Prevalence and characterization of urinary tract infections in dogs with surgically treated type 1 thoracolumbar intervertebral disc extrusion

OBJECTIVE: To determine the prevalence of urinary tract infections (UTI), factors that correlate positively with UTI, and whether identified UTI are most likely community- or hospital acquired in dogs with surgically treated type 1 thoracolumbar intervertebral disc (IVD) extrusions. STUDY DESIGN: Prospective cross-sectional clinical study. SAMPLE POPULATION: Dogs (n=92) that were surgically treated for a thoracolumbar extradural compressive spinal cord lesion that was consistent with type 1 IVD extrusion. METHODS: Dogs were evaluated for bacterial lower UTI when possible by cystocentesis and urine culture before surgery, and 48-72, 96-120 hours, and 7 days after surgery while hospitalized. Paraparesis, confirmation of thoracolumbar extruded nucleus pulposus, and informed owner consent were required for study inclusion. Urine specimens (n=297) were cultured and both objective and subjective clinical data were obtained. RESULTS: Prevalence of UTI in dogs with surgically treated type 1 thoracolumbar IVD extrusion was 27% (25 dogs). Temporal prevalence of UTI was 15% (13/89) before surgery, 12% (11/91) at 2-3 days, 16% (12/76) at 4-5 days, and 20% (8/41) at 7 days after surgery. Statistically significant factors affecting UTI prevalence included neurologic and urinary status, sex, administration of perioperative antibiotics, and amount of time body temperature was <35 degrees C during anesthesia. CONCLUSION: UTI are common in dogs with surgically treated type 1 thoracolumbar IVD extrusion. Females, dogs that cannot ambulate or voluntarily urinate, dogs not administered perioperative cefazolin, and dogs whose body temperature falls <35 degrees C during anesthesia have a higher incidence of UTI. CLINICAL RELEVANCE: All dogs with surgically treated type 1 thoracolumbar IVD extrusion should be monitored for the presence of UTI; however, close attention should be paid to females and dogs that cannot ambulate or voluntarily urinate.     

Retrospective evaluation of urinary tract infection in 42 dogs with hyperadrenocorticism or diabetes mellitus or both

A retrospective study was performed to determine the proportion of dogs with hyperadrenocorticism or diabetes mellitus or both that had urinary tract infection (UTI) and to describe clinical and laboratory findings. Dogs with these endocrine disorders were included if results of quantitative urine culture were available and dogs were not receiving antimicrobials. Dogs with positive urine cultures were considered to have UTI and dogs with negative urine cultures were used as controls. Information including history, clinical signs, physical examination findings, and results of laboratory tests and urine culture was extracted from all records. Findings in dogs with UTI were compared with control dogs. There were 101 dogs with hyperadrenocorticism or diabetes mellitus or both that met inclusion criteria; 42 (41.6%) had UTI and 59 (58.4%) did not. UTI was present in 46% of dogs with hyperadrenocorticism, 37% of dogs with diabetes mellitus, and 50% of dogs with both endocrine disorders. There was no association between endocrine group and occurrence of UTI. Escherichia coli was the most common bacteria isolated, and cultures from 29 dogs (69%) showed growth of this organism. Of dogs with UTI, <5% had stranguria, pollakiuria, or discolored urine, whereas 60% had pyuria and 69% had bacteriuria. We conclude that UTIs are common in dogs with hyperadrenocorticism, diabetes mellitus, or both diseases. Clinical signs of UTI, however, are uncommon and results of urinalysis may be normal. Therefore, it is appropriate to recommend urine culture as part of the evaluation of dogs with these endocrine disorders.     

Persistent urinary tract infections and reinfections in 100 dogs (1989-1999)

