Hello,
First of all, good on you for doing a rescue! A few of my reptilian/amphibian pets are rescues and it can be a challenge, but also quite rewarding. However based on what you're describing, I am somewhat worried about how far gone this little friend is. Can you post images of the animal for us to look at? We can tell a lot more about how good/bad prospects are based on facial and limb shape.
Do you have a reptile veterinarians near you? Do you have the disposable income to go to one? If you don't know if you have a reptile vet near you, I recommend
this site to find one - it's the Association of Reptilian and Amphibian Veterinarians, which is globally recognized though admittedly US-skewed (from my own observation at least).Specifically you want
this page to find a reptile vet near you.
The care you will get at a reptile vet will likely be a few hundred dollars, just to give you a heads up. It will, however, give the animal the best chance at recovery. If you can't afford that but you do have a reptile vet near you, you may still want to reach out to them. Be honest and transparent with them - essentially say "I want help but I only have $$ to spend on this". While it varies widely from vet to vet, and you should NOT EXPECT this kind of treatment, some veterinarians will work with people who can't afford vet care by setting up payment plans or by giving reduced or partial treatment. This is much more likely if you have a long-term history with the veterinarian, of course.
What would the vet do if you were to go to them? Well, to be perfectly honest a lot of what the vet would do are things that you yourself can do at home. So here I will only list the things most people wouldn't be able to do themselves: injections with vitamin D3, injections of calcitonin (a hormone that helps with calcium regulation), and non-oral fluid administration. If you're on the fence about going to the vet, specifically ask if they offer those three things and how much it would cost to be seen and worst-case scenario get all three of those treatments. The most important thing the vet would do, though, is analyse the rest of the animal's health. If the animal is neglected to this degree, it in very likely to have other health issues. Keep in mind, however, that I am NOT a reptile vet and they may have many other treatments that I do not know about!
Now, here is my advice outside of taking the animal to the vet (this includes treatments the vet would likely give but that you are perfectly capable of doing yourself as well):
-Make sure the animal has proper UVB and heating, obviously.
-Give the animal a relatively small enclosure size while recovering and limited things to climb. Beardies are normally fairly active, however an animal with MBD is at risk for injuring itself. You still want to give the animal a couple of hides to escape the UVB from, but aside from that and food/water trays the enclosure should be pretty much empty.
-Temporarily house the animal on clean paper towel or other similar product. You want it to be something absorbent and lightly colored so that the waste is as "clean" as possible should the animal defecate and not be able to get away from it and so you can easily check the urates and feces.
-Get the animal on a proper diet. Take this slowly, however. It is common for neglected reptiles to have issues going back on properly portioned meals - starving reptile's systems will shut down to the point where a sudden increase in nutrition can cause organ damage if they get too much at once.
-Animals with MBD are often also dehydrated. Make sure to give the animal proper bathes and offer
hydrating foods.
-Animals with MBD need both calcium and D3, generally speaking. Dust everything - bugs AND salads - with a trusted Calcium with D3 powder. I recommend
Rep-Cal Supplements personally, as they tend to use sources that are least likely to cause overdoses in your animal. Also make sure the supplements are low or free of phosphorus.
- Since the animal is probably dehydrated and desperately needs calcium and D3, you may want to try a liquid diet with some of the powdered supplements mixed in. I personally like
Fluker's Repta+Boost for temporary situations where the animal will eventually move on to a normal diet, but for more permanent liquid diets I recommend Oxbow Critical Care (There are two types -
Find Grind and
Regular. I vastly prefer the Find Grind for syringe feeding, but the regular is great if the animal will lap the food up itself) and
Carnivore Care. Whichever liquid diet you use, I would mix it with twice the normal amount of water and a little bit of Calcium+D3 powder for the first few feedings.
-For salads, try to stick to high nutrient foods only and stay away from greens with oxalates in them (avoid feeding kale, spinach, broccoli) and avoid most fruit for now as they tend to have both oxalates and phosphorus (as oxalates and phosphorus will decrease the amount of calcium the animal can absorb. Instead, go for things like Collard Greens, Mustard Greens, Dandelion Greens, Escarole, and Endive, which are high in nutrition and relatively low in oxalates. Consider adding cooked and cooled Winter Squash, Green Beans, and Sugar Snap Peas for more variety and enrichment.
-For protein, try to stay away from high fat and high chitin insects for a while, as they are most challenging to process. This means stay clear of meal worms and super worms, in particular. Roaches, BSFLs, and Hornworms are the best feeders for your animal right now, as they have a high nutritional and high moisture content. Crickets are fine, but make sure to gut load them. Once you know the animal isn't having any issues processing foods - essentially once it's pooped 3-4 times - you might offer higher fat content insects as the animal is probably somewhat thin considering the care you describe. Waxworms and Superworms are both high in fat content, however wax worms are softer bodied and easier to digest. Do not offer any "worm" type (waxworms, superworms, meal worms - less so hornworms they're actually pretty healthy) food alone, as they are generally the less healthy insects and sometimes BDs will get "addicted" to them and refuse other foods, always offer about half "worm" foods and half another feeder, such as Crickets, Roaches, or BSFL.
