Wobbly Hedgehog Syndrome as the waste-bin diagnosis

Wobbly Hedgehog Syndrome might just be the most wellknown diagnosis in hedgehog species, especially in species that are in captivity. But the diagnosis is also grossly overused and misused for a lot of health issues that might have a very different cause. With veterinarians often lacking the specialty knowledge on hedgehogs, they might overlook issues related to ear infections, tumors and even a far less known diagnoses called IVDD. So what are the differences and how can we safely and accurately diagnose WHS?

Wobbly Hedgehog Syndrome

This illness is well-known amongst enthusiasts, but still, people hardly know anything about it besides the name. Wobbly Hedgehog Syndrome is an illness with an unknown cause. It is speculated it might be genetic or caused by a lacking diet, but no studies on the subject come with concrete conclusions. What we do know about WHS is that it affects the brain. Lesions in the brain It is described as a decrease in myelin in a bilateral, symmetrical spongy shape from multiple sites in the central nervous system including the cerebellum, medulla oblongata -the part that connects the brain stem to the spinal cord- and the spinal cord. Nerves outside the central nervous system may also be affected.

Due to these lesions in the brain, the mobility of the hedgehogs starts to decrease. This begins with tilting its head and a loss of muscle strength in the hind legs. It progresses over a time period of 9-15 months and hedgehogs generally pass away 18 to 25 months after onset of the first symptoms.

There is no cure against WHS due to the lack of a known cause. Treatment consist of pain treatments and sometimes mobility aids, but ultimately leads to palliative care with euthanasia when living conditions become too heavily compromised. With the unknown cause, also comes a lack of possibilities to properly diagnose WHS. Currently there are two options to diagnose WHS:

1. Ruling out options: Ruling out health issues with similar symptoms like ear infections, brain injury, neurological issues, intervertebral disc disease, etc. Only after ruling out every other possible health issue, a WS diagnose can be safely given to provide palliative care for the hedgehog.
2. Autopsy: A diagnose can be given through autopsy after the hedgehog has passed away. The hedgehog’s brain will be examined to locate lesions in the brain. If these lesions are found in the parts where WHS usually affects the brain, a diagnoses can be given to conclude WHS.

More information about WHS can be read on this page about WHS & IVDD.

Intervertebral Disc Disease

Intervertebral disc disease is a damage in the cervical and lumbar vertebrae, leading to degeneration of the cartilage and jelly core of the affected intervertebral discs, protrusion of disc material and mineralization of the jelly core. The disease isn’t very well-known and often overlooked due to lack of knowledge on the subject both by owners and rescues of the species as well as veterinarians. IVDD can be found in hedgehogs of all ages, but is more common in older hedgehogs.

Due to the damage in the vertebrae, symptoms may include increasing protrusion of the hind legs, inability to empty the bladder, loss of position awareness and ultimately paralysis. The onset is very slow, much like the case in WHS and with the onset of symptoms often being in older hedgehogs, it can easily be confused with WHS.

There is no cure for IVDD, but treatment with corticosteroids can show a temporary improvement. Ultimately, treatment would focus on palliative care with euthanasia when living conditions become too heavily compromised. There are two ways to diagnose IVDD:

1. MRI scan: An MRI scan of the spine, focussing especially on the cervical and lumbar vertebrae, can conclude IVDD. However, these don’t always show damages of the vertebrae.
2. Autopsy: A diagnose can be given through autopsy after the hedgehog has passed away. If damage on the cervical and lumbar vertabrae is found, with or without disc mineralization, it can conclude IVDD.

More information about WHS can be read on this page about WHS & IVDD.

Ear infection

Ear infections are very well-known and often properly diagnosed and treated. The symptoms are relatively easy to determine, and yet, it is also very often mistaken for WHS and vice versa. Ear infections however set on and progress very quickly, leading to severe symptoms in mere days. Without proper treatment, ear infections can also lead to an early death. Untreated ear infections that heal on their own can return more severe the next time, especially if the infection is chronic.

Hedgehogs of all ages can contract ear infections. It is a syndrome name, meaning its a name used or several health issues that are very similar and have a similar cause. Ear infections can be placed in any part of the ear: outside and inside of the head. The symptoms set on quickly and progress quickly and include tilting of the head, shaking the head, developing a wobbly gait, falling to the side, walking in circles and many more depending on the exact infection. Because of these symptoms, it is often mistaken for WHS and left without treatment. Some of these hedgehogs recover on their own, but a lot of hedgehogs are left to a different fate: an early death.

