Evaluation of automated staple sizes on gastric layer incorporation and intraluminal pressure for partial gastrectomy closure in an ex vivo canine model.

OBJECTIVE: To evaluate the performance of automated staple sizes on a cadaveric canine partial gastrectomy model. METHODS: Stomachs were transected through the gastric body axis and randomly allocated to two closure groups: Group B, thoracoabdominal (TA) stapler 3.5 mm staple cartridge (blue); Group G, TA stapler 4.8 mm staple cartridge (green). After construct completion, leak testing was performed for both groups and compared. Initial leakage pressure (ILP), maximal leakage pressure (MLP) and leakage location were recorded. Staple lines were evaluated by direct observation and fluoroscopy to assess sub-mucosal layer incorporation and staple conformation. Staple shape was classified as optimal or suboptimal. Significance was set at p less than 0.5. RESULTS: Following gastrectomy, the mean double gastric wall thickness was 7.82 ± 2.05 mm at the gastric body. Mean ILP was significantly lower in groups G (17.13 ± 1.19 mmHg) compared to group B (50.46 ± 6.03 mmHg, p = 0.0013). Similarly, mean MLP was significantly lower in group G (21.41 ± 1.39 mmHg) compared to group B (64.61 ± 10.21 mmHg, p < 0.0001). Although group G had higher percentage of B-shaped staple formation compared to group B, this was not significant (group G; 92.38%, group B; 54.56%; p = 0.054). CONCLUSION: The 3.5 mm TA staple cartridge (blue) achieved superior bursting pressures compared with the 4.8 mm TA staple cartridge (blue) for the closure of a canine partial gastrectomy model. Both staple sizes incorporated all gastric layers. No differences were noticed in optimal staple conformation between groups. In vivo investigation is warranted to evaluate the use of different staple sizes on gastric tissue perfusion, successful healing and post-operative stasis and dehiscence.

Adrenal tumors treated by adrenalectomy following spontaneous rupture carry an overall favorable prognosis: retrospective evaluation of outcomes in 59 dogs and 3 cats (2000-2021).

OBJECTIVE: To conduct a retrospective multi-institutional study reporting short- and long-term outcomes of adrenalectomy in patients presenting with acute hemorrhage secondary to spontaneous adrenal rupture. ANIMALS: 59 dogs and 3 cats. METHODS: Medical records of dogs and cats undergoing adrenalectomy between 2000 and 2021 for ruptured adrenal masses were reviewed. Data collected included clinical presentation, preoperative diagnostics, surgical report, anesthesia and hospitalization findings, histopathology, adjuvant treatments, and long-term outcome (recurrence, metastasis, and survival). RESULTS: Median time from hospital admission to surgery was 3 days, with 34% of surgeries being performed emergently (within 1 day of presentation). Need for intraoperative blood transfusion was significantly associated with emergent surgery and presence of active intraoperative hemorrhage. The short-term (≤ 14 days) complication and mortality rates were 42% and 21%, respectively. Negative prognostic factors for short-term survival included emergent surgery, intraoperative hypotension, and performing additional surgical procedures. Diagnoses included adrenocortical neoplasia (malignant [41%], benign [12%], and undetermined [5%]), pheochromocytoma (38%), a single case of adrenal fibrosis and hemorrhage (2%), and a single case of hemangiosarcoma (2%). Local recurrence and metastasis of adrenocortical carcinoma were confirmed in 1 and 3 cases, respectively. Overall median survival time was 574 days and 900 days when short-term mortality was censored. No significant relationship was found between histopathological diagnosis and survival. CLINICAL RELEVANCE: Adrenalectomy for ruptured adrenal gland masses was associated with similar short- and long-term outcomes as compared with previously reported nonruptured cases. If hemodynamic stability can be achieved, delaying surgery and limiting additional procedures appear indicated to optimize short-term survival.

Laparoscopic ultrasonography of the liver is feasible and safe in dogs.

