Brad,
Before I get started, damn you for bringing back painful memories of toxicology and organic chemistry. . .Also, it is not my fault this is so boring, you asked.---------------------------
I believe the biggest confusion you may be having is the difference between a plant that has oxalates, and a plant containing insoluble calcium oxalate crystals.
As I understand it, (and I'll have to go back to my toxicology notes to confirm this) plants that contain oxalates have 3 potential problems-2 short term consequences and 1 long term consequense.
All three are due to the fact that some positively ionized electrolytes (Ca++, Mg++, etc...) like to bind with the oxalates and will precipitate out into a crystalized form. The question is when they percipitate out (before ingestion or after ingestion).
Before ingestion-
Pothos (a previous genus name- now Epipremnum) contains already crystalized calcium oxalate. This is a bonded form. It will not draw any calcium from the body as it already has a Ca++ present. Thus no hypocalcemia. It is also an insoluble form so is unlikely to pass through GI lining to get into the bloodstream, thus no kidney issues.
On the other hand (First short term consequence-), "Peace lilies, Calla lilies, Philodendrons, Dumb Cane, Mother in Law, and Pothos plants contain insoluble calcium oxalate crystals. These crystals can cause mechanical irritation of the oral cavity and tongue when plant material is ingested. Clinical signs that are usually include regurgitation, oral pain, dysphagia, and anorexia. The signs are rarely severe and usually respond to supportive care."
Peace lilies (Spathiphyllum sp)
Calla lily (Zantedeschia aethiopiea)
Philodendron (Philodendron sp)
Dumb Cane ( Dieffenbachia sp)
Mother in Law plant (Monstera sp)
Pothos (Epipremnum sp)
After ingestion-
Plants containing oxalic acid in an unbound form will be looking for Ca++ and Mg++ to bind. It can pass through the GI and into the bloodstream.
(Second short term consequence)-If enough plant is injested at one time, this can cause enough calcium to bind in the bloodstream, causing a sudden and severe hypocalcemia. Since the heart and muscles are dependent on Ca++ to function correctly, seizures(tremors), bradycardia(slowing of the heart), secondary anoxia (low oxygen saturation), and many other not so fun things begin to occur.
I haven't worked with cattle in a long time but I remember seeing cows that broke into fields they weren't supposed to. Due to the lack of available grass they would eat the toxic brush and have mild to moderate muscle tremors. Usually in cattle it was not too bad, but could be potentially lethal. (I can't say I've ever seen a reptile have tremors due to this sort of toxicosis. I have no idea how much of a singular plant a cham would have to eat in order for this to happen.) The problem with this sort of plant that has unbound oxalic acid usually has some sort of other chemical defense mechinisms- ie alkaloids, tasting bitter and causing its own problems. So maybe a cham would take a nibble. Would this be enough? I don't know. . .
(Long term consequence-) If an animal doesn't ingest enough oxalic acid to cause hypocalcemia, but does continually over time ingest the toxic plant (darn stubborn stupid animal), the crystalized calcium oxalate in the bloodstream gets caught in the kidneys who are trying to filter the blood. Since the crystals are to big to pass through the nephrons, they accumulate, and destroy kidney function. After 70+% of kidney function is gone, you will see renal failure which cannot be fixed and will continue to get worse.
Summary- Pothos is fine. If your cham tries to eat it, it may sting the tongue/mouth and cause mild GI issues, but otherwise okay.
I will try to check to make sure this info is correct, but if you need more info, I'll try to be less boring next time.
Matthew
There seems to be five or six different scientific names for this plant; which one is correct?
