To determine effects of bite depth for placement of an epitendinous suture on the biomechanical strength and gap formation of repaired canine tendons.
48 superficial digital flexor tendons (SDFTs) obtained from 24 canine cadavers.
Tendons were assigned to 3 groups (16 tendons/group). Each SDFT was transected and then repaired with a continuous epitendinous suture placed with a bite depth of 1, 2, or 3 mm for groups 1, 2, and 3, respectively. Specimens were loaded to failure. Failure mode, gap formation, yield force, peak force, and failure force were analyzed.
Yield, peak, and failure forces differed significantly between groups 1 and 3 and groups 2 and 3 but not between groups 1 and 2. Comparison of the force resisted at 1 and 3 mm of gapping revealed a significant difference between groups 1 and 3 and groups 2 and 3 but not between groups 1 and 2. Failure mode did not differ among groups; suture pull-through occurred in 43 of 48 (89.6%) specimens.
CONCLUSIONS AND CLINICAL RELEVANCE
Increasing bite depth of an epitendinous suture toward the center of the tendon substance increased repair site strength and decreased the incidence of gap formation. Repair of tendon injuries in dogs by use of an epitendinous suture with bites made deep into the tendon should result in a stronger repair, which potentially would allow loading and rehabilitation to begin sooner after surgery. Suture techniques should be investigated in vivo to determine effects on tendinous healing and blood supply before clinical implementation.
To compare the biomechanical strength and incidence of gap formation among canine superficial digital flexor tendon (SDFT) constructs that underwent core tenorrhaphy only and those in which the core tenorrhaphy was augmented with skin staples or a continuous Silfverskiold cross-stitch (SXS) suture pattern.
42 cadaveric forelimb SDFTs from 21 musculoskeletally normal dogs.
Tendons were randomly assigned to 3 groups (14 SDTFs/group), sharply transected, and repaired with a core locking-loop suture alone (group 1) or augmented with circumferential placement of skin staples (group 2) or a continuous SXS suture pattern (group 3) in the epitenon. All constructs underwent a single load-to-failure test. Yield, peak, and failure loads, incidence of gap formation, and mode of failure were compared among the 3 groups.
Mean yield, peak, and failure loads differed significantly among experimental groups and were greatest for group 3 and lowest for group 1 constructs. The incidence of gap formation differed among the tested groups and was lowest for group 3 and highest for group 1. The most common mode of construct failure was the suture pulling through the tendon for group 1, staple deformation for group 2, and epitendinous suture breakage for group 3.
CONCLUSIONS AND CLINICAL RELEVANCE
Results indicated epitendinous placement of skin staples around a core SDFT tenorrhaphy site improved the biomechanical strength and resistance to gap formation for the repair but was inferior to epitendinous placement of SXS sutures. Further research is necessary before skin staples are used for tenorrhaphy augmentation in clinical patients.
To evaluate the effect of suture caliber on the tensile strength of tenorrhaphies performed with a locking-loop technique in cadaveric canine tendons
60 superficial digital flexor tendons (SDFTs) from 30 cadaveric adult dogs.
Transverse tenotomy was performed, and SDFTs were repaired with a locking-loop technique and polypropylene suture of 5 randomly assigned calibers: size-0, 2-0, 3-0, 4-0, or 5-0 (n = 12 SDFTs/suture caliber). Tendon constructs were tested to failure. Yield, peak, and failure forces and causes of failure were compared between groups.
Mean ± SD failure force for the constructs was significantly greater with large-caliber suture (size-0: 73.5 ± 3.1 N; size 2-0: 54.4 ± 7.1 N; size 3-0: 28.7 ± 4.9 N; size 4-0: 18.7 ± 3.4 N; and size 5-0: 8.8 ± 2.8 N). The likelihood of construct failure by suture pullout through the tendon substance increased with large-caliber suture (size-0: 12/12), whereas the likelihood of construct failure by suture breakage increased with small-caliber suture (2-0: 10/12; 3-0, 4-0, and 5-0: 12/12 each).
CONCLUSIONS AND CLINICAL RELEVANCE
Large-caliber suture had greater tensile strength for tenorrhaphies performed with a locking-loop technique in cadaveric canine tendons. Prior to the use of large-caliber suture in patients requiring tenorrhaphy, however, in vivo studies are required to confirm the results obtained here.
To evaluate the effects of a single dose of orally administered gabapentin in alleviating stress at a veterinary visit in privately owned dogs.
22 healthy client-owned dogs (1.5 to 8.5 years old) were enrolled in this study.
Each dog received a 50-mg/kg oral dose of either gabapentin or placebo 2 hours before the beginning of each visit protocol. The dog’s behavioral responses were coded from recorded video clips during a 5-minute-long standardized physical examination and pre– and post–physical examination phases. The veterinary technician separately rated each greeting behavior at each visit. Physiological variables during veterinary visits (ie, eye surface temperature and salivary cortisol concentrations) were also compared between the pre– and post–physical examination phases. The owner was queried 24 hours after a visit to determine the incidence of adverse events.
