Inmuno-mediated polyneuritis in a kitten

Here you can see the video of this kitten at presentation. He’s a 6 weeks, unvaccinated kitten presented for  progressive difficulties walking to the point he was unable to walk at all.

You can see he’s bright and alert, responsive, wanting to interact but he’s very weak. He can’t hold his weight on the hind limbs and he’s very shaky when walking: this is the main sign of weakness on this cat. This cat is non ambulatory tetra paretic. The 4 limbs are affected and he’s unable to take more than 5 steps without support.

What is a polyneuritis

Poly: multiples

Neuro: nerves

itis: inflammation

So the word says it all: inflammation of multiple nerves, on these cases the nerves of the limbs.

Why haven’t you heard about polyneuritis in kittens?

There is not much published yet regarding this condition. Which means
that we might be all talking about different diseases with a similar
clinical presentation. Few papers have described this condition but have
all reported slight different findings and treatment.

The diagnosis is made via electrodiagnosis and nerve biopsy and this
is where we might find differences on published research papers.

What’s the good news? Some resolve spontaneously, others respond really well to immunosuppressive doses of steroids.

Clinical presentation of polyneuritis in kittens

These cases are presented in very young kittens, always less than a year old and sometimes even only weeks. These cats have a slow progression but tend to arrive as an emergency when the cat can no longer walk. The first clinical signs tend to be difficult to recognize as the cat is just more clumsy or “tired” and doesn’t want to jump.

On the neuro exam we have an ascending lower motor neuron disease, with the hind limbs more affected than the front. Abnormal proprioception and reduced or absent spinal reflexes. The severity of the neurological deficits are related to the timing of the exam within the progression of the disease.

Click here for the full reference

Juvenile-onset motor polyneuropathy in Siberian cats

Kelly C. Crawford, Dayna L. Dreger, G. Diane Shelton, Kari J. Ekenstedt, Melissa J. LewisFirst published: 11 November 2020



Polyneuropathies are infrequently described in cats. There is a genetic predisposition in several breeds.


To clinically characterize a novel motor polyneuropathy in a family of Siberian cats.


Thirteen closely related Siberian cats, 4 clinically affected and 9 clinically unaffected individuals.


Retrospective study. Clinical data and pedigree information were obtained from the medical records and breeder. Electrodiagnostic testing and muscle and peripheral nerve biopsy samples were obtained from 1 affected cat. Follow-up information was obtained for all affected cats.


Onset of signs was 4 to 10 months in affected cats. Clinical signs were progressive or waxing/waning neuromuscular weakness (4/4), normal sensory function (4/4), and variably decreased withdrawal reflexes (3/4). All cats returned to normal neurologic function within 1 to 4 weeks. All cats had a recurrence of weakness (3/4 had 1 recurrent episode, 1/4 had 3 relapses) from which they recovered fully. In 1 cat, electromyography and motor nerve conduction studies showed multicentric spontaneous activity, normal motor nerve conduction velocity, reduced compound muscle action potential amplitude, and polyphasia. Histologic evaluation of muscle and nerve in that cat showed mild muscle atrophy consistent with recent denervation, endoneurial and perineurial edema, and mild mononuclear cell infiltration within intramuscular nerve branches and a peripheral nerve. Pedigree analysis suggests an autosomal recessive mode of inheritance, although neither a genetically complex/polygenic condition nor an acquired inflammatory polyneuropathy can be ruled-out.

Conclusions and Clinical Importance

We describe a motor polyneuropathy in juvenile Siberian cats characterized by self-limiting weakness with potential relapse.