Common Jumping Spider Health Issues

Jumping spiders are hardy when humidity stays consistent, and most health problems in this species trace back to that one factor, either too little or, less commonly, too much. For the regal jumping spider the target is 50 to 60%, and tropical species need 75 to 80%.

Dehydration

One of the most common reasons captive jumping spiders die. Watch for a shriveled abdomen, curled legs, and general lethargy. It's caused by humidity running too low or an absence of drinkable water droplets. It's manageable at home. Bring the enclosure back to 50 to 60% and mist so droplets sit on the wall right in front of the spider. For a spider showing real signs of dehydration, move it to a spider ICU: a small container with air holes, lined with paper towel soaked in warm water, with a damp cotton ball it can drink from.

Curled legs are the sign that dehydration is advanced. A jumping spider extends its legs hydraulically, by pumping hemolymph into them, so when fluid runs low the legs fold under the body.

Retained Molt (Dysecdysis)

A spider that gets stuck in its old exoskeleton during a molt can lose limbs or die. Hydration is the main factor: a spider that goes into a molt short of water, or in a dry enclosure, is the one that gets stuck. Raise humidity in the lead-up to a molt, and never feed or disturb a spider that's in or approaching one. A molt that stays stuck after humidity has been corrected is a vet case.

Silk Impaction

A spider that stops producing silk normally. This is genuinely serious and often fatal, and it's tied to chronic low humidity over time.

Pesticide Exposure

Jerky tremors and loss of coordination point here. It's caused by exposure to household sprays or residue from pet flea treatments, even indirect contact can affect a spider this small. There's no antidote, moving the spider to clean air immediately is the only real response.

Heat Stress

From direct sunlight or an unregulated heat mat. It's manageable by correcting placement and always running supplemental heat through a thermostat if you use it at all.

Finding a Vet Who Treats Spiders

Few vets see arachnids, so the search is worth doing before a spider is sick. The Association of Reptile and Amphibian Veterinarians directory lists exotic vets by region, and some of them treat invertebrates. Call ahead and ask directly whether the practice has seen spiders. Exotic animal hospitals and university veterinary teaching hospitals are the other good starting points, and teaching hospitals sometimes run a service that covers fish, amphibians and invertebrates.

A vet visit makes sense when:

• The spider has stopped eating for weeks outside a premolt fast
• There are visible lesions, fungal growth, or leaking fluid
• A molt stays stuck after humidity has been corrected
• Worms are visible, or the spider shows tremors, seizure-like movement, or partial paralysis
• It keeps declining after temperature, humidity, and ventilation have all been corrected

Bring photos or video of the symptoms, since behavior often stops at the clinic, plus the last molt date, last meal, temperature and humidity readings, and where the feeders came from. Transport the spider in a small ventilated deli cup with a little substrate and a misted paper towel, and keep it at a steady temperature. Expect a diagnosis and a supportive-care plan more than a cure, since some conditions carry a poor outlook whatever the treatment.

The Husbandry Pattern Worth Remembering

Low humidity is directly responsible for both dehydration and failed molts, the two most serious risks this species faces. Chemical exposure is entirely preventable by keeping cleaning products and treated pets away from the enclosure. And heat stress is avoidable simply by never using unregulated supplemental heat. A digital hygrometer and a fine mist spray bottle cover the two tools that prevent nearly everything on this list.

Dehydration and molting complications sit at the top of the list for tarantulas and emperor scorpions too, for the same husbandry reasons.

Sources & Further Reading