Atrophic Rhinitis

Rhinitis is inflammation of the tissues inside the nose where the nose may become distorted (atrophy).

Alternative names: Progressive Atrophic Rhinitis

Information

Rhinitis means nostril’s tissue swelling, and can be caused by a wide variety of bacteria, virus and irritating substances. This condition rarely originates a clinical disease in adult pigs. Atrophy means upper respiratory tract tissue is damaged, shrink and deformed. The disease has two presentations:

  • Mild and non-progressive, in which the infection or irritation occurs during a period of 2 to 3 weeks. After that, the swelling stops and nasal turbinates cure, being normal again.
  • The most severe form of progressive atrophic rhinitis (PAR) in which strains of Pasteurella multocida type D and Bordetella bronchiseptica produce toxins that damage the nasal tissue. When both pathogens are present in the farm, they cause a continuous inflammation in lactating piglets and growing pigs, causing atrophy of tissues and deformities in the nose.

Symptoms

Sows

  • Not clinical signs.
  • Distortion of the nose

Lactating piglets

  • Sneezes.
  • Tearing.
  • Nasal discharges that sometimes present blood.
  • Distortion of the nose

 Weaners and growers

  • Blood stained sneezes
  • Tearing
  • The nose twists, shrinks and wrinkles.
  • Weight gain and daily growth decrease.
  • Feed conversion ratio increases.
  • Increase of respiratory diseases.

Causes / Contributing Factors

  • The disease is transmitted from one farm to another through carrier pigs, clothes, equipment, etc.
  • The transmission inside the farm is through aerosols between pigs, or through mouth-to-mouth contact.
  • Is more frequent in farms with a young breeding herd, especially those ones having high gilt numbers.
  • Multi-lactation systems (piglets suck from more than one sow) increase the disease spread.
  • Inadequate ventilation.
  • Environments with high amounts of dust.
  • Toxic gases.
  • Deficient environment and nutrition increase the severity.

Diagnosis

In piglets, the diagnosis is made using clinical signs. Sneezing is frequent in piglets, although they are not necessarily related to a PAR. Some piglets can develop facial distortions due to trauma or a cause different to PAR.

Nasal swabs must be taken and sent to the lab. Perform post mortem analysis of the nose. 


Control/Prevention

  • All adult animals must be vaccinated twice with a difference of 4 to 6 weeks between vaccinations. Modern vaccines are very efficient.
  • Then, sows must be vaccinated 4 to 6 weeks before farrowing.
  • Sometimes piglets must also be vaccinated at 1 and 4 weeks of age.
  • All weaned pigs must be medicated through the diet until the clinical outbreak has disappeared.
  • Antibiotic must be applied to the piglets. A possible routine is:
    • Inject long life oxytetracyclin or amoxicillin to piglets 3 and 10 days old, as well as at the weaning day.
    • The starter feed given to weaners must be medicated with oxytetracyclin, clortetracyclin or trimethoprim/sulpha during three weeks, starting the weaning day.
  • Other antibiotics may be used, depending on the bacteria sensitivity.
  • Sow’s feed must be medicated with oxytetracyclin or trimethoprim/sulpha 5 to 7 days before farrowing until the farrowing day, or the lactation feed can be medicated with trimethoprim/sulpha.
  • Vaccinating the sows normally prevents the infection until piglets reach 10 weeks of age. After that, unless the growing pens have been depopulated, pigs will be infected presenting mild symptoms. However, the infection increases predisposition to other respiratory diseases and decreases feed intake and production.
  • PAR can be eradicated from a farm using vaccines, antibiotics and early medicated weaning (< 12 days). Replacement gilts must originate from negative farms.