Preliminary evaluation of a novel method for computed tomography quantification of lumbosacral articular process displacement in dogs with and without degenerative lumbosacral stenosis.

Objective: This study aimed to describe the diagnostic discrimination and reliability of a novel technique for quantifying lumbosacral articular process displacement (LSAPD) on dorsal plane computed tomography (DPCT) imaging in dogs with and without degenerative lumbosacral stenosis (DLSS). Study design: DPCT surveys of the lumbosacral vertebral column were performed with dogs positioned in extension and flexion. LSAPD is defined as the distance between the cranial aspects of the L7 and S1 articular processes. The LSAPD ratio is identified by dividing the LSAPD by the length of the L7 articular process. Intraclass correlation coefficients (ICCs) for intra- and inter-observer reliability were calculated, and logistic regressions were used to test for the association of LSAPD and LSAPD ratio with odds of DLSS. Significance was set at 0.05. Receiver operator characteristic (ROC) curves were calculated to determine diagnostic discrimination and optimal cutoff for LSAPD and LSAPD ratio in the diagnosis of DLSS. Results: Intra- and inter-observer reliabilities were excellent for most measurements. In the current cohort, excluding covariates, the area under the curve (AUC) (95%CI) for LSAPD and LSAPD ratio measured in a flexed position were both 0.89 (0.82-0.96), suggesting potentially excellent discrimination for using this measurement as a marker for diagnosing DLSS, pending further studies. The cutoffs for flexed LSAPD and LSAPD ratio that maximizes Youden's index were ≥ 1.2 mm and ≥ 9%, respectively. When age and weight were subsequently included as covariates in a multivariable analysis, a significant relationship between LSAPD or LSAPD ratio and odds of diagnosis of DLSS was not demonstrated, suggesting the need for a larger sample size. Conclusion: The results of this study suggest that measurements of LSAPD and LSAPD ratio on DPCT are feasible and reliable, although their diagnostic discrimination in DLSS should be evaluated further in future prospective studies.

Secondary fastener (tape) placement on a blood pressure cuff causes interindividual Doppler blood pressure measurement variability in healthy large-breed dogs.

OBJECTIVE: The objective of this study was to compare Doppler blood pressure (DBP) measurements between blood pressure cuffs (BPCs) with and without a secondary fastener (tape) in healthy nonanesthetized large-breed dogs. ANIMALS: 28 healthy dogs. METHODS: Superficial palmar venous arch DBP measurements with and without tape on the BPC were performed in lateral recumbency with Doppler ultrasound. Each method was performed 6 consecutive times, with the final 5 values averaged. Bland-Altman plots were made and limits of agreement calculated. RESULTS: The limits of agreement were -40.8 (95% CI, -55.6 to -26.0) to 45.6 (95% CI, 30.8 to 60.4), indicating that the DBP measured with tape would be expected to be between 40.8 mm Hg below and 45.6 mm Hg above that measured without tape 95% of the time. The mean bias estimate was 2.4 mm Hg (SD, 22.0; 95% CI, -6.1 to 11.0; P = .724), indicating that DBP measurements with tape averaged 2.4 mm Hg higher than without tape. CLINICAL RELEVANCE: Doppler blood pressure measurements obtained with secondary fasteners on the BPCs differed by > 10 mm Hg compared to the BPCs' standard hook-and-loop fasteners 54% (30 of 56) of the time. Blood pressure cuffs with dysfunctional hook-and-loop fasteners should be replaced due to poor clinical reliability of DBP measurements. However, it is unclear whether Doppler sphygmomanometry is more accurate with the use of traditional Velcro BPC fasteners or with tape BPC fasteners.

Photobiomodulation therapy using a class 3b laser does not cause premature rupture of multivesicular liposomal bupivacaine suspensions in a cadaver model.

