Bearded dragon femoral pores are found on the inner thigh as with many lizard species. Underneath the femoral pores are the epidermal glands.
The anatomical positioning of the bearded dragon femoral pores are preanal and femoral.
Not all lizards have femoral glands but most agamid lizards, including bearded dragons, do (Witten, 1993).
The number and layout of the pores differs in lizard species and as such is a characteristic used to describe and identify lizard species (Baeckens et al, 2015).
- Purpose and Secrets Bearded Dragon Femoral Pores Reveal
- Leaving a Trail of Secrets
- Secretions Reveal Secrets to Other Lizards
- Androgens: The Key to Secretions
- Cleaning and Unclogging Bearded Dragon Femoral Pores
- How to Clean Femoral Pores
- Bearded Dragon Femoral Pores Conclusion
The femoral pores become much more noticeable in maturity, which is typical of lizard species.
Female bearded dragons have femoral pores but they are much smaller than males (Bowmanville Veterinary Clinic; Avian and Exotic Animal Care; Pine Tree Veterinary Hospital).
Purpose and Secrets Bearded Dragon Femoral Pores Reveal
Femoral pores are epidermal structures connected to glands that produce a waxy holocrine secretion and is part of the pheromonal communication in lizards (Aragon et al, 2001).
Holocrine secretion means releasing a secretion that is a product of disintegrating cells.
The two most widely accepted hypotheses for the purpose of the femoral pore secretions are that they are a chemical signature which is:
- Used by males to mark territory (Brown, 2012; Mayerl et al, 2015), and
- Used to recognise of their own species, sex and individuals (Mayerl et al, 2015).
Leaving a Trail of Secrets
The femoral pores (ducts) continuously and slowly release a thick waxy solid secretion (holocrine secretion) known as a secretion plug (Imparato, 2007). The secretion in agamids is mostly protein (likely keratin), pheromones and other chemical compounds (Gans and Crews, 1992).
The waxy secretion is smeared on substrate and objects such as rocks, branches and vegetation within the male’s territory. Small pieces of the femoral secretion plug fall off onto the substrate leaving a chemical signature.
In studies on Tegu’s they were observed rubbing their thighs and cloacal region on the ground. The femoral secretion left on the ground was not obvious enough to see by eye however, the reactions of other males indicated they could very much detect the previous males scent (Chamut, 2009).
The duration of the scent markings depends on the substrate it is left on. For example, Regnier and Goodwin (cited in Baeckens, 2015) found that clay surfaces were slower to lose the scent than wood. During breeding season the glands secrete more and increase in size however the pore size stays the same (Mayerl et al, 2015). The make up of the secretion also changes during breeding season.
Secretions Reveal Secrets to Other Lizards
The femoral secretions tell a story about the lizard revealing secrets such as species, age, sex, health and more (Baeckens et al, 2015).
Female lizards can pick up on what the secretions reveal and assess how good a mate he will be.
Mayerl et al (2015) reviewed studies on what a female lizards can detect from the chemical signature of the secretions. Amazingly females can pick up on, and subsequently favour, the quality of a male from the scent of the secretion. Female lizards are so adept at reading the chemical signature that they were able to detect the quality of a male such as size, health, diet and even its access to thermal resources.
In the male wall lizards, it was found that the chemical composition of the male’s scent markings changed based on basking resources and access (Mayerl et al, 2015). It has also been shown in some species of lizards that secretions varied with level of immune response giving away clues as to how healthy the lizard is (Mayerl et al, 2015).
The female Psammodromus algirus lizards demonstrated how capable they are of picking up on the quality of a male through their femoral pore secretions. The females were able to detect and show preference to male lizards with lower parasite infections and good immune responses (Mayerl et al, 2015).
In some species of lizards, females were even able to detect and show preference to areas marked with secretions by males with essential nutrients (Norris and Lopez, 2011; Mayerl et al, 2015). The essential nutrients of interest to the females included provitamin D, vitamin E and oleic acid.
The male secretions are so revealing that females of some lizard’s species have also been shown to be able to detect the age of a male. Females have a preference for older males (Mayerl et al, 2015).
Far less research has been conducted on female lizards than males. Mayerl et al (2015) reviewed that glands of female lizards are only active premating. This makes it easy for the males to detect unmated females. However, insufficient studies have been conducted to provide adequate evidence.
It’s not all about the girls though. The chemical signature of stools and femoral gland secretions provide information for male lizards to size up their potential rivals (Aragón et al, 2001).
