Melissa Kaplan's
Herp Care Collection
Last updated January 1, 2014

Laxative Use In Reptiles

©1997 Melissa Kaplan


The problem with treating constipated iguanas (and other reptiles) with a laxative of some type is that constipation is a symptom - not the primary condition. Laxatives can be harsh on any animal's system (humans included). Using a laxative developed for mammals on a reptile, especially an herbivorous lizard, who has a very different digestive system and metabolism, may result in the 'cure' being worse than the condition which prompted the curative.

Humans typically use laxatives because their diets do not include enough fiber and they do not drink enough water during the course of the day. Boost the fiber and water intake, and laxatives are no longer necessary. It is much the same with reptiles: feed them right, heat them right, house them right, provide sufficient room and incentive for exercise, and regularity is not a problem.

Just as forcing food down an animal who will not voluntarily eat without first knowing the reason for the failure to self-feed can kill an animal, so too can forcing laxatives down an animal without knowing why they are constipated.

Common reasons for a reptile not defecating include:

  • it is too cold
  • its digestive system has shut down due to metabolic bone disease
  • it is impacted with "iguana-approved bark" or "lizard litter" or similar substrates
  • it is clogged with parasitic worms
  • it is dehydrated
  • it is impacted with a foreign object (in the past year, I've heard of igs who have had condoms, rubber bands, pennies and pushpins removed from their gut as well as clumps of shavings, litter and pieces of bark).

The three most common reasons for iguanas to be constipated is that they are kept in enclosures that are too cool, are suffering from advanced metabolic bone disease, or are impacted with ingested substrate (even iguanas who were never seen by their owners to have ever ingested any of their particulate substrate). In the first two cases, the environmental conditions must be corrected (temps adjusted, proper lighting, diet and vitamin/mineral supplementation provided). In the last case, the substrate must be changed but the iguana may need surgery to remove the impaction if the bathing, gentle massage, and mild laxative do not work.

Laxatives are rarely needed when they are too cold - just getting their temperatures up where they need to be is enough to get the digestive tract functioning again. However, bathing in warm water and massaging the belly gently while you are waiting for the temps in their enclosure/room to rise does help things move along more quickly.

The same is true for MBD - the massage helps stimulate the ingesta and fecal matter to move through the gut and rectum while waiting for the calcium or D3 administered by the vet takes effect; and the proper temperatures and diet (whether regular food through self-feeding or proper force-feeding slurry) help restore gut function as well. If the gut has been not functioning properly for some time, as during prolonged starvation, suboptimal temperatures, or antibiotic therapy, one or two doses of beneficial gut flora may be administered (see the Emaciation article for more information).

Note that some foods may cause mechanical constipation by indigestible matter failing to break down or otherwise cluttering up, and clogging, the gut: whole-kernel corn, fig seeds, whole peas, whole grapes, and whole berries such as blueberries. Corn, of course, isn't a great food to feed anyway. Figs are, but dried must be thoroughly reconstituted and you may wish to scoop out the seeds, especially if feeding them frequently, especially when feeding to very small igs or igs recovering from MBD who had sluggish or stopped gut function. Peas should be mashed or processed (food processor or ground in blender) to break their skins. Grapes and berries should at least be cut in half, cut further for large ones.

Pumpkin is reputed to be a sort of natural anthelmintic (wormer)...the problem is that as far as I know, no research as been done to validate this or to determine exactly which types of worms it kills. Feeding large quantities of the orange veggies, such as several meals of all squash or all carrots, will give an animal loose stools, so may be effective in loosening things up (they may also give a disturbingly orange tint to things, so don't be alarmed). Figs, prunes (again, reconstitute by soaking in hot water), and honey have all been recommended as stool softeners, too.

As with most health problems with reptiles, we need to adopt a two-pronged approach: evaluate the physical environment, including diet, as well as have the animal checked out internally by a reptile vet. So, before you grab that bottle of cat laxative or mineral oil, do a thorough check of your reptile's environment (see the appropriate species care article and the Signs of Illness & Stress article for guidelines on what to look for), follow the bath and massage procedure outlined in Constipation in Reptiles, and have your vet check for impactions if the bath and massage do not work. If you treat the symptom without addressing the cause, you will just make matters worse.

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