Several cases are submitted to SESC of pigs with shortened or deformed snouts and, in section, atrophy or absence of nasal turbinates.

Inspectors reported lesions consistent with atrophic rhinitis, but the aim of distinguishing between progressive and non-progressive atrophic rhinitis. Both processes are of a multifactorial etiology and with morphologically similar lesions but the pathological significance is different.

Nonprogressive atrophic rhinitis

Progressive atrophic rhinitis 

Etiology

 Bordetella bronchiseptica

Pasteurella multocida

(dermonecrotic toxin positive).

Predisposing factors

Poor air quality  (dust,  ammonia…).

Concurrent B.bronchiseptica infection

Poor air quality  (dust,  ammonia…).

Lesions

Snout distortion.

Atrophy and malformation of nasal turbinates.

Brachyignathia superior (shortening of the maxillary bone).

Diagnosis

Microbiological culture of B. bronchiseptica from nasal swabs samples.

Determine the presence of dermonecrotic toxin positive –   P.multocida

Microbiological culture from nasal swabs or via direct nasal swab PCR.

Observations

Limited pathological significance.

Might cause significant production losses.

Export restrictions.

For diagnosis in slaughterhouse animals the ideal sample are nasal swabs taken before scalding.  But tissue samples (nasal turbinates) of scalded and/or frozen carcasses can also be submitted for direct PCR identification of P.multocida and its toxin.

 Pig skull with shortened snout  (brachyignathia). The presence of P. multocida could not be confirmed with the direct PCR.

Pig skull with shortened snout  (brachyignathia). The presence of P. multocida could not be confirmed with the direct PCR.

 Another case of a pig carcass with distorted snout. In this case, direct PCR revealed the presence of dermonecrotic toxin positive P. multocida.

Another case of a pig carcass with distorted snout. In this case, direct PCR revealed the presence of dermonecrotic toxin positive P. multocida.

Longitudinal section of the skull,  complete turbinate atrophy can be appreciated. In this case PCR revealed the presence  of dermonecrotic toxin positive P. multocida.

Longitudinal section of the skull,  complete turbinate atrophy can be appreciated. In this case PCR revealed the presence  of dermonecrotic toxin positive P. multocida.

 Another case of pig skull with shortened snout  (brachyignathia) and, in the cross section, atrophy of the nasal turbinates.

Another case of pig skull with shortened snout  (brachyignathia) and, in the cross section, atrophy of the nasal turbinates.

The morphologic diagnosis of atrophic rhinitis is ideally done evaluating a cross section of the skull at the level of the 1st upper premolar (or the labial commissure) that allows evaluating the atrophy of the turbinates. The image on the left corresponds to a pig with a normal turbinate morphology, on the right a clear case of atrophic rhinitis.

The morphologic diagnosis of atrophic rhinitis is ideally done evaluating a cross section of the skull at the level of the 1st upper premolar (or the labial commissure) that allows evaluating the atrophy of the turbinates. The image on the left corresponds to a pig with a normal turbinate morphology, on the right a clear case of atrophic rhinitis.