OBJECTIVE To evaluate the time and number of laser beam passes required to make full-thickness skin incisions and extent of laser-induced tissue artifacts following use of a CO(2) laser at various settings. SAMPLE 24 skin specimens from six 5-month-old porcine carcasses. PROCEDURES 4 full-thickness skin specimens were harvested from the flank regions of each carcass within 30 minutes after euthanasia and randomly assigned to 4 treatment groups. Three 5-cm-long incisions were made in each specimen with a CO(2) laser (beam diameter, 0.4 mm) set to deliver a continuous wave of energy alone (groups 1 and 2) or in superpulse mode (groups 3 and 4) at 10 (groups 1 and 3) or 20 (groups 2 and 4) W of power. The time and number of passes required to achieve a full-thickness incision were recorded, and extent of laser-induced tissue artifact (as determined by histologic evaluation) was compared among the 4 groups. RESULTS Mean time required to make a full-thickness skin incision for groups 2 and 4 (power, 20 W) was significantly less than that for groups 1 and 3 (power, 10 W). Mean number of passes was lowest for group 2 (continuous wave at 20 W). Extent of laser-induced tissue artifact was greatest for group 4 (superpulse mode at 20 W). CONCLUSIONS AND CLINICAL RELEVANCE Results provided preliminary information regarding use of CO(2) lasers to make skin incisions in veterinary patients. In vivo studies are necessary to evaluate the effect of various CO(2) laser settings on tissue healing and patient outcome.

OBJECTIVE To determine whether cell-free DNA (cfDNA) was detectable in CSF samples from dogs, whether CSF sample volume impacted CSF cfDNA concentration measurement, and whether CSF cfDNA concentration was associated with CNS disease category or CSF RBC count (RBCC), nucleated cell count (NCC), or protein concentration, which could aid in the diagnosis of neurologic diseases in dogs. SAMPLE 80 CSF samples collected from dogs with (n = 60) and without (20) clinical neurologic disease between February 2017 and May 2018. PROCEDURES Results for CSF RBCC, NCC, protein concentration, and cfDNA concentration were compared across CSF groups established on the basis of whether they were obtained from dogs with (case groups) or without (control group) clinical signs of neurologic disease In addition, 5 paired CSF samples representing large (3.0-mL) and small (0.5-mL) volumes, were used to evaluate whether sample volume impacted measurement of CSF cfDNA concentration. RESULTS cfDNA was detected in 76 of the 80 (95%) CSF samples used to evaluate parameters across disease categories and in all 5 of the paired samples used to evaluate whether sample volume impacted cfDNA quantification. There were no substantial differences in cfDNA concentrations identified between groups (on the basis of disease category or sample volume), and the CSF cfDNA concentration did not meaningfully correlate with CSF RBCC, NCC, or protein concentration. CONCLUSIONS AND CLINICAL RELEVANCE Although results indicated that the CSF cfDNA concentration could not be used to differentiate between categories of neurologic disease in dogs of the the present study, further investigation is warranted regarding the use of CSF analysis, including sequencing specific cfDNA mutations, for diagnosing and monitoring neurologic disease in dogs.

OBJECTIVE To investigate the activities of gelatinases (matrix metalloproteinase [MMP]-2 and MMP-9) and serine proteases in the colorectal mucosa of Miniature Dachshunds (MDs) with inflammatory colorectal polyps (ICRPs). ANIMALS 15 MDs with ICRPs and 5 dogs with non–ICRP-related large bowel diarrhea (controls). PROCEDURES Zymographic methods were used to evaluate the activities of MMP-2, MMP-9, latent forms of MMP-2 and MMP-9 (pro–MMP-2 and pro–MMP-9), and serine proteases in inflamed and noninflamed tissue samples from MDs with ICRPs and in noninflamed tissue samples from control dogs. The associations of serine protease activities with MMP-2 or MMP-9 activity were also analyzed. RESULTS Activities of pro–MMP-2 and pro–MMP-9 were detected in most tissue samples, regardless of the tissue type, whereas activities of MMP-2 and MMP-9 were not detected in control tissue samples. In the inflamed tissue samples from MDs with ICRPs, the activities of MMP-2, pro–MMP-9, and MMP-9 were significantly higher than those in the noninflamed tissue samples from those dogs. Serine protease activities were significantly higher in the inflamed and noninflamed tissue samples from MDs with ICRP, compared with findings for control tissue samples. A weak correlation was detected between serine protease activities and MMP-9 activity. CONCLUSIONS AND CLINICAL RELEVANCE Study results suggested that gelatinase and serine protease activities are upregulated in the colorectal mucosa of MDs with ICRPs, possibly contributing to the pathogenesis of this disease through the functions of these enzymes in degradation of extracellular matrix and promotion of inflammatory cell migration and inflammatory responses.

