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A plantigrade stance means a cat's hocks, the ankle joints of the back legs, have dropped toward the floor. The two most common causes are diabetic neuropathy, which is nerve damage from diabetes, and an injury to the calcaneal (Achilles) tendon.1,2 Diabetic neuropathy tends to affect both back legs. A tendon injury almost always affects one. I would recommend an exam within a few days either way, and sooner if your cat is diabetic or seems unwell.
Key Takeaways
Call us right away if your cat suddenly can't use its back legs, cries out in pain, or has cold back feet. That can be a blood clot called aortic thromboembolism, which is an emergency and a different problem from a plantigrade stance.5 A diabetic cat that stops eating, vomits or becomes weak also needs to be seen today, because those can be signs of diabetic ketoacidosis.6 Call us at (519) 896-0532, or use our emergency page after hours.
In a plantigrade stance the hock, the joint partway up the back leg that matches our ankle, sinks toward the floor, and the cat stands on the whole back foot the way people do. A healthy cat stands up on its toes, which vets call a digitigrade stance.
It ranges from mild, with the hocks only a little lower than normal, to severe, with the hocks resting on the ground. The same change in the front legs, with the wrists sinking toward the floor, is called a palmigrade stance.3
Two structures hold the hock up: the calcaneal tendon at the back of the lower leg, and the tibial nerve that controls the muscles attached to it. Damage to either one lets the hock drop.1,2
Which legs are affected, how fast it started and the position of the toes usually point to one cause or the other before any tests are run.1,2,3,6,7
| Diabetic neuropathy | Tendon injury | |
|---|---|---|
| Legs | Usually both back legs, sometimes the front legs too | Usually one back leg |
| Onset | Gradual | Often sudden, sometimes after a jump or fall |
| Toes | Not curled | Often curled into a claw |
| Other signs | Drinking, urinating and eating more, weight loss | Limping, swelling or a wound at the back of the hock |
| Age | Middle-aged and older cats | Any age; tears without trauma average 10 years |
| First tests | Blood and urine glucose, fructosamine | Exam, X-rays, ultrasound |
I would check blood sugar in any cat with a new plantigrade stance, even when an injury looks like the obvious cause. A cat can have diabetes and a tendon injury at the same time.
Diabetic neuropathy is nerve damage caused by diabetes mellitus that isn't well controlled or hasn't been diagnosed yet. It's seen in cats far more often than in dogs.1 In a 2024 trial of 116 diabetic cats, 35 had a plantigrade or palmigrade stance when they enrolled, and in 20 of them it was mild.3
Blood sugar that stays high for a long time damages the nerves.1 It mainly injures the Schwann cells, which wrap nerve fibres in an insulating layer called myelin. In severe cases the nerve fibres themselves break down.7
When the damage reaches the tibial nerve, which runs down the back of the lower leg, the hock drops.1 The damage isn't limited to the back legs, though. Nerve testing in diabetic cats has found it in the front legs as well.7
A plantigrade stance is the most striking sign.7 The problem usually starts as weakness in the back legs, and in my experience owners often notice their cat struggling to jump onto the bed or couch before they notice the hocks. Other signs include:1,3,6
If your cat hasn't been diagnosed with diabetes, the stance may be what first brings you in. A bigger appetite with weight loss is a classic diabetes sign and one reason a cat can seem constantly hungry.6 Drinking more can also come from kidney disease, so blood and urine tests sort out which it is.
Your vet will start with a physical and neurological exam, then blood and urine tests to confirm diabetes. One high blood sugar reading isn't enough in a cat. The stress of a vet visit can raise blood sugar for a few hours, though it rarely pushes it above 16 mmol/L (288 mg/dL).6
Diabetes is confirmed when blood sugar stays high and sugar shows up in the urine. A fructosamine test helps too. It reflects the average blood sugar over roughly the past week, so a stressful car ride is unlikely to throw it off.6
In a diabetic cat with a plantigrade stance and no sign of injury, those findings are usually enough for a diagnosis. Nerve testing or a nerve biopsy at a referral centre can confirm it.1 X-rays may be taken to rule out a problem in the leg itself.
There's no treatment aimed at the nerves themselves. The aim is to get blood sugar under control and keep it there.1 The usual plan includes:6,8
Some cats can take a once-daily oral liquid, velagliflozin (Senvelgo), instead of insulin. It's approved in Canada for cats whose diabetes doesn't depend on insulin.9 The 2024 trial of 116 cats compared it with insulin and was funded by the drug's manufacturer. The stance improved within 45 days in 10 of 15 affected cats on velagliflozin and 5 of 20 on insulin.3
It isn't safe for every cat. Velagliflozin can cause diabetic ketoacidosis, so cats starting it are checked for ketones every one to three days for the first two weeks.9
Many cats improve once their blood sugar is under control. Some recover completely, and others keep some weakness or muscle loss in the back legs.1 Improvement can start within weeks. By day 45 of the 2024 trial, the stance had improved in 15 of the 35 affected cats.3
Some cats also reach diabetic remission and no longer need treatment. Remission is more likely when blood sugar is brought under control early and well.6 One survey put the average remission rate at 26%, and about 30% of cats in remission later relapse.8
The calcaneal tendon, also called the Achilles tendon, runs down the back of the lower leg and attaches to the point of the hock. When it's torn, cut or worn through, the hock can't be held up and sinks toward the floor.2
It's a bundle of tendons rather than one. In cats the main parts are the gastrocnemius (calf muscle) tendon and the superficial digital flexor tendon, which also curls the toes. Cats also have a soleus tendon, which dogs don't.2
Together they straighten the hock and hold it up, which is what lets your cat stand on its toes and jump.