OBJECTIVE: To describe the feasibility and technique for performing laparoscopic ultrasound (LUS) of the liver in dogs. ANIMALS: 12 client-owned dogs presenting for elective laparoscopic surgery from January 1, 2022, to October 31, 2022. METHODS: Laparoscopic exploration and LUS of the liver were performed in all dogs. Dogs were positioned in reverse Trendelenburg and laterally rotated to facilitate access to all liver lobes. Time to perform laparoscopic exploration and LUS, ability to visualize and access each liver lobe entirely, and any complications were recorded. Each dog underwent an elective laparoscopic procedure. The surgeon completed a National Aeronautics and Space Administration Task Load Index (NASA-TLX) questionnaire after surgery. RESULTS: Mean body weight was 25.9 kg (SD, ± 4.1 kg; range, 5.7 to 62 kg). All liver lobes were scanned to the level of the hilus in 10/12 dogs. In 2 dogs, the caudate lobe could not be completely imaged. Median time to perform LUS was 9 minutes (IQR, 5 to 16.5 minutes), and median NASA-TLX score was 9/100 (IQR, 6.3 to 20). There was a significantly strong negative correlation between time to perform LUS (r = -0.77; P = .0037) and NASA-TLX score (r = -0.84; P = .0006) with trial number. Minor complications occurred in 2 dogs during laparoscopic exploration. No complications occurred during LUS. CLINICAL RELEVANCE: LUS was feasible and safe in all dogs. The right lateral and caudate lobes were occasionally challenging to access. Technical demand and time to perform LUS improved with experience, suggesting a learning curve. Evaluation of LUS in dogs with clinical disease is warranted.

Biomechanical comparison of canine median sternotomy closure using suture tape and orthopedic wire cerclage.

OBJECTIVE: To compare the mechanical properties of suture tape and orthopedic wire cerclage in an ex vivo canine median sternotomy model. STUDY DESIGN: Ex vivo. ANIMALS: Twelve large-breed canine cadaveric sternums. METHODS: Median sternotomies were performed, leaving the manubrium intact. The specimens were randomly assigned to group W (20-gauge stainless steel orthopedic wire cerclage in a figure-of-eight pattern) or group ST (suture tape in a figure-of-eight pattern). Each specimen was laterally distracted until failure using an electrodynamic materials-testing system. RESULTS: No differences were observed for displacement, yield load, maximum load, implant failure between the groups. The orthopedic wire construct was stiffer than the suture tape construct. CONCLUSION: Suture tape was biomechanically similar to orthopedic wire cerclage for sternotomy closure in dogs, although wire constructs were stiffer. CLINICAL SIGNIFICANCE: Suture tape may represent an alternative to cerclage wire for sternotomy closure in dogs. Additional studies evaluating its clinical use are needed.

Geometric, landmark-guided technique reduces tissue trauma, surgery time, and subjective difficulty for canine peripheral lymphadenectomies: an educational crossover study.

OBJECTIVE: To compare the effect of a geometric, landmark-guided lymphadenectomy (LL) approach to peripheral lymph nodes (LNs) on successful LN identification, surgical time, tissue trauma, and ease of LN identification compared to standard lymphadenectomy (SL) and methylene blue-guided lymphadenectomy (MBL). SAMPLE: 18 adult, mixed-breed canine cadavers operated on by 7 veterinarians and 5 fourth-year veterinary students between July 23 and October 12, 2022. METHODS: Participants were provided standardized, publicly available materials regarding the anatomy and surgical techniques for SL of 3 peripheral lymphocentrums: superficial cervical, axillary (ALN), and superficial inguinal (SILN). Participants performed the 3 SLs unilaterally on canine cadavers. Thereafter, they were randomly assigned to 2 crossover groups: MBL and LL. All dissections were separated by at least 2 weeks for each participant. Primary outcome measures included successful LN identification, surgical time, tissue trauma scores, and subjective difficulty. RESULTS: Successful LN identification was highest with LL (86%) compared to SL (69%) and MBL (67%). Subjective difficulty scores were reduced with LL for SILN dissections. Tissue trauma scores were reduced when using LL for ALN and SILN compared to MBL and SL. Time to LN identification was reduced for ALN with LL. No significant differences were observed between MBL and SL, or for the superficial cervical dissections. CLINICAL RELEVANCE: Peripheral lymphadenectomies are time consuming and difficult for veterinarians in early stages of surgical training. Little surgical guidance is provided within current literature. Geometric, landmark-guided lymphadenectomies may improve LN identification success and reduce surgical time, tissue trauma, and procedure difficulty, which could encourage their clinical application.