OBJECTIVE To determine the degree of histomorphometric damage in dorsal colon and pelvic flexure biopsy specimens (DCBSs and PFBSs, respectively) obtained from horses with large colon volvulus (LCV) and assess the accuracy of predicting short-term outcome for those horses on the basis of DCBS or PFBS characteristics. ANIMALS 18 horses with ≥ 360° LCV that underwent large colon resection. PROCEDURES During surgery, biopsy specimens from the dorsal colon resection site and the pelvic flexure (when available) were collected from each horse. Interstitial-to-crypt (I:C) ratio (ratio of the lamina propria space occupied by the interstitium to that occupied by crypts), hemorrhage within the lamina propria (mucosal hemorrhage score [MHS] from 0 to 4), and percentage losses of glandular and luminal epithelium were determined in paired biopsy specimens and compared to determine optimal cutoff values for calculating the accuracy of DCBS and PFBS characteristics to predict short-term outcome (survival or nonsurvival after recovery from surgery). RESULTS Paired biopsy specimens were obtained from 17 of the 18 horses. The I:C ratio and percentage glandular epithelial loss differed between DCBSs and PFBSs. For DCBSs, an I:C ratio ≥ 0.9 and MHS ≥ 3 each predicted patient nonsurvival with 77.8% accuracy. For PFBSs, an I:C ratio ≥ I and MHS ≥ 3 predicted patient nonsurvival with 70.6% and 82.4% accuracy, respectively. CONCLUSIONS AND CLINICAL RELEVANCE Although different, histomorphometric measurements for either DCBSs or PFBSs could be used to accurately predict short-term outcome for horses with LCV that underwent large colon resection, and arguably PFBSs are easier to collect.

OBJECTIVE To determine whether a customized unilateral intervertebral anchored fusion device combined with (vs without) an intervertebral spacer would increase the stability of the L1-L2 motion segment following complete intervertebral diskectomy in canine cadaveric specimens. SAMPLE Vertebral columns from T13 through L3 harvested from 16 skeletally mature Beagles without thoracolumbar disease. PROCEDURES Complete diskectomy of the L1-2 disk was performed in each specimen. Unilateral stabilization of the L1-L2 motion segment was performed with the first of 2 implants: a unilateral intervertebral anchored fusion device that consisted of a locking compression plate with or without an intervertebral spacer. The resulting construct was biomechanically tested; then, the first implant was removed, and the second implant was applied to the contralateral side and tested. Range of motion in flexion and extension, lateral bending, and torsion was compared among intact specimens (prior to diskectomy) and constructs. RESULTS Compared with intact specimens, constructs stabilized with either implant were as stable in flexion and extension, significantly more stable in lateral bending, and significantly less stable in axial rotation. Constructs stabilized with the fusion device plus intervertebral spacer were significantly stiffer in lateral bending than those stabilized with the fusion device alone. No significant differences in flexion and extension and rotation were noted between implants. CONCLUSIONS AND CLINICAL RELEVANCE Findings did not support the use of this customized unilateral intervertebral anchored fusion device with an intervertebral spacer to improve unilateral stabilization of the L1-L2 motion segment after complete L1-2 diskectomy in dogs.

The objective of this study was to document tidal variations in tracheal height during normal respiration in 19 healthy adult (> 1 y old) small-breed dogs (< 10 kg) using fluoroscopy and radiography. Each dog underwent tracheal fluoroscopic examination on inspiration and expiration while in a standing position (F-S) and in right lateral recumbency (F-RL), followed by radiographic projections obtained in right lateral recumbency. The percent variation in tracheal height during maximal inspiration and expiration was determined at 3 different locations [cervical region (CR), thoracic inlet (TI), and intrathoracic (IT) region]. When all imaging procedures and sites of measurement were considered, tracheal height varied during physiologic inspiration and expiration from 0% to 21.1%, with a mean of 4.5%. The mean percent variation in tracheal height was not significantly different among imaging modalities (F-S versus F-RL versus radiography) (P = 0.16) or measurement sites (CR versus TI versus IT) (P = 0.89). The body condition score (BCS) (P = 0.96), age (P = 0.95), and breed (P = 0.19) did not significantly influence the mean percent variation in tracheal height. The average variation in tracheal height during maximal physiological inspiration and expiration is small (< 6%) in most healthy adult small-breed dogs as assessed by fluoroscopy and radiography, although tracheal height may vary by as much as 21.1% in some healthy individuals. Inspiratory and expiratory radiographs acquired in right lateral recumbency provide an accurate assessment of tracheal height as an alternative to fluoroscopy.

