Prevalence of Urinary Tract Infection in Dogs after Surgery for Thoracolumbar Intervertebral Disc Extrusion

Background: Urinary tract infection (UTI) is a common complication in people with spinal cord injury (SCI). Dogs with acute intervertebral disc extrusion (IVDE) have similar risk factors for UTI when compared with human SCI patients and have a high perioperative prevalence of UTI. Objectives: Determine the prevalence of UTI in dogs for 3 months after surgery for thoracolumbar IVDE and identify risk factors for development of UTI. Animals: Twenty‐five dogs treated surgically for 26 acute disc extrusions. Methods: Prospective study. Urinalysis and urine culture were performed perioperatively. At home, owners monitored urine with dipsticks every 48 hours for 1 month then once a week until 3 months. Dogs returned for assessment of motor function, urinalysis, and urine culture at 1 and 3 months after surgery. Presence of UTI over the 3‐month period was correlated to potential risk factors. Results: Ten dogs (38%) developed 12 UTIs over the 3‐month period, with the majority occurring between weeks 1 and 6; 60% of the UTIs were occult. Hematuria in the absence of pyuria or UTI was a common finding in the perioperative period. Sex, breed, and ambulatory status influenced the risk of developing a UTI. Conclusions and Clinical Importance: There is a high prevalence of UTIs, many of which are occult, in the 3 months after surgery for thoracolumbar IVDE. These dogs should be routinely monitored for UTI with urine culture regardless of urinalysis results.     

Surgical Decompression in Dogs with Thoracolumbar Intervertebral Disc Disease and Loss of Deep Pain Perception: A Retrospective Study of 46 Cases

The case details and outcome after surgical decompression of 46 dogs with thoracolumbar intervertebral disc disease with loss of deep pain perception prior to surgery were reviewed. Nineteen dogs (41.3%) recovered with a median follow-up period of 12.5 months. Recovery was defined as an ambulatory paraparesis, or better, with urinary and fecal continence. There was a better outcome in dogs with loss of deep pain for less than 24 hours prior to surgery (19/41; 46.3% recovered) than in dogs without deep pain perception for more than 24 hours (0/5; 0% recovered). Dogs with deep pain perception present at two weeks postoperatively had significantly higher success rate (8/12; 66.7% recovered) than dogs without deep pain perception at this time period (1/10; 10.0% recovered). The return of deep pain perception by two weeks postoperatively can be a useful positive prognostic indicator.     

Magnetic Motor Evoked Potentials for Assessing Spinal Cord Integrity in Dogs with Intervertebral Disc Disease

Magnetically elicited transcranial motor evoked potentials (MEPs) were studied in 37 dogs with type 1 intervertebral disc (IVD) disease. The waveforms were recorded from both cranial tibial muscles before and after surgery. The latencies and amplitudes obtained were compared to those of a control population (n = 14). MEPs were recordable in all dogs with mild or no neurologic deficits, but they were recordable in only 50% of ambulatory dogs that were severely ataxic. MEPs could not be elicited from nonambulatory dogs. There was a significant attenuation of the amplitudes in all clinical cases, even if the dogs demonstrated back pain alone. Significantly prolonged latencies were associated with neurologic deficits. MEPs were not good predictors of neurologic recovery. The responses obtained from the side where the disc material was found were not different from those recorded from the opposite side. MEPs were very sensitive to lesions of the spinal cord, as indicated by the significant changes in the waves in patients with mild or no neurologic deficits and in the loss of response in dogs that still demonstrated purposeful movement. Neurologic exams provided more accurate diagnoses and prognoses than did MEPs in dogs with IVD disease.     

Distraction–Fusion for Caudal Cervical Spondylomyelopathy Using an Intervertebral Cage and Locking Plates in 14 Dogs

