chapter 10 Anal Sac Disorders....................................
DEFINITION/OVERVIEW
Anal sacs are infoldings or pouches between the muscle layers of the external and
internal anal sphincters; they are lined by squamous epithelium and contain large
apocrine glands.Wide variability in color, consistency, and contents of normal and abnormal anal sac
secretions.
Function of anal sacs unknown; may be vestigial structures for marking territory.
Anal sac diseases include impaction, inflammation (sacculitis), infection/
abscessation, and neoplasia.
Inflammatory anal sac disorders are more common in dogs than in cats.
More common in small breed dogs, spaniels, poodles, and obese dogs and cats.
Impaction occurs when the anal sacs fail to empty and become distended, causing
discomfort/pain.
Sacculitis is inflammation that can lead to secondary bacterial infection and absces-
sation; may lead to rupture and fistulation.
Anal sac neoplasia: adenocarcinoma; rarely squamous cell carcinoma.
ETIOLOGY/PATHOPHYSIOLOGY
The exact cause is unknown.
Often associated with gastrointestinal disease including chronic diarrhea or constipa-
tion (dogs and cats), and anal sphincter laxity or muscle weakness.
May be associated with hypersecretion as well as with obstruction.
Anal sacculitis has a proposed association with food hypersensitivity.
SIGNALMENT/HISTORY
Scooting.
Licking or biting at the anal area (Figures 10.1, 10.2).
Pain with defecation.
Constipation.
Blackwell’s Five-Minute Veterinary Consult Clinical Companion: Small Animal Dermatology, Third Edition.
Karen Helton Rhodes and Alexander H. Werner.
©2018 John Wiley & Sons, Inc. Published 2018 by John Wiley & Sons, Inc.
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