Cranial Cruciate Ligament Tear Research Articles

Novel crescentic, medial-closing, medially translating, centre-of-rotation-of-angulation-based, levelling osteotomy for lateral compartment stifle disease with partial cranial cruciate ligament tear in two dogs

ABSTRACT Case history Two mature, large breed dogs presented with chronic lameness and discomfort localised to the stifle. Clinical findings No hindlimb deformities were present on physical examination or radiographic evaluation. No stifle instability was present. Arthroscopy revealed severe (grade 5/5 modified Outerbridge score) cartilage erosion in the lateral compartment (femorotibial), marked degeneration of the lateral meniscus and early cranial cruciate ligament disease in both patients. Treatment and outcome Medial-closing, medially translating, centre-of-rotation-of-angulation-based, levelling osteotomy (mcmtCBLO) was performed in both patients. The procedure aims to shift the pelvic limb’s mechanical axis medially to reduce pressure in the lateral compartment while also reducing craniocaudal shear forces by lowering the tibial plateau angle. Eight weeks after surgery one patient’s lameness had resolved while the other had improved significantly. Second-look arthroscopy performed at this time revealed fibrocartilage formation in the lateral compartment without progression of cruciate disease in both cases. At long-term follow-up (approximately 3 and 5 years), favourable outcomes (no or minimal lameness, mild or moderate osteoarthritis) were identified on the long-term owner survey, lameness examination and radiographs. Clinical relevance mcmtCBLO reduced or eliminated short- and long-term lameness in these two cases afflicted by concurrent lateral compartment and early cranial cruciate ligament disease.

Correlation of spontaneous radiographic cranial tibial translation with complete cranial cruciate ligament rupture and medial meniscal tears in dogs.

The primary objective of our study was to determine the prevalence of cranial tibial translation on a single unstressed, standing angle, mediolateral radiograph of the stifle and the accuracy of diagnosing complete cranial cruciate ligament rupture in dogs with this finding using a previously published method. The secondary objective was to determine if there was a higher incidence of meniscal injuries associated with spontaneous radiographic cranial tibial translation as previously proposed. Medical records were reviewed for client owned dogs with cranial cruciate ligament rupture that underwent surgical stabilization with intra-operative evaluation of the stifle joint via arthrotomy between June 2013 to January 2022 and had pre-operative radiographs performed within 60 days prior to surgery. Pre-operative radiographs were evaluated for cranial tibial translation via the previously published method. Three hundred twenty-three dogs met the inclusion criteria for the study. Intra-operative findings and radiographic assessments were evaluated for correlations. Cranial tibial translation on pre-operative standing angle radiographs detected cranial cruciate ligament tears in 24.8% of cases but had a positive predictive value of 97.5% for diagnosing complete cranial cruciate ligament rupture with a specificity of 95.4% and an overall accuracy of 36.8%. Meniscal tears were present in 58.75% of cases with radiographic cranial tibial translation and 41.25% of cases without. There was no significant increase in the incidence of meniscal tears between the two groups. The presence of radiographic cranial tibial translation in dogs on an unstressed, standing angle, mediolateral radiograph of the stifle is diagnostic for cranial cruciate ligament rupture, but cannot be used to determine the presence of a meniscal tear.

Multiparametric Comparison of Two TTA-Based Surgical Techniques in Dogs with Cranial Cruciate Ligament Tears.

Tearing of the cranial cruciate ligament causes hindlimb lameness in dogs. Different surgical procedures have been proposed to treat this condition. In this study, two different TTA-based techniques and implants were compared. A total of 30 dogs were separated into two groups according to the technique and implant used (Porous TTA® or Model Xgen®). The aim of the study was to assess whether one of these techniques has better functional recovery of the joint, better bone consolidation after the osteotomy procedure and fewer osteoarthritic changes. We compared both groups up to 3 months after surgery. No significant differences were found in any of the assessed parameters. Thus, both procedures were found to be equally effective and safe.

