Cats with internal injuries often show subtle signs that are easy to miss in the first few hours. Unlike a broken leg or an open wound, damage to organs, the bladder, or the brain may not be obvious right away. Some internal injuries take 48 to 72 hours to fully reveal themselves. Knowing what to watch for can help you act quickly enough to make a real difference.
Breathing Changes Are Often the First Clue
A cat with chest trauma, bruised lungs, or air leaking into the chest cavity will change the way it breathes before it shows almost any other sign. You may notice a breathing rate that’s noticeably faster than normal, open-mouth panting (which cats rarely do under normal circumstances), or frequent coughing. Some cats will lower their heads, stretch their bodies forward, and appear to gag as if about to vomit.
Pay attention to posture. A cat that refuses to lie on its side, or that seems to breathe worse when lying down, likely has a chest or lung injury. Cats in respiratory distress will often sit upright with their elbows pushed outward to open the chest as wide as possible. Any of these patterns after a fall, a car strike, or blunt impact to the body warrants an emergency vet visit.
Check the Gums for Signs of Shock
One of the fastest at-home checks you can do is look at your cat’s gums. Healthy gums are salmon pink or light bubblegum pink. If the gums look white, very pale pink, or bluish, the cat may be in shock from internal blood loss or poor circulation.
You can also test capillary refill time. Press a finger firmly against the gum for a second, then release. The color should return within one to two seconds. If it takes longer, blood isn’t circulating properly, and the cat needs veterinary care immediately. This simple test can reveal internal bleeding that you’d otherwise have no way to see.
Abdominal Injuries and What They Look Like
Internal abdominal damage can involve the spleen, liver, intestines, or the abdominal wall itself. The most common visible signs are a swelling or bulge beneath the skin, bruising on the belly, or an asymmetrical abdominal shape. Your cat may cry or flinch when you touch its abdomen, or it may guard the area by tensing up and pulling away.
A distended belly that seems to be growing firmer or larger over time can indicate free fluid (blood or urine) collecting inside the abdomen. This is a serious finding. Cats with significant free abdominal fluid or signs that organs have shifted out of position typically need emergency surgery once they’re stabilized.
Urinary Tract Damage Is Easy to Miss
Any trauma involving the hindquarters or pelvis raises the risk of bladder, kidney, or urethral injury. Early signs include straining to urinate, blood in the urine, abdominal pain, or producing no urine at all. One important and counterintuitive detail: a cat that can still urinate and has a bladder you can feel does not necessarily have an intact urinary tract. Partial tears can still leak urine into the abdomen while the cat continues to pass some urine normally.
When urine leaks into the abdominal cavity, waste products like creatinine and potassium build up in the bloodstream. This makes the cat progressively sicker over hours to days, with increasing lethargy, vomiting, and loss of appetite. If your cat was hit by a car or fell from a height and has any pelvic pain, urinary tract injury should be high on your list of concerns even if the cat seems to urinate.
Head Trauma and Neurological Signs
The most important thing to evaluate after a head injury is your cat’s level of consciousness. Veterinarians grade this on a spectrum from normal alertness, to depression, to a stupor-like state where the cat can only be roused by pain, to full coma where no stimulus gets a response. Any decline in alertness after trauma is significant.
Pupil size tells you a lot. Normally, both pupils should be the same size and shape. After a head injury, unequal pupils suggest damage on one side of the brain. Very small (constricted) pupils in both eyes can indicate widespread forebrain injury. If those small pupils later become large and unresponsive to light, it suggests the brain is swelling dangerously, and the situation is critical. Fixed, dilated pupils that don’t react to light at all carry a poor prognosis.
Other signs of brain injury include a head tilt, walking in circles, loss of balance, involuntary eye movements, or sudden blindness. A cat that was alert after an injury but then becomes increasingly drowsy or unresponsive is deteriorating and needs immediate care.
Symptoms Can Be Delayed by Days
This is one of the most dangerous aspects of internal injuries in cats. A cat can appear stable for hours after a traumatic event and then suddenly worsen. In one documented case, a cat hit by a car was treated and seemed to respond well, only to develop vomiting and severe abdominal pain roughly 72 hours later from a delayed intestinal perforation, where damaged bowel tissue slowly broke down and eventually ruptured.
This means the first 72 hours after any major trauma are a critical monitoring window. Watch for new vomiting, sudden increases in breathing rate or effort, decreased responsiveness, refusal to eat, or new pain when the abdomen is touched. A cat that initially improves and then takes a turn is showing a pattern that strongly suggests a complication like a delayed organ rupture or worsening internal bleeding.
What Vets Look for With Imaging
When you bring a traumatized cat to the vet, one of the first tools they’ll use is a focused ultrasound scan. These rapid exams check for free fluid in the abdomen (which could be blood, urine, or intestinal contents) and for air or fluid in the chest cavity. The abdominal scan looks specifically for fluid pooling between organs, while the chest scan checks for fluid around the lungs or heart and for collapsed lung tissue.
These scans take minutes and give the vet critical information about whether your cat needs surgery, fluid support, or close monitoring. X-rays, blood work, and contrast imaging (where dye is used to trace the urinary tract) may follow depending on what the initial scan reveals. Vets use standardized trauma scoring systems that rate injury severity across six body systems, including circulation, breathing, neurological function, and skeletal damage, to predict outcomes and guide treatment urgency.
How to Safely Move an Injured Cat
Rough handling can worsen internal bleeding, shift broken bone fragments into soft tissue, or aggravate spinal injuries. The goal is to keep your cat as still and supported as possible during transport.
For most cats, a hard-sided carrier or a sturdy cardboard box with a lid works well. If you suspect a spinal injury (the cat seems paralyzed or can’t stand), slide it onto a flat, rigid surface like a piece of plywood, a cutting board, or a collapsed cardboard box. Grasp the skin over the back of the neck and the lower back, slide the cat on gently, and try to keep the spine straight. If possible, loosely secure the cat to the board with tape or strips of fabric so it can’t thrash and make things worse.
A few specific rules matter here. Don’t put pressure on the stomach, especially if the cat is vomiting, has abdominal pain, or is struggling to breathe. If the cat resists lying on its side or breathes worse in that position, let it choose its own posture. For an unconscious cat, keep the head aligned naturally with the body, not flexed down or tilted up, and position the head slightly below heart level if there’s any vomiting so fluid drains out of the mouth instead of into the airway. Covering the cat with a towel or blanket helps prevent heat loss and has a calming effect.