Multiple biliary duct hamartomas in a cat resulting in a hepatic mass: A case report.

A 13-year-old, male neutered domestic short-haired cat was diagnosed with multiple biliary duct hamartomas after liver lobectomy for a suspected malignant hepatic mass. Distinguishing ultrasonographic findings included a lobular, mostly well-defined, heterogeneous, predominantly hyperechoic, left hepatic mass. Computed tomography (CT) confirmed the presence of a lobular, well-defined, fluid to soft tissue attenuating, heterogeneously hypoenhancing left divisional hepatic mass. Grossly, a large left sided multilobular pale pink gelatinous hepatic mass was surgically excised. Histopathologically, the mass was composed of irregular cystic spaces lined by cuboidal epithelium and separated by mature regular fibrous tissue. Three months following surgery there was no evidence of recurrence or progression of disease on repeat abdominal ultrasound (AUS).

Acellular fish skin may be used to facilitate wound healing following wide surgical tumor excision in dogs: a prospective case series.

OBJECTIVE: To prospectively evaluate clinical outcomes using acellular fish skin grafts (FSGs) for the management of complete wound healing by secondary intention after wide surgical excision of skin tumors in dogs. ANIMALS: 5 dogs undergoing wide surgical excision of skin tumors on the distal extremity. CLINICAL PRESENTATION AND PROCEDURES: FSGs were applied to surgical wound beds following wide excision of the tumor. Bandages were changed weekly and additional grafts placed when integration of the previous graft was complete. The wounds were assessed for the following: dimensions, tissue health (color), time to complete epithelialization, complications, and tumor recurrence. RESULTS: All masses were excised with 2-cm lateral margins and 1 fascial plane deep to the tumor. Tumor diagnoses included 3 mast cell tumors and 2 soft tissue sarcomas. Surgical wounds had a median area of 27.6 cm2 (range, 17.6 to 58.7 cm2). The median number of FSG applications was 5 (range, 4 to 9 applications). Complete epithelialization occurred within 7 to 9 weeks for uncomplicated wounds (3 of 5) and 12 to 15 weeks for complicated wounds (2 of 5) that sustained self-trauma. There were no adverse events related to the use of FSGs. Local recurrence was not seen over a follow-up period ranging from 239 to 856 days. CLINICAL RELEVANCE: Wide surgical excision of distal extremity skin tumors, followed by repeated application of acellular FSGs, resulted in complete healing of all wounds with no adverse events. This treatment method does not require advanced reconstructive surgical skills and may be useful for the management of skin tumors on the distal extremities.

Client perceptions improve with collaborative care when managing dogs with cancer: a Collaborative Care Coalition study.

OBJECTIVE: Collaboration between primary care veterinarians (pcVets) and veterinary oncologists is common for dogs diagnosed with cancer, but no data exist that explore dog owner utilization and perceptions of collaborative care. The objectives were to describe dog owner perceptions of the value of collaborative veterinary cancer care and identify drivers of a positive collaborative care experience between the pcVet and oncologic specialists. SAMPLE: 890 US dog owners who had pets diagnosed with cancer in the past 3 years. PROCEDURES: Online contextual survey. Data were analyzed using group comparisons and multiple regression analysis. Significance was set at P < .05. RESULTS: 76% of clients sought specialty care following cancer diagnosis in their dog. Seventy percent of owners across all income brackets indicated that referral to a specialist was a very good value based on money spent and outcomes. Delayed referral resulted in lower client satisfaction scores for pcVets. Top predictors of client satisfaction with pcVets were as follows: responsiveness to questions, staying involved with their dog's care, and willingness to work with other veterinarians and specialists. For specialists, top predictors were as follows: providing accurate cost estimates, cancer knowledge, and effectiveness of care. Client perceptions of pcVets were 6 times more likely to improve following referral to a specialist. All were significant predictors of owner advocacy (P < .0001). CLINICAL RELEVANCE: Dog owners perceived early collaboration between pcVets and specialists favorably, fostering client satisfaction and positive perceptions of the value for service provided for dogs diagnosed with cancer.

Superficial anatomic landmarks can be used to triangulate the location of canine peripheral lymphocentrums: superficial cervical, axillary, and superficial inguinal.

