Weight-bearing stress may be a risk factor for both human and canine primary bone cancer. A cohort of Leonbergers (LB) was followed from birth to death and the cause of death recorded. We hypothesised that dogs dying due to primary bone cancer would be larger; measured by bodyweight (BW) and the circumference of the distal radius and ulna (CDRU) than those of the same breed that died of other causes. Information obtained from breeders, owners and veterinary surgeons were questionnaire-based. The dogs were examined by a veterinary surgeon at pre-specified "observational ages" (3, 4, 6, 12, 18, and 24 m). Data were recorded, including BW and CDRU. The study population consisted of 196 LB, 9 of which died due to primary bone cancer (6 males, 3 females). Individual growth curves, showing BW and CDRU during the first 2 years of life, were made for these 9 dogs and compared to gender-specific mean values for LB that died from other causes. These curves showed that LB succumbing to primary bone cancer generally had a higher BW during the growth period than the remaining dogs, and that this difference appeared to be largest in the male LB. Male LB that developed primary bone cancer later in life also had a larger CDRU during most part of this period, as compared to those that did not develop this disease. Logistic regression showed a statistically significant effect of BW on the odds ratio of developing primary bone cancer at 12 m and 18 m and of CDRU at 18 m, and a Poisson regression verified consistency of these results. At these ages, an increase in BW of 1 kg yielded a nearly 20% higher risk of developing primary bone cancer, while a 1 cm larger CDRU was associated with a nearly 70% increased risk. These findings support that weight-bearing stress during the period of high proliferative activity in the long bones associated with growth may increase the risk of canine primary bone cancer.
Erratum In: Prev Vet Med. 2015 Jun 15;120(2):252Trangerud, Cathrine [added]
The study-objective was to measure the effect of weight and growth related parameters on the risk of development of Canine Hip Dysplasia (CHD). The hypothesis was that heavy and fast growing dogs of large sized breeds were at increased risk of development of CHD compared to lighter and slower growing dogs. A prospective cohort study was conducted among dogs of four large breeds: Newfoundland (NF), Leonberger (LEO), Labrador retriever (LR), and Irish wolfhound (IW). The dogs were privately owned with individualized nutrition and environment, and they were followed from birth and throughout the growth period until the official screening for CHD was performed. The study sample consisted of 501 dogs from 103 litters, with the breed distribution 125 NF, 180 LEO, 133 LR, and 63 IW. Because the dogs were clustered in litters a multivariable random effects logistic regression model was used to assess statistically significant growth-related risk factors for CHD. The estimated incidence risk of CHD was 36% in NF, 25% in LEO, 20% in LR, and 10% in IW. Based upon the final multilevel model it appears that the odds of CHD among both LR and IW (odds ratio (OR) 0.22) are about one-fifth of the odds for NF. The odds for LEO (OR 0.60) are not significantly different from NF. There appeared to be an inverse relationship between body weight at 3 months of age and odds of CHD, with an OR of 0.89 (P=0.044). The degree of clustering at the litter-level was high (22.6%) and highly significant (P
Pathological changes in the vertebral column of farmed Atlantic salmon in Norway have been reported since the 1990s. Based on the characteristic radiographic findings, we here present a vertebral column deformity named "curved cross-stitch vertebrae" that mainly affects the middle aspect of the vertebral column. Sixty fish, from the west/northwest coast of mid-Norway, were sampled at slaughter and examined by radiography, computed tomography (CT), necropsy, macrophotography, and histology. The vertebral deformities were radiographically graded as mild, moderate, or marked. The main differences between these grades of changes were defined by increased curving of the peripheries of endplates, reduced intervertebral spaces, and vertical displacement of the vertebrae. The curved rims of endplates were located peripheral to a continuous and approximately circular borderline. The CT studies revealed small, multifocal, hypo-attenuating, round to crescent-shaped areas in the notochord, compatible with the presence of gas. Additionally, histology revealed that the axial parts of endplates had circular zones with perforations, through which either notochordal tissue prolapsed into the vertebrae or vascularized fibrochondroid proliferations extended from the vertebrae into the notochord. Inflammation was present in many vertebral bodies. To the best of our knowledge, this is the first report of gas in the notochord of fish.