Infectious Progressive Atrophic Rhinitis

Scoring of nasal sections


Other names

Atrophic Rhinitis AR PAR

Causal agent

Toxigenic forms of Bordetella bronchiseptica combined with toxigenic Pasteurella multocida mainly types D and A. Both of these agents are bacteria

Age group

The deviation may be seen in any pig older than 10 kg. However, clinical signs usually seen in pigs up to 5 months of age


Atrophic rhinitis covers any disorder that results in shrinkage of the nasal turbinates which may be accompanied by deviation of the face. Many factors may result in atrophic rhinitis:- dust, ammonia, disease agents and genetics. Infectious Progressive Atrophic Rhinitis is the major category of atrophic rhinitis that requires to be controlled on pig units

Clinical signs


Note virtually all herds are infected with Bordetella bronchiseptica and therefore occasional moderate turbinate atrophy is normal

Sneezing and snuffling in farrowing area and then throughout the growing phase

Nose bleeding (epistasis) usually unilateral

Snout deformation

Growth retardation, which may be up to 7% loss of daily gain, but this is very variable

Turbinate atrophy possibly with septum deviation

Tear staining causing brown streaks on the face originating from the medial canthus of the eye. In modern breeds this is quite common without atrophic rhinitis

Non immune piglets infected in the first week of life show most severe signs

Pigs infected after 4 weeks show less severe lesions

Pigs infected after 9 weeks of age show virtually no lesions

Twisted face and blood at nostrils

Twisted snouts in a group of pigs

Skull of a pig with atrophic rhinitis

Acquired atrophic rhinitis



Pig to pig

Droplet infection

P. multocida can survive for 8 days in water, 6 days in liquid manure and 49 days in nasal washings

Piglets are infected from their mother's mouth and possibly from the vagina during birth

The disease may be transmitted by air between 200 and 1000 m

Litters in the farrowing area are rapidly infected from a shedding mother and also at weaning

Stress factors


Re-occurrence, failure of vaccination or even first clinical signs on previously normal herds may occur when the unit is severely stressed by viruses such as PRRSv, PMWS or Swine Influenza Virus


Post-mortem Lesions


Distortion of the face

Atrophy of the nasal turbinates

The atrophy can be scored particularly by sawing the nasal cavities at the level between the 1st and 2nd pre-molar teeth. Note a straight cut is required. This is indicated by the lateral canthus of the mouth (commissure)

Normal turbinates

Atrophic score 3

Atrophic score 4

Score 5 + Deviation



All herds with clinical infectious progressive atrophic rhinitis as a problem are infected with toxigenic Pasteurella multocida, however, not all herds with toxigenic P. multocida have clinically significant atrophic rhinitis. 20% of normal 'non clinical' herds may actually be infected

Slaughterhouse check

By sectioning the nose. However, the tests only look for 'atrophic rhinitis' not the infectious progressive atrophic rhinitis

Scoring of pig snouts

Toxin check

Detection of the toxigenic Pasteurella multocida by examination of samples obtained by nasal and/or throat swabs test pigs at 4, 8 and 12 weeks of age.




Feed wet food

Antibiotics will not reduce deviation but will help support the pigs if co-infectioned with other secondary pathogens exist



Acute outbreaks

Consult with your veterinarian for precise details, the following is a guide

Vaccinate sows and gilts with a vaccine containing the toxin and B. bronchiseptica and P. multocida

Administer in-feed antibiotics to sows for the last month of pregnancy

Administer tetracycline LA or Tulathromycin to piglets at 3 and 10 days of age

Medicate weaner feed with tetracycline 800 g per tonne

It is possible to vaccinate piglets within the first week of life

Essential other requirements

Improve general management, All-in/all-out programmes. Allow the sow herd age to rise

Review breeding animal purchases. Reduce stocking rates. Reduce gas and dust concentrations. Move wet feeding finishing herd


Vaccinate all sows and gilts as appropriate


Depopulation and restock from a known free herd only possible option. Clean, disinfect and fumigate all buildings and leave for 8 weeks. Note eliminate mice and rats. The disease may rarely be transmissible over 1000 m. Elimination protocols

It is possible to save genetic material by SEW programmes to set up a new unit followed by depopulation and restocking of old unit

Common differentials


Sneezing in farrowing area may be due to a range of other organism in particular uncomplicated B. bronchiseptica and porcine Cytomegalovirus.

Facial deformity can occur through other defects such a genetics, dust, ammonia and behaviour (playing with drinkers or bars for example)

Zoonotic Implications


Note it is possible that humans may become infected with toxigenic P. multocida and this may result in a variety of upper respiratory diseases, tonsillitis and rhinitis