BACKGROUND: While commercial poultry and captive birds are exposed to antimicrobials through direct medication, environmental pollution may result in contamination of wild birds. Fluoroquinolones are commonly used medications to treat severe avian bacterial infections; however, their adverse effects on birds remain understudied. Here, we examine toxicity of enrofloxacin and marbofloxacin during the egg incubation period using the chicken (Gallus Gallus domesticus) as a model avian species. Laboratory tests were based on eggs injected with 1, 10 and 100 μg of fluoroquinolones per 1 g of egg weight prior to the start of incubation and monitoring of chick blood biochemistry, reproductive parameters and heart rate during incubation. RESULTS: Eggs treated with fluoroquinolones displayed reduced hatchability due to embryonic mortality, particularly on day 13 of incubation. Total hatching success showed a similar pattern, with a significantly reduced hatchability in low and high exposure groups treated with both enrofloxacin and marbofloxacin. From 15 to 67% of chicks hatching in these groups exhibited joint deformities. Hatching one-day pre-term occurred with a prevalence of 31 to 70% in all groups treated with fluoroquinolones. Embryonic heart rate, measured on days 13 and 19 of incubation, increased in all enrofloxacin-treated groups and medium and high dose groups of marbofloxacin-treated eggs. Blood biochemistry of chicks sampled at hatch from medium dose groups showed hypoproteinaemia, decreased uric acid and increased triglycerides. Chicks from the enrofloxacin-treated group displayed mild hyperglycaemia and a two-fold rise in the blood urea nitrogen to uric acid ratio. Principal components analysis based on blood biochemistry clearly separated the control bird cluster from both enrofloxacin- and marbofloxacin-treated birds. CONCLUSIONS: Fluoroquinolones induce complex adverse effects on avian embryonic development, considerably reducing the performance of incubated eggs and hatching chicks. Cardiotoxicity, which quickens embryonic heart rate, meant that the total number of heart beats required for embryogenesis was achieved earlier than in the standard incubation period, resulting in pre-term hatching. Our data suggest that enrofloxacin has a higher potential for adverse effects than marbofloxacin. To conclude, care should be taken to prevent exposure of reproducing birds and their eggs to fluoroquinolones.

• Keywords
• Antibiotics, Avian embryonic heart rate, Enrofloxacin, Hatchability, Marbofloxacin, Pre-term hatching, Reproduction,
• MeSH
• Anti-Infective Agents toxicity   MeSH
• Enrofloxacin toxicity   MeSH
• Fluoroquinolones toxicity   MeSH
• Hypoproteinemia chemically induced   veterinary   MeSH
• Chickens * blood   MeSH
• Chick Embryo drug effects   MeSH
• Poultry Diseases chemically induced   MeSH
• Reproduction drug effects   MeSH
• Heart Rate drug effects   MeSH
• Animals MeSH
• Check Tag
• Chick Embryo drug effects   MeSH
• Female MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Anti-Infective Agents MeSH
• Enrofloxacin MeSH
• Fluoroquinolones MeSH
• marbofloxacin MeSH Browser

BACKGROUND: Lead, a serious threat for raptors, can hamper the success of their conservation. This study reports on experience with accidental lead intoxication and responses to chelation therapy in captive Cinereous (Aegypius monachus) and Egyptian (Neophron percnopterus) Vultures. RESULTS: Soil contamination by lead-based paint sanded off the steel aviary resulted in poisoning of eight Cinereous and two Egyptian Vultures. A male Egyptian Vulture developed signs of apathy, polydipsia, polyuria, regurgitation, and stupor, and died on the next day. Liver, kidney and blood lead concentrations were 12.2, 8.16 and 2.66 μg/g, respectively. Laboratory analyses confirmed severe liver and kidney damage and anaemia. Blood Pb levels of Pb-exposed Cinereous Vultures were 1.571 ± 0.510 μg/g shortly after intoxication, decreased to 0.530 ± 0.165 μg/g without any therapy in a month and to 0.254 ± 0.097 μg/g one month after CaNa(2)EDTA administration. Eight months later, blood lead levels decreased to close to the background of the control group. Blood parameters of healthy Pb-non-exposed Cinereous Vultures were compared with those of the exposed group prior to and after chelation therapy. Iron levels in the lead-exposed pre-treatment birds significantly decreased after chelation. Haematocrit levels in Pb-exposed birds were significantly lower than those of the controls and improved one month after chelation. Creatine kinase was higher in pre-treatment birds than in the controls but normalised after therapy. Alkaline phosphatase increased after chelation. A marked increase in the level of lipid peroxidation measured as thiobarbituric acid reactive species was demonstrated in birds both prior to and after chelation. The ferric reducing antioxidant power was significantly lower in pre-treatment vultures and returned to normal following chelation therapy. Blood metallothionein levels in lead-exposed birds were higher than in controls. Reduced glutathione dropped after CaNa(2)EDTA therapy, while oxidised glutathione was significantly lower in both pre- and post-treatment birds. A chick in an egg produced by a Cinereous Vulture female two months after lead toxicosis died on day 40 of artificial incubation. Lead concentrations in foetal tissues were consistent with levels causing avian mortality. CONCLUSIONS: The reported blood parameters and reproduction impairment in captive birds may have implications for professionals dealing with lead exposure in wild birds.

• MeSH
• Chelation Therapy methods   veterinary   MeSH
• Edetic Acid therapeutic use   MeSH
• Falconiformes * blood   MeSH
• Bird Diseases chemically induced   drug therapy   MeSH
• Lead blood   MeSH
• Lead Poisoning drug therapy   veterinary   MeSH
• Animals, Zoo MeSH
• Animals MeSH
• Check Tag
• Male MeSH
• Female MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Case Reports MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Edetic Acid MeSH
• Lead MeSH