Anterior cruciate ligament (ACL) rupture is a common condition that can be devastating and life changing, particularly in young adults. A non-contact mechanism is typical. Second ACL ruptures through rupture of the contralateral ACL or rupture of a graft repair is also common. Risk of rupture is increased in females. ACL rupture is also common in dogs. Disease prevalence exceeds 5% in several dog breeds, ~100 fold higher than human beings. We provide insight into the genetic etiology of ACL rupture by genome-wide association study (GWAS) in a high-risk breed using 98 case and 139 control Labrador Retrievers. We identified 129 single nucleotide polymorphisms (SNPs) within 99 risk loci. Associated loci (P<5E-04) explained approximately half of phenotypic variance in the ACL rupture trait. Two of these loci were located in uncharacterized or non-coding regions of the genome. A chromosome 24 locus containing nine genes with diverse functions met genome-wide significance (P = 3.63E-0.6). GWAS pathways were enriched for c-type lectins, a gene set that includes aggrecan, a gene set encoding antimicrobial proteins, and a gene set encoding membrane transport proteins with a variety of physiological functions. Genotypic risk estimated for each dog based on the risk contributed by each GWAS locus showed clear separation of ACL rupture cases and controls. Power analysis of the GWAS data set estimated that ~172 loci explain the genetic contribution to ACL rupture in the Labrador Retriever. Heritability was estimated at 0.48. We conclude ACL rupture is a moderately heritable highly polygenic complex trait. Our results implicate c-type lectin pathways in ACL homeostasis.

Augmentation of primary Achilles tendon repair with a semitendinosus flap can be considered in dogs with chronic rupture but further investigation of the long-term outcome using this technique is needed.

Results suggested that a toggle rod or toggle pin can be used for stabilization of hip joint luxations in dogs. Of the materials tested, braided polyester had the best in vitro mechanical properties.

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Using the described method of muscle measurement in Labrador Retrievers only measurement of the proximal antebrachium was reliable; a single (1st) measurement was as reliable as using the mean of triplicate measurements.

Objective To determine the effect of 3 differing transfusion techniques on survival of autologous canine red blood cells (RBCs). Design Prospective, blinded study. Setting University Teaching Hospital. Animals Nine healthy dogs. Interventions Three distinct preparations of RBCs, each representing ∼1% of red cell mass, were generated for each dog by biotinylation of RBCs at varying biotin densities. Labeled cells were transfused using 3 techniques (gravity, volumetric pump, syringe pump). Serial determinations of red cell survival were carried out by flow-cytometric analysis of RBCs collected at 7-day intervals for 49 days. In vitro analysis of the effect of transfusion methods on RBC integrity and osmotic fragility were carried out in 7/9 dogs. Measurements and Main Results RBCs administered via volumetric and syringe pumps exhibited a marked decrease in short-term probability of survival compared to RBCs delivered by gravity flow. At 24 hours, only 4/8 and 1/7 dogs had surviving cell populations delivered by volumetric and syringe pump respectively, compared with 8/8 dogs which had surviving cell populations delivered by gravity flow. Circulating half-life of cells surviving at 24 hours after delivery by volumetric pump was not significantly different to that delivered by gravity flow . No significant effect on in vitro RBC integrity or osmotic fragility was detected in relation to transfusion technique. Conclusions Delivery of autologous canine RBCs via mechanical delivery systems was associated with a high risk for early loss of transfused cells.

Urinary isoprostane-to-creatinine ratios were higher in dogs with IVDD before and after surgery. Analysis of these data suggests that dogs with IVDD are in a state of oxidative stress and that preemptive treatment with antioxidants warrants further investigation.

BackgroundThe objective was to determine the effects of agility exercise on dogs of different skill levels with respect to urinary eicosanoids, urinary 15F2t-isoprostane (lipid peroxidation marker) and hematological/biochemical changes in plasma. Fifteen adult dogs had blood and urine samples obtained prior to, immediately and 4-hours following an agility exercise.ResultsHematocrit, red blood cells (RBC), albumin, and hemoglobin increased following exercise, with greatest increases correlating to increased skill group (novice, intermediate, masters); at 4-hours post-exercise, hematocrit, RBC, and hemoglobin were decreased. Phosphorus increased following exercise with the greatest increase in novice and intermediates. Plasma lactate increased 3.6-fold in masters, 3.2-fold in intermediates, and 1.2-fold in novice dogs. Urine thromboxane B2 (TXB2) more than tripled 4-hours post-exercise while 6-keto prostaglandin F1α (PGF1α, prostacyclin metabolite), prostaglandin E2 metabolites (13,14-dihydro-15-keto-prostaglandin A2 and 13,14-dihydro-15-keto-prostaglandin E2), and 13,14-dihydro-15-keto prostaglandin F2α were unaffected as determined by a competitive enzyme immunoassay and standardized by division with urine creatinine. Urine 15F2t-isoprostane increased insignificantly.ConclusionsAlterations in the plasma post-exercise were likely due to hemoconcentration from insensible water loss, splenic contraction and sympathetic stimulation while 4-hours later autohemodilution reduced RBC parameters. Elevations in plasma lactate and urinary TXB2 correlated with advanced skill level/speed of the dogs.