OBJECTIVE To define learning curves for fourth-year veterinary students performing ovariohysterectomy procedures in dogs and cats and castration in dogs.
DESIGN Retrospective study.
SAMPLE 3,196 ovariohysterectomies or castrations performed in dogs and cats by 88 veterinary students during a spay-neuter surgery and animal shelter rotation (n = 3,056) or by 1 experienced general practitioner (n = 140).
PROCEDURES Data collected from medical records included patient signalment, type and duration of procedure, and sequence (by date and time) of the procedure within a list of procedures of the same type generated for each student. For each procedure type, geometric mean surgery time and 95% confidence intervals were determined for each number of surgeries completed by ≥ 10 students. Median surgery times for the same procedure types were determined for the experienced practitioner. The learning curve for each procedure was modeled with nonlinear (3-factor exponential equation with a nonzero asymptote) and linear regression. For each procedure, the asymptote (optimal surgery time) for students was compared with the experienced practitioner's median surgery time.
RESULTS 2,945 surgeries (mean, 33/student) performed by ≥ 10 students were analyzed. Surgery time decreased in a nonlinear manner as student experience increased for castration of adult or pediatric dogs and ovariohysterectomy of pediatric dogs and adult or pediatric cats. Surgery time decreased in a linear manner as experience increased for ovariohysterectomy of adult dogs.
CONCLUSIONS AND CLINICAL RELEVANCE To the authors' knowledge, this was the first study to map surgery times for common surgical procedures consecutively performed by veterinary students. Results clearly indicated the value of repetition to improve surgical skills (as measured by surgery time) during a 3-week period.
Objective—To report and compare the surgical site infection (SSI) rates for clean and clean-contaminated procedures performed by either a minimally invasive surgical or open surgical approach in a large population of dogs and cats.
Design—Prospective case series.
Animals—179 patients (dogs and cats) undergoing minimally invasive abdominal or thoracic surgery.
Procedures—Case information from all animals that underwent minimally invasive abdominal or thoracic surgery was prospectively collected and compared with an existing database of the same information collected from 379 patients undergoing laparotomy or thoracotomy via an open surgical approach. For both groups, an SSI was defined as any surgical wound in which purulent discharge was observed within 14 days after the procedure. Follow-up for all patients was obtained by direct examination or telephone interviews.
Results—Overall SSI rate in the minimally invasive surgery (MIS) group was 1.7% and in the open surgery (OS) group was 5.5%. On univariate analysis, there was a significantly lower SSI rate in the MIS group, compared with the SSI rate for the OS group. On multivariable logistic regression analysis, this difference appeared to be a result of the fact that surgery times were longer (median, 105 vs 75 minutes) and hair was clipped ≥ 4 hours prior to surgery for more animals (23% vs 11 %) in the OS group, compared with the MIS group.
Conclusions and Clinical Relevance—MIS may be associated with a lower SSI rate, compared with OS, but confounding factors such as differences in surgery time and preoperative preparation contributed in part to this finding. As such, surgical approach cannot be categorized as an independent risk factor for SSIs in small animals until further studies are performed.
Case Description—A 4-year-old spayed female Mastiff was evaluated for treatment of chronic nonhealing pressure wounds over both elbow regions resulting from attempts at hypertrophic callus excision.
Clinical Findings—The wound bed granulation tissue was mottled red and yellow with hyperemic, rolled epithelial edges. The right wound communicated with a large fluid pocket along the thoracic wall. The dog had an inflammatory leukogram with a left shift.
Treatment and Outcome—The wounds were debrided, and tissue specimens were collected for histologic evaluation, microbial culture, and bacterial identification by means of molecular diagnostic techniques. The left wound was closed immediately. Calcium alginate rope with silver was packed into the right wound. Vacuum-assisted closure was applied for 6 days. Debridement was repeated, and a thoracodorsal axial pattern flap was used to cover the wound. Systemic treatment with antimicrobials was initiated, and pressure over the elbow regions was relieved. Bacterial biofilms were identified histologically in tissue specimens from both wounds. Staphylococcus intermedius, Staphylococcus epidermidis, and Streptococcus canis were cultured and identified by 16S rRNA fragment sequencing. Pyrosequencing identified multiple bacterial species and no fungal organisms. Both wounds healed successfully.
Clinical Relevance—Biofilms are implicated in infected orthopedic implants in veterinary patients; however, this is the first report of a bacterial biofilm in chronic wounds in a dog. In human wound care, extensive debridement is performed to disrupt the biofilm; a multimodal treatment approach is recommended to delay reformation and help clear the infection. In this case, biofilm reformation was prevented by systemic treatment with antimicrobials, by reducing local pressure on the wounds, and by wound closure.
