Oh dear does one of your buns have Myxi? Have you seen Parsnipbun's thread in the Health section? She has been keeping a diary of how she has dealt with her Myxi bun for this reason - to help others.
Normally it would be pain relief, fluids and antibiotics to protect against 2nd infections. Possibly also nebulised antibiotics and anti-mucolytics and even Oxygen for buns who's respiratory system is compromised. It also depends on what form of Myxi it is and if bun has had some immunity from vaccination as to how successful treatment is.
p.s no risk to humans I am aware of.