A syndrome in commercial turkeys in California and Oregon characterized by a rear-limb necrotizing skeletal myopathy.

A necrotizing skeletal myopathy of rear limbs was diagnosed in 17 flocks of commercial turkeys. The mean mortality attributed to the myopathy was 2.29% (range = 0.13-9.7%) over a mean period of 9.6 days (range = 6-14 days). The mean age of the birds at the time of onset was 7.4 weeks (range = 4-10.5 weeks). Clinically, birds experienced an episode of watery droppings and high-pitched crying, followed by rear-limb paresis or paralysis. Creatine kinase and aspartate aminotransferase were markedly elevated in birds with the myopathy. Grossly, a few birds had pale streaking in the muscles of the thighs and legs. Histologically, acute and subacute degeneration was present in myofibers of the legs, abdomen, thighs, back, and tail. The subacute lesion was characterized by marked sarcolemmal cell proliferation. Feed analyses ruled out selenium deficiency and the presence of mycotoxins as etiologies. Monensin was present in approved usage or only slightly elevated levels. A known potentiating antibiotic was being used concurrently with monensin in only one flock.     

The first case of genetically confirmed monozygotic twinning in the dog

Monozygotic twinning has not previously been genetically confirmed in the dog. This case report describes the finding of two viable male monozygotic foetuses within one placental site during caesarean section. Their umbilical cords attached to a single placenta. Genetic profiling using a total of 38 microsatellite markers, as well as amelogenin and SRY for sex determination, revealed identical DNA profiles, whether derived from blood or tissue (buccal swabs) samples. To the best of our knowledge, this is the first report of monozygotic twinning in the dog confirmed using DNA profiling.     

Cardiopulmonary effects and recovery characteristics of horses anesthetized with xylazine–ketamine with midazolam or propofol

Objective

To evaluate cardiopulmonary and recovery characteristics of horses administered total intravenous anesthesia (TIVA) with xylazine and ketamine combined with midazolam or propofol.

Expression of Occludin in Testis and Epididymis of Wild Rabbits, Lepus sinensis coreanus

Tight junctions (TJs) in inter-Sertoli junctional areas and epididymal epithelia build up the blood–testis barrier (BTB) and the blood–epididymal barrier (BEB), respectively. In this study, the expression of occludin, an integral member of the TJs, was examined in testis and different regions of epididymis of Lepus sinensis coreanus , an Korean wild rabbit species. In testis, intense occludin immunoreactivity was found in the basally located inter-Sertoli junctional area together with diffused immunoreactivity of occludin in the cytoplasm of Sertoli cells. It can be suggested that occludin is one of the robust elements of BTB in seminiferous tubules of rabbit testis. In proximal and distal caput epididymis, occludin immunoreactivity was found in the lateral as well as apical contacts of epithelial cells. In corpus epididymis, intense occludin immunoreactivity was found in the basolateral as well as apical contacts of epithelial cells together with cytoplasmic signal. In cauda epididymis, occludin immunoreactivity in luminal epithelia was relatively strong but largely found in the cytoplasm. This suggests that intriguing regulatory mechanisms differentially recruit occludin to the TJ in the different regions of epididymal epithelia. The differences in the subcellular localization as well as expression levels of occludin among the epididymal segments may reflect differential paracellular permeability of epithelia along the epididymal tubules and be correlated with sperm maturation in rabbit. In Western blot, a major form of occludin was MW 62 kDa together with small fragments of MW 34–39 kDa in testis and epididymis, suggesting the peptide cleavage of occludin. This is the first report on the molecular nature of TJs in a wild rabbit testis and epididymis.     

Lythrum hyssopifolia (lesser loosestrife) poisoning of sheep in Victoria

Objective To document an ovine disease attributed to the consumption of Lythrum hyssopifolia (lesser loosestrife). Procedures Historical and histological review of field and experimental cases. Results 1–20% mortality occurred in sheep flocks grazing paddocks where L. hyssopifolia was the predominant green vegetation. Well‐documented disease outbreaks occurred in summer on nine farms across Victoria between 1974 and 2002. Liver damage occurred in all nine outbreaks, with kidney damage in at least eight. Hepatocyte necrosis was usually zonal to midzonal (zone 2) in the liver samples from four farms and periacinar (zone 3) in those from three farms, but some livers showed only single‐cell necrosis. Multinucleate hepatocytes near necrotic areas were a feature in six cases. Proximal tubular epithelium appeared to be the primary renal target and brown granules were often present in renal tubules. Biochemical and histological evidence of liver and kidney damage was obtained from two sheep experimentally pen‐fed harvested L. hyssopifolia. Conclusion Chemicals in L. hyssopifolia are toxic to ovine hepatocytes and renal tubular epithelial cells.     