Objective—To evaluate a technique for minimally invasive excisional brain biopsy and intracranial brachytherapy catheter placement in dogs.
Animals—5 healthy adult female dogs.
Procedures—Computed tomographic guidance was used to plan a biopsy trajectory to a selected area of brain with reference to a localizer grid. The procedure was performed through a 1-cm skin incision and 6-mm burr hole by use of a 9-gauge biopsy device. Five cylindrical samples (3 to 4 mm in diameter and 7 to 12 mm in length) were removed over 5 cycles of the vacuum-assisted tissue excision system, leaving approximately a 2-cm3 resection cavity. A balloon-tipped intracranial brachytherapy catheter was placed through the burr hole into the resection cavity, expanded with saline (0.9% NaCl) solution, and explanted 7 days later.
Results—4 of 5 dogs survived the procedure. The fifth died because of iatrogenic brain damage. Neurologic deficits were unilateral and focal. Twenty-four hours after surgery, all surviving dogs were ambulatory, 2 dogs exhibited ipsiversive circling, 4 had contralateral proprioceptive deficits, 3 had contralateral menace response deficits, 2 had a reduced contralateral response to noxious nasal stimulation, and 1 had dull mentation with intermittent horizontal nystagmus and ventrolateral strabismus. Neurologic status improved throughout the study period. Histologic quality of biopsy specimens was excellent.
Conclusions and Clinical Relevance—This technique enabled histologic diagnosis from high-quality biopsy specimens obtained through a minimally invasive technique and has potential applications for multimodal treatment of deep brain tumors in dogs.
OBJECTIVE To determine the effects of 3 topically applied treatments (1% silver sulfadiazine cream [SSC], triple antimicrobial ointment [TAO], and hyperosmolar nanoemulsion [HNE]) on microbial counts, exuberant granulation tissue (EGT) development, and reepithelialization of contaminated wounds at the distal aspect of the limbs of horses.
ANIMALS 8 healthy adult horses.
PROCEDURES A 2.5 × 2.5-cm, full-thickness, cutaneous wound was created at the dorsal aspect of each metacarpus and metatarsus (1 wound/limb/horse), covered with nonadhesive dressing, and bandaged. Wounds were inoculated with bacteria and fungi the next day. Each wound on a given horse was randomly assigned to 1 of 4 treatment groups (SSC, TAO, HNE, or no topical treatment [control]). Bandage changes, culture of wound samples, treatments, photography for wound measurements, and biopsy were performed at predetermined time points. Time (days) until wound closure, number of EGT excisions, microbial counts, and scores for selected histologic characteristics were compared among groups.
RESULTS Median time to wound closure for all groups was 42 days. Time to wound closure and histologic characteristics of wound healing did not differ among groups. Least squares mean microbial counts were significantly higher for HNE-treated wounds on days 9 and 21, compared with SSC-treated and TAO-treated wounds, but not controls. Proportions of SSC-treated (7/8) or HNE-treated (5/8) wounds needing EGT excision were significantly greater than that of TAO-treated (1/8) wounds. The proportion of SSC-treated wounds with EGT excision was greater than that of controls (3/8).
CONCLUSIONS AND CLINICAL RELEVANCE None of the treatments resulted in more rapid wound closure, compared with that for untreated control wounds under the study conditions. When treatment is warranted, TAO may help to limit EGT formation.
Case Description—An 8-year-old 12.2-kg (26.9-lb) spayed female American Cocker Spaniel was referred for evaluation of abdominal discomfort and a suspected intra-abdominal lipoma with possible invasion into the thorax.
Clinical Findings—Physical examination revealed a tense abdomen, and the margins of a large abdominal mass could be appreciated. Abdominal imaging revealed a mass of fat opacity in the abdominal and thoracic cavities. Computed tomography with precontrast and postcontrast peritoneograms was used to determine whether the masses connected via a diaphragmatic defect.
Treatment and Outcome—Exploratory laparotomy revealed a retroperitoneal lipomatous mass that had focally invaded the hypaxial musculature and had extended across the dorsolateral aspect of the diaphragm via the lumbocostal trigone into the intrathoracic extrapleural space. Surgical resection required transdiaphragmatic thoracotomy. Histologic examination of excised tissue confirmed the preoperative diagnosis of a lipoma. The dog recovered from surgery with no complications and had no disease recurrence for at least 32 months after surgical resection.