OBJECTIVE: To determine if photobiomodulation causes a premature release of liposomal bupivacaine (LB) suspensions. ANIMALS: A 25-kg mixed breed dog cadaver euthanized for reasons unrelated to this study. METHODS: In September 2022, a proximomedial tibial incision was made in a dog cadaver, and a tibial plateau leveling osteotomy plate was implanted. A stab incision was made one-half inch distal to the incision, and a tunnel to the plate was created prior to closure of the primary wound. A 3-cc anal sac catheter was advanced through the distal incision until the bulb rested against the face of the plate. Seven treatment groups of treatment power (watts) and total energy (joules/cm2) were defined as: A, 0.5 W, 2.0 J/cm2; B, 0.5 W, 4.0 J/cm2; C, 0.5 W, 6.0 J/cm2; D, 1.0 W, 2.0 J/cm2; E, 1.0 W, 4.0 J/cm2; F, 1.0 W, 6.0 J/cm2; and sham, 0.0 W, 0.0 J/cm2. Ten samples per group of 2 mL of LB were infused into a new catheter and treated percutaneously with a class 3b laser. All samples remained in the catheter for 12 seconds to reflect the longest treatment time. Post-treatment free bupivacaine concentrations were identified with high-performance liquid chromatography. RESULTS: The median free bupivacaine concentration was reported as: sham, 1.89 mg/mL; A, 1.93 mg/mL; B, 2.01 mg/mL; C, 2.05 mg/mL; D, 1.92 mg/mL; E, 2.03 mg/mL; and F, 2.00 mg/mL. There were no differences in median free bupivacaine concentrations between groups (P = .988). CLINICAL RELEVANCE: Concurrent LB and photobiomodulation are recommended during the postoperative period. The results of this proof-of-concept study suggest that concurrent use of LB and photobiomodulation may be safe, but in vivo studies at similar and stronger photobiomodulation settings are warranted.

Results of routine thoracic radiographic examinations rarely impact the plan to proceed with anesthetic procedures in dogs with presumed acute intervertebral disc herniation.

Introduction: Acute thoracolumbar intervertebral disc herniation (IVDH) constitutes an emergency because associated neurological clinical signs can be progressive, with prognosis dependent on preoperative presence of deep pain perception. Pre-anesthetic thoracic radiographs are routinely performed to evaluate for potential pathology that could result in increased risk or change in overall prognosis. However, due to the emergent nature of this disease, the weight of thoracic radiographic findings on treatment plans for these dogs in unknown. The objective of this study was to investigate the clinical benefit of thoracic radiographs prior to advanced spinal imaging and surgery for acute non-ambulatory dogs with suspected T3-L3 myelopathy. Methods: Consecutive dogs presented with presumed acute IVDH between July 2020-July 2022 were identified, and medical records were reviewed retrospectively. Age, body weight, and alteration of treatment plan were compared between the dogs with positive thoracic pathology identified on thoracic radiographs and those with negative thoracic pathology. Results: Only 2/105 dogs had their diagnostic and treatment plans changed due to thoracic radiographic findings. Dogs with radiographic pathology diagnosed (2/16) were more likely to have their treatment plans changed than dogs with no radiographic pathology (0/89) (p = 0.014). The odds of radiographic thoracic pathology were 4.6 times higher in dogs aged 12 years or older [OR 4.6 (95%CI 1.2-17, p = 0.026]. Discussion: Performing routine thoracic radiography prior to advanced (anesthetized) diagnostic spinal imaging in presumed IVDH cases rarely resulted in a change to the treatment plan, thought eh practice may be clinically relevant in dogs 12 years of age or older.

Spontaneous pneumothorax in a dog with a history of successfully treated heartworm disease: A case report.

OBJECTIVE: To describe a dog presented with spontaneous pneumothorax secondary to chronic pulmonary changes associated with a history of resolved canine heartworm disease. CASE OR SERIES SUMMARY: A 7-year-old 25.2kg female spayed German Shepherd mix was presented for management of spontaneous pneumothorax. The dog had a history of heartworm disease that underwent therapy prior to adoption, and the dog was heartworm antigen negative (SNAP 4Dx) during hospitalization for the pneumothorax. An exploratory thoracotomy was performed due to an unresolving pneumothorax requiring multiple thoracocenteses. Perioperatively, the lungs did not expand with positive pressure ventilation and diffuse, multifocal to coalescing areas of darkened tissue that were grossly consistent with necrosis and/or hemorrhage were noted. The dog was euthanized intraoperatively due to an assumed poor prognosis. Histopathologic examination findings were consistent with chronic reactive changes related to previous heartworm infection. No neoplastic or infectious etiologies were identified. NEW OR UNIQUE INFORMATION PROVIDED: Spontaneous pneumothorax is a known complication of active heartworm infection. However, this case represents the first report of spontaneous pneumothorax secondary to chronic pulmonary changes caused by resolved heartworm infection.

