A veterinarian explains four possible causes of sudden weakness in your dog’s back legs, and what you must do.

When your dog’s hind legs suddenly go weak, there could be any number of causes, says veterinarian Dr. Jules Benson, BVSc, and VP of Veterinary Services at Petplan pet insurance, whom I interviewed just for this article.

“Sudden hind limb weakness or paralysis can be a clinical sign of several conditions, including degenerative myelopathy, in which parts of the nerves in the spinal cord responsible for hind limb mobility degenerate,” begins Dr. Benson.

Another possible cause of sudden back leg weakness in a dog is intervertebral disc disease, says Dr. Benson.

He explains that this occurs when bulging discs put pressure on the dog’s spinal column.

Next is vertebral instability (“wobbler syndrome”), in which “the spinal canal narrows, placing pressure on the nerves affecting hind limb motor function,” says Dr. Benson.

An infection with the bacteria that causes botulism can also cause a dog’s hind legs to suddenly go weak, though this is rare, says Dr. Benson.

Accompanying symptoms of this would be excessive drooling, slack jaw and dilated pupils.

Treatments

Degenerative Myelopathy

While physical therapy and vitamin therapies can help maintain a better quality of life, Dr. Benson says, unfortunately there’s no treatment or cure for the condition.

Intervertebral Disc Disease and Vertebral Instability

The faster these cases are caught and treated, the better the prognosis, says Dr. Benson.

He adds, “Mild cases of IVDD will respond well to anti-inflammatories and muscle relaxers, while more severe cases will require surgery to allow the affected pet to return to normal function.

“Petplan recently paid out a claim for over $3,000 for a 12-year-old German Shepherd who needed treatment for IVDD.”

Botulism

Pets are treated with an anti-toxin and supportive therapy, including IV fluids.

Paralysis or extreme weakness in your dog’s back legs for more than 24 hours?

Dr. Benson says the prognosis here is poor. With wobbler syndrome, surgery is usually needed, in addition to anti-inflammatory drugs.

“Petplan recently paid over $8,000 for a 9-year-old Standard Poodle who required advanced imaging (MRI) and surgery,” says Dr. Benson.

Other possible causes of sudden (acute) hind limb weakness in a dog:

Dr. Benson explains that hip and knee problems, such as cruciate ligament injury and hip dysplasia, can present with what appears to be sudden-onset weakness in a dog’s back legs.

You must contact your veterinarian immediately if you notice this kind of symptom.

Dr. Benson is regularly consulted by many media outlets including ABC, NBC, FOX, The Wall Street Journal and The New York Times to provide pet health advice to pet parents nationwide.