Ethylene glycol intoxication in ducks.

Ducks maintained over winter in an area used for automobile storage and repair were poisoned by anti-freeze. Signs were weakness, depression, ataxia, and death. Post-mortem lesions consisted of marked nephrosis; numerous oxalate crystals occluded the renal tubules. Levels of ethylene glycol were markedly elevated compared with levels in normal tissues. To further characterize the disease, six healthy ducks were given ethylene glycol in oral doses ranging from 1.1 to 17.8 ml/kg. As the dosage was increased, blood and tissue concentrations of ethylene glycol increased and time to death decreased. Histologic lesions were similar to those seen in the accidentally poisoned ducks.

Comparison of bioavailability of two chloramphenicol preparations in dogs after intramuscular injection.

Aqueous chloramphenicol glycinate was compared with propylene glycol solution of chloramphenicol after equivalent intramuscular doses (22 mg/kg) were given to 10 normal, healthy dogs in a crossover study. Duration and magnitude of plasma concentrations of chloramphenicol were significantly longer and higher with the glycinate than with the propylene glycol solution.

Plasma and tissue concentrations of oxytetracycline in the horse after intravenous administration.

Oxytetracycline (OTC) was administered IV to 3 clinically normal horses at a dosage of 10 mg of OTC/kg of body weight. Plasma OTC concentrations were determined at 30-minute intervals until postinjection minute (PIM) 240. At PIM 240, the mean OTC concentration in pulmonary tissue was 3.96 microgram/g of tissue (wet weight) and in renal tissue was 25.47 micrograms/g. diluted bronchial fluid had a mean concentration of 0.288 microgram of OTC/ml at PIM 240. The data demonstrated that OTC has adequate tissue distribution in horses.

Influence of time interval between administration of chloramphenicol and thiamylal on the sleeping time of mice.

The influence of the time interval between chloramphenicol and thiamylal administrations on the sleeping time of mice was studied. Two hundred 20- to 25-g mice were given (intraperitoneally) chloramphenicol or isotonic saline solution and then thiamylal at different time intervals between drugs. The duration of anesthesia was measured as the time between the loss and the return of the righting reflex. The results indicated that in mice given chloramphenicol simultaneously with thiamylal (0 time interval), the sleeping time was increased by a factor of about 10 as compared with the sleeping time in mice given thiamylal alone. As the time interval between administrations of thiamylal and chloramphenicol was increased (from 0.25 to 4 hours), the prolongation of sleeping time decreased correspondingly.

Oxytetracycline concentrations in healthy and diseased calves.

Pneumonia was induced in a group of calves that were then treated with oxytetracycline (OTC). When the plasma pharmacokinetics and tissue concentrations of this group were compared with those of healthy controls, obvious differences were observed. The volume of distribution and the half-life of OTC were increased in the group with pneumonia. Tissue concentrations of OTC (1.48 +/- 0.29 microgram/ml) were greater in the lungs of calves with pneumonia than that in the lungs (1.09 +/- 0.09 microgram/ml) of healthy controls. For the dose of OTC used, the correlation between serum concentration and tissue concentrations at 24 hours was poor. Seemingly, current concepts of antibiotic dosages and dosage intervals may be inadequate because they are based on blood and tissue values of healthy animals.

Fate of sodium pentobarbital in rendered products.

The fate of pentobarbital through rendering was evaluated by following a group of euthanatized animals through a commercial rendering facility. Samples of material were collected at various points in the rendering process, and assays for pentobarbital were conducted by an ultraviolet spectrophotometric method. The results indicated that the pentobarbital, or a closely related analogue, survived rendering without undergoing degradation. The pentobarbital was distributed approximately equally between the meat and bone meal and tallow fractions. If pentobarbital-euthanatized animals are processed along with other raw materials throughout a day's production, the likelihood of significant residues being present in rendered products is minimal.

A clinical comparison of CT1341, ketamine, and xylazine in cats.

The new anesthetic agent CT1341 was compared to ketamine and xylazine in experimental and clinical situations with cats. Anesthesia with CT1341 was characterized by fast recovery times, good muscle relaxation, eyelid closure, occasional vomition, defecation, or urination during induction and recovery, generally smooth induction, and occasional hyperreflexive recoveries with much sneezing. The agent was moderately hypotensive, but caused little change in heart rate, central venous pressure, arterial pH, or blood gases.

Serum and urine inorganic fluoride concentrations and urine oxalate concentrations following methoxyflurane anesthesia in the dog.

