Use of a vessel-sealing device versus conventional hemostatic techniques in dogs undergoing thyroidectomy because of suspected thyroid carcinoma.

OBJECTIVE: To compare use of a vessel-sealing device (VSD) versus conventional hemostatic techniques in dogs undergoing thyroidectomy because of suspected thyroid carcinoma. DESIGN: Retrospective cohort study. ANIMALS: 42 client-owned dogs undergoing thyroidectomy because of suspected thyroid carcinoma. PROCEDURES: Medical records of dogs treated at 4 referral centers from 2010 through 2016 were reviewed, and information was obtained on patient signalment, surgical technique, tumor-specific factors, and operative duration. Postoperative hospitalization time and complications were compared between dogs grouped on the basis of hemostatic technique. RESULTS: Thyroidectomy was performed with a VSD in 23 dogs and with conventional hemostatic techniques (ie, ligatures, hemoclips, or electrocautery) in 19 dogs. Hemostatic technique (ie, use of a VSD vs conventional hemostatic techniques) was the only factor significantly associated with operative duration (median time, 28 vs 41 minutes). Postoperative hospitalization times and complication rates did not differ between groups. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that use of a VSD, rather than conventional hemostatic techniques, in dogs undergoing thyroidectomy because of suspected thyroid carcinoma resulted in shorter operative times without significantly affecting complication rates or postoperative hospitalization times.

Short- and long-term outcomes after shoulder excision arthroplasty in 7 small breed dogs.

This study reports short- and long-term clinical outcomes following excision arthroplasty in 7 small breed dogs with shoulder pathology. Lameness and pain were scored before surgery, and reassessed at short- and long-term follow-ups with measurements of range of motion (ROM), scapulo-humeral angles of extension (EA) and flexion (FA), and muscle girth (MG) of the operated and contralateral limbs. All dogs improved clinically for lameness and pain. Range of motion, EA, and FA of the operated limb were not significantly different compared with the contralateral limb at short-term follow-up, but ROM and EA were significantly decreased at long-term examination. Muscle girth was not significantly different than the contralateral limb. Radiographic re-evaluations showed bony proliferation around osteotomies without interosseous union in most dogs and all owners were satisfied with the surgery outcome. Excision arthroplasty seems to be an effective treatment for chronic shoulder pathologies in small dogs. Range of motion and EA were decreased and a mild lameness remained present at long-term follow-up.

Évolution à court et à long terme suite à une arthroplastie d'épaule chez sept chiens de petite race. Cette étude rapporte l'évolution clinique à court et long terme suite à une arthroplastie d'excision chez sept chiens de petite race avec des anomalies de l'épaule. Les degrés de boiterie et de douleur ont été évalués avant la chirurgie et réévalués à court et à long terme avec l'amplitude de mouvement (ADM), les angles d'extension (AE) et de flexion (AF) de l'épaule, et le périmètre musculaire (PM) du membre opéré et du membre controlatéral. Tous les chiens se sont améliorés cliniquement concernant la boiterie et la douleur. Il n'y avait pas de différence significative entre l'ADM, AE et AF du membre opéré par rapport au membre controlatéral à court terme, par contre l'ADM et l'AE étaient significativement réduits à long terme. Le PM n'a pas changé de façon significative comparativement au membre controlatéral. Les réévaluations radiographiques ont montré une prolifération osseuse le long des traits d'ostéotomie sans évidence d'union interosseuse sur la majorité des chiens et tous les propriétaires ont été satisfaits du résultat de la chirurgie. L'arthroplastie d'excision semble être un traitement efficace des pathologies chroniques de l'épaule chez les petits chiens. Une diminution de l'ADM et l'AE et une légère boiterie restaient présents à long terme.(Traduit par les auteurs).

Comparative outcomes between ameroid ring constrictor and cellophane banding for treatment of single congenital extrahepatic portosystemic shunts in 49 dogs (1998-2012).

