Table 7 Definition of clinical severity scores modified according to [16]

0

No pathological signs

1

Unilateral sero-mucous nasal discharge, palpably enlarged submandibular lymph nodes, discrete developing cutaneous nodules (n = ≤ 5) on hind quarters with tendency to ulceration on palpation, inappentence (25 % reduction in feed intake), debility, exercise intolerance (exercise tolerance test (ETT) ≤ 12 min exercise 6 min walk + 6 min trot).

2

Uni- or bilateral mucopurulent blood-tinged nasal discharge, nasal septum ulcers (n = ≤ 7), mild dyspnea (audible respiratory sounds from a distance of 3 m), discrete cutaneous nodules and ulcers; slightly to palpably enlarged submandibular lymph nodes, inappentence (40 % reduction in feed intake), exercise intolerance (ETT ≤ 8 min exercise; 4 min walk + 4 min trot) and cough

3

Bilateral blood tinged purulent nasal discharge, confluent nasal septum ulcers, moderate dyspnea (audible respiratory sound from a distance of 7 m), cutaneous nodules and ulcers in perineal region, groin, medial aspects of thighs with lymphangitis (pearly cord); visibly enlarged submandibular lymph nodes; inappentence (65% reduction in feed intake) oedema of hock joints, exercise intolerance (ETT ≤ 4 min exercise; 3 min walk +1 min trot) and cough

4

Bilateral copious purulent discharge with epistaxis, bilateral nasal septum ulcers with perforation, severe dyspnea (audible respiratory sounds from a distance of 10 m), cutaneous nodules and ulcers throughout the body, cording of lymphatics (pearly cords) on trunk/abdomen, legs; oedema of hind quarters and lameness, diagonal spreading in the hind quarters; inappentence (85 % reduction in feed intake), exercise intolerance (ETT ≤ 2 min exercise; 2 min walk) and cough