are recommended before clinical use.

Ex vivo and in vivo evaluation of a modified interrupted Lembert pattern for small intestinal anastomoses in horses.

OBJECTIVE: To compare single-layer anastomoses (modified continuous Lembert [mod-CL] and modified-interrupted Lembert [mod-IL]) and a 2-layer simple continuous anastomosis (2 L; seromuscular and mucosal) for jejunojejunal anastomoses in equine cadavers and to compare ex vivo to in vivo time to complete the anastomosis and stoma size with a mod-IL pattern. STUDY DESIGN: Measurements in jejunum from cadaver and anesthetized horses. ANIMALS: Ten live horses and 18 equine cadavers. METHODS: Time to complete anastomosis, bursting pressures (BP), leakage sites, and anastomotic index (size ratio of anastomotic lumen to control lumen) were recorded. Time to completion and lumen size were compared between in vivo and ex vivo mod-IL patterns. RESULTS: The mod-CL pattern was fastest (8.44 ± 1.30 min, p < .05), and the 2 L pattern was slower (17.07 ± 2.0 min) than the mod-CL and mod-IL (p < .05). The anastomotic index exceeded 100 and did not differ between patterns. Segments reached higher bursting pressures when anastomosed with mod-IL (145.94 ± 24.18 mm Hg) than mod-CL (p < .05). In vivo closure was approximately 8 minutes slower than ex vivo, and with a smaller anastomotic index. CONCLUSIONS: All anastomoses increased lumen size over control segments ex vivo. Lumen size after placement of a mod-IL was greater ex vivo than in vivo, and completion was slower in vivo than ex vivo. [Corrections added on 26 Dec 2022, after online publication: added "ex vivo" to the first line of Conclusions in the Abstract.] CLINICAL SIGNIFICANCE: Slower and smaller anastomoses should be anticipated in vivo compared to ex vivo results. Anastomoses with a mod-IL pattern appear clinically advantageous, producing a comparable lumen size in less time than 2 L.

Mechanisms of bicarbonate secretion in the equine colon ex vivo.

OBJECTIVE: To examine bicarbonate (HCO3-) secretion ex vivo in the equine large colon to determine any differences between the right dorsal colon (RDC) and right ventral colon (RVC). The effect of phenylbutazone (PBZ) on HCO3- secretion was examined in the RDC. ANIMALS: 14 healthy horses. PROCEDURES: In anesthetized horses (n = 10), segments of mucosa from RDC and RVC were harvested to measure HCO3- secretion ex vivo with the pH Stat method. The effect of PBZ on HCO3- secretion in the RDC was studied in 4 additional horses. RESULTS: Three distinct mechanisms of HCO3- secretion previously described in a murine model were confirmed in the equine colon. The RDC had a greater capacity for electrogenic, Cl--independent HCO3- secretion than the RVC (P = 0.04). In the RDC, all HCO3- secretion was decreased by PBZ (P < 0.02) but was not studied in the RVC because of low baseline secretion. CLINICAL RELEVANCE: Secretion of HCO3- by the RDC could play a pivotal role in equine colon physiology, because intense microbial fermentation in this site could require HCO3- secretion to buffer short-chain fatty acids. Inhibition of this secretion by PBZ could interfere with mucosal buffering and predispose to changes associated with right dorsal colitis.

J-incision to approach the cranial abdomen in the adult horse.

OBJECTIVE: To describe a modified celiotomy to improve access to cranial abdominal structures in horses. ANIMALS: Four horses. STUDY DESIGN: Short case series. METHODS: Three horses with gastric impactions were treated with gastrotomies. One horse was treated for a diaphragmatic hernia with herniorrhaphy and mesh augmentation. In all horses, the ventral midline celiotomy was modified cranially with a J-incision through the body wall, along the paracostal arch. RESULTS: The only surgical complications were midline incisional infections in all horses. Three of the four horses had good long-term outcomes; the remaining horse underwent euthanasia for reasons likely unrelated to incisional complications. CONCLUSION: The J-incision improved access to the stomach and diaphragm in these horses. The paracostal component healed in all cases without evidence of infection or dehiscence. CLINICAL SIGNIFICANCE: This modified celiotomy may be considered to improve access during gastrotomy and repair of dorsally located diaphragmatic hernias.