OBJECTIVE: To compare outcomes and identify prognostic factors in dogs with single congenital extrahepatic portosystemic shunt (CEHPSS) gradually attenuated with an ameroid ring constrictor (ARC) or cellophane banding (CB). STUDY DESIGN: Retrospective, multi-institutional study. ANIMALS: Forty-nine dogs with CEHPSS (n = 23 for ARC; n = 26 for CB). METHODS: Medical records of dogs with CEHPSS treated by ARC or CB were reviewed for postoperative (<1 month), midterm (1-6 months), and long-term (> 6 months) outcomes. Data were evaluated to detect factors associated with postoperative complications, residual shunting, and long-term outcome. RESULTS: Postoperative complication rates did not differ between ARC (26.1%) and CB (23.1%, P = .89) and were negatively associated with body weight (P = .03). Overall, postoperative mortality was low (2.0%). Clinical long-term outcome was excellent in 45.0% and 39.1% and good in 55.0% and 60.9% of dogs after ARC and CB, respectively. Suspected residual shunting rate upon abdominal ultrasonography was greater after CB (31.6%) than after ARC (0%). CONCLUSION: ARC and CB were both effective for attenuation of CEHPSS, resulting in good to excellent outcomes with low morbidity and mortality. Residual shunting was suspected in a higher proportion of dogs treated with CB on the basis of abdominal ultrasonography results. However, further prospective randomized studies must be conducted with validated evaluation methods to verify this assumption.

Mechanical evaluation of hydrogen peroxide gas plasma sterilization of nylon lines used for extra-articular stabilization of the canine stifle joint.

OBJECTIVE: To compare the effects of hydrogen peroxide gas plasma (HPGP) and ethylene oxide (EO) sterilizations on the mechanical properties of nylon lines used for stabilization of the canine stifle. Secondarily, to compare the performance of crimped and knotted lines. STUDY DESIGN: In vitro mechanical evaluation. SAMPLE POPULATION: Nonsterilized, EO- and HPGP-sterilized specimens of 36.3 kg test nylon leader line (NLL) and 57.8 kg test nylon fishing line (NFL). METHODS: Single strands and looped specimens of NLL or NFL were positioned on a material testing machine. To create looped specimens, NLL were crimped using the Securos system, and NFL were knotted, as used clinically. Elongation (%) and ultimate load (N) variables were studied. RESULTS: Elongation and ultimate load of NLL groups were not significantly different between EO and HPGP. For NFL, HPGP sterilization led to slightly greater elongation than EO in loops only. Ultimate load of NFL single strands was not significantly different between EO and HPGP, but was higher after HPGP compared with EO in NFL loops. All NLL groups had less elongation and ultimate load than NFL. CONCLUSION: The effects of HPGP on NLL compared positively to EO, making HPGP an attractive alternative. As HPGP led to a slightly greater elongation of NFL than EO, the latter could be favored to sterilize NFL. Crimped NLL minimized elongation better than knotted NFL. CLINICAL RELEVANCE: Sterilization with HPGP seems a good alternative to EO for NLL. EO may be a better choice for NFL; however, it is difficult to judge the clinical relevance of this result. Crimped NLL minimizes elongation and may help reducing the recurrence of stifle instability postoperatively.

A mouse surgical model for metastatic ovarian granulosa cell tumor.

We recently described a genetically engineered mouse model that develops ovarian granulosa cell tumors (GCTs) that mimic many aspects of the advanced human disease, including distant dissemination. However, because the primary tumors killed their hosts before metastases were able to form, the use of these mice to study metastatic disease required the development of a simple, reliable, and humane surgical protocol for the excision of large GCTs from debilitated mice. Here we describe a protocol involving multimodal anesthesia, tumor removal through ventral midline celiotomy and perioperative fluid therapy, and analgesia that led to the postoperative survival of more than 90% of mice, despite the removal of tumors representing as much as 10% of the animal's body weight. Intraabdominal recurrence of the GCT did not occur in surviving animals, but most developed pulmonary or adrenal metastases (or both) by 12 wk after surgery. We propose that this mouse model of metastatic GCT will serve as a useful preclinical model for the development of novel treatment modalities and diagnostic techniques. Furthermore, our results delineate anesthetic and surgical principles for the removal of large abdominal tumors from mice that will be applicable to other models of human cancers.

Comparison of the selection of antimicrobial resistance in fecal Escherichia coli during enrofloxacin administration with a local drug delivery system or with intramuscular injections in a swine model.

