A cat shaking after giving birth can be a normal response to the physical exhaustion of labor, but it can also signal a serious medical emergency like dangerously low calcium levels. The key is knowing what other signs to look for. Brief, mild trembling in the first hour or two after delivery is common as your cat’s body recovers from the stress and hormonal shifts of birth. Shaking that continues beyond those first hours, gets worse, or comes with other symptoms like refusing food, panting, or stiffness is a different situation entirely.
Normal Post-Birth Trembling
Giving birth is one of the most physically demanding things your cat’s body will ever do. Mild shivering in the immediate aftermath is the body’s response to exhaustion, adrenaline, and a slight drop in body temperature. A healthy cat’s temperature normally sits between 100.5°F and 102.5°F, and labor can push it slightly outside that range. This type of shaking typically resolves on its own within a couple of hours as your cat settles in with her kittens, starts nursing, and rests.
You can help by keeping the nesting area warm, quiet, and draft-free. Offer fresh water and food nearby so she doesn’t have to leave her kittens. If the trembling is mild and she’s alert, eating, and allowing the kittens to nurse, there’s likely no immediate cause for alarm.
Eclampsia: The Most Dangerous Cause
Eclampsia, sometimes called milk fever, is the most urgent reason a cat shakes after giving birth. It happens when calcium drains out of the mother’s bloodstream into her milk faster than her body can replace it. The bones can’t release calcium quickly enough to keep up with the demand of feeding a litter, and blood calcium plummets to dangerous levels.
Eclampsia is less common in cats than in dogs, but when it does occur it tends to strike during early lactation, often within the first few weeks after birth. The early signs are subtle: restlessness, panting, and a general sense that something is off. This quickly progresses to visible muscle tremors, stiff or uncoordinated movement, and hypersensitivity to sounds or touch. Your cat may drool, pace, or seem disoriented. Without treatment, the tremors can escalate to full-body muscle spasms (tetany), seizures, coma, and death.
Other signs to watch for include pale gums, slow breathing or rapid shallow breathing, a slowed heart rate, and a body temperature that climbs abnormally high. Eclampsia is a true medical emergency. If you see any combination of trembling with stiffness, disorientation, or pale gums, stop the kittens from nursing immediately and contact a veterinarian. Minutes matter with this condition.
Uterine Infection (Metritis)
Metritis is an infection of the uterus that typically shows up within the first three days after birth. It can cause shivering because of fever, pain, or both. The hallmark sign is a foul-smelling vaginal discharge. Some vaginal discharge after birth is normal and can last up to three weeks, but healthy discharge gradually decreases in amount and doesn’t have a strong odor. If the discharge increases, turns dark or greenish, or smells bad, that points toward infection.
A cat with metritis will also be visibly unwell in other ways: loss of appetite, vomiting, lethargy, reduced interest in her kittens, and decreased or absent milk production. She may have a fever, which you’d notice as ears and paw pads that feel unusually hot. Metritis requires antibiotic treatment and veterinary care promptly.
Retained Placenta or Kitten
Each kitten should be followed by a placenta (afterbirth). If a placenta or, in rarer cases, an undelivered kitten remains inside the uterus, it can cause infection, pain, and shaking. A cat with a retained placenta often seems restless and uncomfortable, unwilling to settle down with her litter. She may have a poor appetite and a brownish vaginal discharge.
This is why it helps to count placentas during the birth, matching one to each kitten. If you’re unsure whether all placentas were passed, mention this to your vet. An examination will typically reveal an enlarged uterus and elevated body temperature. Retained tissue usually requires antibiotics and sometimes medication to help the uterus contract and expel what’s left.
Mastitis
Mastitis is an infection of one or more mammary glands, and it can make a nursing cat systemically ill. The affected gland becomes firm, swollen, painful, and sometimes discolored (reddish or purplish). Your cat may flinch or pull away when kittens try to nurse on that side.
Beyond the local swelling, mastitis triggers a bodywide inflammatory response. The combination of infection, fever, and the metabolic stress of lactation can leave a cat shaking, lethargic, and refusing food. In severe cases, the gland can abscess or develop gangrene. Kittens nursing from an infected gland may also become weak and cry more than usual. If you notice a hard, hot, or discolored mammary gland alongside your cat’s trembling, that’s a clear signal to get veterinary help.
Pain and Stress
Cats are notoriously good at hiding pain, so trembling can be one of the few visible clues. Expert consensus among veterinary pain specialists identifies trembling as an infrequent but recognized sign of pain in cats, often overlapping with fear and stress. Post-birth pain from uterine contractions (which continue as the uterus shrinks back to normal size), tissue swelling, or a difficult delivery can all produce shaking.
Stress-related trembling is more likely if the environment is noisy, unfamiliar, or if people are handling the kittens too much. A first-time mother is especially prone to this. Giving your cat a quiet, enclosed space where she feels safe can make a significant difference.
How to Tell What’s Happening
The most useful thing you can do is observe the full picture, not just the shaking itself. Ask yourself these questions:
- How long has it been? Mild trembling in the first one to two hours is common. Shaking that starts or continues hours or days later is more concerning.
- Is she eating and drinking? A cat who refuses food after the first few hours post-birth is showing a red flag for infection, eclampsia, or retained tissue.
- Is she nursing? Loss of interest in the kittens, refusing to let them nurse, or decreased milk production all point to a medical problem.
- What does the discharge look like? Foul-smelling, increasing, or darkly colored discharge suggests uterine infection or retained placenta.
- Is the shaking getting worse? Progressive trembling that moves toward stiffness, twitching, or uncoordinated walking is consistent with eclampsia and needs emergency attention.
- Do the mammary glands look normal? Check for swelling, heat, hardness, or color changes.
Any combination of shaking with pale gums, muscle stiffness, seizure-like activity, foul discharge, fever, or refusal to eat warrants an immediate call to a veterinarian. Eclampsia in particular can deteriorate from mild trembling to life-threatening seizures in a matter of hours. When in doubt, treating post-birth shaking as potentially serious is always the safer choice.