Hello, my name is***** and I have over 20 years of experience as a veterinarian. I am sorry that you have been waiting for a response, but your requested expert isn't online which delayed your question coming up on the list for all to answer. I would like to help if you are still interested in an opinion. Miller's moths are not toxic for cats, so ingesting one or even several should not cause vomiting or orange stools. Vomiting and nausea can be due to stress, a change in diet, parasites, a viral or bacterial infection, eating something she should not (like a piece of a toy or string), inflammatory bowel disease or even a food allergy. But it can also be related to metabolic organ disease (such kidney
or liver disease) due to organ wastes irritating the gut or an obstruction in the gastrointestinal tract. The color of a cat's stool is variable but is influenced by what they eat as well as their ability to metabolize the food that they eat, and the metabolic wastes that their body produces. Metabolic wastes can be influenced by organ disease, gastrointestinal parasites, as well as the bacteria population living in their gastrointestinal tract. Orange stool can be indicative of increased amounts of bilirubin in her stool, which can be indicative of liver disease or red blood cell lysis (breaking apart). If this continues it is well worth having her see your family veterinarian for an examination and some blood tests. There are some things we can do to try and settle her stomach.To try and settle her stomach today you can try either:1) Pepcid-ac (famotidine) at a dose of one quarter of a 10mg tablet per 5 to 10 pounds of body weight every 12 hours.OR 2) Prilosec (omeprazole) at a dose of one quarter of a 10mg tablet per 5 to 10 pounds of body weight every 24 hours.These will reduce stomach acid and should help if this is related to simple nausea and gastrointestinal irritation. They can be given for several days if necessary. I would wait to feed her any food for a good 6 hours after the acid reducers are started. This should help stop gut spasms and restore normal gut motility. Small amounts of water or clear broths like low salt chicken broth offered frequently are fine as she needs fluids. You can give her pedialyte to replace electrolytes too, although most cats don't like the taste. After her food fast offer her a bland diet mix of 2/3 boiled, white skinless chicken, all fats and juices drained off the meat, mixed with 1/3 boiled, plain white rice. Feed several small meals a day. Once he feels better (no retching for 48 hours) start mixing in his regular cat food very slowly, less bland more regular with each day. It should take a week or so to convert him back.If she is continuing to vomit, runs a fever or has a tense painful abdomen and is feeling poorly though it would be best that she see a veterinarian now as anything you give her orally will just come back up worsening her dehydration. Best of luck with your girl, please let me know if you have any further questions.