A retrospective study was performed of 100 dogs with persistent urinary tract infections (UTIs) or reinfections presenting to the North Carolina State University (Raleigh, NC) Veterinary Teaching Hospital between 1989 and 1999. Criteria for selection included > or = 2 positive urine cultures within a 6-month period. Signalment, presence of predisposing disorders, urinalysis and urine culture results, and treatment strategies were extracted from the medical records. Dogs were a median age of 7 years when the UTI was 1st diagnosed. Dogs younger than 3 and older than 10 years were at increased and decreased risks, respectively, for reinfections or persistent UTIs. Spayed females were more common in the UTI population. More than half of the dogs were asymptomatic for a UTI at 1st presentation. Urine sediment examinations identified hematuria, pyuria, and bacteriuria in 47, 72, and 85% of the samples, respectively. The most commonly isolated organisms were Escherichia coli and Streptococcus/Enterococcus spp.; multiple isolates also were common. Of the isolates, 29.5% were resistant to achievable serum concentrations of all antibiotics commonly prescribed for PO administration. Dogs with abnormal micturition were more likely to have infections by organisms resistant to commonly prescribed antibiotics. Potentially predisposing disorders were identified in 71 dogs. A correction of these disorders was accomplished in 35% of these 71 dogs. Dogs given standard antibiotic therapy without addressing predisposing disorders experienced poor control of their UTIs; 74.5% of these dogs had an apparent disease-free interval (ADFI) of < 8 weeks. By comparison, dogs in which predisposing disorders were corrected or those that were treated with low-dose, long-term antibiotic regimens subjectively had better control.     

Diagnosis of urinary tract infections.

Urinary tract infections (UTIs) are a common cause of urinary tract disease and may be associated with systemic disease. Diagnosis cannot be made on urinalysis and other findings alone. A urine culture is the "gold standard" for diagnosis of UTI. Antimicrobial susceptibility testing performed as part of a urine culture aids in selection of appropriate treatment for patients with confirmed bacterial UTI.     

Evaluation of catheter-associated urinary tract infections and multi-drug-resistant Escherichia coli isolates from the urine of dogs with indwelling urinary catheters

OBJECTIVE: To determine the frequency of urinary tract infections (UTIs) in dogs with indwelling urinary catheters in an intensive care unit (ICU) and the frequency of multi-drug-resistant (MDR) Escherichia coli UTIs in those dogs. DESIGN: Prospective study. ANIMALS: All dogs in the ICU with an indwelling urinary catheter from January 2003 through December 2003. PROCEDURES: Urine samples and rectal swab specimens were collected at admission and every 3 days until discharge from the hospital. Escherichia coli isolates from urine samples and rectal swab specimens and those from dogs that were temporally or spatially associated with dogs with MDR E coli UTIs underwent antimicrobial susceptibility testing. Pulsed-field gel electrophoresis was performed on MDR isolates from urine and rectal swab specimens. RESULTS: Urinary catheters were placed in 137 dogs. Twenty-six UTIs were diagnosed, 15 on the day of admission and 11 after 3 or more days of catheterization. Of 12 dogs with E coli UTIs, 6 were infected at admission and 6 acquired the infection in the ICU. Two MDR E coli UTIs were detected, 1 of which was acquired in the ICU. One MDR E coli urinary isolate had an electrophoresis pattern similar to that of rectal isolates from the same dog. Urinary E coli isolates were most frequently resistant to ampicillin and cephalothin. CONCLUSIONS AND CLINICAL RELEVANCE: The ICU-acquired MDR E coli UTI likely originated from the dog's intestinal flora during hospitalization. Dogs that have been referred from a community practice may have MDR E coli UTIs at the time of admission.     

Evaluation of colposuspension for treatment of incontinence in spayed female dogs

OBJECTIVE: To determine the long-term effects of colposuspension in spayed female dogs with urinary incontinence and identify preoperative anatomic or urodynamic measurements associated with a successful outcome. DESIGN: Prospective study. ANIMALS: 23 client-owned spayed female dogs with urinary incontinence. PROCEDURE: Prior to surgery, a history was obtained, and a physical examination, CBC, serum biochemical analyses, urinalysis, bacterial culture of a urine sample, vaginourethrocystography, urethral pressure profilometry, and leak point pressure test were performed. Colposuspension was performed, and preoperative tests were repeated 2 months after surgery. Clients were interviewed 2 weeks, 1 month, and 1 year after surgery. RESULTS: 22 dogs were followed up for 1 year. Twelve had complete urinary control 2 months after surgery, and 3 had complete urinary control 1 year after surgery. Dogs with normal urinary control at 2 months had an increased leak point pressure (LPP), compared with preoperative measurements, and their LPP was the same as normal dogs. Eight dogs had complete urinary control, and 9 were considered greatly improved 1 year after surgery when medical treatment was added to the effect of colposuspension. Client satisfaction was high, with 19 of 22 (86%) owners being pleased with their decision to have surgery performed. The only predictors of complete urinary control 2 months after surgery were a more caudal position of the external urethral opening in relation to the pubis on preoperative radiographs and a longer overall urethral length. CONCLUSIONS AND CLINICAL RELEVANCE: Colposuspension alone will result in complete urinary control in few dogs with urinary incontinence but may improve urinary control sufficiently that owners will be pleased. Preoperative vaginourethrocystography may be helpful in predicting response to surgery, and the LPP test correlates with improved urinary control.     