Colobomas of the iris in a flock of rosecomb bantam chickens

A defect in the pupil shape ofrosecomb bantam chickens was noticed by a breeder. The pupil in affected birds appeared to be elongated at the lower margin and consistent with a coloboma of the iris. Upon examination of all birds in the flock, the defect was found in 26% of females and 9% of males. Examination of breeders older than 1 yr led to the discovery ofcolobomas, although there were not enough birds to accurately determine the prevalence of the problem for previous generations. Affected birds were examined for other lesions, and none were found. Specific-pathogen-free (SPF) eggs were incubated and hatched with eggs from the affected flock as sentinels. No SPF chicks developed colobomas of the iris, while 37% of the bantams in the same hatch were affected. This experiment eliminated many possible infectious agents and incubator or brooder malfunction as causes of this eye lesion. An analysis of the flock pedigree suggested that the defect might be inherited and might be related either to feather color or to gender. No statistically significant correlation could be made between feather color and the iris colobomas. However, the trait was twice as likely to occur in females as in males, which suggests that it is a sex-influenced trait. Based on the determination that this was an inherited trait, a breeding strategy to reduce the prevalence of the lesion in which affected birds were removed from the breeding flock was developed and followed for 2 yr. The prevalence of colobomas was 22% in females and 2.9% in males after the first year and 7.8% and 0.8% in females and males, respectively, after the second year.     

Influence of Zinc Bacitracin and Bacillus licheniformis on Microbial Intestinal Functions in Weaned Piglets

The influence of zinc bacitracin (ZB) and of Bacillus licheniformis on host microbial-related functions in young piglets was investigated by applying the concept of microflora-associated characteristics. Six biochemical parameters were determined before and after weaning in faecal samples from piglets in four litters having access to a diet containing ZB, to a diet containing B. licheniformis, to a diet with both additives, or to a diet with no additives, from 3 weeks of age. Statistically significant differences were found in three of the intestinal functions investigated: formation of short-chain fatty acids (at 7 and 10 weeks of age), degradation of mucin (at 7 and 10 weeks of age) and conversion of bilirubin to urobilins (at 7 weeks of age). We also found age-dependent influences on the formation of short-chain fatty acids, on conversion of cholesterol to coprostanol and on conversion of bilirubin to urobilins. We conclude that a functional approach is appropriate for measuring exogenous influence(s) on the microbial intestinal metabolisms in weaned piglets.     

Chicken anemia virus in broilers: dynamics of the infection in two commercial broiler flocks

Chicken anemia virus (CAV) can cause a disease syndrome characterized by severe anemia, bone marrow atrophy, and severe immunosuppression in young chicks. Maternal antibodies prevent these clinical signs but do not prevent infection, transmission of the virus, or immunosuppression. The clinical disease is rare today because of the widespread practice of vaccinating breeders, but the subclinical form of the disease is ubiquitous. The dynamics of CAV infection, CAV antibody responses, relative lymphoid organ weights, and associated lesions were studied in two broiler flocks from a commercial producer. Both groups had detectable CAV antibodies at hatch, which waned over the first 3 wk of life. Both groups had detectable CAV DNA in both thymi and bursae over the same period. At 35 days of age, virus was detectable by polymerase chain reaction in 16 of 20 chickens, and 7 of 20 had detectable antibodies. By 42 days of age, virus was detectable in 18 of 20 chickens, and 18 of 20 had antibodies to CAV. We observed a decrease in relative thymic weights beginning at 35 days of age, coincidental withthe detection of CAV in the thymus. Bursal sizes began to decrease at 28 days of age, coincidental with a rise in antibody titers to infectious bursal disease virus. In this study, we demonstrated that under typical field conditions CAV infections in broilers have unique dynamics unlike those reported in egg laying strains of chickens managed under specific-pathogen-free conditions.     

A persistent outbreak of ulcerative enteritis in bobwhite quail (Colinus virginianus)

Ulcerative enteritis is a disease that typically responds well to medication. An outbreak of ulcerative enteritis that was persistent and unresponsive to treatment is described. The outbreak started in semimature birds and progressively spread to younger birds. Confounding factors leading to this persistence were a significant coccidosis problem, a feed mixing error, and suspected antibiotic resistance. Although Clostridium colinum was never isolated, a bacitracin-resistant Clostridium perfringens was cultured from affected birds. Only the combined treatment of the flocks with an anticoccidial and tylosin was effective in controlling clinical disease. Numerous other management and treatment strategies were unsuccessful in lowering the severe mortality.