Femoral Pores in Reptiles

Basic Reptile Health and Anatomy

Lizard
Chamaiphorn Phanusathit / EyeEm/ Getty Images

Femoral pores in reptiles have several purposes but can also cause a problem for your pet. Along with abdominal, inguinal, and preanal pores, reptiles can have a number of glands. They are useful in identifying species and the sex of the reptile but the pores and their secretions are also still somewhat a mystery.

What are Femoral Pores?

Bearded dragons and iguanas are two species of pet reptiles that have femoral pores. These pores are located on the underside of the lizard on each thigh in close proximity to the anal opening and are actually openings of follicular glands. Pores that are on the thighs and then continue to form a “V” over the anus are considered preanal pores.

In male iguanas, these openings increase in size as they age but stay fairly small in females. Seasonal changes also occur in the males suggesting the glands play a role in reproduction (such as releasing pheromones to attract mates). Some studies have even shown that when the male reproductive organs are removed the femoral pores shrink up.

What is the Substance Inside of the Pores?

What you see inside of the pores (or what your exotics vet extracts from the pores) can vary depending on what species of reptile you are looking for. Some secretions are made up of a material called keratin (the same thing that is in your hair and fingernails) while other secretions have a more lipid (or fatty) substance.

More secretions may be produced during your reptile’s mating season and the pores may even protrude.

Who Has Femoral Pores?

Not all reptiles have them. All genera in the Anguidae, Chamaeleonidae, Dibamidae (legless lizards), Helodermatidae, Scincidae, Xenosauridae, and Varanidae families are missing femoral pores. Also, females in some species of geckos do not have them and there are variations within families as well.

What Do the Pores Do?

Aside from attracting mates with the pheromones they release, femoral pores are not only useful in identifying what sex a reptile is to humans but in some species of reptiles, they are used by the reptiles themselves to tell if a lizard is a male or female.

The secretions of the femoral pores in leopard geckos are used to differentiate males versus females by the flick of a tongue. Leopard geckos actually taste these secretions to know whether or not they need to fight or mate with the other gecko in their path.

Secretions of the pores can also be used to determine age and create an individual identity in some species when a chemical analysis is performed or to simply mark territory.

What are Impacted Femoral Pores?

In the wild, the keratin or lipid secretions of the femoral pores naturally fall out while walking or rubbing on tree branches but in captivity, things don’t always go as nature intended and these secretions may stay in the pores and cause an impaction.

Normal femoral pores may protrude during mating season and appear much larger than usual. The “plugs” in the pore openings sometimes look like horny protrusions in larger reptiles such as iguanas. An impacted pore is when there is fluid seeping out around the plugs, the pore is red or swollen, or they seem to be sore to the touch. If you suspect your reptile has impacted femoral pores you should have him checked out by your exotics vet.

How Can I Prevent Femoral Pores from Becoming Impacted?

The key to caring for reptiles is in providing proper husbandry. The more natural an environment, the better off your reptile will be. Humidity and temperatures should be as recommended for the species of reptile you have, water baths should be provided for soaking, and rocks or tree branches and logs should be in the enclosure to help your reptile shed and rub out pore secretions. Also, make sure your enclosure and water is clean to decrease the likelihood of bacterial contamination.​​​