The greeting test score, eye surface temperature, and cortisol concentrations did not differ substantially between the gabapentin and placebo treatment groups. Lip licking frequency during the physical examination phase was significantly lower in the gabapentin treatment group than in the placebo group (P = 0.001). Lip licking frequency during the pre– and post–physical examination phases was also significantly lower in the gabapentin treatment group than in the placebo treatment group (P = 0.004). No serious adverse events were reported by the owners following gabapentin treatment.
Results showed that the 50-mg/kg dose of gabapentin was well tolerated without serious adverse effects in healthy dogs. Further studies are recommended of dogs with documented stress in response to a veterinary visit.
To compare the biomechanical properties and gapping characteristics following loop modification of a 3-loop-pulley (3LP) pattern in an ex vivo canine common calcaneal tendon (CCT) avulsion repair model.
56 skeletally mature hindlimbs from 28 canine cadavers.
The CCTs were randomized to 1 of 4 experimental groups (n = 14/group) then sharply transected at the teno-osseous junction. Groups consisted of a 3LP, 4-loop-pulley (4LP), 5-loop-pulley (5LP), or 6-loop-pulley (6LP) pattern with loops placed 60° apart using size-0 polypropylene. Yield, peak, and failure loads, construct stiffness, loads to produce a 3-mm teno-osseous gap, and failure mode were evaluated and compared between groups.
Yield (P = 0.001), peak (P < 0.001), and failure loads (P < 0.001), construct stiffness (P < 0.001), and loads to 3-mm gap formation (P = 0.005) were all significantly greater for 6LP compared to all other groups. Mode of failure did not differ among groups (P = 0.733) with 75% (42/56) of repairs failing by mechanism of core sutures pulling through the tendinous tissue. Pattern modification by increasing the number of loops increased the repair site strength by 1.4, 1.6, and 1.8 times for 4LP, 5LP, and 6LP compared to 3LP, respectively.
Increasing the number of suture loops compared to a traditional 3LP repair is a relatively simple technique modification that significantly increases teno-osseous repair site strength and loads required to cause 3-mm gap formation. The results of this study justify further focused investigation of increasing the number of suture loops in vivo for teno-osseous CCT repair in dogs.
OBJECTIVE To develop a model of hip joint synovitis on the basis of intra-articular injection of a sodium urate suspension in dogs and to characterize associated gait changes.
ANIMALS 6 healthy adult dogs.
PROCEDURES Each dog was sedated, and synovitis was induced by injection of 1 mL of a sodium urate suspension (20 mg/mL) into the right hip joint under ultrasonographic guidance. Observational and instrumented gait analyses to determine temporospatial, kinetic, and kinematic variables were performed prior to and 4, 8, and 24 hours after sedation and synovitis induction.
RESULTS Injection of a sodium urate suspension into the hip joint of healthy dogs resulted in lameness of the ipsilateral pelvic limb as determined by observational and instrumented gait analyses. For all dogs, lameness was clinically detectable within 1.5 to 2 hours after injection, reached its maximum intensity at 4 hours after injection, and had subsided by 24 hours after injection.
CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that injection of a sodium urate suspension into the hip joint of healthy dogs reliably induced synovitis and signs of pain and lameness in the ipsilateral pelvic limb that lasted 24 hours. This model can be used in conjunction with instrumented gait analysis to provide information on gait changes associated with hip joint disease and might be useful for evaluating the efficacy of analgesics or other interventions for the treatment of hip joint disease in dogs.
Objective—To investigate the effects of heparin administration on urine protein excretion during the developmental stages of experimentally induced laminitis in horses.
Procedures—Horses received unfractionated heparin (80 U/kg, SC, q 8 h; n = 7) or no treatment (control group; 6) beginning 3 days prior to induction of laminitis. All horses were given 3 oligofructose loading doses (1 g/kg each) at 24-hour intervals and a laminitis induction dose (10 g of oligofructose/kg) 24 hours following the final loading dose (designated as 0 hours) via nasogastric tube. Serum glucose and insulin concentrations were measured before administration of the first loading dose (baseline) and at 0 and 24 hours; urine protein-to-creatinine (UP:C) ratio was determined at 0 hours and every 4 hours thereafter. Lameness was evaluated every 6 hours, and horses were euthanized when Obel grade 2 ameness was observed.
Results—Mean ± SD time until euthanasia did not differ significantly between the heparin-treated (28.9 ± 6.5 hours) and control (29.0 ± 6.9 hours) horses. The UP:C ratio was significantly increased from baseline at 20 to 28 hours after induction of laminitis (ie, 4 ± 4 hours before lameness was evident) in control horses but did not change significantly from baseline in heparin-treated horses. Serum glucose or insulin concentration did not change significantly from baseline in either group.