Incidence of postoperative administration of opioids in dogs undergoing a tibial plateau leveling osteotomy after intra-operative liposomal bupivacaine administration with or without morphine epidural

ObjectiveTo determine the influence of two intraoperative pain management protocols on the need for additional opioids in patients receiving an epidural and periarticular liposomal bupivacaine (PLB) vs. PLB alone in the 12–24 h period after undergoing a TPLO.Study designRetrospective study.AnimalsOne hundred seventy-four dogs with cranial cruciate ligament tears presenting for TPLO.MethodsMedical records of dogs presenting for a unilateral or bilateral cranial cruciate ligament tear who had a TPLO performed were reviewed for signalment, weight, body condition score, and peri-operative pain management protocol. Dogs were divided into two groups: those who received an epidural and PLB, and those who received only PLB. Post-operative opioid administration was recorded for each group.ResultsPatients who received an epidural and PLB received fewer postoperative opioids. There were 36% fewer opioid injections administered to dogs who received epidurals compared to dogs who did not receive epidurals (IRR) (95% CI) = 0.64 (0.45–0.92), P = 0.02). BCS was not a significant predictor of the post-operative opioid requirement (IRR (95% CI) = 1.3 (0.75–2.4), P = 0.38). When adjusting for BCS as a possible confounder, there were 39% fewer opioid injections in dogs who received epidurals than dogs without (IRR (95% CI) = 0.61 (0.42–0.88), P = 0.009).ConclusionsThe incidence of postoperative opioid administration was significantly diminished in patients receiving both an epidural and PLB.Clinical significanceAdministration of an epidural in addition to infiltration of PLB significantly decreased the incidence of postoperative opioid administration in dogs undergoing a TPLO.

Tibial tuberosity transposition advancement for treatment of concomitant cranial cruciate ligament rupture and medial patellar luxation in four feline stifles.

Case series summaryThree cats (four stifles) were diagnosed with varying grades of medial patellar luxation and stifle instability in cranial tibial thrust. Radiographs showed periarticular osteophytosis, intra-articular mineralization and opacification encroachment of the infrapatellar fat pad. Stifle exploration revealed either partial (n = 2) or complete (n = 2) cranial cruciate ligament tear and medial meniscal injury in all cases. Medial meniscectomy, partial parasagittal patellectomy, femoral trochleoplasty and tibial tuberosity transposition advancement using a 6 mm cage, two-fork plate and 4 mm spacer were performed in four stifles. Screws (2.0 mm) and washers were used in the cranial cage ears rather than conventional 2.4 mm screws. By the 2-week recheck, lameness was minimal and stifles were stable. Radiographic follow-up at 8 weeks showed appropriate progression of osseous union in all cases. One cat experienced a major complication, suffering tibial fracture following a lapse in exercise restriction, and revision surgery was performed successfully with subsequent osseus union of the osteotomy site. At the mid-term follow-up, all cats had a return to previous level of function, as assessed by both owner questionnaire and clinical evaluation.Relevance and novel informationTibial tuberosity transposition and advancement has been shown to be successful in dogs for the treatment of concomitant medial patellar luxation and cranial cruciate ligament rupture. To date, there have been no reports of tibial tuberosity transposition and advancement in cats. A benefit of this approach is concomitant alignment of the extensor mechanism and neutralization of the femorotibial shear force. Our case series describes successful use of tibial tuberosity transposition advancement in cats.

Prevalence and Risk Factors for Bilateral Meniscal Tears Identified during Treatment for Cranial Cruciate Ligament Disease Via Tibial Plateau Levelling Osteotomy in Dogs.

