Pigs shake for many reasons, ranging from simple cold exposure to serious infections and neurological conditions. A brief shiver after a bath or in a drafty room is usually harmless, but persistent or violent shaking, especially paired with other symptoms like fever, loss of balance, or refusal to eat, signals a problem that needs veterinary attention. Understanding the pattern and context of the shaking is the fastest way to figure out what’s going on.
Cold Stress and Shivering
The most common and least concerning cause of shaking is that your pig is simply cold. Pigs have very little insulating body hair, and piglets are especially vulnerable because they lack the brown fat reserves that many other newborn mammals use to generate heat. When a piglet’s core body temperature drops from its normal range of about 101.6 to 103.6°F down toward 91°F, muscle activity (shivering) increases dramatically, by roughly 142%. Below a core temperature of around 93°F, a piglet’s ability to warm itself back up becomes seriously impaired, and hypothermia sets in.
Adult pigs handle cold better but still shiver in drafty, damp, or poorly bedded environments. If the shaking stops once your pig is warm and dry, cold was almost certainly the cause. Provide deep bedding, a heat lamp for piglets, and make sure the sleeping area is free of drafts.
Congenital Tremor in Newborn Piglets
If an entire litter of piglets is trembling from the moment they’re born, the likely cause is congenital tremor, sometimes called “shaker pig” syndrome. These piglets shake all over their bodies and often have difficulty standing or walking to nurse. The condition has several forms, but the most common infectious type is linked to a virus called atypical porcine pestivirus, which passes from the sow to her piglets before birth. The sow herself typically shows no symptoms.
In affected litters, 100% of piglets can show tremors. Mortality runs higher than normal because shaking makes it hard for piglets to latch on and nurse. In one documented outbreak, mortality in affected litters averaged about 25% by weaning age, compared to roughly 13% in unaffected litters. The good news is that surviving piglets usually recover completely within two to three weeks, though some may retain a faint tremor in their ear tips or flanks for up to 14 weeks before it disappears on its own. There’s no specific treatment; the focus is on helping affected piglets stay warm and nurse successfully, sometimes with supplemental feeding.
Bacterial Meningitis
A piglet between 5 and 10 weeks old that suddenly develops shaking, wobbliness, or an inability to stand may have bacterial meningitis, most often caused by Streptococcus suis. This bacterium infects the brain and spinal cord, producing tremors, incoordination, paddling movements (where the pig lies on its side and moves its legs as if running), and an arched-back posture. Affected piglets often have poor body condition and deteriorate quickly.
Without treatment, meningitis can be fatal within a few weeks. Early antibiotic therapy from a veterinarian gives the best chance of recovery, so a piglet showing these neurological signs needs prompt attention.
Salt Poisoning and Water Deprivation
Salt toxicity is one of the more dramatic causes of shaking in pigs, and it usually happens not because a pig ate too much salt, but because it didn’t have enough water. When pigs go without adequate water for one to five days, sodium builds up in the brain. Early signs include wandering aimlessly, bumping into objects, apparent blindness, and complete indifference to food or surroundings. This progresses to intermittent seizures where the pig sits on its haunches, jerks its head backward and upward, then falls onto its side with full-body convulsions.
Critically, giving a water-deprived pig unlimited water all at once can make brain swelling worse. If you suspect salt poisoning, offer small amounts of water frequently and contact a veterinarian immediately. Without careful rehydration, the condition is often fatal.
Porcine Stress Syndrome
Some pigs carry a genetic mutation that makes them extremely sensitive to physical stress. The classic form involves a mutation in a calcium channel gene and is well known in heavily muscled breeds. A more recently identified form involves a mutation in the dystrophin gene on the X chromosome, which reduces the structural protein in heart and skeletal muscle by about 50%.
Pigs with stress syndrome can appear perfectly healthy until they’re transported, handled roughly, or exposed to heat. Triggers as routine as weighing or moving pigs between pens can set off an episode. Symptoms include open-mouth breathing, skin that turns red or purple with blotchy patches, muscle tremors, loud vocalizations, and refusal or inability to move. Some episodes are fatal. If your pig repeatedly trembles or collapses after handling, a genetic predisposition to stress is worth discussing with your vet.
Mineral Deficiencies
Low blood calcium or magnesium can cause involuntary muscle twitching and tremors in pigs. Severe calcium deficiency may also trigger full seizures, a rapid heartbeat, and loss of coordination. This is more common in nursing sows who are losing large amounts of calcium through their milk, but it can occur in any pig on an unbalanced diet. Muscle fasciculations from mineral deficiency tend to look different from whole-body shivering: you’ll often see rippling or twitching in specific muscle groups rather than generalized shaking.
Pain-Related Shaking
Pigs in significant pain may tremble. Unlike dogs, pigs don’t always vocalize when they’re hurting. Researchers have developed a piglet grimace scale that identifies pain through three facial changes: tightening around the eyes, a bulge or tightening of the cheeks and nose, and ears pinned back or rotated. If your pig is shaking and you also notice squinted eyes, a tense face, or ears held flat and stiff, pain from an injury, abscess, urinary blockage, or internal problem could be the cause.
How to Assess the Situation
Start by checking the basics. Is the environment cold or drafty? Take your pig’s rectal temperature if you can do so safely. A normal reading falls between 101.6 and 103.6°F. A temperature above that range suggests infection or inflammation. Below that range points to hypothermia.
Next, consider the timing and pattern. Shaking that started at birth in multiple piglets points toward congenital tremor. Shaking that began suddenly in a previously healthy pig, especially with wobbliness, circling, or seizures, suggests a neurological emergency like meningitis, salt poisoning, or toxin exposure. Shaking that only happens during or after handling, transport, or excitement fits the pattern of stress syndrome.
Certain combinations of symptoms warrant urgent veterinary care: violent or rhythmic shaking, stiffness, circling, head tilt, inability to stand, skin discoloration, or a pig that is completely unresponsive to its surroundings. These patterns rarely resolve on their own and can deteriorate quickly.