OBJECTIVE: To utilize the geometry of superficial anatomic landmarks to guide incisional location and orientation for peripheral lymphadenectomy, document deep anatomic landmarks for lymphocentrum identification, and develop novel surgical approaches to the superficial cervical, axillary, and superficial inguinal lymphocentrums in dogs. ANIMALS: 12 canine cadavers. PROCEDURES: 2 cadavers were used for a pilot investigation to determine optimal body positioning, select superficial anatomic landmarks for lymphocentrum identification, and evaluate novel surgical approaches to the 3 lymphocentrums. These lymphocentrums were then dissected in 10 additional cadavers using these novel surgical approaches. Measurements of the distances from lymphocentrum to landmark and between landmarks were obtained for each lymphocentrum. Deep anatomic landmarks were recorded for each dissection. The mean and SD were calculated for each measurement and used to develop geometric guidelines for estimating the location of each lymphocentrum for these surgical approaches. RESULTS: Each peripheral lymphocentrum was found in the same location relative to the respective, predetermined, superficial, anatomic boundaries in all cadavers. Briefly, the superficial landmarks to each lymphocentrum were as follows: (1) superficial cervical: wing of atlas, acromion process of scapula, greater tubercle of humerus; (2) axillary: caudal border of transverse head of superficial pectoral muscle, caudal triceps muscle, ventral midline; and (3) superficial inguinal: origin of pectineus muscle, ipsilateral inguinal mammary gland, ventral midline. The proposed superficial and deep surgical landmarks were identified within every cadaver. The previously undescribed surgical approaches were effective for lymphocentrum identification. CLINICAL RELEVANCE: Anatomic landmarks provided in this study may help reduce surgical time and tissue trauma during peripheral lymphadenectomy in dogs. This study was also the first to describe a surgical approach to the superficial inguinal lymphocentrum and ventral approaches to the superficial cervical and axillary lymphocentrums and provided previously unpublished anatomic landmarks for a lateral approach to the superficial cervical lymphocentrum.

Endoscopic application of fibrin glue may be a feasible method of treatment for postintubation tracheal lacerations in cats.

OBJECTIVE: To determine the feasibility of endoscopic application of fibrin glue for the treatment of experimentally induced postintubation tracheal laceration (PITL) in feline cadavers. The secondary objective was to determine the optimal technique for application of the fibrin glue. ANIMALS: 20 feline cadavers (n = 10 fresh and 10 frozen). PROCEDURES: An experimentally induced tracheal rupture was created via overinflation of an endotracheal tube cuff. After endoscopic identification of the tracheal tear, fibrin glue was instilled into the tracheal defect in either a bridging or filling fashion. Following the procedure, the airway of each cat was examined and leak tested. Length of tear, volume of glue applied, procedural time, and glue efficacy were recorded. RESULTS: Experimentally induced tracheal lacerations were full thickness with a mean length of 3.27 ± 0.96 cm. A complete seal was attained in 6 of the 9 fresh cadavers when filling the defect with fibrin glue. In the remaining 3 fresh cadavers, air leakage was restricted to the dorsal mediastinum. Bridging the defect with fibrin glue did not attain a seal in fresh or frozen cadavers. The median volume of glue used to fill defects in fresh cadavers was 0.5 mL (range, 0.4 to 2 mL). Procedural time for the application of fibrin glue was 10.5 ± 4.1 minutes for bridging the defect and 7.8 ± 1.5 minutes for filling the defect. CLINICAL RELEVANCE: Endoscopic application of fibrin glue may be a feasible method of treatment for PITL in cats.

A narrative review on the role of carbon nanoparticles in oncology.