Some tendon tears follow trauma, and some happen without any. In the largest study, of 66 cats treated at five referral centres, 38% had a closed injury from trauma, 30% had an open wound, most often a cut, and 32% had no traumatic cause.2 Jumping down from furniture came before about 1 in 5 injuries.2
Tears without trauma come from slow degeneration inside the tendon, possibly linked to a less active lifestyle. Those cats were older, averaging 10 years compared with 5 for cats injured by trauma.2 A weakened tendon can give way while a cat does something ordinary, like running or jumping down, with no sign of trouble beforehand.
The most common injury, in 53% of cats, was the calf muscle tendon pulling away from the point of the hock while the toe-curling tendon stayed intact.2
A dropped hock on one back leg is the main sign. Only 3 of the 66 cats in that study injured both legs.2
The toes give a clue to which part is torn. When the toe-curling tendon is still intact, it pulls the toes into a claw as the hock drops. About two-thirds of the cats in the study stood this way, and the rest had a fully flat plantigrade stance.2 Other signs include:
Your vet can usually find it on exam, by feeling along the tendon and checking how far the hock bends. X-rays and ultrasound show where the damage is and help plan treatment. Before surgery, 70% of the cats in the study had X-rays and a third had an ultrasound.2
Most cats have surgery to stitch the tendon together or reattach it to the heel bone. Of the 66 cats in the study, 55 (83%) were treated this way.4
After surgery the hock is held still while the tendon heals, with a frame of pins and bars outside the leg or a temporary screw between the heel bone and shin. Cats in the study were immobilized for about seven weeks on average.4 Pain relief such as buprenorphine keeps them comfortable afterwards, and gabapentin can help a cat cope with strict rest.
Some cats are treated without surgery, with the hock kept in a cast or splint for several weeks instead.4 I would consider this for an older cat whose tendon wore through over time, especially if anesthesia or a frame carries more risk for that cat.
Most cats do well, even when the hock ends up sitting a little lower than before. At their long-term check, 86% of the cats in the study had no lameness.4 On an owner questionnaire, cats averaged about 85% of the best possible score after surgery and 82% without it. Cats whose tendon gave way with no trauma scored a little lower than cats injured by trauma.4
Complications in the first three months are common, affecting 41% of cats, but most are minor, such as infection where the pins pass through the skin. Only 6% had a major problem in the long term.4
Less often, the hock drops because of damage to the sciatic nerve, which runs down the back leg, or its lower branches. A hip fracture or surgery to repair a broken leg can injure the sciatic nerve.10 Damage to its lower branches leaves the paw and toes unable to flex or extend properly, with less feeling on the foot.10
A blood clot called aortic thromboembolism can also cause a sudden problem in the back legs, but it looks different. The back legs become painful, weak or paralyzed, and cold.5 It's most often caused by heart disease such as hypertrophic cardiomyopathy, and it needs emergency care.5
I would recommend booking an exam within a few days. A plantigrade stance on its own is rarely an emergency, but the cause needs finding. Before the visit:
If your cat is already being treated for diabetes, a new plantigrade stance usually means blood sugar isn't as well controlled as it should be. Don't change the insulin dose yourself. Your vet will want a glucose curve or fructosamine result before changing it, because too much insulin can drop blood sugar dangerously low.6
If you've noticed your cat walking on its hocks, call us at (519) 896-0532 to book an exam.
Often, yes, depending on the cause. Cats with diabetic neuropathy usually improve once their blood sugar is under control, some completely and some partly. In a 2024 trial, the stance had improved within 45 days in 15 of 35 affected cats. Cats with a calcaneal tendon injury also tend to do well: in a study of 66 cats, 86% had no lameness at their long-term check.
Yes. A calcaneal (Achilles) tendon injury causes the same stance, usually in one back leg and often with the toes curled into a claw. Less often, it comes from damage to the sciatic nerve or its branches, for example after a hip fracture. Your vet will still check blood sugar, because diabetes is the most common cause.
It varies. Some cats improve within weeks of good blood sugar control. In a 2024 trial, the stance had improved by day 45 in 10 of 15 affected cats on velagliflozin and 5 of 20 on insulin. Others improve more slowly, and some keep a degree of weakness or muscle loss in the back legs.
Yes. When the front legs are affected, the wrists sink toward the floor, which is called a palmigrade stance. Nerve testing in diabetic cats has found damage in the front legs as well as the back, and in a 2024 trial some cats had a palmigrade stance when they enrolled.
Usually not, but it needs an exam within a few days. It's an emergency if your cat suddenly can't use its back legs, cries out in pain or has cold back feet, which can mean a blood clot. A diabetic cat that stops eating, vomits or becomes weak also needs to be seen the same day, because those can be signs of diabetic ketoacidosis.
Most can. In a study of 66 cats with calcaneal tendon injuries, most of them treated with surgery, 86% had no lameness at their long-term check. The hock is held still with a frame, a screw or a cast for about seven weeks while the tendon heals. Complications in the first few months are common but mostly minor. A hock that ends up a little lower than before usually still works well.
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