Search Results

You are looking at 1 - 10 of 17 items for

  • Author or Editor: Stephen Werre x
  • Refine by Access: All Content x
Clear All Modify Search

Abstract

Objective—To measure effects of dog position on L7-S1 intervertebral foraminal area and lumbosacral (LS) angle by means of computed tomography (CT) and determine whether changes in values between positions are associated with clinical signs in dogs with LS disease.

Animals—86 dogs examined via a positional CT protocol that included flexion and extension scans of L7-S1.

Procedures—Archived CT images and medical records were reviewed. Included dogs had good-quality flexion and extension CT scans of L7-S1 and no evidence of fractures, neoplasia, or previous LS surgery. One person who was unaware of CT findings recorded clinical status with regard to 3 signs of LS disease (right or left hind limb lameness and LS pain) at the time of CT evaluation. One person who was unaware of clinical findings measured L7-S1 foraminal areas and LS angles, with the aid of an image-analysis workstation and reformatted parasagittal planar CT images.

Results—Intraobserver variation for measurements of L7-S1 foraminal area ranged from 6.4% to 6.6%. Mean foraminal area and LS angle were significantly smaller when vertebral columns were extended versus flexed. Percentage positional change in L7-S1 foraminal area or LS angle was not significantly different among dogs with versus without each clinical sign. There was a significant correlation between percentage positional change in L7-S1 foraminal area and LS angle in dogs with versus without ipsilateral hind limb lameness and LS pain.

Conclusions and Clinical Relevance—Positional CT is a feasible technique for quantifying dynamic changes in L7-S1 intervertebral foraminal morphology in dogs with LS disease.

Full access
in American Journal of Veterinary Research

Abstract

Objective—To determine whether a high dosage of pimobendan, when administered concurrently with moderate-dosage furosemide to healthy dogs, would activate the renin-angiotensin-aldosterone system (RAAS) more than furosemide alone.

Animals—12 healthy dogs.

Procedures—6 dogs received furosemide (2.0 mg/kg, PO, q 12 h) only, as an RAAS activator, for 10 days. The other 6 dogs received furosemide (2.0 mg/kg, PO, q 12 h) and pimobendan (0.6 mg/kg, PO, q 12 h) for 10 days. The effect of these drugs on the RAAS was determined by measurement of the aldosterone-to-creatinine ratio (A:C) in urine collected in the morning and evening of study days −2, −1, 1, 5, and 10.

Results—Although there was an increase in the urine A:C during the study period in both groups, it was significant only for dogs that received both drugs. The urine A:C only differed significantly between groups on day 1, at which time A:C was greater in the group that received both drugs.

Conclusions and Clinical Relevance—High-dosage pimobendan administration neither substantially suppressed nor potentiated the RAAS when administered with furosemide in healthy dogs.

Full access
in American Journal of Veterinary Research

Abstract

OBJECTIVE

To determine the effect of a food toy on owner-perceived quality of life (QOL) of overweight cats during a weight loss plan.

ANIMALS

44 adult cats, 1 to 10 years of age with a body condition score (BCS) ≥ 7/9.

PROCEDURES

Cats were randomly assigned to the food toy or food bowl group. Cat owners completed an initial questionnaire and received a prescribed weight loss plan, bag of dry veterinary therapeutic cat food formulated for weight loss, measuring cup, and food bowl or ball-type food toy. Body weight and BCS were checked monthly. Owners completed a monthly questionnaire to assess their cat’s QOL. Low-calorie vegetables were offered to 32 cats whose owners reported disruptive food-seeking behavior.

RESULTS

Of the 44 cats in the final analysis, 29 cats either lost ≥ 2 BCS points or achieved an ideal BCS. Owner-perceived QOL was higher at the final weigh-in, compared with that at the initial weigh-in. An effect of food toy versus food bowl on owner-perceived QOL was not detected. Of the cats offered vegetables, 28 cats would eat the vegetables with a palatability additive; 4 cats ate vegetables plain.

