Haemorrhagic pneumonia is caused by Pseudomonas aeruginosa. Mink of all ages are affected, particularly during fall probably due to the high air humidity.
Pseudomonas aeruginosa is a gram negative, nonsporogenic rod. There are several different serotypes, of which serotype 06 is the most common in mink. The bacteria are ubiquitarius in soil and water.
The transmission is most often aerogen or can be per oral trough contaminated water/feet.
The incubation period is 18-60 hours.
Aerogen infection is followed by septicaemia. The bacteria are causing serious damage in the lungs with haemorrhagic necrosis. The necrosis is seen both in arteries and veins. The damage is not caused by P. aeruginosa itself but by the produced endotoxins.
Haemorrhagic pneumonia is normally a per acute sickness. Often mink are only clinical sick for a few hours before dead occur. The farmer usually finds the animals dead with bloody nasal exudates.
Gross lesions include a severe haemorrhagic pneumonia with swelling and consolidation of 1 or more lung lobes. In the cavity is serohaemorrhagic exudation.
P. aeruginosa can be grown from the lungs, liver, spleen and kidneys.
Prophylactic vaccination can be done. If it is not immediate vaccination of the entire herd should be done starting just around the animal where the sickness occurred. This can be supplemented with an antibiotic treatment with sulfonamides.
