My underweight rescue dog is on steroids. How to make her healthy?

Poor pup! Unfortunately, weight gain is a very common side effect of steroids, especially at high doses - there isn't much you can do to prevent it or make him lose weight as long as he's still taking them. Depending on what his medical condition is, there may be other medications that he could take that would allow him to reduce his steroid dose or even discontinue the steroids altogether - I would recommend talking with your vet about your concerns, since the best option for Diogie will depend a lot on his medical history and the reason he's currently taking steroids.

I think therapeutic diets work best: Hill's Metabolic or Royal Canin Satiety are the two I most frequently recommend. They have increased protein and vitamins/minerals but are much lower in calories. You could also try sticking with your current food but cutting back on how much you give (I usually recommend cutting back about 25%) and increasing exercise as well as minimizing treats or replacing them with lower calorie options like frozen green beans. While there are over the counter foods that are designed for weight loss they can still have very different calorie contents and some weight loss foods even have more calories than regular foods.

He likely has inflammatory bowel disease or some type of malabsorption problem. Keeping him on lifelong steroids (prednisone) is not recommended. The first thing you have to do is get a diagnosis. I recommend he have an abdominal ultrasound and/or x-rays and some blood testing to start with. A fecal test is also a good idea to rule out any intestinal parasites. If you can't afford testing then speak to your vet about doing a trial of Tylosin powder to control IBD symptoms instead of steroids.

I recommend to work with your veterinarian to find the lowest effective dose of the prednisone and to discuss any other alternatives such as pain medication, surgery to correct the jaw pain if possible or diet modification to help negate the weight gain. Have Mary Shiloh examined by her veterinarian at least every few weeks to keep any eye on her heart and weight. I hope this helps.

Well done on making such progress! Be sure to keep him dewormed monthly for at least 3 months and feed him up gradually, I would tend to feed at the feeding guideline for his actual weight plus 15-20%, reassessed every 14days in order to encourage gradual weight gain and strength whilst allowing his system to adjust. A probiotic/fiber supplement such as fortiflora can be helpful to promote healthy digestive balance also

There is not much you can do other than to ensure good nutrition and health from this moment forward. I would recommend starting a high quality puppy food. In addition you want to make sure that they are up to date on vaccines per your veterinarian. They should be dewormed at least twice. Finally, you should endure they are on flea prevention and heartwo preventative if endemic in your area. All of these things should improve their overall condition. I also recommend neutering between 6-8 months. Good luck!

Getting her spayed would definitely be the most effective and easiest way, if this isn't something you would consider then i would recommend switching to a better quality food such as Orijen, Acana or Taste of the wild.