The aim of this study was to report the prevalence and risk factors of bilateral meniscal tears during a tibial plateau levelling osteotomy (TPLO). Data from 362 dogs that underwent staged or simultaneous TPLO between January 2006 and April 2019 were retrospectively collected. Variables such as breed, sex, weight change and intervals between surgeries were analysed with logistic regression. Preoperative tibial plateau angle, age, cranial cruciate ligament status and body weight were analysed with a generalized linear mixed model. All analyses were performed to assess the likelihood of bilateral meniscal tears versus unilateral tears and no tears. Correlation of meniscal tears between stifles was assessed with Cohen's kappa coefficient. Prevalence of bilateral meniscal tears was 48.0% (95% confidence interval [CI]: 43.0-53.0%). There was moderate agreement of the presence of meniscal tears between stifles (Cohen's kappa coefficient = 0.41, 95% CI: 0.31-0.51).The odds for bilateral meniscal tears were higher for Rottweilers (odds ratio [OR:] 4.5 [95% CI 1.1-30.3], p = 0.033), older dogs (OR: 1.2 [95% CI: 1.1-1.4 per year], p < 0.0001), smaller dogs (OR: 0.98 [95% CI: 0.97-0.99 per 0.45-kg], p = 0.001), stifles with complete cranial cruciate ligament tears (OR: 21.1 [95% CI: 7.1-62.4], p < 0.0001). Contralateral meniscal tears, breed, older age, lower patient weight and complete cranial cruciate ligament tear were significant risk factors for bilateral meniscal tears. Surgeons can use these results to determine prognoses and propensities for meniscal tears in at-risk dogs.

Assisting Decision-Making on Age of Neutering for Mixed Breed Dogs of Five Weight Categories: Associated Joint Disorders and Cancers.

The early neutering of male and female dogs and its relationship to an increased risk of joint disorders and some cancers has recently become a concern, raising questions about the standard practice in the U.S. and much of Europe of neutering by 6 months of age. A noteworthy recent finding from this center is that there are major breed differences with small-dog breeds generally showing little vulnerability to neutering compared with breeds of larger body size. These findings on purebreds raise questions for dog owners and veterinarians about mixed-breed dogs. The purpose of this study was to examine a sample of mixed breed dogs of five weight categories using the same veterinary hospital database and diagnostic criteria for joint disorders and cancers as used in the newly published paper on 35 breeds and previous papers on the Golden Retriever, Labrador Retriever, and German Shepherd Dog. The weight categories were <10 kg (739 cases), 10–19 kg (546 cases), 20–29 kg (992 cases), 30–39 kg (604 cases), and over 40 kg (258 cases). Males and females were analyzed separately, as were various ages at neutering. The joint disorders examined were hip dysplasia, cranial cruciate ligament tear or rupture, and elbow dysplasia. The cancers were lymphoma, mast cell tumor, hemangiosarcoma, and osteosarcoma. There was no significant increased occurrence of one or more cancers, compared with intact dogs, in any weight category. However, in the three categories of dogs weighing 20 kg or more, neutering before 1 year generally was significantly associated with risks of one or more joint disorders above that of dogs left intact, commonly to 3 times the level of intact dogs, with sex differences in the degrees of joint disorders associated with neutering. For the dogs in the two weight categories <20 kg, no increased risks were found for joint disorders. This information can be useful to dog caregivers in deciding on the age at which to neuter specific dogs, and for veterinarians offering guidance to pet owners.

Assisting Decision-Making on Age of Neutering for 35 Breeds of Dogs: Associated Joint Disorders, Cancers, and Urinary Incontinence.

Neutering (including spaying) of male and female dogs in the first year after birth has become routine in the U.S. and much of Europe, but recent research reveals that for some dog breeds, neutering may be associated with increased risks of debilitating joint disorders and some cancers, complicating pet owners' decisions on neutering. The joint disorders include hip dysplasia, cranial cruciate ligament tear or rupture, and elbow dysplasia. The cancers include lymphoma, mast cell tumor, hemangiosarcoma, and osteosarcoma. In previous studies on the Golden Retriever, Labrador Retriever and German Shepherd Dog, neutering before a year of age was associated with increased risks of one or more joint disorders, 2–4 times that of intact dogs. The increase was particularly seen with dogs neutered by 6 months of age. In female Golden Retrievers, there was an increase in one or more of the cancers followed to about 2–4 times that of intact females with neutering at any age. The goal of the present study was to expand and use the same data collection and analyses to cover an additional 29 breeds, plus three varieties of Poodles. There were major breed differences in vulnerability to neutering, both with regard to joint disorders and cancers. In most cases, the caregiver can choose the age of neutering without increasing the risks of these joint disorders or cancers. Small-dog breeds seemed to have no increased risks of joint disorders associated with neutering, and in only two small breeds (Boston Terrier and Shih Tzu) was there a significant increase in cancers. To assist pet owners and veterinarians in deciding on the age of neutering a specific dog, guidelines that avoid increasing the risks of a dog acquiring these joint disorders or cancers are laid out for neutering ages on a breed-by-breed and sex basis.

