There is an article in the online news media today (24th August 2024) about a female mountain lion in Colorado, USA, which was seen staggering around with paralysed hind legs. The journalist said that the cat suffered from “staggering disease”. That’s a generic term which doesn’t specify the virus causing it.
But in this instance, they are referring to a study about this particular mountain lion which was sedated and shot in the chest in order to preserve their brain, which was a form of euthanasia and I’m not sure why they couldn’t have simply euthanised the animal in the usual way but anyway.
They discovered that the cougar was suffering from a variant of the rustrela virus, called Rubivirus strelense, or RusV. It was first discovered in various mammals and was named after the Strelka River in Russia where it was initially identified.
The research surrounding this disease is at an early stage. It has been detected in various animals including this Colorado mountain lion. It’s also been detected in rodents and bats in Europe and its potential impact on human health is still being investigated. More research is required.
In 2021, researchers discovered RusV in several mountain lions in California making it the first instances where this virus was identified in North American wildlife. The study indicated that the virus might be more widespread among wild mammals that had previously been thought. However, at this time we don’t know the impact that this virus has had on wildlife. There’s been no clear indications that it causes significant illness or mortality but of course we can see, in this mountain lion, how destructive it is.
The Colorado mountain lion referred to was discovered on May 12, 2023. Colorado Parks and Wildlife received a report from, I guess, a member of the public about a one-year-old free ranging female mountain lion who had been seen in a residential area of Douglas County. She was reluctant to rise and had a markedly decreased capacity to move and bear weight on her hind legs.
She was depressed but was still responsive to stimuli. The study (citation below) indicated that the RusV variant within this mountain lion had diverged from those previously described in Europe. The scientists agreed that the cat was suffering from “staggering disease”.
They concluded that the “causative role for RusV is likely”. That indicates that they are not completely sure but it appears this was a pretty certain case of this virus affecting this cat. There are no other reports of this virus affecting mountain lions in Colorado but that doesn’t mean it hasn’t happened.
Florida 2019
In fact, I can remember writing about the Florida panther, a specific sub-species of mountain lion living in Florida which I believe now is more generic because the Florida panther was inbred and they had to inject genetic diversity into that small population of about a hundred cats by importing cougars from the West.
Within that population they discovered some individuals staggering and decided it looked like an epidemic of feline leukomyelopathy which also affects bobcats. That was the diagnosis at the time and I didn’t see any follow-up articles about it but I wonder whether it is possible that these cats were suffering from the same disease of RusV? It looks entirely plausible because the symptoms are very similar with ataxia (lack of coordination due to the effect of the virus on the brain).
More: What is ataxia in cats?
Tip of iceberg
The American Veterinary Medical Association say that the virus lasts for a few days to a few weeks but it can linger for more than a year. It would appear that some wild animals are dying of starvation having contracted the disease.
Dr. Karen Fox, a wildlife pathologist at Colorado State University, and the lead author of the study I refer to on this page, remarked in a conversation with National Geographic, that “Traditionally when we find diseases, it means you’re the tip of an iceberg, and there’s a bunch more you’ve missed over time.”
That’s the argument: there are more animals including wild cats out there with the disease.
| Fox, K. A., Breithaupt, A., Beer, M., Rubbenstroth, D., & Pfaff, F. (2024). Rustrela Virus in Wild Mountain Lion (Puma concolor) with Staggering Disease, Colorado, USA. Emerging Infectious Diseases, 30(8), 1664-1667. https://doi.org/10.3201/eid3008.240411. |
Borna disease virus
And I would like to add another point here which is that there is another virus which causes similar symptoms and also described as ‘staggering disease’. Staggering disease in cats is typically associated with a viral infection caused by Borna disease virus (BoDV-1). It’s a neurotropic virus that can lead to severe neurological symptoms. It was first recognised in Europe particularly in Germany where it affected cats. It causes similar symptoms to RusV such as ataxia, behavioural changes, seizures, head tilt and a lack of coordination and importantly staggering. It affects the brain and central nervous system. The disease is often fatal and there is no specific treatment available.
Domestic cats
As of the latest research, there have been no documented cases of domestic cats suffering from Rubivirus strelense (RusV). The virus has primarily been detected in wildlife, such as mountain lions and other mammals, and there is limited information on its impact on domestic animals, including cats.
Most studies on RusV have focused on its presence in wild animal populations, and the implications for domestic animals remain largely unexplored. Since the virus is still relatively newly identified, ongoing research is needed to determine its potential impact on different species, including domestic cats.
If domestic cats were to be affected by RusV, it would likely be reported in future studies or veterinary cases as the scientific community continues to monitor and investigate this virus. However, as of now, there are no confirmed cases of domestic cats being infected with RusV.
Full list of viruses causing staggering in cats
Several viral infections in felines can lead to neurological symptoms, including staggering or ataxia. Here’s a comprehensive list of feline viruses known to cause staggering:
1. Feline Infectious Peritonitis (FIP)
- Cause: Feline coronavirus (FCoV)
- Description: FIP is a fatal, immune-mediated disease that occurs when a benign feline coronavirus mutates within the cat’s body. It can lead to a “dry” or “wet” form, with the dry form affecting the nervous system.
