If your sheep cannot stand or walk, it is almost always because of a medical issue.
It is normal for sheep to lay down intermittently, but they should not have difficulty standing or walking.
If your sheep is “down” or recumbent, seek immediate veterinary care.
Many diseases can cause sheep to not be able to stand or walk. These may be neurological, unrelated to the nervous system, or nutrition-related. Regardless, veterinary care is almost always indicated. Help by providing your vet with symptoms, diet, and flock management information.
You will need to consult a veterinarian if your sheep cannot stand or walk.
Keep reading to learn how to help your veterinarian diagnose your sheep’s inability to stand or walk.
Categorizing Causes for Inability to Stand or Walk in Sheep
For sheep unable to stand or walk, dividing the possible causes into a few categories is helpful.
A sheep’s ability to stand or walk may be compromised due to neurological disease.
Neurological disease affects the ruminant nervous system, which comprises the brain, spinal cord, and peripheral nerves.
Sheep may also have difficulty standing or walking due to non-neurological disease, or disease which does not affect the nervous system.
These conditions include orthopedic and muscular disorders as well as severe systemic illnesses.
Several diseases that weaken a sheep’s ability to stand or walk are related to nutrition.
These may be due to deficiencies in important electrolytes or vitamins and are often associated with certain life stages, diet, and composition of available pasture.
Examples of reasons sheep cannot stand or walk include:
Primary neurological disease
- Listeriosis
- Tetanus
- Meningeal worm (aka “brain worm”)
- Scrapie
- Spinal cord trauma
- Border disease (aka “hairy shaker disease”)
- Louping-Ill
- Ryegrass staggers
Non-neurological disease
- Musculoskeletal disease
- Non-suppurative arthritis (aka “stiff lamb disease”)
- Fractures or soft tissue injuries
- Lameness caused by foot lesions (e.g., Bluetongue virus, footrot)
- Systemic diseases indirectly cause difficulty standing or walking
- Any process causing severe debilitation
- Any process causing widespread infection (e.g., mastitis)
Nutrition-related
- Hypocalcemia (aka parturient paresis or “milk fever”)
- Nutritional muscular dystrophy (aka “white muscle disease”)
- Polioencephalomalacia
- Laminitis (aka “founder”)
- Hypomagnesemia (aka “grass tetany”)
- Copper deficiency
Neurological Vs. Non-neurological Causes of Sheep Not Standing Up
To distinguish between primary neurological and non-neurological diseases, the veterinary examination of sheep assesses for neurologic deficits.
Your vet may observe whether the animal circles in one direction, has a head tilt, or demonstrates weakness in one or more limbs.
The distribution, symmetry, and severity of these neurological signs will be noted.
The Importance of Assessing Flock Management
To determine why your sheep cannot stand or walk, I recommend assessing the history behind your sheep’s problem.
For example, how long have your sheep been unable to stand or walk, and how has the severity progressed?
Certain disease processes are more likely depending on whether the clinical signs are acute, chronic, static, waxing and waning, etc.
The presence of other symptoms will also help guide you to the underlying cause of your sheep’s recumbency.
Your veterinarian may also ask you if any other animals are affected and, if so, look for patterns regarding which populations are showing symptoms.
For instance, some diseases are more likely to affect newborns, lactating animals, or animals recently introduced to the flock.
As the owner, be prepared to answer questions about your sheep’s diet, medical treatment, possible nutritional deficiencies associated with the pasture, and any other recent changes.
The answers to these questions may be especially enlightening in cases of nutrition-related processes.
Primary neurological Diseases Affecting Sheep’s Ability to Stand or Walk
Primary neurological disease affects the brain, spinal cord, or peripheral nerves.
Below are some, but not all, of the neurological diseases which can cause recumbency in sheep.
Listeriosis is caused by bacteria, which commonly presents as encephalitis (inflammation of the brain) in sheep.
Symptoms include circling and incoordination.
Tetanus is caused by a neurotoxin produced by the bacteria, Clostridium tetani.
Affected sheep will display muscle stiffness and spasms, also described as antagonistic muscle tone.
Meningeal worm is a parasite replicating in white-tailed deer but may also infect sheep during grazing.
If a sheep ingests the parasite, it can travel up the nerves to the brain.
Scrapie in sheep is due to “the accumulation of an abnormal form of a cellular protein in the brain.”
Black-faced breeds of sheep appear to be more predisposed.
Affected sheep display abnormal gait, which can progress to recumbency and, unfortunately, death.
Non-neurological Diseases Causing Recumbency in Sheep
Non-neurological diseases include musculoskeletal disorders and systemic diseases resulting in widespread infection and debilitation.
An example of a musculoskeletal disorder that makes sheep reluctant to move is non-suppurative arthritis.
These sheep spend excessive time laying down and are reluctant to move.
Other processes causing difficulty standing or walking include fractures or soft tissue injury.
Lameness caused by foot lesions is also a possibility.
For instance, the Bluetongue virus is transmitted by biting flies and can cause inflammation of sheep’s hooves.
Other examples include footrot and foot scald caused by bacterial infection of the foot.
Additionally, any process causing severe debilitation or loss of muscle mass is possible due to generalized weakness.
Difficulty Standing or Walking as Related to Nutrition
Many problems with standing or walking in sheep are related to nutrition.
One example is hypocalcemia, caused by insufficient calcium intake in pregnant or lactating ewes.
Hypocalcemia causes many symptoms, including a stiff gait, and is often fatal if untreated.
Another common nutrition-related issue is nutritional muscular dystrophy, which “is caused by a deficiency of selenium and/or vitamin E.”
This nutritional deficiency results in degenerative muscle disease.
Sheep can develop polioencephalomalacia, especially if fed high-concentrate diets, receive excessive sulfur, or have a thiamine deficiency.
Affected animals exhibit many neurological signs, including recumbency and even seizures.
Another common nutrition-related problem is laminitis.
Sheep fed high amounts of carbohydrates can develop inflammation in the hooves, resulting in lameness.
