WATERY mouth disease in young lambs is a significant loss to many sheep farmers and costs the industry dearly. In this article, supplied by the National Animal Diseases Information Service, we look at what causes it and how to prevent it, and treat it.


• It is caused by colonisation and rapid multiplication of e-coli within the lamb’s small intestine.

Economic implications:

• Extra time/drugs involved in treating sick lambs.

• Large numbers of lambs can be affected necessitating treatment.

• A high percentage of affected lambs may die.

• Fostering replacements when lambs die.

• Administration of an oral antibiotic preparation to every lamb in a 1000 ewe flock costs approximately £400.

Clinical signs:

• Affects twins but especially triplet lambs aged 12 to 36 hours.

• Affected lambs are dull, lethargic, depressed and reluctant to suck.

• Retained meconium.

• Profuse salivation develops causing a wet lower jaw.

• Increasing abdominal distension.

• Profound muscle weakness.

• Lamb unable to stand.

• Diarrhoea in latter stages.

• Condition can quickly progress to coma and death.

Differential diagnoses:

The other conditions your veterinary surgeon would also consider include:

• Starvation/hypothermia/hypoglycaemia.

• Septicaemia.

• Intra-partum injury.

• Injury postpartum, such as chest trauma.

• Toxoplasmosis.

• Border disease.


• Based on clinical findings.

• Post mortem findings.

• Bacteriology of little value.

• Clinical biochemistry little used.


• Oral rehydration solution (50ml/kg) every three to six hours.

• A broad spectrum (amoxicillin, oxytetracycline) should be injected intramuscularly.

• Seek veterinary advice regarding NSAID injection to counter endotoxaemia.

Prevention and control:

Husbandry of the shed.

• Good hygiene.

• Appropriate stocking density.

• Abundant clean, dry straw bedding.

• Use of paraformaldehyde powder on straw bedding.

• Cleaning and disinfection of individual pens between lambing ewes.

• Collection and disposal of placentae.

Husbandry of lambs.

• Ensure that lambs suck colostrum as soon as possible following birth preferably within the first two to three hours.

• Probiotics including lactobacilli and streptococcus faecium.

• Administration of an oral antibiotic preparation (spectinomycin or similar) within 15 minutes of birth is effective but is this practice justified and sustainable?

• Soapy water enemas and mild laxatives/purgatives.

Husbandry of the ewes.

• Clean (dagged).

• Well fed.

• Good body condition – plenty of milk.

A review of the veterinary flock health plan is overdue if oral antibiotics are necessary to prevent watery mouth disease in every newborn lamb. The British Veterinary Association policy on the responsible use of antimicrobials in veterinary practice states:

1, Work with clients to avoid need for antimicrobials;

2, Avoid inappropriate use;

3, Choose the right drug for the right bug;

4, Monitor antimicrobial sensitivity;

5,Minimise prophylactic use.

However, farmers must remember that the indiscriminate use of antibiotics in animals increases the risk of antibiotic resistance in humans significantly, so great care must be taken with their use.

Clinical Images Gallery

1. Affected lambs are dull, lethargic, depressed and reluctant to suck.

2. Affected lambs are dull, lethargic, depressed and reluctant to suck.

3. Profuse salivation develops causing a wet lower jaw.

4. Profuse salivation develops causing a wet lower jaw.

5. Increasing abdominal distension, weakness leading to recumbency.

6. No clean bedding, no food, and no water.

7. Many people would question antibiotic administration to every newborn lamb.