Epidemiology of Cranial Cruciate Ligament Rupture and Patellar Luxation in Dogs from the Province of Buenos Aires, Argentina.

OBJECTIVE: The aim of this study was to investigate the prevalence of cranial cruciate ligament rupture and patellar luxation and the associated risk factors in dogs. MATERIALS AND METHODS: A total of 13,072 clinical records of dogs were reviewed from School Hospital (Faculty of Veterinary Sciences, National University of La Plata). Data of age, breed, sex, body weight, patellar luxation and cranial cruciate ligament rupture condition were registered. Chi-squared and Fisher's exact tests were used to compare the prevalence of cranial cruciate ligament rupture and patellar luxation with the variables and then univariable logistic regression was used to evaluate the risk of having cranial cruciate ligament rupture and patellar luxation. Multivariable logistic regression was used including all variables to assess the odds of having patellar luxation and cranial cruciate ligament rupture. RESULTS: Of 13,072 patients treated, 72 and 51 had cranial cruciate ligament rupture and patellar luxation respectively. Sex was not a major risk factor for either condition. Adult (odds ratio [OR] = 8.2) and senior (OR = 4.3) patients had increased risk of having cranial cruciate ligament rupture, while for patellar luxation age was not a risk factor. Groups 2, 3 and 8 were more likely to have cranial cruciate ligament rupture (OR = 5.5, OR = 9.1 and OR = 2.6), and group 11 had lower risk of having patellar luxation (OR = 0.08). Maxi (OR = 2.4) and giant (OR = 6.0) breeds had higher risk of having cranial cruciate ligament rupture, and medium and maxi breeds had higher risk of patellar luxation (OR = 0.05 and OR = 0.3). Multivariate OR test confirmed that age (adult), body size (giant and maxi) and breed group (Group 3) were significantly associated with having cranial cruciate ligament rupture, and age was associated with having patellar luxation. CLINICAL SIGNIFICANCE: This is the first epidemiological study of cranial cruciate ligament rupture and patellar luxation in dogs from School Hospital (Faculty of Veterinary Sciences, National University of La Plata). Giant and large adult dogs from the Molossoid and Terrier breeds were more likely to have cranial cruciate ligament rupture, while mixed and large dog breeds showed the lowest risk of having patellar luxation.

von Willebrand disease type 1 in Doberman Pinscher dogs: genotyping and prevalence of the mutation in the Buenos Aires region, Argentina.

von Willebrand disease (vWD) is the most common inherited coagulopathy in dogs, particularly in Doberman Pinschers. We developed a pyrosequencing-based assay to estimate the frequency of the c.7437G>A mutation associated with vWD type 1 in the Doberman Pinscher population of Buenos Aires, Argentina. We found a 0.41 frequency for the mutated allele, which varied significantly within families (family 1 = 0.43, family 2 = 0.58, unrelated animals = 0.35). The use of a popular founder male carrier of mutant allele A increased vWD incidence within a family and in the general population. The mode of inheritance was confirmed as autosomal dominant with incomplete penetrance. No differences were found between sexes and coat colors. Pyrosequencing was a good complement to clinical and coagulation tests for vWD type 1 diagnosis and a useful alternative for detecting the c.7437G>A mutation.

A study of the association between chronic superficial keratitis and polymorphisms in the upstream regulatory regions of DLA-DRB1, DLA-DQB1 and DLA-DQA1.

Canine chronic superficial keratitis (CSK) is an inflammatory corneal disease that primarily occurs in German shepherd dogs (GSDs). Several studies support the hypothesis that CSK is an immune-mediated disease. To investigate the genetic factors associated with CSK development, the upstream regulatory regions (URRs) of the DLA-DRB, -DQA and -DQB genes were genotyped in 60 dogs, including 32 CSK animals. LD analysis identified two blocks (r(2)≤45), with two DLA-DRB1 and five DLA-DQB1 haplotypes. Analysis of DLA-URR alleles/haplotypes showed a significant association between DQB1*-154 [C/T] (p=0.016) and CSK, suggesting that the T variant may increase the risk for developing CSK disease (OR=3, 95% CI=1.25-7.68). When haplotype associations were performed, the URR-DQB*CATT haplotype was significantly associated with CSK (p=0.016), increasing the risk of develop this disease over two-fold (OR=3, 95%, CI=1.25-7.68). These results showed that dogs homozygous at DRB1*69 [C/T] had a risk for developing CSK disease that was over four times the risk for heterozygotes. This genetic association supports the previous clinical, histological and pharmacological studies that suggest that CSK is an immune-mediated disease, and this association could potentially be used to identify susceptible animals.