Frequency of urinary tract infection among dogs with pruritic disorders receiving long-term glucocorticoid treatment

OBJECTIVE: To determine frequency of urinary tract infection (UTI) among dogs with pruritic disorders that were or were not receiving long-term glucocorticoid treatment. DESIGN: Observational study. ANIMALS: 127 dogs receiving glucocorticoids for > 6 months and 94 dogs not receiving glucocorticoids. PROCEDURE: Bacterial culture of urine samples was performed in dogs receiving long-term glucocorticoid treatment, and information was collected on drug administered, dosage, frequency of administration, duration of glucocorticoid treatment, and clinical signs of UTI. For dogs not receiving glucocorticoids, a single urine sample was submitted for bacterial culture. RESULTS: Multiple (2 to 6) urine samples were submitted for 70 of the 127 (55%) dogs receiving glucocorticoids; thus, 240 urine samples were analyzed. For 23 of the 127 (18.1%) dogs, results of bacterial culture were positive at least once, but none of the dogs had clinical signs of UTI. Pyuria and bacteriuria (present vs absent) were found to correctly predict results of bacterial culture for 89.9% and 95.8% of the samples, respectively. Type of glycocorticoid, dosage, frequency of administration, and duration of treatment were not associated with frequency of UTI. None of the urine samples from dogs not receiving glucocorticoids yielded bacterial growth. The frequency of UTI was significantly higher for dogs treated with glucocorticoids than for dogs that had not received glucocorticoids. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that dogs receiving long-term glucocorticoid treatment have an increased risk of developing a UTI. On this basis, we recommend that urine samples be submitted for bacterial culture at least yearly for such dogs.     

Frequency of urinary tract infection in catheterized dogs and comparison of bacterial culture and susceptibility testing results for catheterized and noncatheterized dogs with urinary tract infections

OBJECTIVE: To determine frequency of urinary tract infections (UTIs) in catheterized dogs that had intervertebral disk disease (IVDD) or disease other than IVDD and compare bacterial culture and susceptibility testing results for catheterized and noncatheterized dogs with UTIs. DESIGN: Retrospective cohort study. ANIMALS: 147 catheterized dogs (105 with IVDD and 42 with other diseases) and 99 noncatheterized dogs with UTIs. PROCEDURES: Medical records were reviewed for signalment, history, clinical problem, duration of urinary tract catheterization, administration of drugs, and urine bacterial culture and susceptibility testing results. RESULTS: Forty-two percent (44/105) of dogs with IVDD and 55% (23/42) of dogs with other diseases had UTIs; this difference was not significant. For catheterized dogs, the odds of UTI were increased by 20% for each year increase in age, 27% for each day increase in duration of catheterization, and 454% with antimicrobial administration. Escherichia coli and Proteus spp were more frequently isolated from noncatheterized dogs, whereas Enterobacter spp and Staphylococcus spp were more frequently isolated from catheterized dogs. There was no significant difference in frequency of 1, 2, or 3 isolates between groups. Proportions of antimicrobials to which the most frequently isolated bacteria were resistant were not significantly different between groups. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that urinary tract catheterization is a reasonable alternative for management of dogs with urinary bladder dysfunction, but that duration of catheterization should be minimized and indiscriminate antimicrobial administration to dogs with indwelling urinary catheters should be avoided.     

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.     

