JAAHA 56.4 Abstracts

ORIGINAL STUDIES

Development of a Training Program for Law Enforcement K9 Handlers to Administer Naloxone

Ashley Mitek, Maureen McMichael, Brad Weir, Michael Smith, Danielle Schneider, David Schaefer

As the opioid epidemic continues across the United States, law enforcement K9s (LEK9s) are at increased risk of accidental exposure and overdose. This study evaluated a novel training program teaching handlers to administer naloxone to their LEK9 in the event of an overdose. Seventy-five LEK9 handlers from a governmental agency attended a naloxone training session. A presurvey given to the handlers evaluated their knowledge of opioid overdose in LEK9s and their confidence administering naloxone. Officers were educated via a PowerPoint presentation about naloxone and how to administer it to their LEK9. A postsurvey evaluated changes in their knowledge and confidence as a result of the presentation. Sixty-two presurveys and 47 postsurveys were completed. Nearly all handlers had never given their LEK9 an intramuscular or intranasal injection. Most handlers were not comfortable monitoring their LEK9’s vital signs for an opioid overdose. After the training, handlers demonstrated a mild increase in comfort level administering intramuscular and intranasal naloxone (15 and 14% increase, respectively). Comfort level monitoring vital signs and symptoms of an opioid overdose increased 38 and 32%, respectively. Handlers may not be fully prepared to assess and treat their LEK9 and may benefit from a targeted training program teaching them to administer naloxone. This article is available for nonsubscirbers

ORIGINAL STUDIES

Dose-Escalation and Pharmacokinetic Study Following a Single Dose of Oxaliplatin in Cancer-Bearing Dogs

Shawna Klahn, Nikolaos Dervisis, Daniel L. Gustafson, Jonathan Abbott

Oxaliplatin is more potent than cisplatin, lacks cross-resistance to other platinum agents, and has a favorable toxicity profile. This study’s objective was to define the maximally tolerated dose and the dose-limiting toxicity (DLT) of oxaliplatin in cancer-bearing dogs. This was a prospective, single-patient-cohort, dose-escalation study of oxaliplatin in client-owned dogs with confirmed, spontaneous malignancy. A single infusion was administered; the starting dose was 50 mg/m², with 10 mg/m² escalation-increments if no DLT was documented, up to a maximum dose of 140 mg/m². Plasma total platinum was measured at multiple timepoints and patients were monitored weekly. Ten dogs were enrolled in single-patient-cohort treatment levels up to the maximum level of 140 mg/m². There were no DLTs, and the maximally tolerated dose was not determined. The area under the curve_{0–7 days} for 100–140 mg/m² ranged from 77,850 to 82,860 ng/mL × hr; the area under the curve_{0–4 hr} for 50–140 mg/m² was linear with dose (r2 = 0.639, P = .0055). The data suggest a single infusion of oxaliplatin is well tolerated in cancer-bearing dogs up to 140 mg/m². There was good correlation between exposure and dose, while achieving plasma levels similar to therapeutic levels documented in humans. Read the full article

RETROSPECTIVE STUDIES

Prognostic Indicators and Clinical Outcome in Dogs with Subcutaneous Mast Cell Tumors Treated with Surgery Alone: 43 Cases

Virginia Gill, Nicole Leibman, Sebastien Monette, Diane M. Craft, Philip J. Bergman

The purpose of this study was to determine if clinical findings, histologic grade, or other histologic features were associated with clinical outcome in dogs with subcutaneous mast cell tumors (MCTs). Medical records of 43 client-owned dogs were retrospectively reviewed, and follow-up information was gathered via phone or follow-up examination. Progression-free survival (PFS), disease-free interval (DFI), and overall survival were calculated. Forty-two and twenty-two dogs, respectively, had grade 2 (Patnaik grading system) or low-grade tumors (two-tier grading system). Median PFS was 1,474 days. Median DFI was not reached at >1,968 days. Overall median survival time was not reached at >1,968 days. In univariate analysis, argyrophilic nucleolar organizer regions (AgNORs), proliferating cell nuclear antigen, and mitotic index were negatively prognostic for PFS whereas Ki-67, proliferating cell nuclear antigen, and microvessel density were negatively prognostic for DFI. In multivariate analysis, AgNORs remained negatively prognostic for PFS. Results suggest that proliferation indices, especially AgNORs, may be useful in predicting the rare poor outcomes in dogs with subcutaneous MCTs. The vast majority of subcutaneous MCTs appear to be low or intermediate grade with excellent outcomes from good local tumor control. Read the full article