Conclusions and Clinical Relevance—Urine protein excretion increased during the developmental stages of carbohydrate-induced laminitis in horses; administration of heparin prevented that increase, but did not delay onset or decrease severity of lameness.
Objective—To determine incidence of and risk factors for adverse events associated with distemper and rabies vaccine administration in ferrets.
Design—Retrospective cohort study.
Animals—3,587 ferrets that received a rabies or distemper vaccine between January 1, 2002, and December 31, 2003.
Procedures—Electronic medical records were searched for possible vaccine-associated adverse events. Adverse events were classified by attending veterinarians as nonspecific vaccine reactions, allergic reactions, or anaphylaxis. Patient information that was collected included age, weight, sex, cumulative number of distemper and rabies vaccinations received, clinical signs, and treatment. The association between potential risk factors and occurrence of an adverse event was estimated with logistic regression.
Results—30 adverse events were recorded. The adverse event incidence rates for administration of rabies vaccine alone, distemper vaccine alone, and rabies and distemper vaccines together were 0.51%, 1.00%, and 0.85%, respectively. These rates were not significantly different. All adverse events occurred immediately following vaccine administration and most commonly consisted of vomiting and diarrhea (52%) or vomiting alone (31%). Age, sex, and body weight were not significantly associated with occurrence
of adverse events, but adverse event incidence rate increased as the cumulative number of distemper or rabies vaccinations received increased. In multivariate logistic regression analysis, only the cumulative number of distemper vaccinations received was significantly associated with the occurrence of an adverse event.
Conclusions and Clinical Relevance—Results suggest that in ferrets, the risk of vaccine-associated adverse events was primarily associated with an increase in the number of distemper vaccinations. (J Am Vet Med Assoc 2005;226:909–912)
Objective—To describe an outbreak of encephalomyelitis
caused by West Nile virus (WNV) in horses in
Procedure—Horses with clinical signs suggestive of
encephalomyelitis caused by WNV were examined.
Date, age, sex, breed, and survival status were recorded.
Serum samples were tested for anti-WNV antibodies,
and virus isolation was attempted from samples of
brain tissue. Climate data from local weather recording
stations were collected. An epidemic curve was constructed,
and case fatality rate was calculated.
Results—The most common clinical signs were ataxia,
hind limb paresis, and muscle tremors and fasciculations.
Eight horses had been vaccinated against WNV from 2 to
21 days prior to the appearance of clinical signs. West
Nile virus was isolated from brain tissue of 2 nonvaccinated
horses, and anti-WNV IgM antibodies were detected
in 132 nonvaccinated horses; in 2 other nonvaccinated
horses, anti-WNV antibodies were detected and WNV
was also isolated from brain tissue. Thirty-one (22.8%)
horses died or were euthanatized. The peak of the outbreak
occurred on September 6, 2002. Ambient temperatures
were significantly lower after the peak of the outbreak,
compared with prior to the peak.
Conclusions and Clinical Relevance—The peak risk
period for encephalomyelitis caused by WNV in northern
Indiana was mid-August to mid-September. Reduction in
cases coincided with decreasing ambient temperatures.
Because of a substantial case fatality rate, owners of
horses in northern Indiana should have their horses fully
protected by vaccination against WNV before June. In
other regions of the United States with a defined mosquito
breeding season, vaccination of previously nonvaccinated
horses should commence at least 4 months
before the anticipated peak in seasonal mosquito numbers,
and for previously vaccinated horses, vaccine
should be administered no later than 2 months before
this time. (J Am Vet Med Assoc 2004;225:84–89)
Objective—To evaluate the antitumor activity and toxic effects of deracoxib, a selective cyclooxygenase-2 inhibitor, in dogs with transitional cell carcinoma (TCC) of the urinary bladder.
Animals—26 client-owned dogs with naturally occurring, histologically confirmed, measurableTCC of the urinary bladder.
Procedures—Dogs were treated PO with deracoxib at a dosage of 3 mg/kg/d (1.36 mg/lb/d) as a single-agent treatment for TCC. Tumor response was assessed via radiography, abdominal ultrasonography, and ultrasonographic mapping of urinary bladder masses. Toxic effects of deracoxib administration in dogs were assessed through clinical observations and hematologic and biochemical analyses.
Results—Of 24 dogs for which tumor response was assessed, 4 (17%) had partial remission, 17 (71%) had stable disease, and 3 (13%) had progressive disease; initial response could not be assessed in 2 of 26 dogs. The median survival time was 323 days. Median time to progressive disease was 133 days. Renal, hepatic, and gastrointestinal abnormalities attributed to deracoxib administration were noted in 4% (1/26), 4% (1/26), and 19% (5/26) of dogs, respectively.
Conclusions and Clinical Relevance—Results indicated that deracoxib was generally well tolerated by dogs and had antitumor activity against TCC.