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Abstract

Objective—To compare the effects of meloxicam, carprofen, and flunixin meglumine administered IV on the concentration of prostaglandin E2 (PGE2) in the aqueous humor of dogs with aqueocentesis-induced anterior uveitis.

Animals—15 adult dogs with ophthalmically normal eyes.

Procedures—Each dog was assigned to 1 of 4 treatment groups. Treatment groups were saline (0.9% NaCl) solution (1 mL, IV), meloxicam (0.2 mg/kg, IV), carprofen (4.4 mg/kg, IV), and flunixin meglumine (0.5 mg/kg, IV). Each dog was anesthetized, treatment was administered, and aqueocentesis was performed on each eye at 30 and 60 minutes after treatment. Aqueous humor samples were frozen at −80°C until assayed for PGE2 concentration with an enzyme immunoassay kit.

Results—For all 4 treatment groups, PGE2 concentration was significantly higher in samples obtained 60 minutes after treatment, compared with that in samples obtained 30 minutes after treatment, which indicated aqueocentesis-induced PGE2 synthesis. For aqueous humor samples obtained 60 minutes after treatment, PGE2 concentration did not differ significantly among groups treated with saline solution, meloxicam, and carprofen; however, the PGE2 concentration for the group treated with flunixin meglumine was significantly lower than that for each of the other 3 treatment groups.

Conclusions and Clinical Relevance—Flunixin meglumine was more effective than meloxicam or carprofen for minimizing the PGE2 concentration in the aqueous humor of dogs with experimentally induced uveitis. Flunixin meglumine may be an appropriate pre-medication for use prior to intraocular surgery in dogs.

Full access
in American Journal of Veterinary Research

Abstract

Objective—To biomechanically evaluate various finger trap patterns and suture materials for securing 5F polyvinylchloride and polypropylene catheters.

Design—In vitro prospective study.

Sample—132 finger trap constructs.

Procedures—Each group of constructs comprised 6 to 10 replicates each of 3 finger trap patterns tied with 2–0 glycolide-lactide copolymer (GLC), braided nylon, and monofilament polypropylene suture on 5F polypropylene and polyvinylchloride catheters. The 3 finger trap variants were of similar lengths but differed in the number of surgeon's throws included in the pattern. Constructs were tested with a universal materials testing machine to the point of failure or a maximum of 100 mm of distraction. Force and distraction data were evaluated for significance with a competing risks model.

Results—There was no difference in performance (as measured by the proportion of test failures, median distraction distance, or median force at failure or end of testing) attributable to the finger trap pattern variants. Sixteen of 66 constructs with polyvinylchloride catheter material failed at ≤ 100 mm distraction, whereas all polypropylene constructs failed during testing. For polypropylene catheters, braided nylon or GLC suture withstood greater distraction distance and force, respectively. For polyvinylchloride catheters, differences among suture types were nonsignificant.

Conclusions and Clinical Relevance—Data suggested that, for the material combinations evaluated, a finger trap suture pattern with fewer knots may provide catheter security similar to that for patterns tied with a more traditional pattern. These results should not be extrapolated to catheters of different diameters or materials, patterns tied with different suture sizes, or clinical performance in vivo without further testing.

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in Journal of the American Veterinary Medical Association

Abstract

OBJECTIVE To determine rate of recurrence of disk herniation in dogs that underwent percutaneous laser disk ablation (PLDA) because of a previous episode of suspected or confirmed thoracolumbar intervertebral disk herniation (IVDH).

DESIGN Retrospective case series.

ANIMALS 303 dogs that underwent PLDA and for which a minimum of 3 years of follow-up information was available (n = 294) or for which recurrence was documented within 3 years after the procedure (9).

PROCEDURES Information on signalment, previous episodes of IVDH, specifics of the PLDA procedure, and recurrence was obtained from the medical records. Owners were contacted to complete a questionnaire regarding outcome and recurrence.