Center of rotation of angulation-based leveling osteotomy combined with a coplanar cranial closing wedge ostectomy to manage cranial cruciate ligament insufficiency in dogs with excessive tibial plateau angle.

To describe outcomes of dogs with excessive tibial plateau angle (eTPA) and cranial cruciate ligament (CrCL) disease treated with center of rotation of angulation-based leveling osteotomy (CBLO) and cranial closing wedge ostectomy (CCWO). Retrospective study. Twenty-one dogs. Medical records of dogs with CrCL disease and eTPA (>34°) treated with CBLO/CCWO were reviewed. Signalment, body weight, intra-articular structure appearance, TPA (preoperatively, postoperatively, and at osteotomy healing), postoperative function, and complications were recorded. Twenty-one dogs (28 stifles) with CrCL disease/eTPA underwent CBLO/CCWO. Twenty stifles had complete CrCL tears and eight tears were partial. Mean age and weight of dogs were 4 years (range, 1-9) and 27 kg (range, 4-65), respectively. Medial menisci were normal in 20 stifles, torn in 5, and degenerative in 3. All lateral menisci were normal. The caudal cruciate ligament was normal in 26 stifles and partially torn in 2. Mean TPA was 43° preoperatively, 10° postoperatively, and 10° at final recheck. Grade 4 healing occurred in all osteotomies by 8 weeks postoperatively. Complications included one pin migration, breakage of two proximal screws (1 case), one late-onset caudolateral band CrCL tear, two late-onset meniscal tears, and one surgical site infection. Eighteen dogs returned to full function, and three dogs achieved acceptable function, at a mean of 27 months. Center of rotation of angulation-based leveling osteotomy/CCWO resulted in grade 4 osteotomy healing by 8 weeks, minimal complications, and acceptable to full return to function. Center of rotation of angulation-based leveling osteotomy/CCWO should be considered to treat canine CrCL disease/eTPA.

Long-term outcome and progression of osteoarthritis in uncomplicated cases of cranial cruciate ligament rupture treated by tibial plateau leveling osteotomy in dogs.

The object of this study is to evaluate the long-term outcome of hind limb weight-bearing function and progression of stifle osteoarthritis (OA) after tibial plateau leveling osteotomy (TPLO). Groups were classified by the degree of cranial cruciate ligament (CrCL) damage and presence or absence of medial meniscus damage as macroscopically evaluated during surgery. Weight-bearing function was assessed via the peak vertical force (PVF), and OA progression was assessed via the radiographic OA score (OAS) preoperatively and 1, 3, 6, 12, 18, 24, and 36 months postoperatively. In all stifles, PVF was significantly higher within 6 months postoperatively than preoperatively, and this high ratio was maintained for 36 months. The OAS was significantly higher 24 months postoperatively than preoperatively in stifles with a partial CrCL tear, and significantly increased at each timepoint after 3 months postoperatively in stifles with complete CrCL rupture. The OAS remained consistently lower in stifles with a partial CrCL tear and no treatment of the medial meniscus than in stifles with complete rupture. Thus, after TPLO, the weight-bearing function improved in the early postoperative period and was maintained for as long as 36 months. Although OA progressed over time after TPLO, the progression was more gradual in stifles with partial tears than in those with complete rupture. Canine patients would benefit from earlier surgical intervention through development of technology that enables early detection of ligament degeneration.

