Doxycycline is used to treat bacterial infections such as pneumonia, skin and soft tissue infections, urinary tract infections, salmonellosis, and colibacillosis in goats. In goats, the single intravenous and intramuscular pharmacokinetics of doxycycline are known. However, there is no information regarding oral pharmacokinetics. This study aims to determine the single and repeated pharmacokinetics, bioavailability, and accumulation of doxycycline hyclate. Although doxycycline hyclate exhibited low intramuscular and oral bioavailability, its oral administration with favorable properties such as weak accumulation, wide distribution volume and long elimination half-life can be useful in the treatment of infections caused by susceptible pathogens in goats.
Doxycycline belongs to the group of tetracyclines and acts bacteriostatic against many Gram-positive and Gram-negative bacteria like Bordetella, Campylobacter, E. coli, Haemophilus, Pasteurella, Salmonella, Staphylococcus and Streptococcus spp. Doxycycline is also active against Chlamydia, Mycoplasma and Rickettsia spp. The action of doxycycline is based on inhibition of bacterial protein synthesis. Doxycycline has good affinity towards the lungs and is
therefore especially useful for treatment of bacterial respiratory infections. Colistin is an antibiotic from the group of polymyxins with bactericidal action against mainly Gram-negative bacteria like E. coli, Haemophilus and Salmonella spp. Polymyxins interact strongly with phospholipids and penetrate into and disrupt the structure of cell membranes. Administered orally, colistin is poorly resorbed and, therefore, performs its action predominantly gastrointestinally.
Features of Doxycycline For Goats
The antimicrobial activity of tetracyclines reflects reversible binding to the bacterial 30S ribosomal subunit, and specifically at the aminoacyl-tRNA acceptor (“A”) site on the mRNA ribosomal complex, thus preventing ribosomal translation. This effect also is evident in mammalian cells, although microbial cells are selectively more susceptible because of the greater concentrations seen. Tetracyclines enter microorganisms in part by diffusion and in part by an energy-dependent, carrier-mediated system responsible for the high concentrations achieved in susceptible bacteria. The tetracyclines are generally bacteriostatic, and a responsive host-defense system is essential for their successful use. At high concentrations, as may be attained in urine, they become bactericidal because the organisms seem to lose the functional integrity of the cytoplasmic membrane. Tetracyclines are more effective against multiplying microorganisms and tend to be more active at a pH of 6–6.5. Antibacterial efficacy is described as time dependent.
The most common mechanism by which microbes become resistant to tetracyclines is decreased accumulation of drug into previously susceptible organisms. Two mechanisms include 1) impaired uptake into bacteria, which occurs in mutant strains that do not have the necessary transport system, and 2) the much more common plasmid- or transposon-mediated acquisition of active efflux pumps. The genomes for these capabilities may be transferred either by transduction (as in Staphylococcus aureus) or by conjugation (as in many enterobacteria). A second mechanism of resistance is the production of a “protective” protein that acts by either preventing binding, dislodging the bound drug, or altering the negative impact of binding on ribosomal function. Among the tetracyclines, tigecycline is characterized by less resistance due to efflux or ribosomal protection. Rarely, tetracyclines can be destroyed by acetylation. Resistance develops slowly in a multistep fashion but is widespread because of the extensive use of low concentrations of tetracyclines.
Gastrointestinal and respiratory infections caused by micro-organisms sensitive to doxycycline and/or colistin like Bordetella, Campylobacter, Chlamydia, E. coli, Klebsiella, Haemophilus, Mycoplasma, Pasteurella, Rickettsia, Salmonella, Staphylococcus and Streptococcus spp. in calves, goats, poultry, sheep and swine.
For oral administration.
Calves, goats and sheep:
Twice daily 1 ml per 20 kg body weight for 4 – 5 days.
1 litre per 2000 litres of drinking water for 4 – 5 days.
1 litre per 1000 litres of drinking water for 4 – 5 days.
Note: for pre-ruminant calves, lambs and kids only. Coloxan Oral is not for use in animals from which milk or eggs are produced for human consumption.
– For meat:
Calves, goats and sheep : 14 days.
Swine : 8 days.
Poultry : 7 days.
Prices of Doxycycline For Goats
$16.00 – $79.97