RESULTS 60 of the 303 (19.8%) dogs had an episode of suspected or confirmed IVDH after undergoing PLDA, but only 11 of the 303 (3.6%) dogs had a recurrence of IVDH confirmed by means of CT or MRI and hemilaminectomy. Recurrence rate following PLDA was not significantly different between dogs that had been treated medically for previous episodes of IVDH and dogs that had been treated surgically. Overall, 270 of 286 (94.4%) owners reported that their dog was the same (109 [38.1%]) or improved (161 [56.3%]) immediately after PLDA, and 265 (92.7%) owners rated their satisfaction with the procedure as ≥ 9 on a scale from 1 (completely dissatisfied) to 10 (completely satisfied).

CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that PLDA was a relatively safe, minimally invasive procedure associated with a low rate of recurrence of disk herniation when performed in dogs with a history of previous episodes of suspected or confirmed IVDH.

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in Journal of the American Veterinary Medical Association

Abstract

Case Description—8 dogs that underwent carbon dioxide (CO2) laser ablation of transitional cell carcinoma in the bladder trigone and proximal portion of the urethra and were also treated with mitotranxone and piroxicam.

Clinical Findings—Transitional cell carcinoma of the bladder frequently involves the trigone and urethra and can be difficult to manage surgically. Dogs underwent laser ablation of the primary tumor and were treated with mitoxantrone at a dosage of 5 mg/m2 every 3 weeks for 4 treatments. Piroxicam was given at a dosage of 0.3 mg/kg (0.14 mg/lb) once daily for the remaining life of the dog.

Treatment and Outcome—Median and mean disease-free intervals were 200 and 280 days, respectively. Median and mean survival times were 299 and 411 days, respectively. Adverse treatment effects were observed in 2 dogs; signs included mild, self-limiting inappetance and lethargy. The procedure appeared to be well tolerated; all treated dogs had rapid resolution of clinical signs of disease of the lower portion of the urinary tract.

Clinical Relevance—Although survival times achieved with CO2 laser ablation and treatment with mitoxantrone and piroxicam were similar to survival times associated with chemotherapy alone, resolution of clinical signs was better with the combined treatment.

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in Journal of the American Veterinary Medical Association

Abstract

OBJECTIVE To evaluate the effect of brachycephaly and body condition score on respiratory thermoregulation of healthy dogs.

DESIGN Prospective study.

ANIMALS 52 brachycephalic and 53 nonbrachycephalic dogs.

PROCEDURES All dogs were exposed to a cool treatment (temperature, 21.8 ± 1.7°C [71.2 ± 3.1°F]; relative humidity, 62.2 ± 9.7%; and ambient enthalpy, 47.7 ± 6.6 kcal/kg) and then a hot treatment (temperature, 32.9 ± 1.7°C [91.2 ± 3.1°F]; relative humidity, 51.9 ± 9.8%; and ambient enthalpy, 74.8 ± 8.7 kcal/kg; heat stress) at least 1 hour later. For each treatment, dogs were allowed to acclimatize to the environment for 15 minutes and then were placed in a sealed whole-body plethysmograph for continuous measurement of the respiratory pattern for 10 minutes. Treatment was discontinued if a dog developed signs of respiratory distress. Respiratory variables and body temperature were compared between the 2 breed types (brachycephalic and nonbrachycephalic) and between treatments.

RESULTS Body condition score was positively associated with body temperature independent of environmental conditions or breed type and negatively associated with tidal volume. Brachycephalic dogs had a greater increase in respiratory rate in response to heat stress than did nonbrachycephalic dogs.

CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that brachycephalic dogs had decreased capacity for thermoregulation, compared with nonbrachycephalic dogs, but body condition score was a greater determinant of body temperature than breed type. Nevertheless, both upper airway conformation and body condition score should be considered when evaluating whether an individual dog is capable of tolerating heat stress.

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in Journal of the American Veterinary Medical Association

Abstract

Objective—To assess gait abnormalities associated with selective anesthesia of the suprascapular nerve (SSN) achieved by use of perineural catheterization and thereby determine the function of that nerve as it relates to gait in horses.