OBJECTIVE To establish a reference interval for glomerular filtration rate (GFR) determined by measuring serum clearance of a single IV dose of inulin in clinically normal cheetahs (Acinonyx jubatus) and compare serum symmetric dimethylarginine (SDMA) concentration in cheetahs with GFR. ANIMALS 33 cheetahs housed at 3 institutions. PROCEDURES A single bolus of inulin (3,000 mg/m2) was administered IV, and 5 serial blood samples were collected and analyzed for serum inulin concentration with the anthrone technique. The GFR was estimated with a modified slope-intercept method for the slow component of the serum concentration-versus-time curve. Blood urea nitrogen and serum creatinine concentrations were measured in samples obtained immediately prior to inulin administration, and serum SDMA concentration was measured in stored samples. RESULTS Mean ± SD measured GFR was 1.58 ± 0.39 mL/min/kg, and the calculated reference interval was 0.84 to 2.37 mL/min/kg. There were significant negative correlations between GFR and serum creatinine concentration (r = −0.499), BUN concentration (r = −0.592), and age (r = −0.463). Serum SDMA concentration was not significantly correlated with GFR (r = 0.385), BUN concentration (r = −0.281), or serum creatinine concentration (r = 0.165). CONCLUSIONS AND CLINICAL RELEVANCE A reference interval for GFR in clinically normal cheetahs was obtained. Further evaluation of animals with renal disease is needed to determine whether measuring serum clearance of a single IV dose of inulin is a reliable diagnostic test for early detection of renal disease in cheetahs.

OBJECTIVE To determine values of F-wave parameters for the tibial nerve in clinically normal Miniature Dachshunds and those with thoracolumbar intervertebral disk herniation (IVDH). ANIMALS 53 Miniature Dachshunds (10 clinically normal and 43 with various clinical grades of thoracolumbar IVDH). PROCEDURES F-waves were elicited in the interosseous muscles of 1 hind limb in each dog by stimulation of the tibial nerve. F-wave parameters were measured for 32 stimuli/dog, and mean values were calculated. Linear regression was performed to assess correlations between F-wave parameters and clinical severity of IVDH. RESULTS For clinically normal dogs, mean ± SD values of shortest F-wave latency, mean F-wave conduction velocity, mean F-wave duration, and ratio of the mean F-wave amplitude to M response amplitude were 8.6 ± 0.6 milliseconds, 83.7 ± 6.1 m/s, 6.6 ± 1.5 milliseconds, and 9.8 ± 8.5%, respectively. F-wave persistence was 100%. Mean F-wave duration was positively correlated with clinical grade of IVDH. Linear regression yielded the following regression equation: F-wave duration (milliseconds) = 6.0 + 2.7 × IVDH grade. One dog with grade 2 IVDH had a mean F-wave duration shorter than that of all 5 dogs with grade 1 IVDH; 1 dog with grade 3 IVDH had a longer duration than that of all 10 dogs with grade 4 IVDH. CONCLUSIONS AND CLINICAL RELEVANCE Mean F-wave duration was correlated with the severity of inhibitory motor tract dysfunction in the spinal cord of dogs. F-wave examination may be useful for objective functional evaluation of upper motor neurons in the spinal cord.

OBJECTIVE To compare the ability of acetaminophen-codeine (AC; 15.5 to 18.5 mg/kg and 1.6 to 2.0 mg/kg, respectively) or carprofen (4.2 to 4.5 mg/kg) administered PO to attenuate experimentally induced lameness in dogs. ANIMALS 7 purpose-bred dogs. PROCEDURES A blinded crossover study was performed. Dogs were randomly assigned to receive AC or carprofen treatment first and then the alternate treatment a minimum of 21 days later. Synovitis was induced in 1 stifle joint during each treatment by intra-articular injection of sodium urate (SU). Ground reaction forces were assessed, and clinical lameness was scored at baseline (before lameness induction) and 3, 6, 9, 12, 24, 36, and 48 hours after SU injection. Plasma concentrations of acetaminophen, carprofen, codeine, and morphine were measured at various points. Data were compared between and within treatments by repeated-measures ANOVA. RESULTS During AC treatment, dogs had significantly higher lameness scores than during carprofen treatment at 3, 6, and 9 hours after SU injection. Peak vertical force and vertical impulse during AC treatment were significantly lower than values during carprofen treatment at 3, 6, and 9 hours. Plasma concentrations of carprofen (R)- and (S)-enantiomers ranged from 2.5 to 19.2 μg/mL and 4.6 to 25.0 μg/mL, respectively, over a 24-hour period. Plasma acetaminophen concentrations ranged from 0.14 to 4.6 μg/mL and codeine concentrations from 7.0 to 26.8 ng/mL, whereas plasma morphine concentrations ranged from 4.0 to 58.6 ng/mL. CONCLUSIONS AND CLINICAL RELEVANCE Carprofen as administered was more effective than AC at attenuating SU-induced lameness in dogs.

The objectives of this study were to investigate the usefulness of mitral flow propagation velocity (Vp) in cats by evaluating the effect of the flow pattern summation and evaluation of Vp variables in cats with hypertrophic cardiomyopathy (HCM). Healthy cats were categorized into summation (Sum) and separation (Sepa) groups to evaluate the effects of the flow pattern summation on Vp. Cats with HCM were categorized into HCM left atrial (LA) (−), LA (+), and LA (++) groups according to the degree of LA enlargement to investigate the feasibility of Vp. There were no significant differences noted in Vp between the Sum and Sepa groups and no significant correlation between Vp and heart rate. Decline of Vp was associated with the degree of LA enlargement. Mitral flow propagation velocity appeared to be clinically feasible in cats and could possibly be useful in the detection of diastolic dysfunctions in cats with HCM.