Effect of fenoldopam on renal function after nephrotomy in normal dogs

OBJECTIVE: To evaluate effects of fenoldopam on renal function in normal dogs subjected to bisection nephrotomy. In addition, effects of bisection nephrotomy on renal function in normal dogs were evaluated. STUDY DESIGN: Controlled, randomized, blinded experiment. SAMPLE POPULATION: Sixteen mixed-breed adult dogs. METHODS: Dogs were paired for sex, body weight, and approximate age and assigned to 1 of 2 groups: fenoldopam (F) or placebo (P). Baseline glomerular filtration rate (GFR) based on quantitative renal scintigraphy using (99m)Tc-DTPA, blood urea nitrogen (BUN), serum creatinine (SCr), urinalysis, and urine culture were performed before surgery. Left nephrotomy was performed via median celiotomy. Group F dogs were administered intravenous (IV) fenoldopam (0.1 microg/kg/min) for 90 minutes, whereas group P dogs were administered an equivalent volume of saline (0.9 % NaCl) solution for 90 minutes. Temperature, heart rate, respiration, direct arterial blood pressure, and urine volume were recorded during anesthesia. Renal function was assessed by measuring SCr, BUN, and GFR at 1, 21, and 42 days after surgery. RESULTS: There was no significant difference between groups in measured physiologic variables. No significant difference in GFR, BUN, or SCr between groups or between operated or control kidneys was detected. CONCLUSIONS: Bisection nephrotomy in normal dogs with renal arterial occlusion of 15 minutes and using a simple continuous capsular closure does not adversely affect renal function. CLINICAL RELEVANCE: Bisection nephrotomy, as described in this study, does not decrease renal function; perioperative administration of renoprotective agents is not necessary in normal dogs.     

Episioplasty for the treatment of perivulvar dermatitis or recurrent urinary tract infections in dogs with excessive perivulvar skin folds: 31 cases (1983-2000).

OBJECTIVE: To evaluate the effectiveness of episioplasty for the treatment of perivulvar dermatitis or chronic or recurrent urinary tract infections (UTI) believed to be secondary to excessive perivulvar skin folds in dogs and to document whether a causal relationship exists between the presence of chronic or recurrent UTI and excessive perivulvar skin folds in female dogs. DESIGN: Retrospective study. ANIMALS: 31 female dogs. PROCEDURE: Medical records of dogs with vulvar dermatitis (group 1; n = 15) or UTI (group 2; 16) were reviewed for history, signalment, physical examination findings, hematologic findings, results of urine or vaginal bacteriologic culture, and results of additional diagnostic procedures. RESULTS: 14 of 15 dogs in group 1 had complete resolution of perivulvar dermatitis and associated clinical signs following episioplasty. One dog had a relapse of clinical signs and vulvar dermatitis 2 years after surgery in association with a 9-kg (1 9.8-1b) weight gain. Sixteen of 16 dogs in group 2 had complete resolution of clinical signs of UTI following episioplasty. Urine samples were obtained via cystocentesis no earlier than 1 month after surgery to confirm resolution of UTI in 13 of 16 of dogs in group 2. Mild-to-moderate incisional swelling was the only surgical complication reported for either group, with the exception of 1 dog in group 2 that had wound dehiscence. All owners were satisfied with surgical outcomes. CONCLUSIONS AND CLINICAL RELEVANCE: All owners reported complete resolution of clinical signs for both groups of dogs. Episioplasty is an effective low morbidity treatment for perivulvar dermatitis and chronic UTI associated with excessive perivulvar skin folds.     

Incidence of catheter-associated urinary tract infection among dogs in a small animal intensive care unit

OBJECTIVE: To determine incidence of and possible risk factors for catheter-associated urinary tract infection (UTI) among dogs hospitalized in an intensive care unit and compare results of bacterial culture of urine samples with results of bacterial culture of catheter tips. DESIGN: Prospective study. ANIMALS: 39 dogs. PROCEDURE: A standard protocol for aseptic catheter placement and maintenance was used. Urine samples were obtained daily and submitted for bacterial culture. When possible, the urinary catheter tip was collected aseptically at the time of catheter removal and submitted for bacterial culture. Bacteria that were obtained were identified and tested for antimicrobial susceptibility. RESULTS: 4 of the 39 (10.3%) dogs developed a UTI. The probability of remaining free from UTI after 1 day in the intensive care unit was 94.9%, and the probability of remaining free from UTI after 4 days was 63.3%. Bacteria isolates were generally common urinary tract pathogens and were susceptible to most antimicrobials. Specific risk factors for catheter-associated UTI, beyond a lack of antimicrobial administration, were not identified. Positive predictive value of bacterial culture of urinary catheter tips was only 25%. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that placement of an indwelling urinary catheter in dogs is associated with a low risk of catheter-associated UTI during the first 3 days after catheter placement, provided that adequate precautions are taken for aseptic catheter placement and maintenance. Results of bacterial culture of urinary catheter tips should not be used to predict whether dogs developed catheter-associated UTI.     

