Microscopic examination of the nasal mucosa of clinically normal specific-pathogen-free pigs and of toxicogenic type-D Pasteurella multocida toxin challenge-exposed specific-pathogen-free pigs indicated that the surface epithelium in pigs of both groups was microscopically normal; erosions or appreciable inflammatory changes were not evident. In pigs of both groups and in aU 3 regions of the nasal cavity, the endothelial lining of all blood vessels appeared normal without detectable changes to the walls at postinoculation day 10. Vascular injury in the cartilage or the bone was not discernible in control or challenge-exposed pigs. There were marked differences in the osseous structures of the conchae when the 2 groups were compared. In control pigs, active bone formation and remodeling were observed, and the septal cartilage was normal. In toxin challenge-exposed pigs, there likewise was normal bone formation and remodeling in the vestibular region, and the septal cartilage was normal. In marked contrast, conspicuous changes were observed in the osseous core of the conchae of the respiratory and, sometimes, the olfactory regions. These changes consisted of bone necrosis and resorption by large numbers of osteoclasts with variable replacement by dense mesenchymal stroma, which resulted in conchal atrophy. In the absence of any discernible damage or injury (angiopathy) to the nasal vessels, it appears that the action of the dermonecrotoxin of P multocida serotype D is on the most active osteoblasts and the associated organic matrix of the bone, with subsequent disruption of normal bone formation and remodeling of the nasal conchae.

From 2 to 4.5 months of age, 80 crossbred gilts were reared in a conventional grower unit where they were naturally exposed to mycoplasmal and bacterial pathogens that cause pneumonia and atrophic rhinitis. At 4.5 months of age, gilts were moved to environmentally regulated rooms (4.9 X 7.3 m) and assigned at random to 1 of 2 treatment groups: low aerial concentration of ammonia (4 to 12 ppm; mean, 7 ppm) or moderate aerial concentration of ammonia (26 to 45 ppm, mean, 35 ppm). Low concentration of ammonia was obtained by flushing of manure pits weekly, whereas moderate concentration of ammonia was maintained by adding anhydrous ammonia to manure pits that were not flushed. Gilts were weighed biweekly. Mean daily gain (MDG) was less (P < 0.01) for gilts exposed to moderate concentration of ammonia than for gilts exposed to low concentration of ammonia after 2 weeks in their respective environments. By 4 and 6 weeks, however, MDG was similar between the 2 treatment groups. After 6 weeks in these environments, 20 gilts from each treatment group were slaughtered, and prevalence and severity of lung lesions and snout grades were determined. At slaughter, body weight was greater (P < 0.01) in gilts exposed to low, rather than moderate, ammonia concentration (94.5 vs 86.8 kg; SEM, 3.3 kg). Percentage of lung tissue containing lesions (18 vs 12) and snout grade (2.8 vs 3.1) were similar between gilts exposed to low or moderate concentration of ammonia. The remaining 20 gilts in each treatment group were maintained in their respective environments, exposed daily to mature boars and bred at first estrus. Age at puberty was similar between gilts exposed to low or moderate concentration of ammonia (208 vs 205 days; SEM, 1.3 days), even though weight at puberty was less (P < 0.03) for gilts exposed to low concentration of ammonia than for gilts exposed to moderate concentration of ammonia (109.7 vs 118.2 kg; SEM, 4.5 kg).

Two groups of 4 dogs underwent nasal and ethmoidal turbinectomies followed by irradiation (mean minimal doses of 5,390 and 6,550 cGy of radiation, respectively) from implanted intracavitary sources of iridium 192. Two dogs from each group were euthanatized for histologic evaluation at 3 months after irradiation. The remaining 2 dogs from each group were euthanatized for similar evaluation at 6 months after irradiation. During the course of the study, few clinical complications were encountered. Histologic evaluation of the tissues forming the nasal passages revealed loss of epithelial lining and fibrous tissue replacement of surrounding bone. A direct correlation of pathologic changes could not be associated with the amount of radiation received, but there seemed to be a tendency for greater change in those dogs given higher doses and those kept alive for 6 months.

A 10-year-old female Yorkshire terrier with the clinical signs of nasal swelling, epistaxis and nasal discharge was presented to the Veterinary Teaching Hospital in the Cheju National University. Abnormal nasal mass detected in physical examination and radiographic findings. After surgical excision, the sample of nasal mass was referred to Pathology Department of Veterinary Medicine. Grossly, the mass was soft, friable, and 2.5 × 4 cm in size. Histopathologically, the mass was composed of medium-sized non-keratinizing columnar to polyhedral cells arranged in anastomosing ribbon and large nest. It has complex in-folding of thick epithelial layers separated by fibrovascular septa. Tumor cells showed characteristic palisading arrangement of columnar cells, and perpendicularly distributed to the basement membrane. The cells had pale basophilic cytoplasm, oval nucleus and one or more nucleoli, and indistinct cellular border. Many tumor cell emboli were presented in lymphatics. Immunohistochemistry revealed that tumor cells were cytokeratic (CK) 19 and CK clone MNF116 positive and but CK7 and CK high molecular weight negative. Based on the gross, histopathologic, and immunohistochemical findings, the mass was diagnosed as transitional carcinoma in nasal cavity. In our best knowledge, this is the first report of transitional carcinoma originated from transitional zone of canine nasal cavity in Korea.

Intranasal administration of plasmid DNA encoding glycoprotein B of pseudorabies virus into mice induced both serum and secretory antibody responses. These mice resisted intranasal challenge with lethal dose of the virus, but did not intraperitoneal challenge. On the other hand, intramuscular injection of the plasmid induced less secretory and higher serum antibody responses than those of intranasally vaccinated mice. None of them was protected from virus challenge. The present results suggest that administration of plasmid DNA encoding glycoprotein B by respiratory mucosal route generates local secretory antibodies which serve to protect animals from pseudorabies virus infection