Anal glands 1981919 219205814 2008-06-14T02:15:19Z Joelmills 794015 remove nonspecific site The '''anal glands''' or '''anal sacs''' are small, paired sacs located on either side of the anus between the [[Sphincter ani externus muscle|external]] and [[Sphincter ani internus muscle|internal sphincter muscles]]. [[Sebaceous gland]]s within the lining secrete a foul smelling liquid that is used for identification of members within a species. These sacs are found in all [[carnivora]] except [[bear]]s<ref name=Dyce>{{cite book | last = Dyce | first = K.M. | coauthors = Sack, W.O.; Wensing, C.J.G. | title = Textbook of Veterinary Anatomy | publisher = W.B. Saunders Company | date = 1987 | id = ISBN 0-7216-1332-2 }}</ref> and [[sea otter]]s.<ref>{{cite book | title=The Sea Otter in the Eastern Pacific Ocean | last=Kenyon |first=Karl W.| year=1969|publisher=U.S. Bureau of Sport Fisheries and Wildlife|location=Washington, D.C.}}</ref> ==Dogs== In [[dog]]s, these glands are occasionally referred to as "scent glands", because they enable the animals to mark their territory and identify other dogs. The glands can spontaneously empty, especially under times of stress, and create a very sudden unpleasant change in the odor of the dog. The anal glands normally empty when the dog defecates. Failure to empty results in discomfort from the full anal gland pushing on the anus. The glands can be emptied by the dog's keeper, or more typically by a groomer or veterinarian, by squeezing the gland so the contents are released through the small openings on either side of the anus. Discomfort is evidenced by the dog scooting its posterior on the ground, licking or biting at the anus, sitting uncomfortably, difficulty sitting or standing, or chasing its tail. [[Image:Anal gland abscess.JPG|thumb|Anal gland abscess]] Discomfort may also be evident with impaction or infection of the anal glands. Anal gland impaction results from blockage of the duct leading from the gland to the opening. The gland is usually nonpainful and swollen. Anal gland infection results in pain, swelling, and sometimes [[abscess]]ation and fever. Treatment is by expression of the gland, lancing of an abscess, and oral [[antibiotic]]s and antibiotic infusion into the gland in the case of infection. The most common [[bacteria]]l isolates from anal gland infection are ''[[Escherichia coli|E. coli]]'', ''[[Enterococcus faecalis]]'', ''[[Clostridium perfringens]]'', and ''[[Proteus (bacterium)|Proteus]]'' species.<ref name=Ettinger_1995>{{cite book|author=Ettinger, Stephen J.;Feldman, Edward C.|title=Textbook of Veterinary Internal Medicine|edition=4th ed.|publisher=W.B. Saunders Company|year=1995|id=ISBN 0-7216-6795-3}}</ref> Anal glands may be removed surgically in a procedure known as [[anal sacculectomy]]. This is usually done in the case of recurrent infection or because of the presence of an [[anal sac adenocarcinoma]], a malignant tumor. Potential complications include fecal incontinence (especially when both glands are removed), [[tenesmus]] from stricture or scar formation, and persistent draining [[fistula]]e.<ref name=Hill>{{cite journal|author=Hill, Lawrence M.; Smeak, Daniel D.|title=Open versus closed bilateral anal sacculectomy for treatment of non-neoplastic anal sac disease in dogs: 95 cases (1969–1994)|journal=Journal of the American Veterinary Medical Association|year=2002|volume=221|issue=5|pages=662–665|url=http://avmajournals.avma.org/doi/abs/10.2460/javma.2002.221.662|accessdate=2006-08-31|doi=10.2460/javma.2002.221.662|format=abstract}}</ref> Anal gland fluid is normally yellow to tan in color and watery in consistency. Impacted anal gland material is usually brown or gray and thick. The presence of blood or pus indicates infection. ==Opossums== [[Didelphimorphia|Opossums]] use their anal glands when they "[[wikt:play possum|play possum]]". As the opossum mimics death, the glands secrete a foul-smelling liquid, suggesting the opossum is rotting. Note that opossums are not members of the carnivora, and that their anal sacs differ from those of dogs and their relatives. ==Skunks== [[Skunk]]s use their anal glands to spray a foul-smelling and sticky fluid as a defense against predators. ==Weasels== Research by the Institute for Pheromone Research and the Department of Chemistry, Indiana University suggests that [[weasels]] may well use their anal glands in gender recognition.<ref>Zhang JX et al. ''Putative chemosignals of the ferret (Mustela furo) associated with individual and gender recognition.'' [http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=16221798&query_hl=1&itool=pubmed_docsum PubMed] <br /> Zhang JX et al. ''Possible coding for recognition of sexes, individuals and species in anal gland volatiles of Mustela eversmanni and M. sibirica.'' [http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=12826534&query_hl=1&itool=pubmed_docsum PubMed] </ref> ==See also== *[[Anal sac adenocarcinoma]] ==References== <references/> ==External links== * [http://www.veterinarypartner.com/Content.plx?P=A&S=0&C=0&A=625 Anal Sacs from The Pet Health Library] * [http://www.marvistavet.com/html/body_anal_sacs.html All about a dog's anal sacs] * [http://dogcarebasics.com/dog_care_anal_glands.shtml Understanding about a dog's anal glands] * [http://dogcarebasics.com/dog_grooming_anal_glands.shtml How to express a dog's anal glands] [[Category:Animal anatomy]] [[Category:Dog health]] [[de:Analbeutel]] [[nl:Anaalzak]] [[fi:Anaalirauhanen]]