Objective: To evaluate clinical and radiographic outcome in dogs with caudal cervical spondylomyelopathy (CCSM) treated with an intervertebral fusion cage and locking plates. Study Design: Prospective clinical study. Animals: Large breed dogs (n=14) with CCSM. Methods: Dogs had single level cervical spine distraction/fusion performed using an intervertebral cage with a hollow center filled with cancellous autograft and 2 ventrally applied locking plates. Outcome was measured using neurologic scores and radiographic interpretation 6 weeks, 6 months, and 12 months postoperatively. Results: The surgical procedure was well tolerated in all dogs. Final outcome at 12 months was available in 9 dogs. Five dogs were judged excellent, 1 dog was good, 2 dogs were satisfactory, and 2 dogs were poor because of adjacent segment disease. Four dogs died for reasons unrelated to the procedure. Radiographically, implants remained stable over the entire follow‐up period. The disc space continued to fill with an immature pattern of new bone, which showed progressive increase in opacity and quantity. Subsidence of the cage (median 2 mm) was detected in 9 dogs at 6 weeks and remained unchanged in those that could be followed further. Conclusion: Distraction–fusion of single level CCSM in dogs with a combination of intervertebral cage and ventral locking plates is clinically effective and results in successful bony fusion.     

Urinary Tract Infection in Dogs with Thoracolumbar Intervertebral Disc Herniation and Urinary Bladder Dysfunction Managed by Manual Expression,Indwelling Catheterization or Intermittent Catheterization

Objective— To evaluate risk factors for lower urinary tract infection (UTI) in dogs with intervertebral disc disease (IVDD) that had manual expression (ME), indwelling catheterization (IDC) or intermittent catheterization (ITC) for urinary bladder management. Study Design— Randomized‐clinical trial. Animals— Dogs (n=62) treated with urinary bladder dysfunction requiring surgery for IVDD and control dogs (n=30) that had surgery for reasons other than IVDD. Methods— Treated dogs were randomly assigned to ME, IDC, or ITC. Urine was collected for culture and antimicrobial susceptibility testing before and after treatment. Incidence and risk factors for UTI were evaluated. Bacterial isolates and antimicrobial resistance patterns were described. Results— Mean (±SD) time to urination was significantly longer for IDC dogs (7.4±2.75 days) than ME dogs (4.2±2.63) and ITC dogs (4.9±3.12). Thirteen treated dogs (21%) and no control dogs developed UTI: 4/25 (16%) ME, 8/25 (32%) IDC, and 1/12 (8%) ITC. Enterobacter sp. was most frequently isolated (4/13; 31%). Duration of treatment was the only risk factor for UTI and each additional day of treatment increased the risk of UTI 1.5 times. Conclusion— For dogs with acute IVDD, the duration of required urinary bladder management establishes the risk of UTI, not the urinary bladder management technique. Clinical Relevance— Duration of treatment for urinary bladder dysfunction is a risk factor for UTI in dogs recovering from acute IVDD. Treatment for urinary bladder management should be limited where possible and no method of treatment is preferred. For dogs managed by IDC, voluntary urination might occur before clinically suspected.     

Video‐Assisted Thoracoscopic Resection of Noninvasive Thymomas Using One‐Lung Ventilation in Two Dogs

Objective— To report the technique and outcome of video‐assisted thoracoscopic surgery (VATS) for resection of cranial mediastinal thymoma in 2 dogs. Study Design— Case report. Animals— Eleven‐year‐old Labrador Retrievers (n=2). Methods— Two dogs had VATS resection of thymoma. Preoperative computed tomography (CT) scans revealed well‐circumscribed cranial mediastinal masses with dimensions of 4.5 cm × 4.2 cm × 3.7 cm and 2.1 cm × 2.1 cm × 4.1 cm (at the time of resection) without CT evidence of vascular invasion. One‐lung ventilation (OLV) was achieved using a bronchoscopically placed double‐lumen endobronchial tube. A 3‐portal technique was used for VATS access to the thorax. Thymomas were dissected from the tissues of the cranial mediastinum with the aid of a harmonic scalpel and retrieved in specimen retrieval bags. Results— Two cranial mediastinal thymomas were resected successfully, with their capsules intact, using a VATS technique. One dog developed aspiration pneumonia postoperatively which resolved with treatment and remains healthy 18 months postoperatively with no radiographic evidence of tumor recurrence. The second dog was diagnosed with myasthenia gravis, megaesophagus, and aspiration pneumonia preoperatively and despite recovering well from the procedure had a second episode of aspiration pneumonia 5 days postoperatively and was euthanatized. Conclusions— VATS resection of modestly sized noninvasive thymoma is possible in dogs. Careful case selection and preoperative imaging are the keys. Clinical Relevance— Thoracoscopic resection of modestly sized mediastinal masses forms part of an increasingly expansive set of indications for minimally invasive surgery in select veterinary patients.     

