Bisphosphonates are commonly used to treat and prevent bone loss, but their effects in active, juvenile populations are unknown. This study examined the effects of intramuscular clodronate disodium (CLO) on bone turnover, serum bone biomarkers (SBB), bone mineral density (BMD), bone microstructure, biomechanical testing (BT), and cartilage glycosaminoglycan content (GAG) over 165 days. Forty juvenile sheep (253 ± 6 days of age) were divided into four groups: Control (saline), T₀ (0.6 mg/kg CLO on day 0), T₈₄ (0.6 mg/kg CLO on day 84), and T₀₊₈₄ (0.6 mg/kg CLO on days 0 and 84). Sheep were exercised 4 days/week and underwent physical and lameness examinations every 14 days. Blood samples were collected for SBB every 28 days. Microstructure and BMD were calculated from tuber coxae (TC) biopsies (days 84 and 165) and bone healing was assessed by examining the prior biopsy site. BT and GAG were evaluated postmortem. Data, except lameness data, were analyzed using a mixed-effects model; lameness data were analyzed as ordinal data using a cumulative logistic model. CLO did not have any measurable effects on the skeleton of sheep. SBB showed changes over time (p ≤ 0.03), with increases in bone formation and decreases in some bone resorption markers. TC biopsies showed increasing bone volume fraction, trabecular spacing and thickness, and reduced trabecular number on day 165 versus day 84 (p ≤ 0.04). These changes may be attributed to exercise or growth. The absence of a treatment effect may be explained by the lower CLO dose used in large animals compared to humans. Further research is needed to examine whether low doses of bisphosphonates may be used in active juvenile populations for analgesia without evidence of bone changes.

Despite increased recognition of caudal vertebral anomalies in the domestic dog (Canis lupus familiaris), studies describing tail deformities remain limited. To address this gap in the literature, this study aimed to identify and classify the caudal vertebral anomaly phenotypes in a pedigree of Beagles. Subjects included 67 dogs (36 males and 31 females), aged eight months to eight years old (M= 38.8 ± 25.6 months). All 67 dogs were visually examined, and tails were palpated to determine if they had any kinks, bends, misalignments, or deformities in their tail prior to radiographic assessment. Radiographs of the caudal vertebrae were obtained from 53 dogs and evaluated for congenital anomalies, including block vertebrae, hemivertebrae, brachyury (very short tail), and axial deviations. Of the 53 radiographed dogs, 25 (47.2%) exhibited at least one congenital caudal vertebral anomaly, with block vertebrae being the most common finding (43.4%). Four dogs (7.6%) had mild congenital abnormalities detected radiographically that were not identified during physical examination. Based on pedigree structure, an autosomal recessive trait is suspected. These findings demonstrate a high prevalence of caudal vertebral anomalies within this pedigree of Beagles and emphasize the importance of radiographic evaluation for accurate identification and phenotypic classification.