Early Signs of Illness in Sheep Raised for Mutton

By Dr Duncan Houston

A mature sheep can still follow the mob, approach the feeder and look reasonably well covered while a health problem is developing.

The first clue may be slower eating, a shorter stride or failure to regain condition despite apparently adequate feed. In older sheep, dental problems and chronic disease deserve particular attention. “Just getting old” is not a diagnosis.

For sheep being raised or finished for mutton, early recognition protects welfare and helps prevent avoidable loss of condition, wasted feed and last-minute problems before sale.

Quick Answer

Early signs of illness in sheep raised for mutton include reduced feed intake or rumination, difficulty chewing, declining body condition, separation from the mob, lameness and changes in manure, breathing or skin. Assess individual sheep and feel beneath the fleece rather than relying on the mob average. Persistent poor appetite or several changes together warrant prompt veterinary assessment. Collapse, severe bloat, breathing distress, marked weakness or straining without passing urine requires immediate attention.

1. Less enthusiasm for feed or grazing

Watch whether sheep actually eat when they reach the feed. Some approach the trough but stand without eating, leave earlier than usual or lose interest while nearby animals continue.

Changes in feeding behaviour, alertness and movement are recognised signs of illness. An animal does not have to stop eating completely before it deserves checking.

Observe cud chewing during normal resting periods as well. A repeated reduction alongside poor intake is useful supporting information, but a single sheep not chewing during one brief observation is not diagnostic.

If intake becomes erratic after a ration change, investigate digestive upset. High-starch feeding without appropriate adaptation can cause ruminal acidosis.

2. Difficulty chewing or dropping feed

Teeth become particularly important in mature sheep.

Watch for:

• Wads of partly chewed forage dropped from the mouth, called quidding.

• Feed hanging from the corners of the mouth.

• Unusual jaw movements or prolonged chewing.

• Drooling or food collecting in the cheeks.

• Interest in feed without maintaining condition.

Worn, damaged or missing cheek teeth can interfere with grinding feed. Problems with the front teeth can affect grazing, particularly on short or rough pasture. Checking the front teeth alone does not assess the whole mouth. Persistent changes warrant a veterinary dental examination.

Tooth wear also needs context. Assess actual intake and condition alongside the dental findings, rather than making a decision from age or tooth appearance alone.

3. Losing condition or failing to finish

A full fleece can disguise loss of muscle and fat. Use hands-on body condition scoring over the loin and follow the trend.

Condition scoring assesses tissue cover and helps monitor the reserves of mature sheep. It provides information that appearance from a distance cannot reliably supply.

Weights are useful too, but interpret them alongside fleece length, shearing, pregnancy and gut fill. A single weight is less informative than comparable records over time.

Failure to regain condition is a reason to investigate, not an automatic instruction to add more grain. Check feeding access, ration suitability, teeth, feet and health. Older sheep with poor teeth or lameness may struggle to consume enough even when feed is available.

4. Hanging back or changing their usual routine

A sheep that repeatedly stands apart, trails behind or becomes less responsive deserves a closer look.

Watch how it rises, walks to water and settles with the group. Compare with its own usual behaviour and similar sheep in the same conditions.

Isolation, weight loss, limping and atypical behaviour are reasons for individual assessment. A sheep may still keep up briefly when disturbed, so observe the mob before moving it.

5. Shorter steps, uneven weight bearing or reluctance to move

Early lameness may show as a shorter stride, slower movement or reduced time grazing before an obvious limp develops.

Examine affected sheep promptly. Footrot, scald, foot abscesses, injuries and joint disease can all affect mobility, and their management differs.

Painful feet also reduce feeding opportunities and can contribute to weight loss. Do not accept persistent lameness as normal because an animal is approaching sale.

6. Scouring, dags, pale eyelids or bottle jaw

Loose manure and increasing dags warrant investigation, especially when appetite or condition also changes. Diet and gastrointestinal parasites are among the possibilities, but appearance alone cannot establish the cause.

