Tarantulas are healthier when captive bred. These spiders can be guaranteed to be clear of pathogens and free of parasites. A healthy barking spider displays fluid movement when in motion and should be lively and alert. A spider seen to have any curled up limbs are ill tarantulas and were already given the short end of the stick. It may have gotten its injuries trying to get away from a persistent human predator desperate to make some fast cash with no regard to the safety of the hairy crawler.
Don't be an unwitting pawn in the continued sustenance and promotion of wild animal poaching and refuse to deal with any "breeders" who have one in its stables. You also have to consider whether you are buying an adult, a juvenile, or a sling. Slings (baby spiders) are inexpensive, but they are also more fragile, more difficult to feed, and more likely to die while molting. However, they can be a wonderful opportunity to actually see the growth and development of a barking spider from youth to adult, and watching the incredible changes as they go through can be a fascinating, exciting, and gratifying journey.
If you purchase adult barking spiders, they can be a bit more expensive than slings or juveniles. However, the major advantage is that they do not require such delicate care as slings; adults do not have to be fed regularly, and are generally easier to care for. Of course, they will be more expensive than the spiderlings.
Before you pick a particular barking spider, you should know that they are naturally shy, but even if that’s the case, they should always alert. They’ll be ready to run if you make any sudden moves, and they will certainly be wary at the approach of a human. But if you find them just lurking in a corner, unmoving, completely exposed, with its legs tucked up underneath it, then it is most likely sick and might even be dying. Try to also avoid barking spiders that are hunched over with their legs curled under them, or that seem incredibly thin. This could be an indication of dehydration. Spiders that have unhealthy-looking cream-colored splotches scattered over their body could be an indication of an infection from unclean water.