CONCLUSIONS AND CLINICAL RELEVANCE

Owner-perceived QOL was higher at the end of the study. Feeding overweight cats by use of a ball-type food toy did not influence owner-perceived QOL. Low-calorie vegetables can successfully be added to the weight loss diet to promote satiety; albeit, a palatability additive is likely needed. Further studies regarding feeding management for cats during a weight loss plan should be explored.

Full access
in Journal of the American Veterinary Medical Association

Abstract

Objective—To determine the effectiveness of cystotomy for complete removal of urocystoliths and urethroliths in dogs, the types and frequency of diagnostic imaging performed to verify complete urolith removal, the complications that develop as a result of cystotomy, and predictors of each of these variables.

Design—Retrospective case series.

Animals—128 dogs that underwent a cystotomy for removal of urocystoliths, urethroliths, or both from 1994 through 2006.

Procedures—The following data were obtained from medical records: sex, body weight, number and locations of lower urinary tract uroliths identified in preoperative and postoperative imaging reports, types of imaging used for urolith detection, number of uroliths recovered during cystotomy, quantitative urolith composition, and major complications attributable to cystotomy. Objective criteria were applied to determine whether a cystotomy failed or succeeded and whether appropriate imaging was performed. Associations between potential prognostic factors and outcomes were statistically assessed.

Results—Effectiveness of cystotomy could be determined in 44 (34%) dogs, of which 9 (20%) had incomplete removal of uroliths. Appropriate postoperative imaging was performed for only 19 (15%) dogs, of which 8 had incomplete removal. Dogs with both urethroliths and urocystoliths were more likely to have a failed cystotomy than dogs with only urethroliths or urocystoliths. Complications developed in 5 (4%) dogs.

Conclusions and Clinical Relevance—Cystotomy was a safe and effective surgical procedure for removal of lower urinary tract uroliths in most dogs. Failure to remove all uroliths occurred in a substantial percentage of patients.

Full access
in Journal of the American Veterinary Medical Association

Abstract

OBJECTIVE

To collect voided urine from dogs with clinical signs of lower UTI and determine the diagnostic performance of a commercially available rapid immunoassay (RIA) immediately after urine collection and after refrigeration at 4 and 24 hours.

ANIMALS

40 client-owned dogs.

METHODS

Aerobic urine culture was performed on urine collected by cystocentesis. Urine samples were collected by voiding, and the RIA performed in triplicate within 30 minutes (time 0) and again in triplicate after 4 and 24 hours of refrigeration. Test precision and agreement between culture results and RIA results at each time point were determined, and factors possibly associated with false results investigated.

RESULTS

14 of 40 dogs (35%) had UTI verified by aerobic urine culture, and all had positive RIA. Three dogs had false positive RIA results. Sensitivity, specificity, positive predictive value, and negative predictive value of the RIA were 100, 88%, 82%, and 100%, respectively, and results were not different after 4 and 24 hours of refrigeration. Precision was excellent.

CLINICAL RELEVANCE

This point-of-care RIA, performed on voided urine refrigerated up to 24 hours, rapidly and accurately identifies bacteriuria in dogs with lower urinary tract clinical signs, inexpensively.

Free access
in Journal of the American Veterinary Medical Association

Abstract

OBJECTIVE To compare the effects of 3 equimolar concentrations of methylprednisolone acetate (MPA), triamcinolone acetonide (TA), and isoflupredone acetate (IPA) on equine articular tissue cocultures in an inflammatory environment.

SAMPLE Synovial and osteochondral explants from the femoropatellar joints of 6 equine cadavers (age, 2 to 11 years) without evidence of musculoskeletal disease.

