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The safety of synthetic levothyroxine sodium tablets (Thyro-Tabs® Canine; LLOYD, Inc.) in dogs was evaluated in a randomized, sham-dose controlled, parallel-group study. Young, healthy, euthyroid Beagle dogs were randomized into four groups (four females and four males per group) and received single daily doses of 0×, 2× (0.044 mg/kg), 6× (0.132 mg/kg), or 10× (0.22 mg/kg) the labeled starting dose of 0.022 mg kg-1 day-1 for 182 days. Every 2 weeks, physical examinations, electrocardiology examinations, and sample collections for thyroid panel, hematology, serum biochemistry, coagulation panel, and urinalysis were performed. At the end of the study, the dogs were euthanized and full necropsies performed. The most overt finding was the expected dose-dependent increase in serum concentrations of total and free thyroxine with dose-dependent suppression of the hypothalamic-pituitary-thyroid axis as evidenced by decreased serum thyroid-stimulating hormone concentrations, decreased thyroid+parathyroid/body weight ratios, and a trend for decreased pituitary weight/brain weight ratios. Clinical signs of thyrotoxicosis (excitation, tachypnea, tachycardia) in the treated dogs were sporadic with no dose-response relationship. Other findings statistically associated with levothyroxine treatment were generally mild and not clinically important. In summary, doses of levothyroxine sodium up to 10× the labeled starting dose were well tolerated in healthy dogs.

Carotid endarterectomy by the eversion technique allows for all of the benefits of conventional endarterectomy but obviates the need for a distal suture line on the smaller internal carotid artery, and thus batching. Carotid artery reanastomosis onto the bifurcation can be quickly and simply performed with almost no risk of closure-related restenosis, given the anastomosis is on the larger of 2 arteries. In our experience of over 3,000 eversion carotid artery endarterectomies, the restenosis rate has been less than 1% judged by rigorous duplex follow-up. In this article, the technique and utility of eversion carotid endarterectomy is discussed.

To test effectiveness of IV administration of tolazoline hydrochloride in reversing xylazine hydrochloride-induced sedation in calves.Prospective study.12 female and 12 male Friesian-cross calves from 5 to 7 months old.Calves were assigned to 1 of 4 treatment groups. Calves were given xylazine (0.3 mg/kg [0.14 mg/lb] of body weight, IM). Twenty minutes later, calves were treated with saline (0.9% NaCl) solution (1 ml/50 kg [1 ml/110 lb], IV) or tolazoline (1, 2, or 4 mg/kg [0.45, 0.9, or 1.8 mg/lb], IV). Behavioral and physiologic measurements included elapsed time from xylazine administration to recumbency, arousal and standing times after reversal drug administration, heart rate, and respiratory rate.Mean (+/- SD) recumbency time for all calves was 5.4 +/- 1.8 minutes. Compared with administration of saline solution, all 3 doses of tolazoline significantly decreased arousal and standing times. Mean arousal time for calves receiving saline solution was 27.8 +/- 11.5 minutes. Administration of tolazoline at 1, 2, and 4 mg/kg resulted in mean arousal times of 4.7 +/- 3.8, 0.9 +/- 0.5, and 0.7 +/- 0.3 minutes, respectively. Mean standing time for calves receiving saline solution was 38.8 +/- 2.8 minutes. Administration of tolazoline at 1, 2, and 4 mg/kg resulted in mean standing times of 14.0 +/- 11.0, 3.0 +/- 1.2, and 2.4 +/- 1.1 minutes, respectively.For routine use, tolazoline doses of 1 to 2 mg/kg should suffice. In cattle, IV administration of tolazoline reverses pharmacologic effects of xylazine, thereby hastening recovery from xylazine-induced sedation.

A computerized pattern recognition system has been developed that is capable of identifying 40 separate spontaneously occurring behavioral acts of the primateMacaca fascicularis. The system, called PROBE (pattern recognition of behavioral events), is described in detail. In its present stage of development, PROBE classifies behavioral activity with a reliability comparable to trained human observers. The potential applications for and improvements to the PROBE system are discussed.

does not appear. First page follows. Losses from obscure causes on certain California turkey ranges, where green feed is limited during much of the growing season, suggested the need for studies on vitamin-A deficiency in turkeys. The experiments reported herein were outlined to determine the possible relation of A-avitaminosis4 to turkey mortality and to obtain information concerning the effect on turkeys of various vitamin-A levels. A-avitaminosis in chickens has been fully described by Beach(1), Emmett and Peacock?(3), Seifried(10), Elvehjem and Neu(4), and many other investigators, so that the pathological changes in chickens are well established. Chicks were included in one experiment as a control on the methods used and as a basis for comparing A-avitaminosis in the two species. Scott and Hughes(9), using yellow corn as the source of vitamin A, showed that turkeys required more vitamin A than did chickens. This paper is concerned chiefly with the disease phases of the problem. Because published data on the vitamin-A requirements of turkeys are limited, the results on the comparative value of dehydrated alfalfa-leaf meal for turkeys and chickens are also included. Certain vitamin-A liver storage data collected in connection with the experiments have already been published by Guilbert and Hinshaw.(6)

THIS paper presents a brief report on the effect of age on the egg production and hatching results of Bronze turkey females during the period 1927 and 1933 inclusive. Some data are also presented on the comparative mortality and rate of growth of the progeny. In compiling the data the age of the males to which the females were mated was disregarded. Egg Production All reports so far published, regarding the effect of age on egg production deal with the domestic fowl. Brody, Henderson, and Kempster (1923) reported that the egg production of the flock studied declined 12 percent each successive year. Jull (1928) and Hall and Marble (1931) have shown that the decline in egg production with age is greater in the case of the Barred Plymouth Rock, Rhode Island Red, and Wyandotte breeds than in the case of the White Leghorn. They as well as Atwood (1928) and . . .