D-penicillamine-associated neutropenia in a Doberman pinscher.

Copper-associated hepatitis in dogs results from elevated copper levels secondary to increased intake or decreased clearance. Treatment is through establishing a negative copper balance and can include chelation therapy. Traditionally, chelation therapy in dogs is uses D-penicillamine, which has been shown to have severe side effects in humans. Side effects have not been well-documented in dogs but can include nephrotoxicity and dermatologic reactions. This article is the first to report neutropenia in a dog secondary to chelation therapy using D-penicillamine. In this case, a complete blood (cell) count (CBC) collected before initiation of chelation therapy was normal and neutropenia was documented 4 mo after starting therapy. A cytologic examination of bone marrow confirmed a myeloid hypoplasia. Following discontinuation of D-penicillamine, the neutropenia resolved. Based on this case report, periodic CBC rechecks following the initiation of D-penicillamine chelation therapy are recommended to guide treatment decisions. Key clinical message: Dogs with confirmed copper-associated hepatitis should be treated cautiously with D-penicillamine for chelation therapy. D-penicillamine may adversely affect bone marrow, causing a leukopenia characterized by neutropenia. It is recommended that clinicians periodically monitor neutrophil counts while treating dogs with D-penicillamine.

Neutropénie associée à la D-pénicillamine chez un Doberman pinscher. L'hépatite associée au cuivre chez le chien résulte de niveaux élevés de cuivre secondaires à une augmentation de l'apport ou à une diminution de la clairance. Le traitement consiste à établir un bilan négatif du cuivre et peut inclure une thérapie par chélation. Traditionnellement, la thérapie par chélation chez le chien utilise la D-pénicillamine, dont il a été démontré qu'elle a de graves effets secondaires chez l'homme. Les effets secondaires n'ont pas été bien documentés chez les chiens, mais peuvent inclure une néphrotoxicité et des réactions dermatologiques. Cet article est le premier à rapporter une neutropénie chez un chien secondaire à un traitement par chélation utilisant la D-pénicillamine. Dans ce cas, une numération globulaire complète (CBC) recueillie avant le début du traitement par chélation était normale et une neutropénie a été documentée 4 mois après le début du traitement. Un examen cytologique de la moelle osseuse a confirmé une hypoplasie myéloïde. Après l'arrêt de la D-pénicillamine, la neutropénie a disparu. Sur la base de ce rapport de cas, des vérifications périodiques de la CBC après le début du traitement par chélation de la D-pénicillamine sont recommandées pour guider les décisions de traitement.Message clinique clé :Les chiens atteints d'hépatite associée au cuivre confirmée doivent être traités avec prudence avec de la D-pénicillamine pour le traitement par chélation. La D-pénicillamine peut affecter négativement la moelle osseuse, provoquant une leucopénie caractérisée par une neutropénie. Il est recommandé aux cliniciens de surveiller périodiquement le nombre de neutrophiles lors du traitement des chiens avec de la D-pénicillamine.(Traduit par Dr Serge Messier).

The effect of two platelet-rich plasma aspiration techniques on plasma cellular concentrations using a double syringe gravitational centrifugation system.

OBJECTIVE: To identify which aspiration technique increased plasma platelet concentration and which technique minimized plasma leukocyte and erythrocyte concentrations using a gravitational double-syringe platelet rich plasma (PRP) system. STUDY DESIGN: Controlled laboratory study. ANIMALS: Thirty adult dogs. METHODS: Whole blood was collected into two autologous conditioned plasma (ACP) syringes and an ethylenediaminetetraacetic acid (EDTA tube) (control samples). The ACP syringes were centrifuged for 5 min at 1500 rpm. The proximal 2 mL of plasma from one ACP syringe was deposited in an EDTA tube (preflash samples). Plasma from the second ACP syringe was withdrawn until the buffy coat was pierced, producing a "flash" of red blood cells, agitated and deposited into an EDTA tube (flash samples). Complete blood counts were performed. RESULTS: Mean plasma platelet concentrations of the control, preflash, and flash samples were 2.4 × 105 /dL, 3.3 × 105 /dL and 4.1 × 105 /dL, respectively. The mean platelet concentration of the flash samples was 7.9 × 104 /dL higher than the preflash samples (p = .005). The mean platelet concentration was lower in the control samples than the preflash (p = .002) and flash (p < .0001) samples. The median plasma leukocyte concentration of the preflash samples (0/dL) was lower than in the flash samples (2.4 × 103 /dL) (p = .001). The median plasma hematocrit value of the preflash samples (0%) was lower than in the flash samples (1.0%) (p = .002). CONCLUSION: The flash method is not necessary to produce a PRP sample. CLINICAL SIGNIFICANCE: Both methods produced PRP. However, clinicians should avoid aspirating the buffy coat when processing PRP for therapies where leukocytes and erythrocytes are contraindicated.

