Kelly - I know HL is not as typical with younger or normal weight cats, but I always raise a flag regarding feline anorexia. It's just too risky in my opinion, especially with the improved prognosis gained with early intervention. My girl wasn't overweight (a petite 6 lbs), and dropped over 25% of her body weight in under a week. She had stopped eating due to a negative reaction to a medication. I love my vet, but even he didn't consider HL until I practically screamed it. A classic "zebra among the horses" scenario. I'd learned about HL in vet class and it was the first and most obvious diagnosis in my partially educated mind. I will always punish myself for not having screamed louder and earlier, as a result of the vet's delayed intervention, she almost succumbed to DIC. Her coagulation profile was way off. It took a week of total parenteral nutrition with a nasoesophageal tube to get her stabilized.
I'm glad Jon's girl is doing better!