Association of meniscal injury to joint space width on standard tibial plateau leveling osteotomy lateral radiographic projections of the canine stifle.

Up to 70% of dogs with cranial cruciate ligament tears have concurrent meniscal injury, and these injuries can increase the risk of developing osteoarthritis and persistent lameness. Studies assessing joint space width on knee radiographs in people have indicated associations between joint space width and meniscal injuries. The aim of this prospective analytical study was to determine if there was an association between stifle joint space width on three different radiographic projections (the standard tibial plateau leveling osteotomy projections and a standing lateral projection) and meniscal injuries identified at surgery in dogs. There was a significant association between dogs with a meniscal tear and the corresponding joint space width on standard tibial plateau leveling osteotomy lateral radiographic projections (P-value=.0028). Based on receiver operator characteristic curve analysis, joint space widths measuring less than 3.43mm may indicate a meniscal tear, with a corresponding 89.5% specificity and 40.5% sensitivity in dogs weighing 31kg. Joint space narrowing is seen with meniscal tears in dogs, and radiography may be a noninvasive way to identify meniscal tears prior to surgery.

Meniscal click in cranial cruciate deficient stifles as a predictor of specific meniscal pathology.

To determine the predictive value of meniscal click for specific meniscal tear morphology. Prospective cohort. Client-owned dogs (104) with cranial cruciate ligament (CCL) deficiency treated with stifle arthroscopy (111). All stifles underwent a standardized examination for meniscal click before anesthesia (EBA) and during anesthesia (EDA). Presence or absence of a medial meniscal tear and diagnosis of tear morphology were confirmed with arthroscopic examination. Complete CCL tears were noted in 93 dogs, and incompetent partial tears were noted in 18 dogs. Medial meniscal tears were noted in 40.5% (55/111) of dogs, including bucket handle tears (BHT) in 65.6% (36/55) of tears. Frays of the lateral meniscus were noted in 6.3% of dogs (7/111). Examination for meniscal click before anesthesia was 38% sensitive and 94.5% specific, and EDA was 38% sensitive and 98.2% specific for all meniscal tear morphologies. Positive meniscal click at EBA was associated with a meniscal BHT but not with a meniscal non-BHT (P < .0001 and P = .3515, respectively). Positive meniscal click at EDA was associated with a meniscal BHT but not with a meniscal non-BHT (P < .0001 and P = .1909, respectively). A meniscal click is more commonly associated with a meniscal BHT than with a non-BHT. Meniscal tear morphology influences the presence or absence of meniscal click. Because of the high incidence of meniscal disease, this study provides evidence to support joint exploration in the treatment of CCL disease.

Rate of return to agility competition for dogs with cranial cruciate ligament tears treated with tibial plateau leveling osteotomy.

OBJECTIVE To determine rate of and factors associated with return to agility competition for dogs with cranial cruciate ligament (CrCL) rupture treated with tibial plateau leveling osteotomy (TPLO). DESIGN Retrospective case series with nested case-control study. ANIMALS 31 dogs involved in agility competition with CrCL tears treated by TPLO at a private veterinary clinic from 2007 through 2013. PROCEDURES Medical records were reviewed to collect information on dog signalment, lesion characteristics, and surgical data. Owners completed a survey regarding whether and when their dog returned to agility competition after TPLO and, if so, how the dog performed. Performance data before and after TPLO were compared. RESULTS 20 of 31 (65%) dogs returned to agility competition after TPLO, 16 (80%) of which returned within 9 months after TPLO. The mean convalescent period for returning dogs was 7.5 months (range, 3 to 12 months). No dog that returned to competition sustained an injury to the affected limb during the follow-up period. No significant difference was identified between dogs that returned or did not return to agility competition regarding severity of osteoarthritis or proportions with meniscal injury or partial (vs complete) CrCL tears. CONCLUSIONS AND CLINICAL RELEVANCE These data suggested that the prognosis for returning to agility competition was good for dogs undergoing TPLO. None of the evaluated lesion characteristics were associated with return to competition. Rate of return to competition and duration of the convalescent period may be useful outcome variables for future investigations involving orthopedic procedures in dogs.