Ferrofluid drop impacts and Rosensweig peak formation in a non-uniform magnetic field.

Vertical drop impacts of ferrofluids onto glass slides in a non-uniform magnetic field have been studied using high-speed photography. Outcomes have been classified based on the motion of the fluid-surface contact lines, and formation of peaks (Rosensweig instabilities) which affect the height of the spreading drop. The largest peaks are nucleated at the edge of a spreading drop, similarly to crown-rim instabilities in drop impacts with conventional fluids, and remain there for an extended time. Impact Weber numbers ranged from 18.0 to 489, and the vertical component of the B-field was varied between 0 and 0.37 T at the surface by changing the vertical position of a simple disc magnet placed below the surface. The falling drop was aligned with the vertical cylindrical axis of the 25 mm diameter magnet, and the impacts produced Rosensweig instabilities without splashing. At high magnetic flux densities a stationary ring of ferrofluid forms approximately above the outer edge of the magnet.

The effect of grip location on Kirschner wire bend characteristics: An in vitro study.

OBJECTIVE: To determine the effect of Kirschner wire (K-wire) grip location on bend angle, bend radius, and torque when performing a Z-bend technique. STUDY DESIGN: Experimental study. SAMPLE POPULATION: Ten samples at each of five grip locations for each of three K-wire diameters. METHODS: K-wires of three diameters (0.9, 1.1, 1.6 mm) were drilled into PVC pipe, and a Jacob's chuck was used to bend the wires at five periodic grip locations (distance from the bone model). Torque, bend angle, and bend radius were determined for each sample. Outcome variables were statistically analyzed by grip location to determine significant relationships. RESULTS: A grip location of 2.0 cm in the 0.9 mm K-wire group minimized bend angle (mean ± SD: 75.92° ± 0.81) and bend radius (2.89 mm ± 0.08). A grip location of 3.0 cm in the 1.1 mm K-wire group minimized bend angle (72.88° ± 0.98) and bend radius (2.47 mm ± 0.20). A grip location of 3.0 cm minimized bend angle (74.38° ± 1.93) and bend radius (2.71 mm ± 0.27) in the 1.6 mm K-wire group. Torque at these grip locations for the 0.9, 1.1, and 1.6 mm K-wires was 6.50 N-m ± 0.0, 11.00 N-m ± 0.0, and 19.05 N-m ± 0.16, respectively. CONCLUSION: Bend angle and bend radius can be minimized by bending K-wires at specific grip locations, though torque is not minimized at these locations. Clinical significance These findings provide an evidence-based recommendation of where surgeons should grip K-wires when bending them.

Diagnosis and Conservative Management of Primary Lymphedema Resulting From Multiple Aplastic Lymphocenters in a Dog.

A 6-week-old 7.4-kg (16.3-lb) sexually intact male Great Dane with a history of severe peripheral edema within the head, neck, limbs, and tail since birth was referred for further evaluation. A whole-body computed tomography examination documented severe subcutaneous edema multifocally associated with numerous hypoplastic and aplastic lymphocenters, particularly the left axillary, iliosacral, inguinal, and popliteal lymphocenters bilaterally. A congenital anomaly of the lymphatic system resulting in lymphedema was strongly suspected. The dog was managed with a combination of low-fat diet, rutin, and furosemide initially. In addition, the owner used a combination of compression socks and therapeutic massage several times daily along with carprofen and gabapentin for pain and inflammation. The patient was hospitalized to receive supportive care several times over a 2-year period for treatment of fever associated with cellulitis resulting in secondary wounds and infections. To the author's knowledge, this report represents the first case of presumed congenital lymphedema diagnosed with computed tomography and successful long-term medical management without surgical intervention.

Evaluation of the clinical value of routine radiographic examination during convalescence for tibial plateau-leveling osteotomy.