PROCEDURES From each cadaver, synovial and osteochondral explants were harvested from 1 femoropatellar joint to create cocultures. Cocultures were incubated for 96 hours with (positive control) or without (negative control) interleukin (IL)-1β (10 ng/mL) or with IL-1β and MPA, TA, or IPA at a concentration of 10−4, 10−7, or 10−10M. Culture medium samples were collected from each coculture after 48 and 96 hours of incubation. Concentrations of prostaglandin E2, matrix metalloproteinase-13, lactate dehydrogenase, and glycosaminoglycan were determined and compared among treatments at each time.

RESULTS In general, low concentrations (10−7 and 10−10M) of MPA, TA, and IPA mitigated the inflammatory and catabolic (as determined by prostaglandin E2 and matrix metalloproteinase-13 quantification, respectively) effects of IL-1β in cocultures to a greater extent than the high (10−4M) concentration. Mean culture medium lactate dehydrogenase concentration for the 10−4M IPA treatment was significantly greater than that for the positive control at both times, which was suggestive of cytotoxicosis. Mean culture medium glycosaminoglycan concentration did not differ significantly.

CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that the in vitro effects of IPA and MPA were similar to those of TA at clinically relevant concentrations (10−7 and 10−10M).

Full access
in American Journal of Veterinary Research

Abstract

OBJECTIVE

To compare the elution characteristics of amikacin-impregnated calcium sulfate (CaSO4) beads based on different drug concentrations and bead size configurations.

SAMPLE

Six groups of amikacin-impregnated CaSO4 beads and one negative control group.

PROCEDURES

Amikacin-impregnated CaSO4 beads were formed with either 500 mg (low-concentration) or 1 g (high-concentration) of amikacin per 15 g CaSO4 hemihydrate powder. The number of beads necessary to approximate 150 mg of amikacin for each of the 3 bead sizes (3 mm, 5 mm, and 7 mm) at both low and high concentrations were placed in 6 mL of phosphate-buffered saline. The saline was sampled at 14 time points over 28 days. Amikacin concentrations were determined using liquid chromatography-mass spectrometry.

RESULTS

Smaller beads reached higher mean peak concentrations than larger beads (P < .0006). Peak concentrations for the low- and high-concentration groups were 20.5 mg/mL and 27.4 mg/mL, 13.1 mg/mL and 14.0 mg/mL, and 8.85 mg/mL and 6.75 mg/mL for the 3 mm, 5 mm, and 7 mm beads, respectively. Bead size also affected the length of therapeutic duration, lasting 6 days for the 3 mm and 5 mm beads and 9 days for the 7 mm beads. However, this was only statistically evident among the high-concentration beads (P < .044). Antimicrobial concentration within the same bead sizes did not affect elution.

CLINICAL RELEVANCE

Amikacin-impregnated CaSO4 beads achieved extreme supratherapeutic eluent concentrations. While additional studies are needed, bead size significantly affected elution with smaller beads reaching higher peak concentrations and 7 mm, high-concentration beads demonstrating a longer therapeutic duration than smaller beads.

Open access
in American Journal of Veterinary Research

Abstract

Objective—To evaluate the effect of administration of the labeled dosage of pimobendan to dogs with furosemide-induced activation of the renin-angiotensin-aldosterone system (RAAS).

Animals—12 healthy hound-type dogs.

Procedures—Dogs were allocated into 2 groups (6 dogs/group). One group received furosemide (2 mg/kg, PO, q 12 h) for 10 days (days 1 to 10). The second group received a combination of furosemide (2 mg/kg, PO, q 12 h) and pimobendan (0.25 mg/kg, PO, q 12 h) for 10 days (days 1 to 10). To determine the effect of the medications on the RAAS, 2 urine samples/d were obtained for determination of the urinary aldosterone-to-creatinine ratio (A:C) on days 0 (baseline), 5, and 10.