Diagnostic utility and cost‐effectiveness of reflex bacterial culture for the detection of urinary tract infection in dogs with low urine specific gravity

Background: Urinary tract infections (UTIs) may be subclinical or difficult to detect in dilute urine as sediment abnormalities may not be observed. In our laboratory, bacterial culture is automatically performed (reflex culture) on samples with urine specific gravity (USG)≤1.013 to increase the likelihood of detecting infection. The value of routine culture of dilute urine, however, has not been fully assessed. Objective: The purpose of this retrospective study was to evaluate the frequency of positive bacterial cultures and analyze the diagnostic utility and cost‐effectiveness of culture compared with routine sediment examination for detecting UTI in dilute urine specimens from dogs. Methods: Urinalysis and concurrent aerobic bacterial culture results were obtained from the electronic medical record system at the University of California–Davis Veterinary Medical Teaching Hospital for samples with USG≤1.013 analyzed from July 1998 through January 2005. Urine collection method, presence of leukocytes and bacteria, bacterial culture results, and clinical diagnosis were recorded. Cost‐effectiveness of reflex culture, based on low USG as the sole criterion, was evaluated. Results: Of 1264 urine specimens, 106 (8.4%) had positive bacterial cultures. Using culture as the gold standard, sediment evaluation had a diagnostic sensitivity of 58.5% and specificity of 98.3% (diagnostic accuracy 94.9%). An additional cost of $60 per patient was incurred, leading to average annual costs of $11,668 for reflex bacterial cultures of all samples with low USG, regardless of collection method. Within our study population, 10 urine samples needed to be cultured for each true positive result. Conclusions: The sensitivity of urine sediment evaluation is low for UTI in dilute urine samples; however, reflex bacterial culture does not appear to be cost‐effective in dogs with USG≤1.013 in the absence of active urine sediment or high clinical suspicion for UTI.     

Use of Electrohydraulic Lithotripsy in 28 Dogs with Bladder and Urethral Calculi

Background: Electrohydraulic lithotripsy (EHL) has been used as an alternative to cystotomy in human medicine to remove urinary calculi. This prospective study evaluated the efficacy and safety of EHL to remove urinary calculi in dogs. Hypothesis: EHL is an efficient and safe method of treatment of bladder and urethral calculi in dogs. Methods: Dogs presented between January 1, 2005 and June 1, 2007 with lower urinary tract calculi diagnosed by radiographs or ultrasound examination were included in the study. Physical examination, CBC, biochemistry, urinalysis, and urine culture were performed at presentation. EHL and voiding urohydropulsion were performed under general anesthesia. Patients received IV fluids for 12 hours after which they were rechecked by ultrasound examination and discharged with antibiotics and anti‐inflammatory drugs for 5 days. All patients were reevaluated 1, 3, and 6 months after presentation by physical examination, urinalysis, and ultrasonography. Results: Twenty‐eight dogs (19 males, 9 females) presented with bladder or urethral calculi or both underwent lithotripsy. Their median weight was 8.3 kg. Calcium oxalate calculi were present in 22 dogs, struvite in 4, and mixed calculi in 2. Fragmentation was done in the bladder (23 dogs) and in the urethra (12 dogs). Calculus‐free rate was higher for urethral than for bladder calculi in males and higher for bladder calculi in females than in males. No major complications were reported. Twelve dogs relapsed within 6 months. Conclusions: Results of this study support the use of EHL as a minimally invasive treatment for bladder calculi in females and for urethral calculi in male dogs.     