Androgens: The Key to Secretions
Femoral glands are controlled by androgens (group of hormones including testosterone). Studies show that hormones cause the increase in femoral gland activity during mating season.
Padoa (cited by Cole, 1966) showed that castration of male lizards results in atrophy of the glands to a point where the glands replicated that of females. However, castrating females had no effect.
Injecting castrated males with testosterone propionate and dihydrotestosterone can restore some production of femoral gland secretions (Norris and Lopez, 2011).
Cleaning and Unclogging Bearded Dragon Femoral Pores
Bearded dragon femoral pores can become clogged. Clogged femoral pores can be easily cleaned before they become impacted and painful.
When the secretion plug starts to show it will appear as little more than a little bump poking out of the bearded dragon femoral pore. Once the secretion plug gets large the bump will get larger, jutting out of the pore perhaps slightly curled. If it becomes very overgrown it may appear something similar to a little worm, a hard protrusion curling from some of the femoral pores.
How to Clean Femoral Pores
As long as the secretion from the femoral pores is not unusually long, the pores aren’t impacted, red or painful; then cleaning is not likely required. The secretion is a normal discharge with a purpose and does not need to be removed.
Provide rough surfaces of branches and rocks in the enclosure for rubbing on and access to water or bathing. This is particularly important during the breeding season when the glands will be extra active.
Clean femoral pores if they appear to be on their way to being clogged. Clean femoral pores by providing a warm bath and a gentle rub with a toothbrush. It may take a number of baths over a period of days if the femoral pores are clogged.
If the pores start to bleed, apply an antiseptic ointment and stem the blood flow with gentle pressure using a sterile swab. If the bleeding continues, call your vets office to discuss best course of action.
Squeezing the secretion out could cause damage to the gland and likely to be uncomfortable or painful.
4 Ways to Prevent Femoral Pores Clogging
Here are 4 ways to help prevent bearded dragons femoral pores from clogging:
- Provide a diet with a wide range of known safe foods.
- Keep humidity at the right level between 30-40% (see humidity).
- Provide regular opportunities to bath or soak in shallow water.
- Providing a large enclosure with rough surfaces including rocks and branches will allow the bearded dragon to maintain his own pores naturally.
3 Signs of Impacted Femoral Pores
3 signs of impacted femoral pores include:
- Significant secretion that is stuck in the pore. The secretion may be bigger than the pore opening.
- Redness and swelling or puffiness.
- Fluid discharge.
Severe swelling should be examined by a vet and the secretions may require minor surgery, cleaning and flushing under anaesthesia.
3 major concerns with cleaning a bearded dragon’s impacted femoral pores are:
- Bleeding, and
- Subsequent infection.
There are a lot of blood vessels around the femoral glands which are easily disrupted causing bleeding when cleaning infected glands.
Significant pain has been noted in iguanas when trying to remove excessive secretion plugs from swollen glands (Klaphake, UD). In addition, bleeding may occur at a later time when basking as the warmth and improved blood flow can dislodge blood clots (Klaphake, UD).
3 Signs Clogged Femoral Pores Need Veterinary Attention
The bearded dragon femoral pores need veterinary attention if:
- It shows behaviour that indicates pain.
- The femoral pore is clogged and impacted. The secretion plug could be bigger than the pore it must come out of.
- The femoral pore is distended and bleeding.
Veterinarians may stem bleeding with a sterile cotton bud (Eatwell, 2010) and 2% chlorhexidine gluconate (Klaphake, UD). Along with good cleaning practices of the reptile keeper, the disinfectant will aid in reducing the risks of subsequent infection.
Causes of Clogged Femoral Pores
3 causes of clogged femoral pores and infection include:
- A deficiency in vitamin A (Eatwell, 2010).
- Insufficient humidity (Klaphake, UD).
- Inadequate rough surfaces to rub on.
Bearded Dragon Femoral Pores Conclusion
The secretion plug from bearded dragon femoral pores is a normal part of communication in lizards. The secretions tell a story to other lizards who can read them giving away intimate secrets of health, size, sex and more.
The pores can be kept in good condition by providing natural rough surfaces in the enclosure (branches and rocks), correct humidity (complete guide to humidity), a good broad diet (safe food list) and occasional baths (bathing) or access to interact with water.
If the femoral pores have large secretion, appear swollen, impacted and/ or causing discomfort, speak with a vet.
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