Objective—To quantitate changes in hoof wall growth and hoof morphology induced by mild exercise in Standardbreds.
Procedures—Horses were exercised at approximately 6 m/s (4,200 to 5,600 m/d) on 4 d/wk for 17 weeks. Both exercise (n = 9) and nonexercise (control group; 9) groups were housed in a large paddock throughout the study. At the beginning and end of the study, right forelimb feet of all horses were digitally photographed and underwent magnetic resonance imaging. Hoof wall measurements were obtained from the images to evaluate hoof wall growth and morphometric variables. Data were compared between the groups and within each group via a quadratic model. Changes in each variable and pairwise correlations between variables were evaluated.
Results—Morphometric variables did not significantly differ between the control and exercise groups. However, differences within each group between the start and the end of the study were significant for several variables; overall, values for hoof wall variables increased and those for solar variables decreased. Between the beginning and the end of the study, the amount of variation in values of hoof capsule variables in the exercise group decreased to a greater extent, compared with control group findings. Patterns of pairwise correlations for variables differed between the groups.
Conclusions and Clinical Relevance—In Standardbreds, mild exercise for 17 weeks caused no significant changes in hoof wall growth or morphometric variables. Subtle changes may develop in equine hooves in response to loading, and mild exercise may not be a strong adaptive stimulus.
Objective—To quantify changes in hoof wall strain distribution associated with exercise and time in Standardbreds.
Animals—18 young adult Standardbreds.
Procedures—9 horses were exercised 4 d/wk for 30 to 45 minutes at a medium trot for 4 months; 9 nonexercised horses served as the control group. Rosette strain gauges were used to measure the principal surface strains at the toe, lateral quarter of the hoof wall (LQ), and medial quarter of the hoof wall (MQ) of the right forefoot at the beginning and end of the experiment. Midstance maximal (msϵ1) and minimal (msϵ2) principal and peak minimal principal (pkϵ2) surface strains were measured; SDs of each of those variables were also calculated. Results were compared through ANOVA of time and exercise effects between and within the groups.
Results—Both the exercised and nonexercised groups had changes in strain distribution in their hooves over time. The msϵ1 did not change significantly with exercise; however, it changed significantly in both groups at both hoof quarters over time. At the beginning of the study, mean msϵ2 and pkϵ2 values were significantly higher in the exercised group than in the control group at the MQ and LQ but not at the toe. At the end of the study, these values were significantly higher in the control group than in the exercised group at the toe but not at the MQ or LQ.
Conclusions and Clinical Relevance—Detected changes in hoof wall surface strain may indicate the ability of hoof capsule material to respond to exercise. A better understanding of hoof adaptation to applied forces may allow implementation of proper trimming and shoeing techniques to promote adaptation to exercise loads in horses.
Objective—To determine the cardiovascular effects
of 60 minutes of abdominal insufflation with CO2 to
an intra-abdominal pressure of 15 mm Hg in standing
horses receiving a constant rate infusion of detomidine.
Procedure—Horses were randomly allocated into
treatment or control groups. A washout period of a
minimum of 7 days separated the 2 experimental
periods of the crossover study. Catheters were
placed into the right atrium, pulmonary artery, jugular
vein, and right transverse facial artery after lidocaine
infiltration. All horses were sedated with detomidine
(8.54 µg/kg/h, IV). Horses in the treatment
group received abdominal insufflation with CO2 via
a laparoscopic cannula to a final and constant intraabdominal
pressure of 15 mm Hg for 60 minutes.