Second-look arthroscopic findings after CORA-based leveling osteotomy.

To describe the arthroscopic appearance of intra-articular structures mid-term (9 months) and long-term (>12 months) after CORA-based leveling osteotomy (CBLO). Case series. Dogs (n = 41) with second-look arthroscopy of the stifle after CBLO for treatment of a cranial cruciate ligament (CCL) deficiency. Both stifles were re-evaluated (stifles n = 42) in 1 dog. Medical records of dogs that had second-look arthroscopy after CBLO were reviewed. Arthroscopic images of the femoral condyles were independently reviewed. The surgical report documented the integrity of menisci and articular cartilage of the tibial plateaus. The population included 7 stifles with stable partial CCL tears, 35 stifles with complete CCL tears (n = 28), or incompetent partial CCL tears (n = 7). Median time to second look arthroscopy was 16 months (9-24 months) for stable partial tears. The CCL remained intact in 6 stifles. The Outerbridge score of the articular cartilage of the femoral condyles was as 0 (6) or 1 (1). The articular cartilage of the tibial plateaus appeared normal in all stifles. Median time to second look arthroscopy of stifles with complete tears was 12 months (range, 9-34 months). The caudal cruciate ligament was normal or mildly fibrillated. The appearance of the articular cartilage of the femoral condyles was scored as 0 or near normal (grade 1-2) in all dogs. The articular cartilage of the tibial plateaus appeared normal, except in 1 dog with grade 4 lesion. CBLO results in minimal to no change in articular cartilage in at a median time of 14 months after surgery. Postoperative clinical lameness is often attributed to late onset meniscal pathology.

Surgical stabilization of concomitant canine medial patellar luxation and cranial cruciate ligament disease. Effect of fixation method on postoperative complication rate and clinical outcome.

To compare complication rates and outcomes between cases of concomitant cranial cruciate ligament (CrCL) disease and medial patellar luxation (MPL) treated using extracapsular stabilization and tibial tuberosity transposition (ECS+TTT) and tibial tuberosity transposition and advancement (TTTA). In a multicentre retrospective study, records from four referral hospitals were reviewed for dogs with concomitant CrCL pathology and MPL treated using ECS+TTT or TTTA. Data retrieved included signalment, partial/complete CrCL tear, MPL grade, treatment performed, occurrence of postoperative complications, and postoperative outcome grade. Associations between surgical procedure and risk of complication and surgical procedure and outcome were investigated using univariable logistic regression and proportional odds logistic regression respectively. Multiple logistic regression was used to explore confounding factors. A total of 72 stifles were evaluated in 66 dogs; 32 stifles were stabilized using ECS+TTT and 40 using TTTA. Overall complications were 2.7 times more frequent in the ECS+TTT group and major complications occurred only in this group. The TTTA group was less likely to suffer complications (17.5%) compared to the ECS+TTT group (46.9%) (p = 0.009) and TTTA cases had lower odds of a poorer clinical outcome (p = 0.047). Stifles stabilized using ECS+TTT are more likely to suffer from postoperative complications and a poorer clinical outcome when compared to TTTA.

Partial Cranial Cruciate Ligament Tears Treated with Stem Cell and Platelet-Rich Plasma Combination Therapy in 36 Dogs: A Retrospective Study.