- Neurological Symptoms: Ataxia, staggering, seizures, behavioral changes, and other neurological signs.
- Affected Areas: Brain and spinal cord.
2. Feline Panleukopenia Virus (FPV)
- Cause: Feline parvovirus
- Description: Also known as feline distemper, this virus primarily affects kittens, causing severe gastrointestinal issues, but it can also affect the brain, leading to cerebellar hypoplasia.
- Neurological Symptoms: Staggering, uncoordinated movements, tremors, and difficulty walking. Kittens infected in utero or shortly after birth may have permanent neurological deficits.
- Affected Areas: Cerebellum, leading to ataxia.
3. Feline Leukemia Virus (FeLV)
- Cause: Feline leukemia virus (a retrovirus)
- Description: FeLV can lead to a variety of health problems, including immunosuppression, anemia, and lymphoma. In some cases, it can also cause neurological symptoms.
- Neurological Symptoms: Ataxia, paralysis, seizures, and other neurological issues can occur, especially if the virus affects the central nervous system.
- Affected Areas: Central nervous system (CNS).
4. Feline Immunodeficiency Virus (FIV)
- Cause: Feline immunodeficiency virus (a retrovirus similar to HIV in humans)
- Description: FIV affects the immune system, making cats more susceptible to various infections, including those that impact the nervous system.
- Neurological Symptoms: Staggering, behavioral changes, seizures, and ataxia can develop in advanced stages, particularly if secondary infections involve the CNS.
- Affected Areas: Brain and spinal cord, secondary to opportunistic infections.
5. Feline Herpesvirus (FHV-1)
- Cause: Feline herpesvirus type 1
- Description: Primarily known for causing respiratory infections and ocular issues, FHV-1 can occasionally cause neurological symptoms if it spreads to the brain.
- Neurological Symptoms: Ataxia and other CNS signs are rare but can occur, especially in cases of severe systemic infection or immunosuppression.
- Affected Areas: Central nervous system, though this is uncommon.
6. Borna Disease Virus (BoDV-1)
- Cause: Borna disease virus (a neurotropic virus)
- Description: BoDV-1 is a virus that primarily affects the nervous system, leading to severe neurological symptoms in infected animals, including cats.
- Neurological Symptoms: Ataxia, staggering, seizures, abnormal behavior, and other signs of encephalitis.
- Affected Areas: Brain, particularly the limbic system, leading to behavioral changes and motor dysfunction.
7. Feline Spongiform Encephalopathy (FSE)
- Cause: A prion disease similar to Bovine Spongiform Encephalopathy (BSE) in cattle.
- Description: This is an extremely rare condition caused by prions, leading to progressive neurodegeneration.
- Neurological Symptoms: Ataxia, staggering, behavioral changes, tremors, and ultimately death.
- Affected Areas: Brain, leading to spongiform changes.
8. Feline Parvovirus (Cerebellar Hypoplasia)
- Cause: Feline parvovirus infection during pregnancy or in newborn kittens.
- Description: This condition results from the virus damaging the developing cerebellum in utero or shortly after birth.
- Neurological Symptoms: Permanent staggering, ataxia, tremors, and uncoordinated movements. Affected cats typically exhibit symptoms from birth or shortly thereafter.
- Affected Areas: Cerebellum.
Summary
Staggering in cats can result from a variety of viral infections, each affecting the nervous system in different ways. While some of these conditions lead to acute and severe symptoms, others may cause chronic or lifelong neurological deficits. Diagnosing the specific cause requires careful clinical evaluation, including blood tests, imaging, and sometimes more advanced diagnostics like cerebrospinal fluid analysis or viral PCR tests.
Source of this section: ChatGPT (what else?). This is how websites are being bypassed. I do it myself. I wonder how long many of these websites will hold out for? I can see the internet shrinking quite fast.
Interesting how many viruses can cause the neurological symptom of staggering.
In response to Tamara, some things can be worse than death. Keeping an incapacitated wild cat alive in captivity for the sake of science might be one of them.
Yes, good point. For me it is very upsetting to see such a superbly athletic animal as the puma reduced to staggering and starvation. It is a cruel world. Thanks for the comment.
Disgusting to shoot her. Seems to me they would learn more by keeping the animal alive than killing it. I remember when parvo first hit cats then jumped to dogs 1979-1982. Cats eventually became immune to parvo but dogs did not. Had they studied cats more maybe they could have figured out a way for dogs to become immune instead of just making a vaccine. They haven’t given one big cat the chance to get well from staggering disease, they immediately kill them for their brain. What they will do is infect 1000’s of mammals, kill them, dissect them and universities will get billions of dollars to do it.
Cows have been getting this staggering disease for years, they call them downers and they have to be destroyed. Do they study them, no. They don’t even bother to take their brains.
I remember in the late 60’s my brother found a squirrel with staggering disease. Animal control picked it up, it was killed for it’s brain to test for rabies which came back negative. But they never told us what the squirrel had.
My point is why not study the big cat and give it life support to see if it can beat the disease.
Thanks Tamara. Good comment.