Systemic arterial pressure, right atrial pressure,
heart rate, cardiac output, core body temperature,
and the pH and gas tensions of arterial and mixed
venous blood were obtained. Cardiac index and systemic
vascular resistance were calculated. Data
were collected in 3 stages: preinsufflation (–10 and
–5 minutes), insufflation (0, 15, 30, 45, and 60 minutes),
and postinsufflation (70 and 80 minutes). The
quality of sedation and level of analgesia were
Results—The PaO2 of horses in the treatment group
was significantly higher after 60 minutes of pneumoperitoneum
than in the control group. Core body
temperature decreased significantly from baseline in
Conclusions and Clinical Relevance—A 60-minute
period of abdominal insufflation to an intra-abdominal
pressure of 15 mm Hg did not induce significant cardiovascular
abnormalities in healthy horses. ( Am J Vet Res 2004;65:357–362)
Objective—To evaluate the dose-related cardiovascular and urine output (UrO) effects of dopamine hydrochloride and dobutamine hydrochloride, administered individually and in combination at various ratios, and identify individual doses that achieve target mean arterial blood pressure (MAP; 70 mm Hg) and cardiac index (CI; 150 mL/kg/min) in dogs during deep isoflurane anesthesia.
Animals—10 young clinically normal dogs.
Procedures—Following isoflurane equilibration at a baseline MAP of 50 mm Hg on 3 occasions, dogs randomly received IV administration of dopamine (3, 7, 10, 15, and 20 μg/kg/min), dobutamine (1, 2, 4, 6, and 8 μg/kg/min), and dopamine-dobutamine combinations (3.5:1, 3.5:4, 7:2, 14:1, and 14:4 μg/kg/min) in a crossover study. Selected cardiovascular and UrO effects were determined following 20-minute infusions at each dose.
Results—Dopamine caused significant dose-dependent responses and achieved target MAP and CI at 7 μg/kg/min; dobutamine at 2 μg/kg/min significantly affected only CI values. At any dose, dopamine significantly affected UrO, whereas dobutamine did not. Target MAP and CI values were achieved with a dopamine-dobutamine combination at 7:2 μg/kg/min; a dopamine-related dose response for MAP and dopamine- and dobutamine-related dose responses for CI were identified. Changes in UrO were associated with dopamine only.
Conclusions and Clinical Relevance—In isoflurane-anesthetized dogs, a guideline dose for dopamine of 7 μg/kg/min is suggested; dobutamine alone did not improve MAP. Data regarding cardiovascular and UrO effects indicated that the combination of dopamine and dobutamine did not provide greater benefit than use of dopamine alone in dogs.
Objective—To determine associations between oral health status and seropositivity for FIV or FeLV in cats.
Procedures—Veterinarians at veterinary clinics and animal shelters completed online training on oral conditions in cats and then scored oral health status of cats with no known history of vaccination against FIV. Age, sex, and results of an ELISA for retroviruses were recorded. Results were analyzed by means of standard logistic regression with binary outcome.
Results—Of 5,179 cats, 237 (4.6%) and 186 (3.6%) were seropositive for FIV and FeLV, respectively, and of these, 12 (0.2%) were seropositive for FIV and FeLV. Of all 5,179 cats, 1,073 (20.7%) had gingivitis, 576 (11.1%) had periodontitis, 203 (3.9%) had stomatitis, and 252 (4.9%) had other oral conditions (overall oral disease prevalence, 2,104/5,179 [40.6%]). Across all age categories, inflammatory oral disease was associated with a significantly higher risk of a positive test result for FIV, compared with the seropositivity risk associated with other oral diseases or no oral disease. Stomatitis was most highly associated with risk of FIV seropositivity. Cats with any oral inflammatory disease were more likely than orally healthy cats to have a positive test result for FeLV. Increasing age was associated with a higher prevalence of oral disease in retrovirus-seronegative cats.
Conclusions and Clinical Relevance—Inflammatory oral disease was associated with an increased risk of seropositivity for retroviruses in naturally infected cats. Therefore, retroviral status of cats with oral inflammatory disease should be determined and appropriate management initiated.
Objective—To evaluate the use of laparoscopic-assistedjejunostomy feeding tube (J-tube) placement in healthy dogs under sedation with epidural and local anesthesia and compare cardiopulmonary responses during this epidural anesthetic protocol with cardiopulmonary responses during general anesthesia for laparoscopic-assisted or open surgical J-tube placement.
