Cartilage effect of enrofloxacin to Scyliorhinus canicula after intramuscular treatment

Quinolones are widely used due to their high efficacy against Gram- positive and anaerobial bacteria. Anyway, among adverse effects of these drugs chondrotoxicity has been observed and recorded, thus leading to a reduced use in pediatric age. These drugs are also commonly used for the treatment of infectious diseases in chondroichtes, but little or no information is at present available concerning potential adverse effect of these active principles on the cartilage of selaceans. Present work reports about the evaluation of chondrotoxicity to Scyliorhinus canicola following intramuscular treatment with a quinolone, enrofloxacin. Three experimental groups were prepared: a control, a low dose and a high dose group, which were treated with saline, 5 mg/kg and 10 mg/kg enrofloxacin respectively, daily for a 14 days period, following normal therapeutic protocols (Smith et al., 2004). Animals were fed daily ad libitum and weight was regularly recorded every 3 days in order to detect for any toxicity. Blood samples were taken at day 0 and 14 of treatment and at day 14 post-treatment. Half of the animals were suppressed at the end of the 14 days treatment period, while all other animals were killed at the end of the 14 days post-treatment period. Ultrastuctural or densitometric alteration in cartilage structure was detected, as well as any changing in hematological parameters. Preliminary results are discussed in present work as well as the possibility to use small sharks as lab animals for this protocols.