IT IS common experience that chickens and other domesticated birds grow better if hatched at certain seasons than they do if hatched at other seasons of the year. Thus Goodale (1926) found that chicks hatched in the early part of the season grew more rapidly, to 30 days of age, than did those hatched later. Upp and Thompson (1927) likewise observed that there were differences in the rate of growth of chicks hatched at different seasons of the year. They conclude that weather has an influence on the growth of chickens. Somewhat similar results are reported in this paper for turkeys hatched only a few weeks apart. There is also a distinct indication of compensatory growth of the later hatched, initially slower growing birds. The same phenomenon has been demonstrated in the growth of razor clams by McMillin and Weymouth (1935). MATERIALS AND METHODS The data presented in this paper . . .

Twenty healthy ponies were given i.v. 1.1 mg/kg of xylazine from 2 manufacturers and the pharmacokinetic parameters calculated from the disposition curves. The disposition curves for the 2 commercial preparations were not different. Yohimbine, an antagonist of the pharmacologic effects produced by xylazine, did not alter the disposition of xylazine in the plasma. A single i.v. bolus of xylazine was completely described in 17 of 20 animals by the biexponential equation: Cp = 1.30e(-0.3955t) + 0.58e(-0.033t) where Cp represents the concentration of xylazine in the plasma at time t (min). The t1/2 beta was 75 +/- 13 min and whole body clearance was 18.9 +/- 1.5 (ml/min.kg).

Sulfamethazine (110 mg/kg of feed) was fed to 4 groups of pigs for 10 days. Each group was then fed withdrawal rations containing 0, 1.1, 11.0, or 110.0 mg/kg of feed for 10 days before slaughter. A 5th group was fed a sulfamethazine-free diet only. Fat, kidney, liver, and muscle from each pig were analyzed by several laboratories, using the Tishler Bratton-Marshall (BM) and gas liquid chromatographic (GLC) methods. Mean background (BG) amounts of sulfamethazine, as measured in control tissues, were essentially negligible using GLC; however, BM BG values (mean +/- SD), expressed as milligrams of sulfamethazine per kilogram of edible animal tissue (ppm) were: fat 0.019 +/- 0.003, kidney 0.048 +/- 0.012, liver 0.053 +/- 0.034, and muscle 0.018 +/- 0.017. Regression of tissue sulfamethazine on feed sulfamethazine, as measured by GLC and BM adjusted for BM-BG values, yielded essentially linear plots. Values obtained by GLC and corrected BM were highly correlated, but the variability was higher, using GLC. The linear model predicted that the dietary sulfamethazine required to produce 0.1 ppm in liver as measured by the BM, BM-BG, and GLC were 1.6, 2.8, and 3.4 ppm, respectively. The concentrations necessary to produce 0.1 ppm in muscle were 5.3, 6.2, and 5.5 ppm. The thin-layer chromatographic method of screening swine plasma was a good predictor of tissue sulfamethazine values.

Although the exact cause of DVT is not known, venous thrombosis and its sequelae remain important clinical problems. Pulmonary embolism is a significant cause of morbidity and mortality in the hospitalized population, and the postthrombotic syndrome affects a large portion of the general population. While specific screening tests are not readily available to detect those patients who are likely to develop DVT, certain clinical risk factors have been identified that predispose to thrombosis. These groups include patients undergoing a wide variety of surgical procedures, patients with cardiac disease or cancer, pregnant or postpartum women, and individuals with previous history of DVT. The diagnosis of thrombosis is based on clinical findings and must be confirmed with appropriate laboratory tests. While contrast venography remains the gold standard, noninvasive tests have become increasingly more accurate. The recent use of real-time B-mode ultrasonic imaging and duplex sonography for the diagnoses of DVT has been shown to be efficacious. The postthrombotic syndrome with its associated chronic pain and ulcerations remains a significant clinical problem. The general diagnosis of this condition is readily made on clinical grounds in the advanced state. However, exact knowledge of the location and cause of the venous pathology can only be obtained using objective diagnostic tests. Older noninvasive and invasive tests may diagnose the presence of venous obstruction, valvular incompetence, and also may document venous hypertension.(ABSTRACT TRUNCATED AT 250 WORDS)

Lead poisoning has been increasingly recognized as a significant and major cause of bovine poisoning in Iowa during recent years [3, 4]. Data from the Iowa Veterinary Diagnostic Laboratory for the years 1965 through 1971 indicate an increasing number of lead poisoning cases in cattle, with 1970 as the peak year. From January, 1967, through June 30, 1971, 80 episodes of bovine lead poisoning have been confirmed by the Veterinary Diagnostic Laboratory. Of this number, 28 were recognized in 1970 alone. Lead poisoning is the single most common toxicosis in cattle in Iowa. In order to further delineate the incidence, clinical severity, sources, seasonal occurrence, and chemical results of affected and non-affected animals, this study was undertaken.

The following paper records experiments made to determine the magnitude of the error involved in the sampling of a soil for survey purposes. While it is not held that the results obtained are true for all localities, they serve to indicate the order of magnitude of the various errors.