Animals—15 healthy mixed-breed dogs.
Procedures—Dogs were randomly assigned to receive open surgical J-tube placement under general anesthesia (n = 5dogs; group 1), laparoscopic-assisted J-tube placement under general anesthesia (5; group 2), or laparoscopic-assisted J-tube placement under sedation with epidural and local anesthesia (5; group 3). Cardiopulmonary responses were measured at baseline (time 0), every 5 minutes during the procedure (times 5 to 30 minutes), and after the procedure (after desufflation [groups 2 and 3] or at the start of abdominal closure [group 1]). Stroke volume, cardiac index, and O2 delivery were calculated.
Results—All group 3 dogs tolerated laparoscopic-assisted J-tube placement under sedation with epidural and local anesthesia. Comparison of cardiovascular parameters revealed a significantly higher cardiac index, mean arterial pressure, and O2 delivery in group 3 dogs, compared with group 1 and 2 dogs. Minimal differences in hemodynamic parameters were foundbetween groups undergoing laparoscopic-assistedandopen surgical J-tube placement under general anesthesia (ie, groups 1 and 2); these differences were not considered to be clinically important in healthy research dogs.
Conclusions and Clinical Relevance—Sedation with epidural and local anesthesia provided satisfactory conditions for laparoscopic-assisted J-tube placement in healthy dogs; this anesthetic protocol caused less cardiopulmonary depression than general anesthesia and may represent a better choice for J-tube placement in critically ill patients.
OBJECTIVE To determine effects of repeated use and resterilization on structural and functional integrity of microwave ablation (MWA) antennas.
SAMPLE 17 cooled-shaft MWA antennas (3 groups of 5 antennas/group and 2 control antennas).
PROCEDURES 1, 2, and 3 ablations in the livers of bovine cadavers were performed at the maximum recommended settings. Antennas were cleaned and sterilized in hydrogen peroxide plasma, and the process was repeated (reprocessing cycle; n = 6). Control antennas were only sterilized (6 times). Aerobic and anaerobic bacterial cultures were performed, and antennas were microscopically assessed for damage.
RESULTS 6 cycles were completed. Thirteen of 15 MWA antennas remained functional for up to 4 cycles, 10 were functional after 5 cycles, and only 7 were functional after 6 cycles. Progressive tearing of the silicone coating of the antennas was observed, with a negative effect of the number of cycles for silicone tearing. Size of the ablation zone decreased mildly over time after cycles 5 and 6; however, this was not considered clinically relevant. No significant changes in the shape of ablation zones were detected. All cultures yielded negative results, except for an isolated case, which was considered a contaminant.
CONCLUSIONS AND CLINICAL RELEVANCE Structural and functional integrity of the microwave antennas remained acceptable during repeated use and reprocessing for up to 4 cycles. However, there was a decrease in functional integrity at cycles 5 and 6. We suggest that these microwave antennas be subjected to > 3 reprocessing cycles. Antennas should be carefully examined before reuse.
Objective—To prospectively assess whether multiple-site disk fenestration decreases the incidence of recurrent thoracolumbar intervertebral disk herniation (IVDH), compared with single-site disk fenestration, in small-breed dogs treated for IVDH.
Design—Randomized controlled clinical trial.
Animals—207 client-owned dogs.
Procedures—Dogs undergoing decompressive surgery of the spinal cord because of thoracolumbar IVDH between 2001 and 2004 were randomly assigned to receive single-site disk fenestration at the level of surgical decompression (n = 103) or multiple-site disk fenestration of all disks from T11 through L4 (104). Follow-up consisted of complete reevaluation of patients, telephone surveys, and further surgery if signs indicative of recurrence occurred.
