The anal sacs are two small skin pouches beside the anus that store a pungent secretion. Non-neoplastic anal sac disease (impaction, sacculitis and abscess) is one of the commonest reasons small dogs are presented for scooting, while apocrine gland anal sac adenocarcinoma is an important cancer of older dogs and one of the two classic causes of hypercalcemia of malignancy. The rectal examination links both halves of the topic, and the exam expects you to do one.
Key facts
Anal sac disease at a glance- Species and system: dog (uncommon in cats); integument and perianal region.
- Spectrum: impaction, sacculitis, abscess and neoplasia; one dog can have more than one.
- Classic non-neoplastic case: a small-breed dog scooting and licking the perineum, with distended sacs that express thick, pasty material.
- Classic neoplastic case: an older dog (often an English Cocker Spaniel) with polyuria and polydipsia, ionized hypercalcemia and a firm sac that will not empty.
- Tumor mechanism: parathyroid hormone-related peptide (PTHrP) causes humoral hypercalcemia of malignancy; PTH is low or normal.
- Not zoonotic and not reportable.
What's inside
12 sections in the full guide- Key facts
- How the NAVLE tests this
- Cause and pathophysiology
- Clinical signs
- Diagnosis
- Differential diagnoses
- Treatment and management
- Prevention and control
- Prognosis
- Quick review
- Test yourself
- References
The full guide also has 8 tables, 3 figures, 3 self-test questions and 23 references, available to NAVLE members.
Read the full study guide
The full guide is part of every NAVLE plan, with diagnosis and treatment tables, figures, a quick review and self-test questions. Start a free trial to try the question bank, or log in if you are already a member.