The estimation of egg weight from egg gradings

A method is described for the estimation of mean egg weight from data giving the proportions of eggs in different weight grades. Tables are presented in which mean egg weights have been calculated for a range of grading figures, using both the British Egg Marketing Board and the European Economic Community grading systems.     

Morphogenesis of vesiculation in foot-and-mouth disease

The morphogenesis of vesiculation in cattle inoculated (aerosol expsoure) with foot-and-mouth disease virus was investigated by examining alternate, frozen sections of selected tissues stained by fluorescent antibody technique and with hematoxylin and eosin. Viremia preceded the development of lesions, and virus appeared to be transported to the epithelium via papillae. Lesions were initiated usually by the infection of single cells in the stratum spinosum adjacent to the papillae. Three types of lesions were observed. A vesicle developed mainly from the lysis of swollen, spherical cells and the release of intracellular fluid. The 2nd type of lesion was formed mainly by the accumulation of intercellular edema. The 3rd type was characterized by the absence of a vesicle due to seepage and loss of edema fluid and desiccation of the lesion.     

Experimental Edema Disease of Swine (E. Coli ENTEROTOXEMIA) III. Pathology and Pathogenesis

Experimental colibacillary (Escherichia coli) enterotoxemia as described in this report mimics natural edema disease both clinically and in gross pathology. The histopathology is characterized by accumulations of non-inflammatory edema and by arteriopathy. The smaller arterial and arteriolar changes recorded here are similar to those described in natural edema disease. The vascular changes described in recovered cases of experimental colibacillary enterotoxemia concur with those reported in so-called subacute and chronic edema disease. The arteriolar changes that occur in colibacillary enterotoxemia of swine are comparable to those associated with hypertension.

Thin sections of cerebral cortex from four pigs with acute experimental edema disease were examined by electron microscopy in an attempt to demonstrate brain edema. Sections from one pig taken during the convulsive phase of disease revealed dilatation of perivascular glial processes. However, examination of sections taken from three other pigs during an earlier phase of the neurological disturbance revealed no significant lesions. We were unable to ascertain the role of brain edema in the pathogenesis of the nervous system disturbance in these experiments.

     

Ocular signs of canine monocytic ehrlichiosis: a retrospective study in dogs from Barcelona, Spain

Canine monocytic ehrlichiosis (CME) is a tick-borne disease caused by the rickettsia Ehrlichia canis. Ocular lesions are a common feature of the disease and can be present in all stages. The purpose of this retrospective study was to determine the prevalence, type and response to treatment of ocular lesions associated with monocytic ehrlichiosis in 46 affected dogs presented to the Autonomous University of Barcelona-Veterinary Teaching Hospital (UAB-VTH) from January 2000 to December 2002. Dogs were included in the study only if they had a positive serologic test for E. canis and information about the clinical outcome was available. Eighteen breeds were represented, with the German Shepherd dog (n = 6) being the most common. There were 25 intact and three castrated males, and 16 intact and two neutered females. Twenty dogs (43.4%) were between 5 and 10 years old. Seventeen dogs (37% of all cases of monocytic ehrlichiosis diagnosed during the study period) had ocular signs, and 11 dogs (64.7% of the ocular cases) had only ocular lesions without apparent systemic signs. Exudative retinal detachment was the most common ocular manifestation; other prevalent findings included anterior exudative uveitis and optic neuritis. Five of the 17 cases with ocular lesions (29.4%) had ocular bleeding disorders (hyphema or retinal hemorrhages). All the dogs with ocular disease presented with bilateral signs. Dogs with posterior segment disease had titers against E. canis that were > or = 1 : 320, while lower titers were noted in dogs with anterior exudative uveitis. Two dogs presented with chronic autoimmune panuveitis after ehrlichiosis treatment. Canine ehrlichiosis should be considered in the differential diagnosis of exudative retinal detachment and anterior uveal inflammatory lesions.