Results—189 dogs were available for long-term follow-up: 95 dogs in the single-site disk fenestration group and 94 in the multiple-site disk fenestration group. Twenty-four dogs developed 28 confirmed episodes of recurrent thoracolumbar IVDH. The rate for first-time recurrence was 12.7% (24/189). First-time recurrence rates for single-and multiple-site disk fenestration groups were 17.89% (17/95) and 7.45% (7/94), respectively. Dogs undergoing single-site disk fenestration were significantly more likely to have recurrent thoracolumbar IVDH than were dogs undergoing multiple-site disk fenestration. Disk mineralization at the time of first surgery was associated with recurrence, and 87.5% (21/24) of recurrences occurred at a disk space adjacent to or 1 disk away from the initial lesion. Regardless of disk fenestration group, 22 of 24 (91.7%) recurrences occurred at a nonfenestrated disk space.
Conclusions and Clinical Relevance—Multiple-site disk fenestration decreased the rate of recurrent IVDH in small-breed dogs, compared with the use of single-site disk fenestration.
OBJECTIVE To determine risk factors for surgical intervention, complications, and outcome in dogs with an esophageal foreign body (EFB).
DESIGN Retrospective observational study.
ANIMALS 224 incidents of EFB in 223 dogs evaluated at a veterinary teaching hospital from 1995 through 2014.
PROCEDURES Hospital records were reviewed to collect data regarding signalment, history, clinical signs, EFB type and location, procedures, complications, and outcomes. Breed distributions were compared between dogs with EFB and the entire canine patient population during the study period. Variables were tested for associations with each other and with outcomes.
RESULTS Terrier breeds were most common (71/233 [30.5%]). Duration of EFB entrapment, body weight, anorexia, lethargy, rectal temperature, and esophageal perforation were associated with the need for surgical intervention. Older age, longer duration of EFB entrapment, and perforation were associated with a poorer prognosis. Endoscopic retrieval or advancement into the stomach was successful for 183 of 219 (83.6%) EFBs, and 16 of 143 (11.2%) entrapments resulted in postprocedural esophageal stricture. Overall median duration of hospitalization was brief (1 day), and the need for surgical intervention was associated with a longer duration. Overall mortality rate was 5.4% (12/223); 90 of 102 (88.2%) dogs with a median follow-up period of 27 months after EFB treatment had an excellent outcome.
CONCLUSIONS AND CLINICAL RELEVANCE Study findings suggested that endoscopic EFB retrieval remains the initial treatment option of choice for affected dogs, provided that esophageal perforation does not necessitate surgical intervention. Although esophageal stricture formation was the most common complication, the overall rate of this outcome was low.
Objective—To assess agreement between arterial
pressure waveform–derived cardiac output (PCO) and
lithium dilution cardiac output (LiDCO) systems in
measurements of various levels of cardiac output
(CO) induced by changes in anesthetic depth and
administration of inotropic drugs in dogs.
Animals—6 healthy dogs.
Procedure—Dogs were anesthetized on 2 occasions
separated by at least 5 days. Inotropic drug administration
(dopamine or dobutamine) was randomly
assigned in a crossover manner. Following initial calibration
of PCO measurements with a LiDCO measurement,
4 randomly assigned treatments were
administered to vary CO; subsequently, concurrent
pairs of PCO and LiDCO measurements were
obtained. Treatments included a light plane of anesthesia,
deep plane of anesthesia, continuous infusion
of an inotropic drug (rate adjusted to achieve a mean
arterial pressure of 65 to 80 mm Hg), and continuous
infusion of an inotropic drug (7 µg/kg/min).
Results—Significant differences in PCO and LiDCO
measurements were found during deep planes of
anesthesia and with dopamine infusions but not during
the light plane of anesthesia or with dobutamine
infusions. The PCO system provided higher CO measurements
than the LiDCO system during deep
planes of anesthesia but lower CO measurements
during dopamine infusions.
Conclusions and Clinical Relevance—The PCO system
tracked changes in CO in a similar direction as
the LiDCO system. The PCO system provided better
agreement with LiDCO measurements over time
when hemodynamic conditions were similar to those
during initial calibration. Recalibration of the PCO system
is recommended when hemodynamic conditions
or pressure waveforms are altered appreciably. (Am J Vet Res 2005;66:1430–1436)