OBJECTIVE: To determine how frequently routine follow-up radiographic findings would result in a change to the postoperative plan following tibial plateau-leveling osteotomy (TPLO) in dogs. STUDY DESIGN: Retrospective study SAMPLE POPULATION: Short-term group: 100 cases; intermediate-term group: 50 cases. METHODS: Medical records of 100 consecutive cases meeting the inclusion criteria were reviewed (the short-term group). The cases had no owner-perceived issues and underwent routinely prescribed radiographic follow up between 40 and 60 postoperative days after TPLO performed by one experienced surgeon. Complications identified on physical examination (PE) and radiographic examination (RE) were recorded, along with any changes to the postoperative plan. Medical records of 50 consecutive cases that had short-term and intermediate-term (≥180 days) REs and PEs were reviewed similarly (intermediate-term group). RESULTS: Fifty-one cases in the short-term group had no complications on PE or RE. Forty-nine dogs were diagnosed with minor complications (patellar ligament desmitis, patella or fibula fracture, gait abnormalities): 42 on RE only; 6 on PE and RE; 1 on PE only. Exercise restriction was extended for 2 weeks in 2 cases with radiographic patellar ligament desmitis. Two cases in the intermediate-term group had minor complications at intermediate-term RE. No new PE or RE complications developed between short-term and intermediate-term evaluations. CONCLUSION: At routine rechecks of dogs with no owner-perceived issues after TPLO, 49% had minor complications but only 2% were deemed significant enough to alter patient management. The likelihood of new radiographic complications developing after short-term evaluation is low. CLINICAL SIGNIFICANCE: Routine radiographic recheck examinations rarely altered the postoperative plan in TPLO cases with unremarkable clinical recoveries.

Evaluation of the risk of patella fracture as the result of decreasing tibial plateau angle following tibial plateau leveling osteotomy.

OBJECTIVE: To evaluate the effect of postoperative tibial plateau angle (TPA) following tibial plateau leveling osteotomy (TPLO) on the risk of patella fracture during the convalescent period. STUDY DESIGN: Retrospective study. SAMPLE POPULATION: Fracture group: 20 stifles; reference group: 65 stifles. METHODS: Medical records were reviewed for stifles with patellar fractures after a TPLO procedure (fracture group) and stifles with >180 days radiographic examination with no complications following TPLO (reference group). Stifle radiographs were masked to group and final TPA (fTPA) was measured, at the time of fracture diagnosis (fracture group) and at last follow-up (reference group), using PACS software. TPAs in the fracture and reference groups were compared using the Wilcoxon rank-sum test. Statistical significance was set at .05. RESULTS: Patellar fractures were diagnosed at a median of 69 days (range 31-189) after surgery. The median duration of follow-up time for the reference group was 471 days (range 180-1868). Median fTPA for the fracture group was 1.4° (range [-10.3]-7.1). Median fTPA for the reference group was 4.1° (range [-3.9]-14.1). The odds of patellar fractures increased by 21.7% (95% CI: 8.6%-35.6%) for every 1° decrease in fTPA. CONCLUSION: The risk of patella fractures increased as TPAs after TPLOs decreased. CLINICAL SIGNIFICANCE: Care should be taken to avoid excessive rotation during TPLO to decrease the likelihood of postoperative patellar fractures.

Evaluation of a Fixed-Angle Wedge Osteotomy Guide.

OBJECTIVE: The aim of this study was to evaluate a fixed-angle cutting guide designed to aid in the performance of coplanar wedge osteotomies using a proximal tibial cranial closing wedge ostectomy model. STUDY DESIGN: A 30-degree cranial closing wedge ostectomy was created using canine tibia models with either a standard template (method T) or a wedge osteotomy guide (method G) by two surgeons. One surgeon was experienced with both procedures, and one surgeon had no previous experience with the wedge guide. The ostectomy wedges were evaluated for wedge angle, using a digital protractor, and coplanarity by using digital photographs and screen-measuring software. RESULTS: The mean (standard deviation) wedge angles of the T and G groups were 28.16 (1.33) and 28.4 degrees (1.46) respectively. The mean (standard deviation) divergence angles of the T and G groups were 3.21 (1.86) and 2.22 degrees (1.69) respectively. The measured reference angles of the template and cut guides were 31.27 and 29.60 degrees respectively. Individual and cross-surgeon analysis of outcomes found no significant differences when comparing wedge angle or coplanarity with either method regardless of surgeon experience. However, mean wedge angle of group G was significantly closer to the measured reference angles than group T (p < 0.01). CONCLUSION: Use of a fixed-angle surgical wedge guide was successful in consistently producing accurate closing wedge ostectomies regardless of surgeon experience. These results show that use of the guide is a valid method for performing wedge ostectomies.