The lymphatic system is the first site of metastasis for most tumors and is a common reason for the failure of cancer therapy. The lymphatic system's anatomical properties make it difficult to deliver chemotherapy agents at therapeutic concentrations while avoiding systemic toxicity. Carbon nanoparticles offer a promising alternative for identifying and transporting therapeutic molecules. The larger diameter of lymphatic vessels compared to the diameter of blood vessels, allows carbon nanoparticles to selectively enter the lymphatic system once administered subcutaneously. Carbon nanoparticles stain tumor-draining lymph nodes black following intratumoral injection, making them useful in sentinel lymph node mapping. Drug-loaded carbon nanoparticles allow higher concentrations of chemotherapeutics to accumulate in regional lymph nodes while decreasing plasma drug accumulation. The use of carbon nanoparticles for chemotherapy delivery has been associated with lower mortality, fewer histopathology changes in vital organs, and lower serum concentrations of hepatocellular enzymes. This review will focus on the ability of carbon nanoparticles to target the lymphatics as well as their current and potential applications in sentinel lymph node mapping and oncology treatment regimens. This article is categorized under: Implantable Materials and Surgical Technologies > Nanoscale Tools and Techniques in Surgery.

Complications associated with iliosacral lymphadenectomy in dogs with metastatic apocrine gland anal sac adenocarcinoma.

Objective: To report intraoperative and immediate postoperative complications associated with removal of metastatic iliosacral lymph nodes in dogs with apocrine gland anal sac adenocarcinoma. Animals: There were 136 client-owned dogs in the study. Procedure: Retrospective multi-institutional study. The database of collaborating institutions was searched for dogs with metastatic apocrine gland anal sac adenocarcinoma that underwent lymphadenectomy for removal of one or more iliosacral lymph nodes. Information of signalment, hematological abnormalities, abdominal computed tomography or ultrasound findings, number and size of enlarged lymph nodes, intraoperative and postoperative complications, treatment and outcome were collected. Results: The overall complication rate associated with metastatic iliosacral lymphadenectomy was 26.1%. The only intraoperative complication recorded was hemorrhage and was reported in 24 (17.6%) surgeries, 11 (45.8%) of which received a blood transfusion. Postoperative complications were reported in 10.4% of surgeries, and included edema formation (n = 4, 2.6%), unilateral or bilateral paraparesis (n = 4, 2.6%), hypotension (n = 3, 2.0%), surgical site infection (n = 2, 1.3%), abdominal incision dehiscence (n = 1, 0.6%), urinary incontinence (n = 1, 0.6%), and death (n = 1, 0.6%). The size of the iliosacral lymph nodes was significantly associated with a greater risk of complications, hemorrhage, and the need of transfusion during lymphadenectomy for metastatic apocrine gland anal sac adenocarcinoma. Conclusion: Complications associated with iliosacral lymphadenectomy for metastatic apocrine gland anal sac adenocarcinoma are relatively common and mostly relate to hemorrhage. These complications are significantly associated with the size of the extirpated metastatic lymph nodes. Clinical relevance: This retrospective study provides information for the clinician regarding the potential surgical complications for extirpation of metastatic iliosacral lymph nodes. These complications, although not common, can be severe and should be discussed with owners before surgery.

Objectif: Rapporter les complications peropératoires et postopératoires immédiates associées à l'ablation des ganglions lymphatiques ilio-sacrés métastatiques chez les chiens atteints d'un adénocarcinome des glandes apocrines des sacs anaux. Animaux: Il y avait 136 chiens appartenant à des clients dans l'étude. Procédure: Étude multi-institutionnelle rétrospective. La base de données des institutions collaboratrices a été recherchée pour les chiens atteints d'un adénocarcinome métastatique des glandes apocrines des sacs anaux qui ont subi une lymphadénectomie pour l'ablation d'un ou plusieurs ganglions lymphatiques ilio-sacrés. Des informations sur le signalement, les anomalies hématologiques, les résultats de la tomodensitométrie abdominale ou de l'échographie, le nombre et la taille des ganglions élargis, les complications peropératoires et postopératoires, le traitement et les résultats ont été recueillis. Résultats: Le taux global de complications associées à la lymphadénectomie ilio-sacrée métastatique était de 26,1 %. La seule complication peropératoire enregistrée était une hémorragie et a été rapportée dans 24 (17,6 %) chirurgies, dont 11 (45,8 %) ont reçu une transfusion sanguine. Des complications postopératoires ont été signalées dans 10,4 % des interventions chirurgicales et comprenaient la formation d'oedème (n = 4, 2,6 %), la paraparésie unilatérale ou bilatérale (n = 4, 2,6 %), l'hypotension (n = 3, 2,0 %), l'infection du site opératoire (n = 2, 1,3 %), la déhiscence de l'incision abdominale (n = 1, 0,6 %), l'incontinence urinaire (n = 1, 0,6 %) et le décès (n = 1, 0,6 %). La taille des ganglions ilio-sacrés était significativement associée à un risque accru de complications, d'hémorragie et à la nécessité d'une transfusion lors d'une lymphadénectomie pour un adénocarcinome métastatique des glandes apocrines des sacs anaux. Conclusion: Les complications associées à la lymphadénectomie ilio-sacrée pour l'adénocarcinome métastatique des glandes apocrines des sacs anaux sont relativement fréquentes et concernent principalement l'hémorragie. Ces complications sont significativement associées à la taille des ganglions lymphatiques métastatiques retirés. Pertinence clinique: Cette étude rétrospective fournit des informations au clinicien concernant les complications chirurgicales potentielles pour le retrait des ganglions lymphatiques ilio-sacrés métastatiques. Ces complications, bien que rares, peuvent être graves et doivent être discutées avec les propriétaires avant la chirurgie.(Traduit par Dr Serge Messier).

