Intranasal administration of Pasteurella multocida toxin in a challenge-exposure model used to induce subclinical signs of atrophic rhinitis in pigs.
A challenge-exposure model was developed for dose-dependent induction of subclinical (moderate) atrophic rhinitis (AR) in conventionally raised Dutch Landrace and Large White pigs, about 4 weeks old. Under favorable climatic and housing conditions, pigs were intranasally challenge-exposed with Pasteurella multocida-derived toxin (Pm-T) 3 days after pretreatment by inoculation with 1% acetic acid. Pigs were challenge-exposed with 1 of the following Pm-T doses: 0 (control), 5, 13, 20, or 40 micrograms of Pm-T/ml of phosphate-buffered saline solution (PBSS), 0.5 ml/nostril/d on 3 consecutive days. Five weeks after challenge exposure, subclinical (moderate) AR status was defined as intermediate conchal atrophy (grade 2 for ventral conchae on a 0 to 4 scale and grade 1 or 2 for dorsal conchae on a 0 to 3 scale, respectively) and perceptible difference in change in brachygnathia superior (cBS) between control and challenge-exposed pigs between the beginning and end of the study. All Pm-T-exposed pigs had nasal damage that was dose-dependent. The higher Pm-T doses resulted in higher ventral conchae atrophy and dorsal conchae atrophy scores. The cBS increased with applied Pm-T dose, resulting in significant (P < 0.05) differences between controls (3.88 mm) and the 13-, 20-, and 40-micrograms Pm-T-treated groups (7.77, 6.58, and 7.98 mm, respectively). In response to the applied dose, weight gain per week for Pm-T-exposed pigs was lower than that of controls after week 3 (P < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)
van Diemen
P M
PM
Department of Animal Husbandry, Agricultural University, Wageningen, The Netherlands.
de Jong
M F
MF
de Vries Reilingh
G
G
van der Hel
P
P
Schrama
J W
JW
D000281:Administration, Intranasal; D000818:Animals; D001284:Atrophy; D001426:Bacterial Proteins; D001427:Bacterial Toxins / Q000008:administration & dosage / Q000633:toxicity*; D009666:Nose / Q000473:pathology; D010326:Pasteurella Infections / Q000473:pathology / Q000662:veterinary*; D016979:Pasteurella multocida; D012222:Rhinitis, Atrophic / Q000473:pathology / Q000662:veterinary*; D013552:Swine; D013553:Swine Diseases
D001426:Bacterial Proteins; D001427:Bacterial Toxins; C062258:Pasteurella multocida toxin