Skin and plumage changes in domestic birds. II. Plumage changes]

The study describes plumage modifications and specific feather malformations, as related to the domestication process of different poultry species. The modifications include naked necks, leg feathering, frizzle feathering, silky feathering, fat quills, and feather abnormalities caused by behavioural hypertrophies. Most of these plumage modifications correspond to the breed standard for exhibition poultry fancy. However, they impair the normal function of these animals. The negative influences comprise disorders in social behaviour, loss of typical plumage functions and disabilities of normal mobility, as well as genetic defects and pathogenic predispositions.     

Plasma triglyceride concentration during intravenous infusions of propofol and Intralipid in sheep

Plasma triglyceride concentrations were measured in sheep given Intralipid or propofol, which is carried in a vehicle very similar to 10% Intralipid. A bolus dose was administered followed immediately by an infusion of the same agent for 2 h. In the animals that received propofol, the measured concentration increased by a mean amount of 3.39 mmol/l when the infusion rate was l ml/min (Group Pl) and by 7.13 mmol/l when it was 2 ml/min (Group P2). When 10% Intralipid was administered and infused at 1 ml/min (Group I10), the measured concentration increased only by 0.95 mmol/l. One hour after stopping the infusion, the excess of measured concentration over baseline had decreased in the Pl and I 10 groups to 0.52 and 0.13, respectively, of the corresponding maximum excess. The method adopted for measuring plasma triglycerides is widely used in hospitals; however, an incidental observation revealed that it is inappropriate in the presence of injections of propofol or Intralipid. Despite this, evidence and argument are presented to support the conclusion that, with propofol, plasma triglyceride concentrations increased more rapidly during the infusions and returned to baseline more slowly than with a corresponding amount of Intralipid.     

Anesthesia for patients with severe systemic debilitation.

Any patient presenting for anesthesia and surgery who has a severe debilitating problem is at great risk for a prolonged recovery, renal failure, or hypotension. A stable hemodynamic state should be maintained. Fluid homeostasis should be ensured. Anesthetic induction techniques using narcotics and benzodiazepines are my preferred approach, with maintenance of anesthesia incorporating isoflurane, narcotics, or both or the use of regional anesthesia.     

Efficacy of abamectin against natural infections of gastrointestinal nematodes and lungworm of cattle with special emphasis on inhibited, early fourth stage larvae of Ostertagia ostertagi.

The anthelmintic efficacy of abamectin (avermectin B1) was evaluated against gastrointestinal nematodes, including Ostertagia ostertagi inhibited larvae and lungworm, in yearling crossbred beef heifers during late spring. The calves were grazed on contaminated pasture for 10 weeks and then held under conditions free of nematode infection for 3 weeks prior to allotment and treatment on 5 June. Thirteen calves were randomly assigned to two groups of six by restricted randomization on body weights; the extra lightest calf was assigned to the non-treated control group. Group 1 calves were treated with abamectin at 200 micrograms kg-1 body weight by s.c. injection and Group 2 calves were not treated; all were killed at 14 days after treatment. Ostertagia ostertagi was present in all controls; arithmetic mean numbers of adults, developing fourth stage larvae (L4) and inhibited EL4 were 7683, 605 and 36,102, respectively. Other nematode genera present in controls in sufficient numbers for the experiment were Haemonchus placei adults, Trichostrongylus axei adults, Cooperia spp. adults, Oesophagostomum radiatum adults, Bunostomum phlebotomum adults, Dictyocaulus viviparus adults and E5 (immature adults). Abamectin was highly effective (consistently greater than 99% efficacy and P less than 0.05) in removing all nematodes present in treated calves as represented in non-treated controls, including the primary target of Ostertagia ostertagi inhibited EL4. The lowest efficacy was 93.8%, against D. viviparus E5.     

Cardiopathological observation on a case of persistent ventricular tachycardia in a pony mare.

A 20-year-old pony mare with persistent ventricular tachycardia (VT) was examined cardiopathologically. At necropsy, the heart was enlarged and rounded with both ventricular dilatation. In a longitudinal section of the ventricular septum, a large grayish white patchy lesion (5 x 25 mm) was detected in the relatively higher portion. Microscopically, the lesion was extensive myocardial fibrosis located in the vicinity of the proximal part of the left bundle branch. Partially the fibrotic lesion was in contact with the branch. Such a lesion might play an important role in creating a suitable background for the development of VT via automaticity or reentry mechanism.     

Prevalence of Cryptosporidium sp in equids in Louisiana

In 1985, 22 pony foals reared in a helminth-free environment were tested daily for oocysts of Cryptosporidium sp by use of fecal flotation. Oocysts were found in all foals. Oocysts were first observed in feces collected from foals 9 to 28 days after birth. The mean period of oocyst shedding was 10 days and ranged from 2 to 18 days in individual foals. Diarrhea was observed in 14 of 22 (64%) foals and began before the period of oocyst shedding. Fecal samples also were examined for other infective agents. Salmonella poona was isolated from 1 foal that did not have diarrhea, and coronavirus particles were observed in the feces of 2 foals with diarrhea. Cryptosporidium sp oocysts also were observed in feces of 2 of 17 Thoroughbred foals, 3 of 14 Quarter Horse foals, and 3 of 26 pony foals reared on pastures with their dams. Samples from pasture-reared foals were collected at irregular intervals. Of the 11 Cryptosporidium-positive fecal samples collected from pastured foals, 2 were from foals with diarrhea. A similar survey was conducted during the 1986 foaling season, using the same procedures. Examination of 300 samples from 58 Quarter Horse, Arabian, and pony foals did not detect oocysts. Daily examination of feces from 10 pony foals reared under helminth-free conditions for 30 days also failed to detect Cryptosporidium oocysts.     