This study evaluated, for the first time, the selection of antibiotic resistance in fecal Escherichia coli, a potential reservoir of genes of resistance, during the prolonged exposure to fluoroquinolones after the implantation of a local drug delivery system (LDDS) in a swine model. Fourteen pigs were randomly assigned to group IM (5 mg/kg/day of intramuscular enrofloxacin--EFX) or LD (surgical implantation of EFX-polymethyl-methacrylate peri-femoral implants). Blood samples were collected daily for determination of plasma EFX and ciprofloxacin (CFX) concentrations. Fecal samples were collected daily to determine the E. coli counts and the susceptibility patterns of its isolates as evaluated by antibiotic disk diffusion tests. In both groups, EFX administration significantly reduced the bacterial counts after 2 days. During recolonization, the bacterial counts remained lower than baseline in group IM but not significantly, and almost reached pre-treatment levels in group LD. Susceptibility to EFX, CFX, and nalidixic acid of recolonizing E. coli in LD pigs slightly decreased but remained within the limit of "susceptible" isolates. In contrast, quinolone susceptibility of recolonizing E. coli in IM pigs dropped dramatically (P < 0.0001). In addition, intramuscular exposure to fluoroquinolones significantly decreased the susceptibility of E. coli to ampicillin and trimethoprim-sulfamethoxazole (P < 0.05). In conclusion, the use of a dosing regimen that minimized the intestinal output of fluoroquinolones also minimized the selection of resistance to several classes of antibiotics. This could represent another advantage of LDDS usage compared to long-lasting systemic administration of fluoroquinolones.

Synergistic effects of Pten loss and WNT/CTNNB1 signaling pathway activation in ovarian granulosa cell tumor development and progression.

The mechanisms of granulosa cell tumor (GCT) development may involve the dysregulation of signaling pathways downstream of follicle-stimulating hormone, including the phosphoinosite-3 kinase (PI3K)/AKT pathway. To test this hypothesis, a genetically engineered mouse model was created to derepress the PI3K/AKT pathway in granulosa cells by conditional targeting of the PI3K antagonist gene Pten (Pten(flox/flox);Amhr2(cre/+)). The majority of Pten(flox/flox);Amhr2(cre/+) mice featured no ovarian anomalies, but occasionally ( approximately 7%) developed aggressive, anaplastic GCT with pulmonary metastases. The expression of the PI3K/AKT downstream effector FOXO1 was abrogated in Pten(flox/flox);Amhr2(cre/+) GCT, indicating a mechanism by which GCT cells may increase proliferation and evade apoptosis. To relate these findings to spontaneously occurring GCT, analyses of PTEN and phospho-AKT expression were performed on human and equine tumors. Although PTEN loss was not detected, many GCT (2/5 human, 7/17 equine) featured abnormal nuclear or perinuclear localization of phospho-AKT, suggestive of altered PI3K/AKT activity. As inappropriate activation of WNT/CTNNB1 signaling causes late-onset GCT development and cross talk between the PI3K/AKT and WNT/CTNNB1 pathways has been reported, we tested whether these pathways could synergize in GCT. Activation of both the PI3K/AKT and WNT/CTNNB1 pathways in the granulosa cells of a mouse model (Pten(flox/flox);Ctnnb1(flox(ex3)/+);Amhr2(cre/+)) resulted in the development of GCT similar to those observed in Pten(flox/flox);Amhr2(cre/+) mice, but with 100% penetrance, perinatal onset, extremely rapid growth and the ability to spread by seeding into the abdominal cavity. These data indicate a synergistic effect of dysregulated PI3K/AKT and WNT/CTNNB1 signaling in the development and progression of GCT and provide the first animal models for metastatic GCT.

Magnetic resonance imaging and marsupialization of a hemorrhagic intramedullary vascular anomaly in the cervical portion of the spinal cord of a dog.