What Is Your Diagnosis?

In collaboration with the American College of Veterinary Radiology.

Clinical outcomes of thyroid tumours with concurrent epithelial and mesenchymal components in 14 dogs (2006-2020).

BACKGROUND: While rare, multiple individual case reports have described mixed thyroid tumours in dogs containing both epithelial and mesenchymal neoplastic components. OBJECTIVES: In this retrospective case series, we describe the clinical presentation, treatment and outcome of 14 dogs of canine thyroid tumours with concurrent mesenchymal and epithelial neoplastic populations. METHODS: Fourteen cases were retrospectively abstracted from nine institutions. Histopathologic samples and reports were collected from 10/14 dogs and reviewed by a single board-certified anatomic pathologist. RESULTS: All 14 dogs had curative-intent surgery to remove the thyroid neoplasm. The most common surgery performed was a unilateral thyroidectomy (10/14 dogs). Postoperatively, systemic therapy was administered in eight dogs. Six dogs developed local recurrence with a median time to loco-regional recurrence of 53 days. Ten dogs developed metastatic disease with the most common metastatic site being the lungs (6/10 dogs), with a median time to metastasis of 93 days. Ten dogs were euthanised due to locoregional or distant progression of their mixed thyroid neoplasm. The overall median survival time was 156 days (95%CI: 49-244). The median survival time for dogs treated with adjuvant therapy was 189 days (95%CI: 24-244), whereas dogs without adjuvant therapy had a median survival time of 156 days (95%CI: 35-upper limit could not be calculated; p = 0.62). CONCLUSION: The thyroid tumours with both mesenchymal and epithelial components in this small sample set were associated with a poor prognosis after surgical excision with or without adjunctive therapy.

Acellular fish skin grafts for the management of wounds in dogs and cats: 17 cases (2019-2021).

OBJECTIVE: To report the clinical outcomes of the use of acellular fish skin grafts (FSGs) for the management of complex soft tissue wounds of various etiologies in dogs and cats. ANIMALS: 13 dogs and 4 cats with complex wounds treated with FSGs between February 2019 and March 2021. PROCEDURES: Medical records were reviewed for information regarding cause, location, size of the wound, management techniques, complications, and clinical outcomes. RESULTS: In dogs, the number of FSG applications ranged from 1 to 4 (median, 2 graft applications). The time between each application ranged from 4 to 21 days (median, 9.5 days). Time to application of the first FSG ranged from 9 to 210 days (median, 19 days). Wounds closed by second-intention healing following the first fish skin application between 26 and 145 days (median, 71 days; n = 12). In cats, 1 or 2 FSGs were used, and the wounds of 3 of 4 cats healed completely by secondary intention. The wounds of 1 dog and 1 cat did not heal. There were no adverse events attributed to the use of the FSGs. CLINICAL RELEVANCE: For dogs and cats of the present study, complete healing of most wounds occurred with the use of FSGs, the application of which did not require special training, instruments, or bandage materials.

Collaborative Care Improves Treatment Outcomes for Dogs with Chronic Otitis Externa: A Collaborative Care Coalition Study.