The effect of extracorporeal shockwave on liposomal bupivacaine in a tibial plateau leveling osteotomy model.

OBJECTIVE: To determine the effect of extracorporeal shock wave (ESWT) on liposomal bupivacaine in a tibial-plateau-leveling osteotomy model. STUDY DESIGN: In vitro study. SAMPLE POPULATION: Ten samples per group. METHODS: In addition to a control group (sham treatment), five treatment groups were defined as A, energy (E) 3 (0.22 mJ/mm2 ), 360 pulses per minute (p/m); B, E6 (0.29 mJ/mm2 ), 360 p/m; C, E8 (0.39 mJ/mm2 ), 360 p/m; D, E6, 480 p/m; E, E8 480 p/m. Two-milliliter aliquots of liposomal bupivacaine were placed in a gelatin chamber and treated with 1000 pulses according to group. All samples remained in the chamber for 170 seconds to reflect the longest treatment group. Free bupivacaine concentrations were determined after treatment with high-performance liquid chromatography. RESULTS: The median free bupivacaine concentration was reported as control, 1.90 mg/mL; A, 2.10 mg/mL; B, 2.03 mg/mL; C, 2.94 mg/mL; D, 2.71 mg/mL; E, 4.35 mg/mL. Groups C (P = .027), D (P = .034), and E (P = .002) were different from the control group. Groups C (P = .0025) and D (P = .0025) were different from group E. Additional intertreatment group differences were found. CONCLUSION: Extracorporeal shock wave therapy caused a dose-dependent release of bupivacaine; however, there was no significant release of bupivacaine from liposomes when ESWT was applied at currently recommended therapeutic settings in this model. CLINICAL SIGNIFICANCE: This in vitro study provides evidence that concurrent electrohydraulic ESWT and liposomal bupivacaine is likely safe at currently recommended settings, however, higher energy and pulse frequency settings should be avoided.

Brucella canis sacroiliitis and discospondylitis in a dog.

A 1.5-year-old neutered male Labrador retriever dog was presented with a 1-month history of pelvic limb lameness. Physical examination revealed lumbosacral and pelvic pain. Diagnostic imaging findings were consistent with discospondylitis and bilateral sacroiliitis. Brucellosis was definitively diagnosed with rapid slide agglutination (RSAT) and agar gel immunodiffusion (AGID) tests. Brucella canis has not been associated with sacroiliitis and should be included as a differential diagnosis for dogs presented with clinical or radiographic signs of sacroiliitis.

Sacro-iliite et discospondylite à Brucella canis chez un chien. Un chien mâle castré de race Labrador âgé de 1,5 ans fut présenté avec une histoire de boiterie du membre pelvien ayant débuté 1 mois plus tôt. L'examen physique révéla une douleur lombo-sacrée et pelvienne. Les trouvailles d'imagerie étaient cohérentes avec une discospondylite et une sacro-iliite bilatérale. La brucellose fut diagnostiquée de manière définitive par un test d'agglutination rapide sur lame (RSAT) et un test d'immunodiffusion en gel (AGID). Brucella canis n'a pas été associé avec une sacro-iliite et devrait être inclus dans le diagnostic différentiel de chiens présentant des signes cliniques ou radiographiques de sacro-iliite.(Traduit par Dr Serge Messier).

Use of an amikacin-infused collagen sponge concurrent with implant removal for treatment of tibial plateau leveling osteotomy surgical site infection in 31 cases.