To evaluate outcomes in 36 dogs with a partial cranial cruciate ligament (CCL) tear treated with autologous bone marrow aspirate concentrate (BMAC) or adipose-derived progenitor cells (ADPC) with platelet-rich plasma (PRP) combination. Medical records of client-owned dogs diagnosed with an early partial (≤50%) tear of the craniomedial band of the CCL that was treated with BMAC-PRP or ADPC-PRP were reviewed from 2010 to 2015. Signalment, medical history, physical and orthopedic examination, objective temporospatial gait analyses, radiographs, day 0 and day 90 diagnostic arthroscopy findings, treatment, and outcome were among the data collected. A functional owner questionnaire, including the validated Helsinki chronic pain index (HCPI), was sent to owners whose dog was known to not have had a tibial plateau leveling osteotomy (TPLO). Statistical analysis was performed on data, where significance was established at p < 0.05. Stifle arthroscopy findings at 90 days posttreatment were available on 13 of the 36 dogs. In nine dogs, a fully intact CCL with marked neovascularization and a normal fiber pattern was found with all previous regions of disruption healed. One dog revealed significant improvement and received an additional injection. The remaining three dogs had a >50% CCL tear, and a TPLO was performed. Four additional dogs were known to have had a TPLO performed elsewhere. Baseline and day 90 posttreatment objective gait analyses were available on 11 of the 36 dogs. A significant difference was found between the treated limb total pressure index percent (TPI%) at day 0 and day 90 (p = 0.0124), and between the treated limb and contralateral limb TPI% at day 0 (p = 0.0003). No significant difference was found between the treated limb and contralateral limb TPI% at day 90 (p = 0.7466). Twelve questionnaires were returned, of which eight were performance/sporting dogs. Seven of the eight had returned to sport; the remaining dog had just begun a return to sport conditioning program 6 months posttreatment. All 12 respondents believed that their dog had an excellent or very good quality of life and rated their dog's procedural outcome as excellent or good. The use of BMAC-PRP and ADPC-PRP shows promise for the treatment of early partial CCL tears in dogs. Further studies are needed and should be randomized, blinded, and controlled.

Neutering of German Shepherd Dogs: associated joint disorders, cancers and urinary incontinence.

German Shepherd Dogs are important in police and military work, and are a popular family pet. The debilitating joint disorders of hip dysplasia, cranial cruciate ligament tear (CCL) and elbow dysplasia can shorten a dog's useful working life and impact its role as a family member. For this study, veterinary hospital records were examined over a 14.5‐year period on 1170 intact and neutered (including spaying) German Shepherd Dogs for joint disorders and cancers previously associated with neutering. The diseases were followed through 8 years of age, with the exception of mammary cancer (MC) in females that was followed through 11 years. The cancers followed, apart from mammary, were osteosarcoma, lymphoma, hemangiosarcoma and mast cell tumour. In intact males, 7% were diagnosed with one or more joint disorders, while in males neutered prior to a year of age, a significantly higher 21% were diagnosed with one or more joint disorders. In intact females, 5% were diagnosed with one or more joint disorders, while in females neutered prior to a year of age, this measure was significantly increased to 16%. The increased joint disorder incidence mostly associated with early neutering was CCL. MC was diagnosed in 4% of intact females compared with less than 1% in females neutered before 1 year. The occurrence of the other cancers followed through 8 years of age was not higher in the neutered than in the intact dogs. Urinary incontinence, not diagnosed in intact females, was diagnosed in 7% of females neutered before 1 year, a significant difference. These findings, profiling the increase in joint disorders associated with early neutering, should help guide the timing of neutering for this breed.

Long-term health effects of neutering dogs: comparison of Labrador Retrievers with Golden Retrievers.

