carbadox and Rhinitis--Atrophic

The sensitivity of ten Bordetella bronchiseptica and ten Pasteurella multocida strains, each isolated from cases of atrophic rhinitis (AR), was examined in tube dilution test. Getroxel, chlorquinaldol and oxytetracycline and the former two ones combined with trimethoprim inhibited the growth of both species in vitro. The minimum inhibitory and the minimum bactericidal concentration was less than 0.5 microgram/ml. When efficacy was tested in SPF in the group fed a combination of Getroxel, chlorquinaldol and oxytetracycline (60 mg, 240 mg and 360 mg/kg of feed, respectively), P. multocida disappeared from the nasal cavity by the end of a 30-day treatment. B. bronchiseptica was reisolated in low numbers from 2 out of 9 piglets. The daily body mass gain was by 7.9% higher and the feed conversion rate was by 19% better than in the control group. After slaughter, only mild signs of AR were seen in 3 out of 9 piglets treated with the above-mentioned drug combination, while in the control group severe lesions were observed in 8 out of 9 pigs. In treated commercial herds P. multocida disappeared from the nasal cavity of the piglets by the end of the treatment (42nd day of life), but the B. bronchiseptica strains could not be completely eliminated. Due to the treatment, mortality between 2 and 6 weeks of age decreased by 0.8-7.6%. Daily body mass gain was, on the average, 16.4% higher, the amount of feed needed for 1 kg body mass gain was by 15.3% lower and the duration of fattening was by 30.8 days shorter than in the control groups.

Topics: Animals; Bordetella bronchiseptica; Carbadox; Chlorquinaldol; Oxytetracycline; Pasteurella multocida; Rhinitis, Atrophic; Specific Pathogen-Free Organisms; Swine; Swine Diseases

Interactions between veterinary pharmacotherapy, toxicology of residues, prevention of residues of veterinary drugs and the evaluation of veterinary drug files are discussed on the basis of a number of examples. Sulphadimidine is used to treat atrophic rhinitis in medicated feeds which do not benefit the animal but are the cause of persistent sulphonamide residues in feed mills and husbandry. Carbadox is a potentially effective prophylactic feed additive for the prevention of swine dysentery, but is mostly used in high dosages which are almost toxic for the animals, and used during unnecessary prolonged periods. It is also prescribed as a therapeutic agent in which case a symptom of poisoning, dry faeces, is mistaken for a sign of recovery. Carbadox and/or its metabolites are carcinogenic and its use should be restricted to a bare minimum. Furazolidone is an example of an effective veterinary drug, the use of which should be limited by the fact that detoxification mechanisms of the animals, may result in the appearance of reactive metabolites which are available in the gastro-intestinal tract of the consumer. The central issue in a 'minimal residue' policy regarding the use of veterinary drugs should be the selection of effective drugs. Such a selection could result in a significant reduction of the incidence of veterinary drug residues. Second to this issue is the question of the extent to which residue toxicology should modulate the use of veterinary drugs.

Topics: Animals; Carbadox; Drug Residues; Drug Therapy; Drug-Related Side Effects and Adverse Reactions; Food Additives; Furazolidone; Humans; Rhinitis, Atrophic; Sulfamethazine; Swine; Swine Diseases

Carbadox in combination with sulfamethazine did not interfere with the activity of sulfamethazine in clearing experimentally induced Bordetella bronchiseptica nasal infection. Evaluations in three field cases of infectious atrophic rhinitis indicated that carbadox in the feed was as effective as chlortetracycline + sulfamethazine + penicillin for improving growth rate and feed efficiency, as compared with nonmedicated controls, and in reducing the prevalence of lesions of infectious atrophic rhinitis.

Topics: Animal Feed; Animal Nutritional Physiological Phenomena; Animals; Bordetella; Bordetella Infections; Carbadox; Chlortetracycline; Drug Therapy, Combination; Penicillins; Quinoxalines; Rhinitis, Atrophic; Sulfamethazine; Swine; Swine Diseases; Turbinates