The purpose of this retrospective study was to compare outcome measures in dogs treated by a primary care veterinarian (pcDVM) before referral and after seeking collaboration with a board-certified veterinary dermatologist (BCVD) for cases of severe recurrent chronic otitis externa. Medical records of 65 client-owned dogs were retrospectively reviewed, and data were obtained regarding treatment history, referral timeframe, recurrence rate, clinical signs, and resolution of signs. The median number of otitis recurrences while under the care of the pcDVM was 4 (range 1-40) versus collaborative BCVD care of 2 (P < .01). There was a longer median time to otitis recurrence with collaborative care (171 days) compared with dogs managed by the pcDVM before referral (21 days; P > .01). Proliferative changes in the ear canals improved in 41/45 (91%) of cases under BCVD care compared with 6/45 (13%) under care by the pcDVM (P < .01). Dogs with chronic otitis had better long-term outcomes when collaboration with a BCVD was pursued within 6 mo of treatment. Referral or consultation with a BCVD should be considered for cases of chronic canine otitis that are persistent or quickly recurrent (20-30 days) over a 6 mo period.

Oral Pharmacokinetics in Beagle Dogs of the Mitragynine Metabolite, 7-Hydroxymitragynine.

BACKGROUND AND OBJECTIVES: 7-Hydroxymitragynine (7-HMG) is an oxidative metabolite of mitragynine, the most abundant alkaloid in the leaves of Mitragyna speciosa (otherwise known as kratom). While mitragynine is a weak partial µ-opioid receptor (MOR) agonist, 7-HMG is a potent and full MOR agonist. It is produced from mitragynine by cytochrome P450 (CYP) 3A, a drug-metabolizing CYP isoform predominate in the liver that is also highly expressed in the intestine. Given the opioidergic potency of 7-HMG, a single oral dose pharmacokinetic and safety study of 7-HMG was performed in beagle dogs. METHODS: Following a single oral dose (1 mg/kg) of 7-HMG, plasma samples were obtained from healthy female beagle dogs. Concentrations of 7-HMG were determined using ultra-performance liquid chromatography coupled with a tandem mass spectrometer (UPLC-MS/MS). Pharmacokinetic parameters were calculated using a model-independent non-compartmental analysis of plasma concentration-time data. RESULTS: Absorption of 7-HMG was rapid, with a peak plasma concentration (Cmax, 56.4 ± 1.6 ng/ml) observed within 15 min post-dose. In contrast, 7-HMG elimination was slow, exhibiting a mono-exponential distribution and mean elimination half-life of 3.6 ± 0.5 h. Oral dosing of 1 mg/kg 7-HMG was well tolerated with no observed adverse events or significant changes to clinical laboratory tests. CONCLUSIONS: These results provide the first pharmacokinetic and safety data for 7-HMG in the dog and therefore contribute to the understanding of the putative pharmacologic role of 7-HMG resulting from an oral delivery of mitragynine from kratom.

Outcomes of dogs undergoing immediate or delayed surgical treatment for gastrointestinal foreign body obstruction: A retrospective study by the Society of Veterinary Soft Tissue Surgery.

OBJECTIVE: To evaluate gastrointestinal injury and outcomes between dogs treated with immediate surgical intervention vs those treated with delayed surgical intervention for gastrointestinal foreign body obstruction (GIFBO). STUDY DESIGN: Retrospective cohort study. SAMPLE POPULATION: Client-owned dogs (n = 855) from five referral hospitals. METHODS: Medical records of dogs in which GIFBO had been diagnosed between 2007 and 2017 were reviewed for preoperative management, timing of surgery, intraoperative findings, postoperative management, outcome, and survival. Surgical intervention was classified as immediate when it occurred within 6 hours of presentation and delayed when it occurred >6 hours after presentation. RESULTS: Outcomes did not differ between dogs treated immediately (n = 584) or over 6 hours after presentation (n = 210). Intestinal necrosis and perforations were more common when surgery was delayed (P = .008; P = .019) but became nonsignificant after controlling for preoperative differences. Risk factors for necrosis and perforations included duration of clinical signs, increased lactate, linear foreign material, and timing of surgery. Enterectomies (P = .004) as well as the duration of surgery (P = .004) and anesthesia (P = .001) were increased when surgery was delayed. Immediate surgery was associated with earlier return to feeding (P = .004) and discharge from the hospital (P < .001); (5%) dogs in each group (n = 33 immediate; n = 11 delayed) either had a negative explore or the foreign body was milked aborally into the colon at the time of surgery. CONCLUSION: Although outcomes were not associated with surgical timing, the unadjusted prevalence of gastrointestinal injury and, thus, the requirement for complex surgical procedures was higher in the delayed group. CLINICAL SIGNIFICANCE: Earlier surgical treatment of stabilized dogs with GIFBO may involve fewer complex procedures and accelerate recovery.