CASE REPORTS

Lamotrigine Toxicosis Treated with Intravenous Lipid Emulsion Therapy in a Dog

Simon P. Hagley, Steven E. Epstein, Joshua A. Stern, Robert Poppenga

A female spayed dachshund/mixed-breed dog was evaluated following ingestion of lamotrigine tablets with subsequent rapid onset of vomiting, diarrhea, and generalized tremoring. On initial examination, the dog was moderately obtunded and nonambulatory with intermittent myoclonus and hyperesthesia. Electrocardiogram revealed sinus tachycardia with prolongation of the QT interval. Intravenous lipid emulsion (ILE) infusion was initiated, with reduction in tremoring and improved patient mentation being noted after approximately 20 min of therapy. An elevated cardiac troponin I value measured at 1.02 ng/mL the day after presentation. Serum toxicological assay revealed marked reduction in serum lamotrigine levels following ILE and continued reduction during hospitalization. The dog’s clinical signs resolved, corrected QT interval returned to normal, and the patient was discharged 38 hr after presentation. Individual cases of lamotrigine toxicosis have not been fully reported in veterinary literature. This case report documents the rapid onset of clinical signs including neurologic dysfunction, cardiac arrhythmias, and transient corrected QT prolongation. Serial serum concentrations of lamotrigine showed a rapid reduction with ILE therapy and corresponded with clinical recovery, suggesting efficacy of ILE treatment in this case. Read the full article

CASE REPORTS

Successful Treatment of Urinary Bladder Hemangiosarcoma by Partial Cystectomy in a Dog

Sarah Townsend, Penny J. Regier, Sunil N. More

A 6 yr old neutered male German shepherd dog was evaluated at a veterinary referral hospital following diagnosis of uroabdomen of unknown origin. A positive-contrast retrograde urethrogram identified diffusely irregular margins of the urinary bladder but no active leakage of urine into the peritoneal cavity. An abdominal ultrasound identified severe thickening and loss of wall layering of the apex of the bladder. The dog was initially managed with an indwelling urinary catheter; however, when the catheter was removed 5 days later, the dog developed a recurrent uroabdomen after an episode of dysuria. Subsequent surgical exploration identified numerous (>5), small (1–2 cm), black cyst-like nodules within the bladder wall at the apex of the bladder. A partial cystectomy, removing approximately 65% of the cranial bladder, was performed. Histopathology and immunohistochemistry of the bladder identified hemangiosarcoma of the bladder wall with chronic neutrophilic and hemorrhagic cystitis. The dog recovered from surgery without major complication and is still alive 9 mo following surgery. To the authors’ knowledge, this is the first report of successful treatment of canine bladder hemangiosarcoma by partial cystectomy in a dog. Read the full article

CASE REPORTS

Caudal Auricular Axial Pattern Flap for the Reconstruction of the Upper Eyelid in Three Cats

Sara Del Magno, Paludi Giuseppe, Guido Pisani, Emanuela Morello, Lisa Adele Piras, Paolo Buracco, Marina Martano

Three cats bearing malignant tumors (two squamous cell carcinomas and one peripheral nerve sheath tumor) affecting the upper eyelid (UE) were treated by en bloc tumor removal. A caudal auricular axial pattern flap was used for reconstruction, and its margin was sutured to only the medial and lateral canthus in two cats; in the third cat, a narrow strip of spared conjunctiva was sutured to the flap margin. Postoperatively, superficial corneal ulcers occurred in two cats, but they healed with topical treatment. Apart from a reduced ability to blink, no further functional deficits persisted, and the long-term cosmetic appearance was considered satisfactory by the owners. Tumor-free excisional margins were achieved in two cases. Tumor recurrence in the long-term was observed for two cats, 350 and 380 days after surgery, one of whom had excisional noninfiltrated margins on histologic examination. UE reconstruction to preserve eyelid function following tumor excision without exenteration is challenging. In selected cases, caudal auricular axial pattern flap is one of the surgical options available to reconstruct the defect resulting from en bloc UE removal without any replacement of the mucosal layer. Read the full article