Evaluation of Fenestration for Treatment of Degenerative Disc Disease in the Caudal Cervical Region of Large Dogs

Seventeen large dogs (15 Doberman pinschers, one Labrador retriever, and one German short-haired pointer) with pain and gait abnormalities resulting from caudal cervical intervertebral disc degeneration were treated by disc fenestration. Four dogs recovered completely, two dogs appeared to have recovered but nerve root compression and pain returned 3 years later, five did not recover completely or did not improve, and six became progressively worse. In the dogs that recovered, preoperative myelograms showed that traction on or flexing the neck relieved the spinal cord compression. Such manipulation did not relieve slight persistent compression in the dogs that did not improve nor did it relieve severe compression by disc herniation or spinal canal stenosis in the dogs that became progressively worse. The return of nerve root compression after 3 years in two dogs was attributed to incomplete removal of dorsal anulus fibrosus. It was concluded that disc fenestration alone provided inadequate treatment of caudal cervical degenerative disc disease in large dogs.     

Efficacy of Omeprazole versus High‐Dose Famotidine for Prevention of Exercise‐Induced Gastritis in Racing Alaskan Sled Dogs

Background: Omeprazole and famotidine both reduce severity of exercise‐induced gastritis, but administering famotidine is easier than administering omeprazole during racing competition. Hypothesis: Famotidine is more efficacious than no treatment in reducing severity of exercise‐induced gastritis; and high‐dose famotidine is more efficacious than omeprazole in reducing severity of exercise‐induced gastritis. Animals: Experiment 1: Randomized placebo‐controlled study, 36 sled dogs (3–8 years); Experiment 2: Randomized positive‐control study, 52 sled dogs (2–8 years). Methods: Experiment 1: Equal numbers of dogs randomly assigned to famotidine (20 mg q24h) or no treatment groups. Gastroscopy was performed 24 hours after the dogs ran 330 miles. Mucosal appearance was blindly scored by previously described scoring system. Experiment 2: Equal numbers of dogs randomly assigned to omeprazole (20 mg q24h) or high‐dose famotidine (40 mg q12h) groups. Gastroscopy was performed 48 hours before and 24 hours after the dogs ran 300 miles. Mucosal appearance was blindly scored by previously described scoring system. Results: Famotidine reduced the prevalence of clinically relevant, exercise‐induced gastric lesions compared with no treatment (7/16 versus 11/16, P= .031). Compared with high‐dose famotidine, omeprazole significantly decreased the severity (0.4 versus 1.2, P= .0002) and prevalence (2/23 versus 7/21, P= .049) of gastric lesions. Conclusions and Clinical Relevance: Although famotidine provides some benefit in the prevention of exercise‐induced gastric lesions, omeprazole is superior to famotidine in preventing gastritis in dogs running 300 miles. Routine administration of omeprazole is recommended to prevent stress‐associated gastric disease in exercising and racing Alaskan sled dogs.     

Efficacy of Low‐ and High‐Dose Trilostane Treatment in Dogs (< 5 kg) with Pituitary‐Dependent Hyperadrenocorticism

Background

Trilostane is commonly used to treat pituitary‐dependent hyperadrenocorticism (PDH) in dogs. There are differing opinions regarding the dose and frequency of trilostane administration in dogs with PDH.

Objectives

To compare the efficacy of 2 trilostane protocols in the treatment of dogs with PDH.

Animals

Sixteen client‐owned dogs with PDH and a body weight <5 kg.

Methods

Prospective observational study. Group A (n=9; low‐dose treatment group) received 0.78 ± 0.26 mg of trilostane/kg PO every 12 h and group B (n = 7; high‐dose treatment group) 30 mg of trilostane/dog PO every 24 h. All of the dogs were reassessed at 2, 4, 8, 12, 16, and 24 weeks after the initiation of treatment.

Results

An improvement in both ACTH‐stimulated serum cortisol concentrations and clinical signs occurred more slowly in group A than in group B; however, after 20 weeks of treatment, 2/7 dog in group B had clinical signs and abnormal laboratory findings consistent with hypoadrenocorticism. At 24 weeks, an improvement in the clinical findings of all of the dogs in both groups was detected.

Conclusions and clinical importance

In dogs with PDH, twice‐daily administration of low‐dose trilostane is an effective approach to the management of PDH. In addition, our results suggest fewer potential adverse effects if trilostane is administered twice daily in the lower dose.