Clinical Relevance—The defect of the lumbocostal trigone is also called the foramen of Bochdalek in humans, and it is recognized as a common location for congenital diaphragmatic hernia. A lumbocostal trigone hernia may be considered as a differential diagnosis for bicavitary masses in dogs, particularly in the absence of a history of trauma.
Procedures—Dogs were allocated to 3 groups (6 dogs/group) and were assigned to receive buprenorphine (20 μg/kg [9.09 μg/lb], IV; a low dose [20 μg/kg] via OTM administration [LOTM]; or a high dose [120 μg/kg [54.54 μg/lb] via OTM administration [HOTM]) immediately before anesthetic induction with propofol and maintenance with isoflurane for ovariohysterectomy. Postoperative pain was assessed by use of a dynamic interactive pain scale. Dogs were provided rescue analgesia when postoperative pain exceeded a predetermined threshold. Blood samples were collected, and liquid chromatography-electrospray ionization-tandem mass spectrometry was used to determine plasma concentrations of buprenorphine and its metabolites. Data were analyzed with an ANOVA.
Results—Body weight, surgical duration, propofol dose, isoflurane concentration, and cardiorespiratory variables did not differ significantly among treatment groups. Number of dogs requiring rescue analgesia did not differ significantly for the HOTM (1/6), IV (3/6), and LOTM (5/6) treatments. Similarly, mean ± SEM duration of analgesia did not differ significantly for the HOTM (20.3 ± 3.7 hours), IV (16.0 ± 3.8 hours), and LOTM (7.3 ± 3.3 hours) treatments. Plasma buprenorphine concentration was ≤ 0.60 ng/mL in 7 of 9 dogs requiring rescue analgesia.
Conclusions and Clinical Relevance—Buprenorphine (HOTM) given immediately before anesthetic induction can be an alternative for postoperative pain management in dogs undergoing ovariohysterectomy.
Objective—To assess the diagnostic utility of transurethral cystoscopic biopsy in dogs with histologically confirmed transitional cell carcinoma (TCC) of the urinary bladder and urethra.
Design—Retrospective case series.
Animals—92 dogs with histologically confirmed TCC.
Procedures—Information on sex, breed, neuter status, body weight, tumor location, biopsy method, number of biopsy procedures, experience level of clinician performing biopsy, and quality of biopsy sample was obtained from medical records. The association of variables with likelihood of achieving a diagnostic-quality biopsy sample was evaluated by use of logistic regression.
Results—If used as the initial biopsy method, cystoscopic biopsy samples were of diagnostic quality in 65% of male dogs and 96% of female dogs with histologically confirmed TCC. Cystoscopic biopsy samples were significantly more likely to be of diagnostic quality in female dogs than in male dogs.
Conclusions and Clinical Relevance—Cystoscopic biopsy is an effective method to obtain biopsy samples in dogs with TCC of the bladder and urethra. Cystoscopy is more likely to produce a diagnostic-quality biopsy sample in female dogs with TCC than in male dogs with TCC. Cystoscopy should be considered as a primary means of biopsy in male and female dogs with masses of the urinary bladder or urethra.
OBJECTIVE To compare time to achieve vascular access (TTVA) between an ultrasound-guided technique (UST) and landmark-based technique (LMT) for central venous catheter (CVC) placement in healthy anesthetized dogs.
ANIMALS 39 purpose-bred hounds.
PROCEDURES Anesthetized dogs that were hemodynamically stable following completion of a terminal surgical exercise were enrolled in the study during 2 phases, with a 45-day intermission between phases. For each dog, a UST and LMT were used for CVC placement via each external jugular vein by 2 operators (criticalist and resident). The TTVA and number of venipuncture attempts and catheter redirections were recorded for each catheterization. Placement of the CVC was confirmed by contrast fluoroscopy. After euthanasia, a gross dissection was performed during which a hematoma score was assigned to the catheter insertion site. For each phase, nonlinear least squares estimation was used for learning curve analysis of the UST.
RESULTS Median TTVA, number of venipuncture attempts and catheter redirections, and hematoma score did not differ significantly between the 2 operators for either technique. Median TTVA for the UST (45 seconds) was significantly longer than that for the LMT (7 seconds). Learning curve analysis indicated that 8 and 7 UST catheterizations were required to achieve performance stability in phases 1 and 2, respectively.
CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that the UST was comparable to the LMT for CVC placement in healthy dogs. The extra time required to perform the UST was not clinically relevant. Additional studies evaluating the UST for CVC placement in clinically ill dogs are warranted.