CASE REPORTS

Kidney-Sparing Surgery for Renal Subcapsular Abscess Caused by Staphylococcus pseudintermedius in a Dog

Veronica Cola, Armando Foglia, Luciano Pisoni, Francesco Dondi, Giancarlo Avallone, Marta Gruarin, Stefano Zanardi, Riccardo Rinnovati, Sara Del Magno

An 11 yr old male Drahthaar dog was presented for dysuria, pollakiuria, and history of uroliths. Abdominal ultrasound revealed a subcapsular fluid-filled lesion of the left kidney, suspected cholecystitis, and a splenic infarct. The renal lesion was fully drained and cytology of the renal subcapsular and perirenal fluids revealed septic exudate. Bacterial culture of the urine, bile, and perirenal and subcapsular fluids were all positive for Staphylococcus pseudintermedius. Antimicrobial therapy was instituted based on culture sensitivity. After 7 days the dog re-presented for vomiting and abdominal pain, and a focal intestinal injury was suspected based on abdominal ultrasound. Enterectomy of an ischemic jejunal loop, a partial splenectomy, and excision of the left renal subcapsular abscess were performed. The renal parenchyma was left intact. Histopathology confirmed the diagnosis of a renal subcapsular abscess, intestinal infarction, and focal pyogranulomatous splenitis. Cholecystitis was confirmed by bile cytology and culture. No major complications and no recurrences were encountered at 1 yr follow-up. This is the first report of a renal subcapsular abscess in the dog, with septic complications, and treated with a kidney-sparing surgery. Read the full article

ONLINE CASE REPORTS

Surgical Treatment of Suspected Meningioangiomatosis in the Thoracolumbar Spinal Cord

Marie Christine Dantio, Amanda J. Dennis, Robert L. Bergman

A 5 yr old male neutered Labrador retriever was evaluated for an 8 wk history of a slowly progressive abnormal hind limb gait that did not respond to treatment with nonsteroidal anti-inflammatories. Initial examination findings were mild pelvic limb ataxia and moderate right pelvic limb lameness. A computed tomography with a myelogram was performed and showed a suspected intramedullary spinal mass. MRI was conducted and supported the computed tomography with myelogram findings of a possible intradural spinal mass at L1. A left-sided hemilaminectomy followed by a durotomy at L1 was performed and a firm, tan mass was removed. The histopathologic findings indicated a vascular proliferation most suggestive of a rare proliferative disorder of leptomeningeal blood vessels termed meningioangiomatosis. Although the dog’s signs initially worsened after surgery and he was nonambulatory with marked paraparesis, he regained ambulation within 3–4 wk after the operation. Eighteen months after surgery, he was ambulatory with mild hind limb ataxia with no progression of signs. This case suggests that surgical resection of lesions of suspected meningioangiomatosis can result in improvement of clinical signs with a good long-term prognosis. Read the full article

ONLINE CASE REPORTS

Effect of Midazolam on Vestibular Signs in Two Geriatric Dogs with Vestibular Disease

Min Jang, F. A. Mann, Alex Bukoski, John R. Dodam, Inhyung Lee

An abrupt balance impairment, including leaning, falling, and rolling, occurred after IV administration of 0.2 mg/kg midazolam as a preanesthetic medication in two geriatric dogs with a history of nystagmus and head tilt. In the second case, leaning, falling, and rolling recurred after recovery from general anesthesia but gradually ceased after IV administration of 0.01 mg/kg flumazenil. These two cases suggest that the IV administration of midazolam was responsible for the balance impairment in dogs who were suspected to have idiopathic peripheral vestibular disease. Read the full article