Barber’s pole worm can cause severe anaemia without scouring. Normal-looking pellets and a clean breech do not rule out a dangerous worm burden.

Pale inner eyelids, weakness or swelling under the jaw raise concern about anaemia or protein loss. These signs may mean disease is already significant. They are not proof that worms are the only problem.

Worm testing and an appropriate parasite-control programme help identify risk before visible illness develops. Marked pallor or weakness needs urgent veterinary advice rather than waiting for a routine test result.

7. Breathing changes while resting

Check breathing before mustering or handling. Persistent coughing, increased effort, nasal discharge or unusual difficulty keeping up deserves assessment.

Respiratory disease in sheep can range from mild depression to rapidly severe illness.

Heat can also increase breathing rate and panting. Check the weather, shade and water supply, and whether the rest of the mob is affected.

Open-mouth breathing with marked effort, weakness or distress is urgent. Keep the sheep calm and avoid forcing it to walk.

8. Rubbing, damaged fleece or suspicious skin patches

Sheep raised for meat still need skin and fleece checks.

Repeated biting, rubbing, foot stamping or a wet, discoloured patch can indicate flystrike. Early affected sheep may remain with the mob. Part the fleece and inspect suspicious areas immediately rather than waiting for obvious maggots or a withdrawn animal.

Confirmed flystrike needs prompt treatment. Seek veterinary help if the sheep is dull, weak, extensively affected or cannot be treated promptly.

Lice, grass seeds and other skin conditions can also cause rubbing. Establish the cause before selecting a treatment.

Why health problems matter during mutton finishing

For mature sheep, useful progress means reaching an appropriate sale condition while remaining healthy and comfortable.

Compare individual results within groups of similar age, size and management. A rising mob average can conceal several animals that are losing condition or repeatedly missing feed.

Some health problems remain difficult to detect on farm. Cheesy gland, for example, may cause internal abscesses without obvious external signs and can lead to carcase trimming or condemnation. Abattoir feedback can therefore help identify flock problems that routine observation has missed.

Use that feedback to review prevention and testing with your veterinarian. It is information for future management, not a substitute for examining an unwell sheep now.

How urgently should you act?

What you notice	What to do
One small change, with the sheep otherwise bright, eating and moving normally	Check the animal and its surroundings promptly. Record the finding and reassess later the same day.
Persistent poor appetite, repeated feed dropping, lameness, scouring or unexplained condition loss	Arrange a closer examination and prompt veterinary advice. Seek same-day advice if the animal is dull, worsening or has several abnormalities.
Suspected flystrike, marked pallor or a late-pregnant ewe eating poorly	Act immediately and obtain urgent advice according to the findings.
Collapse, inability to stand, severe bloat, seizures, breathing distress or suspected urinary blockage	Contact a veterinarian immediately.

What could be causing persistent poor condition?

A sheep that continues losing weight despite suitable feed needs a broader investigation.

Dental disease or painful feet: the animal may be willing to eat but unable to graze, chew or reach feed comfortably.

Gastrointestinal parasites: adult sheep can still be affected, particularly when nutritional demands or other stressors reduce resilience. Use testing and treatment-effectiveness information rather than repeatedly guessing which drench to use.

Ovine Johne’s disease: this chronic intestinal infection can cause progressive weight loss despite a good appetite and adequate feed. Scouring is not a consistent feature, and clinical disease often becomes apparent in adult sheep. Diagnosis has implications for the flock as well as the individual.

Caseous lymphadenitis, or cheesy gland: internal abscesses can cause chronic wasting. External swellings may provide a clue, but their absence does not exclude internal disease. Have suspicious lumps examined rather than opening them in shared yards, where infectious material can spread.

Pregnancy-related disease: if a ewe may be pregnant, reduced appetite needs particular attention. Pregnancy toxaemia and hypocalcaemia can progress to weakness and recumbency and may occur together. Do not assume a ewe entering a finishing group is empty unless her reproductive status is known.

When is this an emergency?

Call your veterinarian immediately if a sheep:

• Collapses, cannot rise or becomes markedly weak.

