Well - your best bet will still be to get to the vet, of course - but there are a few other basic husbandry concerns to address.
Given the info that you have provided the biggest thing on the list currently would be impaction. Despite what you may have heard, calci-sand is well known for causing impaction. Even though you are feeding from the bowl, Leos are known for tasting their environment and ingesting peices of substrate. Young Leos are more prone to impaction than adults as they have more delicate G.I symtpoms. I am not a vet, this is obviously not a diagnosis - but it may be the problem. Either way, ditch the calci-sand. For young Leos all loose substrate is risky, your best options are paper towels, non adhesive shelf liner, tiles, or reptile carpet.
The stress of having the two housed togeher is undoubtly contributing to the issues.
The temps are also too low, which is likely contributing to the issue. If it is an impaction, impaction is an issue that is usually caused by multiple factors...its not JUST the substrate...but the substrate plus inadequate temps, or supplementations, or feeder insects, or stress etc etc. If its not impaction, then the low temps may well be contributing to the overall poor health.
In this case the temps are too low - warm side temp on the substrate floor should be 88-92 degrees. The best way to heat Leopard Geckos is using an undertank heater, as this delivers heat directly to the Leos belly - which is what they need for proper health and digestion. If it is impation (which can be confirmed or ruled out at the vet) then a heat pad will definately be needed as direct belly heat will also help to pass impaction. The risk of fire with heat pads is EXTREMELY low...TONS of reptile keepers use them, and have been using them for years and years with no issues. As long as you use them as directed, and use a thermostat or dimmer to control the heat output (which is also needed to prevent the belly temps from getting too hot - heat pads will often heat to over 100 degrees if left uncontrolled. I personally use plug in lamp dimmers - available at home depot - to control this) then you will not have a problem.
The thermometers you are using are extremely inacurate, and are also measuring the wrong area of temps. For Leos, you need to know the temps on the floor - not up on the glass. Digital themrometers with probes are the most acurate way to do this. You can purchase these at wal mart, home depot, and petco. Tape the probe down to the warm side of the tank and you will get an acurate measurement of the temps. As stated before, these temps should be 88-92 degrees.
If she is defecating straight blood then things are very serious. Most vet clinics are open for a few hours on saturday, if you can find one that treats reptiles and you explain the situation they should be able to see you.
Overall, you will want to adjust and correct some of your husbandry issues...
- Separate the Leos
- Change the substrate
- If impaction is the issue, defiantely use an undertank heater - and if not then still consider it, if you cannot get the floor temps up with the heat bulb
If you cant get her to the vet tomorrow then try to keep her going through the weekend with supportive care. Soaking her daily, or a couple times a day to help maintain hydration and aid in passing any possible impaction. Keep her separated and make sure she has an undertank heater, controlled with a dimmer with adequate belly temps to reduce stress and also aid in fixing any possible impaction.
Is she strainging to defecate at all, since passing the blood??
Good luck with your little girl - keep us posted, i hope she pulls through!
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1.1 Bearded Dragons
2.2 Leopard Geckos
1.0 Uromastyx (Mali)
1.1 Corn snakes
0.1 Mexican Black Kingsnake
1.0 Bairds Ratsnake
1.0 Rosy Boa
1.1 Green Anoles
1.1 House Geckos
0.0.2 Flying Geckos
0.0.1 Red Eye Tree Frog