Ear infections -most of the times- is easily treated with antibiotics. Sometimes a longer treatment is needed and in severe cases the hedgehog might need IV-fluids and syringe feeding to survive due to a loss of energy and mobility.

Neurological issues

Neurological issues are alterations of the brain, leading to permanent behavioral issues and mobility issues, that can be very similar to WHS. And that is exactly why some neurological issues are mistaken for WHS. Neurological issues can be genetic and thus have a very early onset, developing slowly into more severe behavioral and mobility issues. Neurological issues can also be caused be a chronic lack of enrichment, in which case the symptoms start when the hedgehog is older and become more severe over time.

Because of this, hedgehogs can develope neurological issues at any age. It often has a very slow progression, which is similar to WHS. Neurological issues is also a syndrome name, meaning it describes several health issues with similar symptoms, though not always the same cause. These are two main causes for neurological issues that are often seen in hedgehogs, especially in captivity:

1. Genetic neurological issues: Neurological issues that are caused by a genetic mutation often display symptoms from a very young age, in which they progress slowly over the course of several months. These neurological issues cannot be cured and often need additional care to aid them in their movement. Sometimes -when symptoms progress into severe cases of immobility- they will need syringe feeding. A lot of the times these hedgehogs do have an early death compared to it’s healthy relatives.
2. Neurological issues caused by neglect: Neurological issues can also be caused by severe chronic lack of enrichment, which is a form of animal neglect that’s often grossly overlooked. A lack of enrichtment through not providing toys or space to run around and dig and eat insects, can cause ‘neurotypical behavior’. Animals display this sort of behavior because they have such a lack of enrichment that they look for ways to replace the needed enrichment. They start to sway their heads or circle around their enclosure in the exact same pattern constantly. Sometimes they can start to bite on bars of their enclosure or other items in their enclosure which usually is uncommon for the species. This behavior can alter their brain if not tended to properly, turning neurotypical beahvior into a permanent neurological issue. These hedgehogs often do not pass away early and live out their lives with this altered behavior.

Neurological issues are sometimes diagnosed through scan of the brain, but more often then not they are diagnosed just by observing the symptoms (their behavior). Another way of diagnosing neurological issues is to look at their enclosure and take steps to enrich the enclosure to see if the behavior changes. Sometimes even changing their diet to observe a change in behavior. But often times, neurological issues are overlooked and confused with other health issues including WHS. This is due to the common symtoms of head tilting, head swaying, running in circles, constantly sniffing the air, self-mutilation and other similar symptoms.

Tumors

Tumors in the skull are very common in hedgehogs. Some are more visible on the outside of the skull, but some are placed within the skull and inivisible. Cancer in general is very common in hedgehogs, but tumors in the head are often left undiagnosed until after a hedgehog’s passing. The tumors can build up pressure inside the skull, creating a range of secundary health issues like mobility issues and behavioral issues. The first category of symptoms leading to the hedgehog’s untimely death.

Tumors can sometimes be removed through surgery or treated with medication, but a lot of the times the treatment is focussed on palliative care with euthanasia when living conditions become too heavily compromised. Hedgehogs can develope tumors at any age, but they are more common in older hedgehogs. The symptoms include a loss of mobility, bulding eyes, inability to urinate and even progressing to complete paralysis and ultimately death.

Veterinary knowledge

With all this information, you can see why having basic knowledge of a hedgehog’s possible health issues is very imporant. As an owner and as a rescue as well, to be able to observe the first symptoms of health issues and to be able to properly diagnose and get the needed treatments. But what’s also important is to find a veterinarian that has the proper knowledge on hedgehogs, including what is WHS and how it can be diagnosed. However, even with a veterinarian that does not have the proper species specific knowledge, as the owners of the animal you can be your hedgehog’s voice in letting the veterinarian rule other options out before diagnosing WHS. It can save their life more often then not. And even when it turns out to be WHS after ruling everything out, your hedgehog has a much better chance on getting the right palliative care.

Articly by Judith Dunkirk.