First off, I have dealt with coccidia in numerous dragons over the years. And I've used many different treatments, and several vets.
1. It **IS** possible to have coccidia free dragons!! And they are perfectly happy and healthy. I had my last male free of it for 4 years. I bought a hatchling female dragon who NEVER had it and still doesn't!! Getting coccidia-free dragons require exceptional cleanliness, and thorough treatment to clear it out. Once it's gone, the only way they get it is to be exposed to it again; either from the ground outside, or from another reptile who has it. Most dragons have it because it takes a lot of time, labor, and a good amount of money to get rid of it, and the breeder or owner can't or won't invest what's needed to do it.
2. Panacure will not work on coccidia, it's for worms. The two most common drugs for treating coccidia (and they ARE rated for treating it!!) are Albon, and T.M.S. solution. Both are commonly used in mammals for treating the problem (usually in kittens and puppies). In reptiles, T.M.S. works much better then Albon and takes a lot LESS time.
3. Normally, a coccidia infection is accompanied by loss of appetite (when very bad), and loose or diarrhea stools that stink. However, it is possible for them to accompany constipation when there are *multiple* problems with the dragons. More then likely, your dragons have multiple problems.
4. Probiotic treatments, like acidopholis, will *not* get rid of coccidia. It's not predatory and it won't out compete coccidia (which are not bacteria). However, coccidia treatments can kill off good bacteria, which means they need to be replaced. The *easiest* way is to get some plain yogurt, that says "active cultures", and use a syringe and squirt some in their mouth (some dragons will eat it on their own). And do that for 3-7 days. The yogurt has other natural beneficial bacteria besides acidopholis.
As to your dragon problem, they are **VERY** sick, constipation is an exceptionally serious problem in dragons. If they are housed together and one tests positive for coccidia (or anything else infectious), they all have it and all of them will have to be treated. Clearing one dragon of the infection, while the rest of the cage mates have it, is pointless and expensive as the newly healthy one is automatically reinfected.
Keep up the warm water baths!! Constipation can kill or paralyze. Make sure they have plenty of clean water. Look for another vet, besides the Association of Reptile and Amphibian Vets website, given in another reply, also try calling your local zoo (might take some phone work to get someone in the animal care department) and ask who they take their reptiles to. Be prepared to drive a good ways away to find another reptile vet.
Strip down the cage, remove all their bedding and toys. Anything wood will have to be tossed as wood is impossible to totally disinfect. If they are in wood cages...you're going to have a hell of a time cleaning them. Anything glass or plastic should be washed in 15% bleach and soaked in said bleach for 30 min, then rinsed really well. Use newspaper or paper towel for the cage floor.
Besides being the start for clearing up any kind of internal sickness, stripping the cage will also allow you to monitor what they are eating, when they drink (if they drink), and when they poo. As soon as you see a pile of dragon feces, remove it and the paper liner. Coccidia cysts in the feces don't become active for about 12-24 hours (temperature dependent). The cysts in the feces are how they re-contaminate themselves. As an added precaution, clean down the bottom of the cage with 15% bleach, and let it sit for 30 min. That will kill any cysts that may be there. Then rinse the cage bottom really well with water.
If the dragon smears themselves with feces, you will have to wash them in warm water. Make sure to rinse them in flowing water (under the tap) after the scrubbing bath, to remove any little pieces that might be sticking on.
The above listed cleaning procedures will take care of every kind of fecal transmitted infection that is no longer inside the dragon: bacteria, worms, and protozoans like coccidia.
As said farther above, coccidia normally doesn't go with constipation. Your dragons are very sick and it is probably several problems combining. Coccidia are likely just one of those problems. You have a lot of work ahead of you to get them healthy, and it's going to take months. Reptiles' systems are slower then mammals, it will take longer to clear out infections. Hence, it also takes longer for them to show serious sicknesses.
Best of luck,
Siri