Spring Barley Responses to Row Spacing and Fungicide Triadimefon in Regions with a Short Crop-growing Season

Aspects of intensive management practices such as high-yielding cultivars, narrow-row spacings and fungicide treatments could potentially increase cereal yields in regions with a short crop-growing season and occasionally dry and hot weather. A field experiment was carried out at McGill University, Canada for three years (1987 to 1989) to test the effects of triadimefon (1-[4-chlorophenoxy]-3,3-dimethyl-1-[1H-1,2,4-triazol-1-yl]-2-butanone, or Bayleton, a trade name) fungicide (0 vs. 140 g a.i. ha⁻¹) and row spacing (10 vs. 20 cm) on the yield components, yield and other agronomic traits (spike emergence, days to maturity, leaf disease and plant height) of spring barley ( Hordeum vulgare L.) cv. Cadette, Laurier and Leger. A cultivar by row spacing interaction resulted in a 11 to 13.5 % increase in grain yield due to narrow rows for Laurier in two out of the three years and up to 16 % for Leger in one year. Over the three years grain yields were on average increased 6 to 12 % due to use of the narrower row spacing. Fungicide application to barley at the early heading stage effectively controlled leaf diseases without influence on yield components or grain yield. Our results indicate that some components of intensive management such as narrow row spacing can be applicable in regions with a short crop-growing season.     

Thermal injury by in vitro incision of equine skin with electrosurgery, radiosurgery, and a carbon dioxide laser.

Freshly harvested equine skin incised with an electrosurgical unit, a radiosurgical device, or a carbon dioxide (CO2) laser was examined by light microscopy to determine the extent of thermal injury caused by each instrument. There was no significant difference between the thermal injury caused by the electrosurgical unit in the pure-cut mode and the CO2 laser in the superpulse mode, or between the electrosurgical unit and the radiosurgical device in the fully filtered cut mode. However, thermal injury caused by the CO2 laser was significantly less than that caused by the radiosurgical device. The amount of thermal injury in this in vitro study was similar to that found in vivo with other species.     

Genomic variability among globally distributed isolates of equine arteritis virus.

Equine arteritis virus (EAV), a non-arthropod borne togavirus, has been shown to have a global distribution. To date, no major antigenic variation has been demonstrated between EAV isolates from different geographic origins. In this study, the genomic RNA of EAV isolates obtained from horses of different breeds in various countries around the world was oligonucleotide fingerprinted. Comparisons of these fingerprints were used to determine the extent of genomic variation among such isolates. Comparisons among isolates from North American horses revealed, for the most part, oligonucleotide homologies of less than 60%. Only 29 of the 98 comparisons revealed greater than 60% oligonucleotide homology. Nonetheless, several comparisons indicated a close epidemiologic relationship between isolates from horses of different breeds located in different states. Though all European isolates were of Standardbred origin and were from horses located in northern European countries, the majority had oligonucleotide homologies of less than 60%. Where oligonucleotide homology was apparent, it was, with one exception, greater than 70%. The two isolates from New Zealand had 93.2% oligonucleotide homology. This is indicative of an extremely close epidemiologic relationship. Comparisons between EAV isolates from around the world revealed oligonucleotide homologies between viruses from North America, Europe and New Zealand. In several instances, this homology was greater than 70% and in one case greater than 80%. No oligonucleotide homology was evident in comparisons involving the virus from South Africa. The high level of genomic conservation between certain EAV isolates of disparate geographic origins may reflect dissemination of the virus associated with the international movement of horses. The extent of genomic variation demonstrated between most of the EAV isolates used in this study confirms the need for further investigation of genomic heterogeneity among strains of this virus before techniques that rely upon nucleic acid hybridization can be effectively applied as diagnostic procedures.     

Toxic peripheral neuropathy with demyelination in Sprague-Dawley rats given CGS 21595--a 5-lipoxygenase inhibitor.

Male and female Sprague-Dawley rats were given CGS 21595, a pro-drug that is almost immediately metabolized to CGS 19213, a naphthoquinone that acts as a 5-lipoxygenase inhibitor. The compound was administered by gavage to five groups of Sprague-Dawley rats (group Nos. 1, 5, n = 30; group Nos. 2-4, n = 20) at daily doses of 0, 50, 150, 500, or 1,000 mg/kg for 13 weeks. Rats in the higher dose groups had a reduced weight gain, but significant neurologic signs were not observed. A peripheral neuropathy consisting predominantly of myelin destruction in the spinal nerve roots and sciatic nerves in male rats treated with greater than or equal to 150 mg/kg CGS 21595 and in female rats treated with greater than or equal to 50 mg/kg CGS 21595 for 13 weeks. This lesion was not fully reversible after a recovery period of 4 weeks. Lesions consisted of ballooning of myelin sheaths, infiltration by macrophages, demyelination, and occasional areas of remyelination. Axons were generally preserved, and the brain and spinal cord were not affected. Male and female rats in all treatment groups had cytoplasmic hyaline droplets in the proximal renal tubules. This change was reversible after 4 weeks and was not associated with any other adverse effects on the kidney.