Femoral Pores in Reptiles

Bearded lizard on a rock

Chamaiphorn Phanusathit / 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 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.

Femoral Pores

Bearded dragons, leopard geckos, and iguanas are just three 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 they 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.

The Substance Inside

What you see inside 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.

Lizards With 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.

Their Function

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 also are used by the reptiles in some species 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 mark territory or to determine age and create an individual identity in some species when a chemical analysis is performed.

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. However, in captivity, things don’t always go as nature intended, and these secretions may stay in the pores, causing 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. Don't try to pop femoral pore material out of place at home; it can be painful and cause infections. Refer to your veterinarian to help your pet with its femoral pores.

Preventing Impactions

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 are clean to decrease the likelihood of bacterial contamination.​​​