SOP 7.18 - Chronic DSS Colitis (Mouse Model)

University Animal Care Committee Standard Operating Procedure

Document No: 7.18

Subject: Chronic DSS Colitis (Mouse Model)

Date Issued: February 16, 2012

Revision: 3

Location: Queen’s University

Responsibility: Principal Investigators (PI), Research Staff, Veterinary Staff

Purpose: The purpose of this Standard Operating Procedure (SOP) is to describe generating an
acute colitis model of intestinal inflammation using Dextran Sodium Sulphate (DSS).

1. Introduction and Definitions:

Dextran sodium sulfate (DSS) is a molecule that induces colitis like that seen in human patients. It is administered to the animal via their drinking water. This is a common model of Inflammatory Bowel Disease (IBD), the condition of chronic intestinal inflammation that is currently incurable. 

Optimal DSS concentrations are determined by preliminary experiments, as disease severity often varies dependent on animal age, gender, and strain. Standard drinking water is given to controls.



Animal Care Services ACS, Principal Investigator PI, subcutaneous SC, intravenous IV, intraperitoneal IP, intramuscular IM, per os PO, per rectum PR


2. Materials:

  • Water bottle
  • DSS solution
  • Lactated Ringer’s solution
  • 1-3ml sterile syringes
  • Sterile needles (26-27g)
  • Alcohol swabs
  • Weigh scale


3. Procedures:

  • Prior to the initiation of a DSS cycle, all the study mice must be weighed to obtain a baseline weight and it is recorded with the date on the cage card. Based on the baseline weight, the 5%, 10% and 15% weight loss values are calculated (see Appendix 1). 
  • DSS is dissolved into standard drinking water to yield the desired (1% - 2%) (“%” = g/100 ml). 
  • Regular water bottles are removed from the cage and replaced with the DSS-dosed bottles. 
  • DSS is administered in drinking water for 5 days, followed by a return to regular water for 5 days. This cycle is repeated 3 times. 
  • Non-standard water bottles are used for the DSS mice, a special request is required and must be submitted to ACS. 


  • Ensure that cages are flagged with specific ACS cage alerts that animals are on a DSS study. 
  • Daily monitoring: cages are checked for DSS-water consumption (volume drop in bottle, urine output) and bottles topped up/cages replaced as necessary by lab. 
  • Daily weight, appearance, and behavioural changes must be recorded at room level. 
  • In the first two (more severe) DSS cycles: All mice in a DSS treated group must receive a daily subcutaneous injection of 1ml lactated Ringer’s solution. Each and every animal requires a new sterile syringe and needle. Refer to SOP 7.9.1 “Subcutaneous Injection Techniques in Mice”. Mice must be weighed before fluid therapy administration. 
  • In the third DSS cycle, when clinical symptoms are expected to be less severe, only mice failing to gain weight over a 24-hour period must receive the subcutaneous injections of 1ml lactated Ringer’s solution. 
  • Mice may receive 2 daily injections of 1ml lactated Ringer’s solution on the advice of Animal Care Services (ACS) or Veterinary staff. 

Clinical Outcomes:

  • Treated mice may develop loose stool or diarrhea with detectable blood in the stool. 
  • Mice show ruffled fur and weight loss while the colitis is present. This should begin to resolve by the third DSS cycle. 
  • Weight loss should not reach a 15% drop from baseline value, unless approved in the Animal Use Protocol. 
  • All humane endpoints as approved in the Animal Use Protocol must be followed. 

Weight Loss Chart 

Starting weight (g) Weight at 5%
weight loss (g)
Weight at 10%
weight loss (g)
Weight at 15%
weight loss (g)
Weight at 20%
weight loss (g)
18g 17.10g 16.20g 15.30g 14.40g
19g 18.05g 17.10g 16.15g 15.20g
20g 19.00g 18.00g 17.00g 16.00g
21g 19.95g 18.90g 17.85g 16.80g
22g 20.90g 19.80g 18.70g 17.60g
23g 21.85g 20.70g 19.55g 18.40g
24g 22.80g 21.60g 20.40g 19.20g
25g 23.75g 22.50g 21.25g 20.00g
26g 24.70g 23.40g 22.10g 20.80g
27g 25.65g 24.30g 22.95g 21.60g
28g 26.60g 25.20g 23.80g 22.40g
29g 27.55g 26.10g 24.65g 23.20g
30g 28.50g 27.00g 25.50g 24.00g
31g 29.45g 27.90g 26.35g 24.80g
32g 30.40g 28.80g 27.20g 25.60g
33g 31.35g 29.70g 28.05g 26.40g
34g 32.30g 30.60g 28.95g 27.20g
35g 33.25g 31.50g 29.75g 28.00g

Date New Version
04/27/2018 Updated
042/25/2021 Triennial Update
10/17/2023 Triennial Update and format change


SOP 7.18 - Chronic DSS Colitis (Mouse Model)

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