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

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

Effect of lidocaine on inflammation in equine jejunum subjected to manipulation only and remote to intestinal segments subjected to ischemia.

OBJECTIVE To examine effects of continuous rate infusion of lidocaine on transmural neutrophil infiltration in equine intestine subjected to manipulation only and remote to ischemic intestine. ANIMALS 14 healthy horses. PROCEDURES Ventral midline celiotomy was performed (time 0). Mild ischemia was induced in segments of jejunum and large colon. A 1-m segment of jejunum was manipulated by massaging the jejunal wall 10 times. Horses received lidocaine (n = 7) or saline (0.9% NaCl) solution (7) throughout anesthesia. Biopsy specimens were collected and used to assess tissue injury, neutrophil influx, cyclooxygenase expression, and hypoxia-inducible factor 1α (HIF-1α) expression at 0, 1, and 4 hours after manipulation and ischemia. Transepithelial resistance (TER) and mannitol flux were measured by use of Ussing chambers. RESULTS Lidocaine did not consistently decrease neutrophil infiltration in ischemic, manipulated, or control tissues at 4 hours. Lidocaine significantly reduced circular muscle and overall scores for cyclooxygenase-2 expression in manipulated tissues. Manipulated tissues had significantly less HIF-1α expression at 4 hours than did control tissues. Mucosa from manipulated and control segments obtained at 4 hours had lower TER and greater mannitol flux than did control tissues at 0 hours. Lidocaine did not significantly decrease calprotectin expression. Severity of neutrophil infiltration was similar in control, ischemic, and manipulated tissues at 4 hours. CONCLUSIONS AND CLINICAL RELEVANCE Manipulated jejunum did not have a significantly greater increase in neutrophil infiltration, compared with 4-hour control (nonmanipulated) jejunum remote to sites of manipulation, ischemia, and reperfusion. Lidocaine did not consistently reduce neutrophil infiltration in jejunum.

Response to early repeat celiotomy in horses after a surgical treatment of jejunal strangulation.

OBJECTIVE: To determine the outcome after early repeat celiotomy in horses operated for jejunal strangulation. STUDY DESIGN: Retrospective case series. ANIMALS: Horses (n = 22) that underwent repeat celiotomy for postoperative reflux (POR) and/or postoperative colic (POC) that did not improve within 48 hours from onset after initial surgical treatment of strangulating jejunal lesions by jejunojejunostomy (n = 14) or no resection (n = 8). METHODS: Medical records were reviewed for clinical signs, duration of signs before repeat surgery, surgical findings and treatment, and outcome. Survival was documented by phone call at long-term follow-up. The influence of POC and POR on timing of surgery were analyzed. Long-term survival was examined by Kaplan-Meier analyses. RESULTS: Repeat celiotomy was performed at a median of 57 hours after initial surgery and 16.5 hours from onset of signs, and earlier in horses with POC compared with POR (P < .05). A total of 3/22 horses were euthanatized under anesthesia. A total of 9 of 11 horses with initial jejunojejunostomy required resection of the original anastomosis due to anastomotic complications. In 8 horses without resection, second surgery included resection (4) or decompression (4). Repeat celiotomy was successful in 13/16 horses with POR. Repeat celiotomy eliminated POC in all horses (n = 9). A total of 19 horses were recovered from anesthesia and all survived to discharge. Incisional infections were diagnosed in 13/17 horses where both surgeries were performed through the same ventral median approach, and hernias developed in 4/13 infected incisions. Median survival time was 90 months. CONCLUSION: Repeat celiotomy can eliminate signs of POR and/or POC, and the additional surgery does not appear to aggravate POR. Criteria for repeat celiotomy in this study could provide guidelines for managing POC and POR after surgery for jejunal strangulation.