Pharmacokinetics and Safety of Mitragynine in Beagle Dogs.

Mitragynine is the most abundant psychoactive alkaloid derived from the leaves of Mitragyna speciosa (kratom), a tropical plant indigenous to regions of Southeast Asia. Mitragynine displays a moderate affinity to opioid receptors, and kratom is often self-prescribed to treat pain and/or opioid addiction. The purpose of this study was to investigate the safety and pharmacokinetic properties of mitragynine in the dog. Single dose oral (5 mg/kg) and intravenous (0.1 mg/kg) pharmacokinetic studies of mitragynine were performed in female beagle dogs. The plasma concentrations of mitragynine were measured using ultra-performance liquid chromatography coupled with a tandem mass spectrometer, and the pharmacokinetic properties were analyzed using non-compartmental analysis. Following intravenous administration, mitragynine showed a large volume of distribution (Vd, 6.3 ± 0.6 L/kg) and high clearance (Cl, 1.8 ± 0.4 L/h/kg). Following oral mitragynine dosing, first peak plasma (Cmax, 278.0 ± 47.4 ng/mL) concentrations were observed within 0.5 h. A potent mu-opioid receptor agonist and active metabolite of mitragynine, 7-hydroxymitragynine, was also observed with a Cmax of 31.5 ± 3.3 ng/mL and a Tmax of 1.7 ± 0.6 h in orally dosed dogs while its plasma concentrations were below the lower limit of quantification (1 ng/mL) for the intravenous study. The absolute oral bioavailability of mitragynine was 69.6%. Administration of mitragynine was well tolerated, although mild sedation and anxiolytic effects were observed. These results provide the first detailed pharmacokinetic information for mitragynine in a non-rodent species (the dog) and therefore also provide significant information for allometric scaling and dose predictions when designing clinical studies.

Pharmacokinetics of platinum and safety evaluation of carboplatin-impregnated calcium sulfate hemihydrate beads after implantation in healthy cats.

OBJECTIVE: To evaluate the pharmacokinetics (PK) of platinum (Pt) and safety of carboplatin-impregnated calcium sulfate hemihydrate (C-I CSH) beads after implantation in healthy cats. STUDY DESIGN: In vivo experimental study. ANIMALS: Six healthy adult cats. METHODS: Three C-I CSH beads were implanted in muscle pockets over the right and left hemithoraces of each cat (~3.9 mg/kg of Pt; 60.4 mg/m2 of calculated carboplatin). Hematology and blood chemistry were tested at baseline and 3, 7, 14, and 21 days postimplantation. Serum was analyzed for Pt at specific times from 1 hour to 21 days. Tissue was obtained for histopathology and analysis of Pt at 3, 7, 14, and 21 days at standardized distances from implantation sites. RESULTS: Platinum was detected in tissues at all times and distances (range, 0.1-4.19 µg/g). Serum Pt increased up to 2.6 hours (3.25 µg/mL) then decreased sharply. Samples containing muscle had higher Pt compared with samples without muscle (P = .004). Mild hypercalcemia was noted in four cats, and mild inflammatory reaction was noted on histopathology of all samples. CONCLUSION: Platinum was released from C-I CSH beads differentially into surrounding tissues over 21 days. Systemic absorption of Pt was minimal, but mild hypercalcemia occurred. CLINICAL SIGNIFICANCE: Implantation was well tolerated by healthy adult cats. Securing beads within muscle may limit Pt diffusion to targeted tissue. Although Pt concentrations did not achieve levels reported to be cytotoxic for feline sarcoma cells in culture, results provide evidence to support evaluation of efficacy in the tumor microenvironment of cats with locally invasive cancers.