bearded dragon sore on foot/age?

Question
We call him Marley, he was a rescue that had been left outside for a while, very skinny when we took him.  He now has a glass tank with top vent. I keep it at 80 degrees, he has fresh water daily along with a warm rock and tree truck hiding spot, he eats crickets, meal worms, grasshoppers, big variety of fruit, veggies,broccoli slaw, mustard,collard, turnip greens,yellow squash,zucinni, water melon,cantaloupe,blueberries,apples,mango.

So Marley has developed a growth on the top of his foot.  It is swollen,just the base of his foot, no toes or leg swelling.  He favors it, this is the second time it has swollen and the sore showed up the 1st time and this second time it is bigger.   I have look at the pet store, but do not see anything to treat him with.   What would you suggest?  Also he seems to prefer meat over the fruits and veggies. I feed him heavy on the crickets about 1 1/2 doz crickets once weekly, between two dragons they go thru 100 worms a week.  Thank you

Answer
Well, the first issue I see is that Marley is being kept much too cool for a bearded dragon.  While 80F is an acceptable temperature for the air on the cool side of his tank, he requires a hot spot of 100F on one side of the tank, to bask.  Hot rocks (which plug in) should never be used for any reptile, but are particularly unsuitable for bearded dragons, because bearded dragons have a 'third eye'--a light sensing organ on top of their head, which they use to detect light and heat, and regulate their body temperature by moving into and out of the sun.  They can sit on a hot rock until they literally cook their insides.

Marley also requires a strong UVB light.  A Mercury-Vapor reptile light is very suitable for bearded dragons, and the UVB production lasts for 3 years.  Since it also produces high heat, it's a good choice.  You can also use a heat lamp along with a fluorescent UVB reptile light.
Although these items aren't cheap, bearded dragons cannot be maintained without them, and if you don't have them, it's possible that this is what Marley's problem is.

The insects sound good, although all of the insects you mentioned need to be dusted with calcium powder each time you feed them, because they are too high in phosphorus.  He should be getting a LOT less fruit.  The bulk of his salad should be the mustard, collard, and turnip greens, with a bit of grated squash or pumpkin, and an occasional bit of cantaloupe, blueberry, or mango.  Apples are not a good choice, and watermelon of course is mainly water.  Cut back on the fruit.

If Marley is under age 1, he should be offered this salad daily, free choice, and be fed insects twice a day.  Remove any uneaten insects after 15 minutes, each time.  If Marley is over age 1, then he should be given insects, all he can eat in 15 minutes, 3 times per week until his weight is back up, and then twice a week after that.  Salad should be offered fresh daily.

If Marley has not been getting UVB light, calcium, and vitamin D supplements, then it is entirely possible that his foot is broken.  UVB enables reptiles to produce vitamin D in their skin, and desert species in particular have high requirements for it, and tend not to be able to absorb vitamin D from supplements very well.  (Too much vitamin D in supplement form is toxic, so you cannot simply increase the amount of vitamin D in the diet).  Vitamin D is crucial in allowing an animal to absorb and use calcium.

Animals deficient in vitamin D and calcium develop a condition called hypocalcemia, and metabolic bone disease.  The bones weaken as the body pulls calcium from them to use.  Weak bones lead to deformities, and bone breaks.

Marley really needs to be taken to a veterinarian for a proper diagnosis at this point.  If his foot becomes infected, he could die from blood poisoning.  A vet will be able to diagnose the problem, and treat it.