OBJECTIVE: To report the use and long-term outcome of dogs with surgical site infection (SSI) after tibial plateau leveling osteotomy (TPO), treated with an amikacin-infused collagen sponge and implant removal. STUDY DESIGN: Retrospective study. ANIMALS: Thirty-one client-owned dogs. METHODS: Medical records were reviewed for dogs with SSI after a TPLO that were treated with surgical implant removal and concurrent implantation of an amikacin-infused collagen sponge. Relevant clinical and surgical data were recorded. The TPLO implants were routinely removed; the surgical site was swabbed for culture. The sponge was aseptically infused with amikacin prior to implantation. Postprocedure examinations consisted of visual inspection of the incision by the surgeon and lameness scoring. RESULTS: Thirty-one dogs met all inclusion criteria. Median follow-up time was 687 days. Short-term examination after implant removal and sponge implantation revealed uneventful incisional healing in 24 dogs. Six (19.4%) dogs exhibited inflamed incision sites a median of 4 days (range, 3-9) postoperatively that resolved without additional treatment. One (3.2%) dog required empirical antibiotic treatment 7 days postoperatively but was lost to long-term follow-up. Long-term follow-up examination revealed no clinical evidence of SSI recurrence and no lameness in the remaining 30 cases. CONCLUSION: Surgical implant removal and implantation of an absorbable collagen sponge infused with amikacin alone was an effective treatment for postoperative TPLO SSI. CLINICAL SIGNIFICANCE: This procedure had a 96.8% long-term resolution of SSI. It should be considered as a treatment option for TPLO SSI.

Modified cranial closing wedge osteotomy for treatment of cranial cruciate ligament insufficiency in dogs with excessive tibial plateau angles: Technique and complications in 19 cases.

OBJECTIVE: To describe short-term outcomes of a modified cranial closing wedge osteotomy (CCWO) for treatment of dogs with cranial cruciate ligament disease and excessive tibial plateau angle (eTPA). STUDY DESIGN: Retrospective clinical study. ANIMALS: 18 client-owned dogs (19 stifles) with cranial cruciate ligament disease and eTPA (>34°). METHODS: A modified CCWO was performed with Kirschner wires as osteotomy alignment aids. A juxta-articular neutral wedge osteotomy equal in angle to the preoperative TPA was performed. Fixation was achieved with a tibial plateau leveling osteotomy (TPLO) plate and tension band wire apparatus (89%) or a TPLO plate (11%). Preoperative and postoperative, and recheck TPA, cranial tibial long axis shift, and major and minor complications were recorded. RESULTS: The mean preoperative TPA (49.5° ± 6.7°) was reduced postoperatively (8.3° ± 4.8°). Four of 19 joints (21%) developed 2 major and 3 minor complications during the intraoperative and follow-up period (577 day mean in-hospital recheck). Two cases were diagnosed with surgical site infections requiring implant removal for resolution. Fixation failure or implant complications were not observed in any dog during the limited radiographic follow-up period. All dogs were sound or recovering as expected, with 15/19 dogs (79%) showing complete radiographic osteotomy healing at their final in-hospital follow-up examination. CONCLUSION: Modified CCWO should be considered for the treatment of cranial cruciate ligament disease in dogs with eTPA. In this case series, the described technique was associated with uneventful osteotomy healing without implant failures in all dogs, although radiographic follow-up was limited in some cases.

Transgenic overexpression of ribonucleotide reductase improves cardiac performance.

We previously demonstrated that cardiac myosin can use 2-deoxy-ATP (dATP) as an energy substrate, that it enhances contraction and relaxation with minimal effect on calcium-handling properties in vitro, and that contractile enhancement occurs with only minor elevation of cellular [dATP]. Here, we report the effect of chronically enhanced dATP concentration on cardiac function using a transgenic mouse that overexpresses the enzyme ribonucleotide reductase (TgRR), which catalyzes the rate-limiting step in de novo deoxyribonucleotide biosynthesis. Hearts from TgRR mice had elevated left ventricular systolic function compared with wild-type (WT) mice, both in vivo and in vitro, without signs of hypertrophy or altered diastolic function. Isolated cardiomyocytes from TgRR mice had enhanced contraction and relaxation, with no change in Ca(2+) transients, suggesting targeted improvement of myofilament function. TgRR hearts had normal ATP and only slightly decreased phosphocreatine levels by (31)P NMR spectroscopy, and they maintained rate responsiveness to dobutamine challenge. These data demonstrate long-term (at least 5-mo) elevation of cardiac [dATP] results in sustained elevation of basal left ventricular performance, with maintained ß-adrenergic responsiveness and energetic reserves. Combined with results from previous studies, we conclude that this occurs primarily via enhanced myofilament activation and contraction, with similar or faster ability to relax. The data are sufficiently compelling to consider elevated cardiac [dATP] as a therapeutic option to treat systolic dysfunction.