Anal gland
[2] In non-human mammals, the secretions of the anal glands contain mostly volatile organic compounds with a strong odor, and they are thus functionally involved in communication.
These sacs are found in many species of carnivorans,[2] including wolves,[5] bears,[6][7] sea otters[8] and kinkajous.
[4] The glands are situated at varying depths in the wall of the anal canal; some between the layers of the internal and external sphincter (the intersphincteric plane).
[4] The cryptoglandular theory states that obstruction of these ducts[clarification needed], presumably by accumulation of foreign material (e.g. fecal bacterial plugging) in the crypts, may lead to perianal abscess and fistula formation.
This is characterized by a build-up of fluid in the anal sac, an uncomfortable condition that can lead to pain and itching.
Dogs and cats with anal glands that do not express naturally may exhibit specific signs, such as scooting the backside upon the ground, straining to defecate, and excessive licking of the anus.
The most common bacterial isolates from anal gland infection are E. coli, Enterococcus faecalis, Clostridium perfringens, and Proteus species.
Potential complications include fecal incontinence (especially when both glands are removed), tenesmus from stricture or scar formation, and persistent draining fistulae.
[18] Castoreum is the chemical compound that is secreted from the castor sacs and is originally a thin, yellowish liquid.
It is composed of a mixture of varied metabolic compounds, from the sacs and other bodily systems, and excreted urine.
[18] An extraction of castoreum, the scent glands from the male and female beaver are used in perfumery and as a flavor ingredient.
These two bacteria are common in the digestive tracts of mammals and are seen across all beaver populations regardless of sex, colony, age, class, and other factors.
[18] Beavers create scent mounds, which are essentially “mud pies”, where they deposit castoreum and other secretions on top of them.
[20] Scent mounding is highest during intergroup interactions, vicinity of abutting beaver populations, and gestation periods.
[21] Anal gland secretions (AGS) of badgers are not commonly studied but contribute to key information for communication due to volatile organic compounds (VOCs).
[21] VOCs in AGS of badger samples have individual-specific information, including health, fitness, reproductive status, and group membership.
[22] Based on a study by Yung Wa Sin 2012, conducted on 79 subcaudal secretions from summer and spring, OTUs fall into four bacterial phyla: Actinobacteria, Firmicutes, Proteobacteria, and Bacteroidetes.
[21] This indicates that the volatile compounds in the anal sac secretions are used to signal information like gender and reproductive status.
[24] Contents of the anal pocket secretions revealed 6 saturated carboxylic acids: acetic, propionic, isobutyric, butyric, isovaleric and valeric.
[24] Evidence shows that the carboxylic acids found in the anal pocket secretions are produced by bacterial metabolism of contents inside the sebum.
[24] The bacteria isolated from anal sac secretions have been identified as Peptococcus spp., Peptostreptococcus plagarumbelli, Bacillus cereus and Eubacterium or Catenobacterium spp.
For females, the most common bacteria found in their paste was Anaerococcus, Anaerovorax, Corynebacterium, Eubacterium, Helcococcus, Porphyromonas, and Propionibacterium.
[14] The secretion of anal gland content contains mucin, that is rich in sialic acid and other anti-microbial proteins, like lysozyme, immunoglobulin A, and lactoferrin.
[14] The anal-sac fluid can be secreted or expressed into the anal channel to serve as a scent marker for an individual's territory through their feces.