Plasma fluoride, urine fluoride and urine oxalate concentrations were measured before administering an anesthetic to 8 dogs, and at 0, 3, 9, 24, 48, and 72 hours following 1.5 hours of anesthesia with 1% methoxyflurane. Plasma and urine osmolalities were measured and compared with fluoride and oxalate values. Fluoride concentration increased in both plasma and urine following anesthesia when compared with the preanesthetic concentrations. Maximum mean plasma inorganic fluoride was 106.71 mumoles per liter (+/- 25.44 SE) at 9 hours after exposure to methoxyflurane was completed. By 72 hours after exposure to methoxyflurane the plasma fluoride concentration was 23.47 microM/L (+/- 5.74 SE). Mean urine inorganic fluoride concentration was highest at 9 hours after exposure to methoxyflurane and reached 6047.03 microM/L (+/- 1378.46 SE) as compared to the mean preanesthetic base-line concentration of 542.68 microM/L (+/- 132.93 SE), and the 72 hour mean urine fluoride concentration which was 1593.78 microM/L (+/- 579.46 SE). Urine oxalate concentrations, when compared with urine osmolality (mg/mOsm), increased throughout the study. The 72-hour concentration after exposure to methoxyflurane was 2.5 times the preanesthetic (mg/mOsm) oxalate concentration. Plasma osmolality did not change markedly during the study. Urine osmolalities varied between animals and collection times, but a consistent pattern did not occur. Clinical and laboratory signs of renal dysfunction were not observed in any animal during the study.

Half-life of cephaloridine in dogs with reduced renal function.

Various degrees of renal insufficiency were produced in 9 dogs by nephrectomy, or segmental ligation of the branches of the renal artery, or both. The serum half-life of cephaloridine, measured after a single intramuscular injection, increased progressively as renal function decreased. In dogs with 85% reduction in renal mass, serum half-life was approximately 3 times that of control dogs. To prevent accumulation of cephaloridine in dogs with renal dysfunction, a modified dose schedule was established on the basis of these experimental results.

Cacao bean shell poisoning in a dog.

Cacao bean shells contain potentially toxic quantities of theobromine, a xanthine compound similar in effects to caffeine and theophylline. A dog, which ingested a lethal quantity of garden mulch made from cacao bean shells, developed severe convulsions and died 17 hours later. Analysis of the stomach contents and the ingested cacao bean shells revealed the presence of lethal amounts of theobromine.

Disposition of oxytetracycline in the bovine genital tract: systemic vs intrauterine administration.

The distribution of oxytetracycline (OTC) in genital tissues, uterine secretions, milk, and plasma was examined after systemic (IM) and intrauterine (IU) administration at various intervals after administration in normal-cycling diestrous cows and in cows with chronic endometritis. The IM route resulted in OTC concentrations in endometrium and uterine secretions that were higher than were concentrations in plasma and milk over 72 hours. Twenty-four hours after IM administration, OTC concentrations in tissues of the genital tract (ovaries, oviducts, myometrium, serosa, cervix, and vagina), muscles, and udder were 100% higher than were concentrations in plasma. The IU administration resulted in a high concentration in the endometrium and uterine cavity over the 72-hour posttreatment period. The plasma concentrations were considerably lower than after the IM injection, indicating a lesser absorption from the uterus than from the IM injection site. This was more pronounced in cows with endometritis. Elimination from plasma and milk occurred in 24 hours. Contrary to results of the IM route, the IU route did not result in detectable concentrations in genital tissues apart from the endometrium 24 hours after administration.

Acute hepatic necrosis associated with the administration of mebendazole to dogs.

Mebendazole was administered to 7 adult Dachshunds and 2 adult Doberman Pinschers at 6-month intervals for routine parasite control. Two weeks after the 1st treatment, a 3-year-old Dachshund died of acute hepatic failure. Approximately 2 weeks following the 2nd treatment, two 5-year-old Dachshunds and one 3-year-old Dachshund had evidence of acute hepatic necrosis; 1 of these dogs died of fulminant hepatic failure. Typical clinical signs in affected dogs included anorexia, depression, vomiting, icterus, and hemorrhagic diarrhea. Two additional Dachshunds had biochemical evidence of hepatic dysfunction, ie. high serum alanine aminotransferase and serum alkaline phosphatase activities. One Dachshund and 2 Doberman Pinschers had no clinical or laboratory evidence of hepatic disease.

Amphetamine poisoning in dogs.

Amphetamine intoxication in dogs referred to the Veterinary Diagnostic Laboratory or the Veterinary Hospital of the University of Minnesota was characterized by excitement, agitation, hyperthermia, and convulsive episodes that could be confused with other convulsant poisonings. Extraction procedures on stomach contents or urine enabled indentification of the drug, using ultraviolet spectrophotometry.

Central nervous system intoxications other than lead.

Other than lead, organophosphates and carbamates are probably the most important classes of toxicants affecting the central nervous system in food animals. Chlorinated hydrocarbons continue to present problems from time to time, as do certain poisonous plants. Less frequently encountered substances such as nitrofurans, certain rodenticides, herbicides, and other miscellaneous poisons are also discussed.