I've just seen a cat in my garden. It looked quite young, and generally healthy. But it had two huge swellings, about the size of tennis balls, in its abdomen- hanging down kind of where a cow's udders would be. Does anyone have any idea what this could be? I'm obviously concerned about the cat, but in all honesty I'm more concerned about my own, as a cursory google threw up a few infectious diseases. My princess is of course fully vaccinated up, but I don't want to put her at risk. Any ideas?