Is it a myth that horses can only get strangles once? I have an 11.2hh welsh pony who had strangles when he was 6 month old (hes now about 25!) and we've never had a problem since - today I noticed a lump under his throat. He spent the night in the field (the first for a long time because he escapes but as we camped up there last night we chanced it and he stayed in!!) and he may have been stung? thistled? kicked?

But my original question - could he have strangles a 2nd time? He has no other symptoms - hes eating fine and being his usual self.

Ths page says that strangles is a bacterial disease, not viral, which implies that immunity following infection/vaccination will not be lifelong.