CASE DESCRIPTION: A 1-year-old female spayed Labrador Retriever was admitted for evaluation of a progressive gait disturbance characterized by tetraparesis and general proprioceptive ataxia in all limbs. CLINICAL FINDINGS: Neurologic examination suggested a dysfunction of the C6-T2 spinal cord segments, which was slightly worse on the right side. Discomfort was suspected upon lateral flexion of the neck. Two magnetic resonance imaging (MRI) examinations at a 3-week interval revealed an intramedullary fluid-filled cavitary lesion adjacent to C7, containing a blood clot. TREATMENT AND OUTCOME: Following unsuccessful initial conservative management, surgical marsupialization of the lesion was performed through a dorsal laminectomy, durotomy, and myelotomy at C6 and C7. Histologic evaluation including immunohistochemistry was diagnostic for a vascular anomaly. Initially, the dog was nonambulatory with tetraparesis and became tetraplegic after surgery; movement was regained 6 days later. Four weeks after the procedure, the dog was able to walk unassisted. One year after surgery, the dog was actively running and jumping, with mild residual ataxia in the pelvic limbs. CLINICAL RELEVANCE: The intramedullary vascular anomaly in this dog was successfully treated with a surgical marsupialization technique. The combination of MRI, histologic evaluation, and immunohistochemistry enabled lesion localization, evaluation of cavity content, and final diagnosis.

Imaging diagnosis--Complex intrahepatic portosystemic shunt in a dog.

An unusual form of congenital intrahepatic portosystemic shunt was identified in a 3 1/2-month-old female Labrador Retriever with neurologic signs. Ultrasonography and contrast-enhanced computed tomography were used to characterize the shunt morphology. An unusual, looping right-divisional shunt connected back to the portal vein that formed an ampula in the right-central portion of the liver. An irregularly shaped window-like opening connected the combined right-divisional loop and aneurysmal portal vein, and the caudal vena cava, while this vascular pool gradually fused more cranially. Imaging features of this complex vascular anomaly, which has not been previously reported, are presented.

[Fibrocartilaginous embolic myelopathy in dogs: a retrospective study]. / L'embolie fibrocartilagineuse chez le chien : une etude rétrospective.

The clinical aspects of 26 dogs suspected of fibrocartilaginous embolic myelopathy (FEM) were documented and compared to results from 2 studies published in the literature. The short-term recovery capacity of 15 of these patients was also evaluated during a 30 day period by giving a neurological score. We have observed, compared to other studies, a larger proportion of cervical localization (15.4%) as well as a larger variety of race sizes for FEM. We have established that, after 30 days, 67% of patients had improved and that 88% of non-ambulatory patients had regained their ambulatory capacity. Also, patients showing signs of grey matter lesions (inferior motor neuron--IMN) as well as those having white matter lesions (superior motor neuron--SMN) had shown signs of neurological progress. Therefore, we have observed that the recovery capacity of an animal suffering from FEM does not seem to be impacted by its initial ambulatory state, nor by its lesions to IMN or SMN, although the low number of cases does not allow us to positively confirm this situation.

Prevention and treatment of experimental osteomyelitis in dogs with ciprofloxacin-loaded crosslinked high amylose starch implants.

Crosslinked high amylose starch (CLHAS) matrix was used as a biodegradable drug delivery implant for the prevention and treatment of osteomyelitis. Thirty-two dogs underwent the femoral insertion of a screw inoculated with Staphylococcus aureus and were then randomly assigned to four groups: (A) prevention with ciprofloxacin-CLHAS implants, (B) surgical debridement (positive control), (C) surgical debridement and oral ciprofloxacin treatment and (D) surgical debridement and treatment with ciprofloxacin-CLHAS implants. At week 4 the osteomyelitis was confirmed, the infected site debrided and respective treatments initiated for groups B, C and D. Radiographs, macroscopic evaluations, bacterial cultures and histopathological examinations were used to evaluate the femora at week 10. Femora from preventive group A were almost normal. Dogs of both ciprofloxacin treatment groups C and D showed better bone healing, less periosteal reaction and less screw mobility than dogs from group B. Eradication of infection was observed at proximal/distal sites in B: 25%/12%, C: 37%/62% and D: 62%/75%. Both ciprofloxacin treated groups improved radiographically from week 4 to week 10. Periosteal and marrow neutrophilic and lymphoplasmocytic infiltrations were less severe in groups C and D versus group B. These data suggest that biodegradable ciprofloxacin-CLHAS implants are a safe and efficient modality for the prevention and treatment of osteomyelitis.