Results—Mean ± SD urinary A:C increased significantly after administration of furosemide (baseline, 0.37 ± 0.14 μg/g; day 5, 0.89 ± 0.23 μg/g) or the combination of furosemide and pimobendan (baseline, 0.36 ± 0.22 μg/g; day 5, 0.88 ± 0.55 μg/g). Mean urinary A:C on day 10 was 0.95 ± 0.63 μg/g for furosemide alone and 0.85 ± 0.21 μg/g for the combination of furosemide and pimobendan.

Conclusions and Clinical Relevance—Furosemide-induced RAAS activation appeared to plateau by day 5. Administration of pimobendan at a standard dosage did not enhance or suppress furosemide-induced RAAS activation. These results in clinically normal dogs suggested that furosemide, administered with or without pimobendan, should be accompanied by RAAS-suppressive treatment.

Full access
in American Journal of Veterinary Research

Abstract

Objective—To determine whether the pattern of extension of modeled infection from the interdigital web spaces in dogs is predictable and whether the distribution differs among initial injury sites.

Sample Population—Thawed frozen forelimbs from 23 cadavers of previously healthy adult medium- to large-breed dogs.

Procedures—The manus of each forelimb was evaluated by use of computed tomography (CT) before and after injection of radiopaque blue-staining contrast medium into the interdigital web spaces. Two veterinary radiologists reviewed the CT images and recorded the extent of contrast medium from each site. Each manus was dissected or sectioned transversely after imaging, and the extent of contrast medium accumulation was recorded and compared with locations of CT contrast enhancement. The Fisher exact test was performed to determine whether the pattern of contrast medium extension differed by injection site.

Results—Injections made in the interdigital web spaces of the canine manus led to unique and predictable patterns of extension into the surrounding soft tissues. That pattern of extension primarily involved the soft tissues of the digits.

Conclusions and Clinical Relevance—In humans, knowledge of common extension patterns from infected soft tissue spaces is used to predict the spread of disease within the hand and develop surgical plans that will minimize patient illness. Identification of the common sites of disease spread from the interdigital web spaces in dogs may help improve surgical planning and treatment for infection in the manus.

Full access
in American Journal of Veterinary Research

Abstract

Objective—To evaluate tissue oxygen saturation (Sto 2) by use of near-infrared spectroscopy in experimental acute hemorrhagic shock and resuscitation in dogs.

Animals—14 healthy adult purpose-bred Beagles.

Procedures—Dogs were anesthetized with isoflurane via facemask, anesthesia was maintained with propofol and rocuronium bromide, and dogs were mechanically ventilated to maintain normocapnia. Dogs were studied under normovolemia (baseline), hypovolemia with target mean arterial blood pressure < 40 mm Hg achieved and maintained steady for 10 minutes (hypovolemia T1), then 20 minutes later (hypovolemia T2), following resuscitation with shed blood (after transfusion), and after administration of 20 mL of hetastarch/kg (hypervolemia). Conditions were executed sequentially during a single anesthetic episode, allowing stabilization between states (10 minutes). Hemoglobin concentration, mean arterial blood pressure, arterial blood gas concentrations, cardiac index, oxygen delivery indexed to body surface area, and Sto 2 were monitored.

Results—From baseline to hypovolemia T1, there was a significant reduction in mean ± SD oxygen delivery index (619 ± 257 mL/min/m2 to 205 ± 76 mL/min/m2) and StO2 (94 ± 4.4% to 78 ± 12.2%). Following resuscitation, Sto 2 (80 ± 8.5% vs 92 ± 6.45%) and oxygen delivery index (211 ± 73 mL/min/m2 vs 717 ± 221 mL/min/m2) significantly increased, returning to baseline values. Hypervolemia had no effect on Sto 2 or oxygen delivery index. A strong correlation (r = 0.97) was detected between mean oxygen delivery index and Sto 2 across all time points.

Conclusions and Clinical Relevance—Under the conditions of this study, there was a strong correlation between Sto 2 and oxygen delivery, suggesting that Sto 2 may be used to estimate oxygen delivery.

Full access
in American Journal of Veterinary Research