Our recent study on the effects of neutering (including spaying) in Golden Retrievers in markedly increasing the incidence of two joint disorders and three cancers prompted this study and a comparison of Golden and Labrador Retrievers. Veterinary hospital records were examined over a 13-year period for the effects of neutering during specified age ranges: before 6 mo., and during 6–11 mo., year 1 or years 2 through 8. The joint disorders examined were hip dysplasia, cranial cruciate ligament tear and elbow dysplasia. The cancers examined were lymphosarcoma, hemangiosarcoma, mast cell tumor, and mammary cancer. The results for the Golden Retriever were similar to the previous study, but there were notable differences between breeds. In Labrador Retrievers, where about 5 percent of gonadally intact males and females had one or more joint disorders, neutering at <6 mo. doubled the incidence of one or more joint disorders in both sexes. In male and female Golden Retrievers, with the same 5 percent rate of joint disorders in intact dogs, neutering at <6 mo. increased the incidence of a joint disorder to 4–5 times that of intact dogs. The incidence of one or more cancers in female Labrador Retrievers increased slightly above the 3 percent level of intact females with neutering. In contrast, in female Golden Retrievers, with the same 3 percent rate of one or more cancers in intact females, neutering at all periods through 8 years of age increased the rate of at least one of the cancers by 3–4 times. In male Golden and Labrador Retrievers neutering had relatively minor effects in increasing the occurrence of cancers. Comparisons of cancers in the two breeds suggest that the occurrence of cancers in female Golden Retrievers is a reflection of particular vulnerability to gonadal hormone removal.

Risk Factors and Diagnostic Accuracy of Clinical Findings for Meniscal Disease in Dogs With Cranial Cruciate Ligament Disease

To determine the risk factors for meniscal disease and diagnostic accuracy of physical examination in dogs with cranial cruciate ligament (CCL) deficiency. Prospective cohort study. Stifles (n = 80) of dogs with CCL deficiency. Each dog was evaluated preoperatively for factors that may increase the risk of, or aid in the diagnosis of meniscal disease including presence of pain on extension and flexion of the affected stifle, range of motion during flexion and extension, thigh circumference, positive cranial-drawer test, positive tibial compression test, tibial plateau angle, complete tear of the CCL, presence of a meniscal click, and gait analysis. Odds ratios were calculated for each of the factors and a multivariate approach was used to create an ROC curve. Subsequent sensitivity, specificity, and area under the curve was used to determine the diagnostic value of clinical tests. Dogs with pain upon flexion of the stifle were 4.3 times more likely to have medial meniscal disease than those without flexion pain and dogs with a complete CCL tear were 9.6 times more likely to have medial meniscal disease than those with partial tears. A meniscal click increased the likelihood of medial meniscal disease by a factor of 11.3. The diagnostic accuracy using a meniscal click and pain upon stifle flexion was 76%. Combining the presence of a meniscal click and pain during flexion of the stifle provide a more accurate diagnosis of medial meniscal disease in dogs with CCL disease over individual examination variables.

Neutering Dogs: Effects on Joint Disorders and Cancers in Golden Retrievers

In contrast to European countries, the overwhelming majority of dogs in the U.S. are neutered (including spaying), usually done before one year of age. Given the importance of gonadal hormones in growth and development, this cultural contrast invites an analysis of the multiple organ systems that may be adversely affected by neutering. Using a single breed-specific dataset, the objective was to examine the variables of gender and age at the time of neutering versus leaving dogs gonadally intact, on all diseases occurring with sufficient frequency for statistical analyses. Given its popularity and vulnerability to various cancers and joint disorders, the Golden Retriever was chosen for this study. Veterinary hospital records of 759 client-owned, intact and neutered female and male dogs, 1–8 years old, were examined for diagnoses of hip dysplasia (HD), cranial cruciate ligament tear (CCL), lymphosarcoma (LSA), hemangiosarcoma (HSA), and mast cell tumor (MCT). Patients were classified as intact, or neutered early (<12 mo) or late (≥12 mo). Statistical analyses involved survival analyses and incidence rate comparisons. Outcomes at the 5 percent level of significance are reported. Of early-neutered males, 10 percent were diagnosed with HD, double the occurrence in intact males. There were no cases of CCL diagnosed in intact males or females, but in early-neutered males and females the occurrences were 5 percent and 8 percent, respectively. Almost 10 percent of early-neutered males were diagnosed with LSA, 3 times more than intact males. The percentage of HSA cases in late-neutered females (about 8 percent) was 4 times more than intact and early-neutered females. There were no cases of MCT in intact females, but the occurrence was nearly 6 percent in late-neutered females. The results have health implications for Golden Retriever companion and service dogs, and for oncologists using dogs as models of cancers that occur in humans.