Clinical features and risk factors for development of urinary tract infections in cats

The clinical and diagnostic features of 155 cats with urinary tract infection (UTI) and 186 controls with negative urine culture/s were characterized retrospectively (signalment, clinical signs, urinalysis, urine culture, concurrent diseases, lower urinary tract diagnostic/therapeutic procedures). Multivariable logistic regression was used to identify risk factors associated with UTI. Cats of all ages were affected by UTI with no sex/breed predisposition. Lower urinary tract signs were absent in 35.5% of cats with UTI. Pyuria and bacteriuria had sensitivities of 52.9% and 72.9%, and specificities of 85.5% and 67.7% for detection of UTI, respectively. Risk factors significantly associated with increased odds of UTI were urinary incontinence [odds ratio (OR) = 10.78, P = 0.0331], transurethral procedures (OR = 8.37, P <0.0001), urogenital surgery (OR = 6.03, P = 0.0385), gastrointestinal disease (OR = 2.62, P = 0.0331), decreased body weight (OR = 0.81, P = 0.0259) and decreased urine specific gravity (OR = 0.78, P = 0.0055). Whilst not independently significant, renal disease and lower urinary tract anatomic abnormalities improved statistical model performance and contributed to UTI.     

Risk factors for recurrence of clinical signs associated with thoracolumbar intervertebral disk herniation in dogs: 229 cases (1994-2000)

OBJECTIVE: To assess risk factors for recurrence of clinical signs associated with thoracolumbar intervertebral disk disease (IVDD) in dogs that had decompressive laminectomy without attempted prophylactic treatment of other disk spaces. DESIGN: Retrospective study. ANIMALS: 229 dogs. PROCEDURE: Medical records of dogs that had decompressive laminectomy without prophylactic fenestration for a first episode of IVDD and were available for follow-up were reviewed. Information on 7 clinical and 8 radiographic potential risk factors were recorded. RESULTS: Clinical signs associated with recurrence of IVDD developed in 44 (19.2%) dogs. Ninety-six percent of recurrences developed within 3 years after surgery. Recurrence developed in 25% of Dachshunds and 15% of dogs of other breeds combined. Number of opacified disks was a significant risk factor for recurrence. Risk increased with number of opacified disks in an almost linear manner; each opacified disk increased risk by 1.4 times. Dogs with 5 or 6 opacified disks at the time of first surgery had a recurrence rate of 50%. CONCLUSIONS AND CLINICAL RELEVANCE: When all likely episodes of recurrence are considered and a long follow-up period is achieved, true rate of recurrence of IVDD appears to be higher than in many previous reports. Dogs with multiple opacified disks at the time of first surgery should be considered a high-risk subpopulation.     

Absence of urinary tract infection in dogs with experimentally induced hyperadrenocorticism

Objectives of this study were to determine occurrence of urinary tract infection and describe results of urine analysis and urine culture in dogs with experimentally induced hyperadrenocorticism. Dogs were randomly assigned to receive either hydrocortisone (nine dogs) or placebo (eight dogs) for 49 consecutive days. Before and on day 49 of treatment, evaluation of dogs included physical examination, abdominal ultrasound, urine culture, urinalysis, adrenal function testing, and measurement of urine protein and creatinine and activity of serum alkaline phosphatase. All dogs in the experimental group had clinical and laboratory findings of hyperadrenocorticism. Urine specific gravity was significantly decreased and urine protein-to-creatinine ratio was significantly increased in dogs with hyperadrenocorticism. Urinary tract infection did not occur in any dogs. We conclude that administration of hydrocortisone created a model of hyperadrenocorticism; however, urinary tract infection did not occur. Additional evaluation is needed to determine association between urinary tract infection and hyperadrenocorticism.     

Effect of perioperative prophylactic antimicrobial treatment in dogs undergoing elective orthopedic surgery.