Animals—3 adult horses with no preexisting clinically apparent lameness at a walk.

Procedure—Each horse was anesthetized; the right SSN was exposed surgically for placement of a perineural catheter to permit delivery of 1 mL of 2% mepivacaine hydrochloride. Six hours after recovery from anesthesia, each horse was videotaped while walking (50-step data acquisition period) before and after administration of mepivacaine. Videotapes were reviewed and the proportion of abnormal steps before and after selective SSN anesthesia was assessed. A step was considered abnormal if a marked amount of scapulohumeral joint instability (ie, lateral luxation of the proximal portion of the humerus) was observed during the weight-bearing phase of the stride.

Results—Clinically apparent gait dysfunction was detected in all 3 horses following perineural administration of the local anesthetic agent. Anesthesia of the SSN resulted in scapulohumeral joint instability as evidenced by consistent lateral excursion of the shoulder region during the weight-bearing phase of gait at a walk. The proportion of abnormal steps before and after SSN anesthesia was significantly different in all 3 horses.

Conclusions and Clinical Relevance—These data support the role of the SSN in shoulder joint stability in horses and define SSN dysfunction as 1 mechanism by which the syndrome and gait dysfunction clinically referred to as sweeny may develop.

Full access
in American Journal of Veterinary Research

Abstract

Objective—To evaluate the musculoskeletal analgesic effect of etodolac administered PO every 12 or 24 hours in chronically lame horses by use of force plate analysis.

Animals—22 horses with navicular syndrome.

Procedure—Horses received etodolac (23 mg/kg, PO, q 12 h; n = 7), etodolac (23 mg/kg, PO, q 24 h; 8), or corn syrup (20 mL, PO, q 24 h; control treatment; 7) for 3 days. Combined forelimb peak vertical ground reaction force (PVF) was measured via force plate analysis before the first treatment (baseline) and at 6, 12, 24, and 36 hours after the last treatment. Differences in mean PVF (mPVF) between baseline and subsequent measurements were analyzed (repeated-measures ANOVA) and evaluated for treatment and time effects and treatment-time interaction.

Results—Once- or twice-daily administration of etodolac resulted in significant increases in mPVF from baseline at 6, 12, and 24 hours after the last treatment, compared with the control treatment. There were no significant differences in mPVF between the etodolac treatment groups at any time point. In both etodolac treatment groups, there was a significant increase in mPVF from baseline at 6, 12, and 24 hours, compared with that at 36 hours. Etodolac-associated adverse effects were not detected.

Conclusions and Clinical Relevance—In horses with navicular syndrome, once-daily oral administration of 23 mg of etodolac/kg appears to provide effective analgesia for as long as 24 hours. Twice-daily administration of etodolac at this same dose does not appear to provide any additional analgesic efficacy or duration of effect.

Full access
in American Journal of Veterinary Research

Abstract

Objective—To establish reference ranges for indices of urine N-acetyl-B-D-glucosaminidase (NAG) and G-glutamyl transpeptidase (GGT) activities in clinically normal adult dogs.

Animals—38 dogs.

Procedures—Each dog underwent a physical examination, CBC, serum biochemical analysis, urinalysis, and serologic testing for heartworm antigen and antibodies against Ehrlichia canis and Borrelia burgdorferi. Activities of NAG and GGT in urine were evaluated, and values of the respective indices were determined as urine NAG or GGT activity (U/L) divided by urine creatinine concentration (g/L).

Results—All dogs were considered clinically normal. A 90% prediction interval based on the 5th and 95th percentiles for GGT and NAG index values from both sexes was used to establish the reference ranges for dogs: 1.93 to 28.57 U/g and 0.02 to 3.63 U/g, respectively. Between males and females, urine NAG index differed significantly, whereas urine GGT index did not. When accounting for sex differences, reference ranges for the urine NAG index in males and females were 0.02 to 3.65 U/g and 0.02 to 2.31 U/g, respectively. Changes in urine pH significantly affected the urine GGT index but not the urine NAG index. Neither index changed significantly with changes in body surface area.