• Has severe breathing difficulty.

• Develops rapid abdominal swelling with distress.

• Shows seizures, marked unsteadiness or disorientation.

• Has very pale eyelids together with weakness.

• Is severely affected by flystrike.

• Repeatedly strains but passes little or no urine.

Urinary obstruction is particularly important in wethers and rams. Stretching, straining, discomfort or apparent constipation may actually reflect a blocked urinary tract. Passing a few drops does not reliably exclude an obstruction.

Sudden depression, diarrhoea, bloating or abnormal walking after access to a large quantity of grain also requires urgent assessment. Grain overload can be fatal.

Keep the sheep calm. Do not force it to walk or force oral fluids into an animal that cannot swallow normally, because aspiration can cause severe lung disease.

What should you do when a sheep seems “not quite right”?

1. Observe before disturbing it. Watch feeding, breathing, stance, chewing and interaction with the mob.

2. Identify the animal. Record its tag, paddock, signs and when they started.

3. Review recent changes. Include new feed, grain introduction, transport, shearing, weather, weaning and treatments.

4. Examine safely. Check body condition, feet and suspicious fleece patches. Arrange a proper mouth examination when chewing appears abnormal.

5. Use targeted testing. Your veterinarian may recommend worm testing, blood tests or investigation of chronic weight loss.

6. Set a recheck and escalation point. Record who will check the sheep again and act sooner if it deteriorates.

When several sheep change together, check shared feed, water and environmental conditions immediately. A group problem may need a flock-level investigation.

Before sale: check health, transport fitness and treatment records

A booked truck does not make a sheep fit to travel.

Assess each animal for the intended journey. Sheep that cannot walk independently while bearing weight on all legs, are emaciated, visibly dehydrated or severely distressed should not be loaded for sale. Arrange veterinary advice and appropriate care on farm.

Maintain identification and treatment records. Before slaughter, confirm the applicable meat withholding period and export slaughter interval for every relevant product. These are not necessarily the same, and meeting the domestic withholding period alone may not satisfy export requirements.

Recovery, transport fitness and chemical-clearance requirements are separate checks. Completing one does not establish the others.

Common mistakes that delay recognition

• Calling unexplained weight loss “old age”.

• Assuming sheep approaching a feeder are eating enough.

• Checking front teeth while overlooking chewing problems.

• Giving extra grain before investigating poor performance.

• Repeating drenches without checking whether they are effective.

• Waiting until loading day to assess health and mobility.

Prevent problems before they interrupt finishing

Introduce grain and high-starch feeds gradually, maintain a balanced ration and provide reliable access to clean water. Monitor condition and review sheep that are failing to respond.

Build parasite control, vaccination, foot care, biosecurity and flystrike prevention into a flock health plan. Newly purchased sheep and animals returning from other properties need appropriate assessment before mixing.

Provide shade in hot weather and suitable shelter after shearing. Recently shorn sheep are particularly vulnerable to cold, wet and windy conditions.

For broader feeding and finishing decisions, see How to Optimise Mutton Production from Mature Sheep.

Can a sheep be unwell while still eating?

Yes. Partial intake, difficulty chewing and chronic diseases can occur while a sheep still approaches feed. Look at actual consumption and condition trends.

Are older sheep naturally supposed to become thin?

No. Age can increase the likelihood of dental and other problems, but unexplained weight loss still needs investigation.

Should I give more grain to a sheep that is not finishing?

Check the cause first. Dental disease, parasites, painful feet and chronic illness need specific management. Increasing grain abruptly can create an additional digestive problem.

Can a treated sheep go to slaughter as soon as it looks better?

Only when it is fit for the intended journey and all applicable treatment, withholding and market requirements have been met. Visible improvement alone is insufficient.

Watch the sheep that changes its routine or stops progressing with its peers. Early examination gives you a better chance to address the cause while protecting welfare and preserving practical management options.

ASK A VET™ supports informed observation and timely veterinary care. Work with your flock veterinarian to investigate unexplained changes, and contact them directly when a sheep needs urgent attention.