OBJECTIVE: To determine whether perioperative antimicrobial prophylaxis would reduce incidence of postoperative infection among dogs undergoing elective orthopedic procedures. DESIGN: Randomized, controlled, blinded, intention clinical trial. ANIMALS: Dogs of any breed, sex, or age undergoing elective orthopedic surgery at a veterinary teaching hospital. PROCEDURES: Dogs were randomly assigned to 1 of 3 groups: treatment with saline solution, treatment with potassium penicillin G, and treatment with cefazolin. Treatments were intended to be administered within 30 minutes prior to surgery; a second dose was administered if surgery lasted > 90 minutes. Dogs were monitored for 10 to 14 days after surgery for evidence of infection. RESULTS: After the first 112 dogs were enrolled in the study, it was found that infection rate for control dogs (5/32 dogs) was significantly higher than the rate for dogs treated with antimicrobials (3/80 dogs). Therefore, no more dogs were enrolled in the study. A total of 126 dogs completed the study. Monte Carlo simulations indicated that compared with dogs that received antimicrobials prophylactically, dogs that received saline solution developed infections significantly more frequently. Difference in efficacy, however, was not observed between the 2 antimicrobial drugs used. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that perioperative antimicrobial prophylaxis decreased postoperative infection rate in dogs undergoing elective orthopedic surgery, compared with infection rate in control dogs. Cefazolin was not more efficacious than potassium penicillin G in these dogs.     

Incidence of Spinal Compressive Lesions in Chondrodystrophic Dogs with Abnormal Recovery after Hemilaminectomy for Treatment of Thoracolumbar Disc Disease: A Prospective Magnetic Resonance Imaging Study

Objective— To investigate causes of the lack of clinical improvement after thoracolumbar disc surgery. Study Design— Case–control magnetic resonance imaging (MRI) study. Animals— Chondrodystrophic dogs with acute thoracolumbar disc disease treated by hemilaminectomy: 10 that had no short‐term clinical improvement and 12 with “normal” clinical improvement. Methods— Dogs that had surgery for treatment of intervertebral disc extrusion (2003–2008) where thoracolumbar disc disease was confirmed by MRI were evaluated to identify dogs that had lack of clinical improvement after surgery. Ten dogs with delayed recovery or clinical deterioration were reexamined with MRI and compared with 12 dogs with normal recovery and MRI reexamination after 6 weeks (control group). Results— Of 173 dogs, 10 (5.8%) had clinical deterioration within 1–10 days after surgery. In 8 dogs, residual spinal cord compression was identified on MRI. Bleeding was present in 1 dog. In 3 dogs, the cause was an incorrect approach and insufficient disc material removal. In 3 dogs, recurrence occurred at the surgical site. In 1 dog, the centrally located extruded material was shifted to the contralateral side during surgery. These 8 dogs had repeat surgery and recovery was uneventful. In 2 dogs, deterioration could not be associated with a compressive disc lesion. Hemorrhagic myelomalacia was confirmed by pathologic examination in 1 dog. The other dog recovered after 6 months of conservative management. Conclusion— Delayed postsurgical recovery or deterioration is commonly associated with newly developed and/or remaining compressive disc lesion. Clinical Relevance— We recommend early MRI reexamination to assess the postsurgical spinal canal and cord, and to plan further therapeutic measures in chondrodystrophic dogs with delayed recovery after decompressive hemilaminectomy for thoracolumbar disc disease.     

Use of the ventrodorsal myelographic view to predict lateralization of extruded disk material in small-breed dogs with thoracolumbar intervertebral disk extrusion: 104 cases (2004-2005)

OBJECTIVE: To determine whether the ventrodorsal myelographic view can be used to accurately predict the circumferential location of extruded disk material in dogs with thoracolumbar intervertebral disk extrusion (IVDE) and to describe paradoxical contrast obstruction (PCO). DESIGN: Retrospective case series. ANIMALS:104 dogs with Hansen type I IVDE. Procedures-Ventrodorsal myelographic views were reviewed, and contrast patterns were categorized according to 8 predetermined patterns. Agreement among observers was compared, and the predicted location of extruded disk material was compared with surgical findings. RESULTS: Agreement regarding myelographic pattern and location of extruded disk material was moderate (kappa = 0.74 and 0.80, respectively) among the 4 observers. Ninety-three (89%) dogs had myelographic evidence of lateralized extrusion, and in 83 of the 93 (89%), predicted location of extruded disk material matched the surgically confirmed location. In 33 of the 40 (83%) dogs with bilateral contrast column gaps of unequal length, disk material was found to be located on the side with the shorter, rather than the longer, contrast gap, a phenomenon described as PCO. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that the ventrodorsal myelographic view could be used to predict the circumferential location of extruded disk material in dogs with thoracolumbar IVDE more often than previously reported. The PCO phenomenon may be useful in determining the side of lateralization when contrast material does not outline the extruded disk material.