Pharmacokinetics and bioavailability of spiramycin in pigs.

The pharmacokinetics of spiramycin in pigs were investigated after intravenous and oral administration. The potential therapeutically effective blood level was established after a single administration and examined in a subsidiary five day study. The rapid intravenous injection of 25 mg spiramycin/kg bodyweight produced marked salivation in all the test animals. The elimination half-life (2.3 +/- 1.2 hours) was relatively short, in accordance with the total body clearance rate (27.3 +/- 10.1 ml/minute/kg). The high volume of distribution (5.2 +/- 2.2 litres/kg) was due to the accumulation of the drug in the body tissues. The maximum plasma concentration (4.1 +/- 1.7 micrograms/ml) after oral administration of 85 to 100 mg spiramycin/kg bodyweight was reached after 3.7 +/- 0.8 hours and the half-life of the elimination phase was 6.0 +/- 2.4 hours. The oral bioavailability was 45.4 +/- 23.4 per cent. Ad libitum feeding of a diet containing 2550 mg spiramycin/kg produced a steady state concentration of 0.96 +/- 0.27 micrograms/ml. This plasma concentration would provide a potentially therapeutically effective blood concentration against Mycoplasma species, Streptococcus species and Staphylococcus species.     

Electrophoresis Study of Extracts of Submaxillary Salivary Glands from Naturally Rabid Dogs

Rabies virus in submaxillary salivary glands from naturally infected dogs was investigated by a paper electrophoresis technique, and the virus activity was quantitated by intracerebral titration in mice. Extracts from these salivary glands were found to contain (a) 10⁴ to 10⁶ mouse ICLD ₅₀ units of wild rabies seed and (b) a protein complex that migrated electrophoretically in the albumin band and more conspicuously in the beta and gamma bands of normal horse serum. The protein complex was interpreted to comprise aggregates of neutralizing antirabies antibody.     

The extraction particles from winter rapeseed with different glucosinolate fractions in swine with regard to the iodine supply. 3. Apparent digestibility of crude nutrients with special regard to the carbohydrate and nitrogen balance]

In two digestibility and N-balance experiments the following solvent extracted meals were examined in a grain (barley and wheat in equal parts) or in a starch diet with four female pigs/group fitted with urethra catheters during the 5 days sampling period: 48% soyabean meal (SBM) (1), 24% conventional rapeseed meal (RSM) (2), 24 (3) or 48% (4) RSM from a newly bred low glucosinolate variety, groups 1 to 4 with grain, 48% low glucosinolate RSM (5) or 48% SBM (6) both with starch. In numeric order of the groups 88, 85, 86, 84, 79 and 89% N were digested. Pigs responded to the additional faecal N excretion from RSM diets by a lower urinary N excretion and thus they reached the N-balance of the animals fed on SBM. In numeric order of the groups 86, 79, 80, 73, 73 and 92% of the organic matter of the solvent extracted meals were digested. In comparison with SBM even 48% RSM in the feed significantly lowered the digestibility of organic matter. Using detergents the additional faecal organic matter excretion of RSM versus SBM could quantified as two third lignin. In the case of 24% RSM in the diet--i.e. 15% of the carbohydrates given--the carbohydrate digestibility is estimated with a high error, that an energetic feed value should not calculated. Investigating 48% SBM or RSM respectively in a grain diet the net energy content was 9.8 MJ (666 Energetic Feed Units, EFU pig) or 8.3 MJ (569 EFU pig)/kg dry matter (DM). Based on the starch diet, however, little relevant for estimation of normal pig diets, there were evaluated 10.6 MJ (720 EFU pig) for SBM and 8.3 MJ (567 EFU pig) net energy/kg DM for RSM.     

Response of pony peritoneum to four peritoneal lavage solutions

Peritoneal lavage was performed on ponies to determine the effect on peritoneal surfaces. Lavage solution (20 L) was introduced into each pony's peritoneal cavity through catheters placed in the paralumbar fossa, and the solution was removed by drainage from the ventral portion of the abdomen. Six ponies each were lavaged with sterile saline (0.9% NaCl) solution, sterile saline solution containing 5 X 10(6) U of potassium penicillin and 3 g of neomycin or povidone-iodine diluted to 3% by volume with sterile saline solution, and 3 ponies were lavaged with povidone-iodine diluted to 10% with sterile saline solution. Peritoneal lavage catheters were inserted in 3 control ponies, but lavage fluids were not administered. Peritoneal fluid specimens were collected at 6, 24, 48, and 96 hours after lavage. Nucleated cell counts, RBC counts, total protein determinations, and cytologic analysis were performed. The ponies were euthanatized at 96 hours, and representative sections of the peritoneum were examined. Lavage with saline solution and saline solution with antibiotics induced a mild, transient inflammatory response in the peritoneal fluid, with minimal or no changes observed at necropsy. Solutions containing povidone-iodine induced chemical peritonitis, which was severe in ponies lavaged with 10% povidone-iodine solution. Peritoneal lavage with povidone-iodine solutions as dilute as 3% cannot be accomplished without causing inflammation of peritoneal surfaces.