Conclusions and Clinical Relevance—Data suggest that increases in urine NAG and GGT indices allow for earlier detection of renal tubular damage in dogs. Such early detection would enable adjustment of the clinical management of affected dogs to decrease morbidity and death rates associated with acute tubular injury and acute tubular necrosis.

Full access
in American Journal of Veterinary Research

Abstract

OBJECTIVE To compare the effects of equivalent volumes of equine plasma and 6% hydroxyethyl starch (600/0.75) solution (hetastarch) administered IV on plasma colloid osmotic pressure (pCOP) and commonly monitored clinicopathologic variables in horses.

ANIMALS 6 healthy mares.

PROCEDURES In a randomized, crossover study, horses were administered hetastarch or plasma (both 10 mL/kg, IV) 18 months apart. The pCOP and variables of interest were measured before (baseline), immediately after, and at intervals up to 96 or 120 hours after infusion. Prothrombin and activated partial thromboplastin times were measured before and at 2 and 8 hours after each infusion.

RESULTS Prior to hetastarch and plasma infusions, mean ± SEM pCOP was 19.4 ± 0.5 mm Hg and 19.4 ± 0.8 mm Hg, respectively. In general, hetastarch and plasma infusions comparably increased pCOP from baseline for 48 hours, with maximum increases of 2.0 and 2.3 mm Hg, respectively. Mean Hct and hemoglobin, total protein, and albumin concentrations were decreased for a period of 72, 96, or 120 hours after hetastarch infusion with maximum decrements of 8.8%, 3.2 g/dL, 1.2 g/dL, and 0.6 g/dL, respectively. Plasma infusion decreased (albeit not always significantly) hemoglobin concentration and Hct for 20 and 24 hours (maximum changes of 1.5 g/dL and 6.6%, respectively) and increased total solids concentration (maximum change of 0.6 g/dL) for 48 hours. Platelet count and coagulation times were minimally affected.

CONCLUSIONS AND CLINICAL RELEVANCE Overall, the hetastarch and plasma infusions comparably increased pCOP in healthy horses for up to 48 hours. Hetastarch induced greater, more persistent perturbations in clinicopathologic variables.

Full access
in American Journal of Veterinary Research

Abstract

Objective—To define the pharmacokinetics of florfenicol in synovial fluid (SYNF) and serum from central venous (CV) and digital venous (DV) blood samples following regional IV perfusion (RIVP) of the distal portion of the hind limb in cows.

Animals—6 healthy adult cows.

Procedures—In each cow, IV catheters were placed in the dorsal common digital vein (DCDV) and the plantar vein of the lateral digit, and an indwelling catheter was placed in the metatarsophalangeal joint of the left hind limb. A pneumatic tourniquet was applied to the midmetatarsal region. Florfenicol (2.2 mg/kg) was administered into the DCDV. Samples of DV blood, SYNF, and CV (jugular) blood were collected after 0.25, 0.50, and 0.75 hours, and the tourniquet was removed; additional samples were collected at intervals for 24 hours after infusion. Florfenicol analysis was performed via high-performance liquid chromatography.

Results—In DV blood, CV blood, and SYNF, mean ± SD maximum florfenicol concentration was 714.79 ± 301.93 μg/mL, 5.90 ± 1.37 μg/mL, and 39.19 ± 29.42 μg/mL, respectively; area under the concentration versus time curve was 488.14 ± 272.53 h•μg•mL−1, 23.10 ± 6.91 h•μg•mL−1, and 113.82 ± 54.71 h•μg•mL−1, respectively; and half-life was 4.09 ± 1.93 hours, 4.77 ± 0.67 hours, and 3.81 ± 0.81 hours, respectively.

Conclusions and Clinical Relevance—Following RIVP, high florfenicol concentrations were achieved in DV blood and SYNF, whereas the CV blood concentration remained low. In cattle, RIVP of florfenicol may be useful in the treatment of infectious processes involving the distal portion of limbs.

Full access
in American Journal of Veterinary Research