CBS Syndrome (Calcified Bulla Syndrome/Walled-in Otitis Media - Symptoms and Care

[Wiebke]

Introduction
1 General information and practical advice on CBS
- What is the difference between a syndrome and a symptom?
- What is CBS (calcified bulla syndrome)?
- How can CBS be diagnosed?
- What is causing CBS and how can I minimise the risk?
- Vet care and customer rights with newly bought guinea pigs
- Support and care information resources
2 Leaflet with list of CBS symptoms and comparison x-ray pictures
3 Neurological and CBS symptoms that can have different causes
4 Home care tips, welfare and end of life considerations


Introduction

CBS is a newly identified complex of mostly neurological but also some physical symptoms that your vet will not be aware of. It is currently making the rounds especially in North America.
In European and other countries it is usually diagnosed as a walled-in otitis media (middle ear infection) and is much rarer.
Please note that the middle ear capsule does gradually calcify in older guinea pigs without causing major symptoms. What distinguishes CBS syndrome is that the calcification happens at a much younger age and in a much quicker way in combination with other symptoms.

This is the reason why we include original the original leaflet and pictures from Saskia Chiesa from Los Angeles Guinea Pig Rescue by her wish and with her express permission in order to give any diagnosing vet of yours the tools to check for it and to be able to identify it.
Please bookmark the link or copy the text when seeing a vet for potential CBS.

The full story of how Saskia Chiesa and her vet, DR Nenn, have discovered CBS syndrome can be read in Guinea Pig Magazine issue 66, January 2022 where it has been first published and where the copyright remains with.
Guinea Pig Magazine website: Home

Symptoms of CBS can overlap or be very similar to other neurological or non-neurological health issues. For this reason, we have in Part 2 of this thread included a discussion of other neurological problems and a list of common CBS symptoms that can have other causes.


1 General information and practical advice on CBS

What is the difference between a syndrome and a symptom?
A syndrome means that it is not a single symptom but a distinct combination of sometimes seemingly disparate symptoms and a distinct progression of the illness that has just one single cause.
Every single symptom on its own can also have other causes; that is why you should be extremely careful when throwing CBS into the round on social media or if you suffer from pet anxiety.

Please also be aware that CBS is NOT good news and is bound to greatly upset the owner, so don’t use your newly gained knowledge to show off of for your own gratification. Be sensitive and kind when introducing it into a discussion where there are at least 2 or more of the characteristic symptoms present. This is not a health issue to play one-upmanship with! An x-ray is very expensive, so make sure that any mention of CBS is justified because many owners will struggle to pay for it.

What is CBS (calcified bulla syndrome)?
CBS is caused by quite a wide range of un- or undertreated bacteria moving eventually into the middle ear capsule, causing chronic middle ear infection and walling it off as the bone becomes affected.
This causes intense vertigo and some pain in the jaw, which is as the bottom of the most commonly seen balance and mobility issues. It can cause repeated or seemingly resistant URI, nasal discharge, increased eye discharge and even blindness, affect the ears and also very often impact on the jaws (making chewing difficult/weaker) and then as a secondary complication can in some cases cause dental overgrowth problems with the need for support feeding and regular dentals with secondary long term digestive issues if the diet is unbalanced as a result of the piggies not eating enough hay/grass fibre in their diet (either directly or as a powdered recovery formula).

CBS can range from only very mild symptoms that require regular vet checks but no special medical treatment to an aggressive sudden onset and progression form that can totally incapacitate a guinea pig in a matter of just a few weeks and require euthanasia. The combination of symptoms can vary but there is a certain characteristic progression especially in the later stages that is distinct from other neurological problems.

The problem is that once the bacteria have walled themselves in, antibiotics struggle to reach them. Treatment and support care has to mainly focus on easing and addressing the symptoms as much as possible to provide quality of life for as long as normal species behaviours and a zest for life are possible and expressed.

How can CBS be diagnosed?
CBS can be easily diagnosed on an x-ray because the middle ear capsules (the two large bullas at the back of the head behind the eye sockets (see reference x-rays attached to the leaflet below) appear as light blobs and not as rings with a dark centre.

CBS is not an instant killer; the slow version can take months or years to progress while the fast onset will still take several weeks with a quite noticeable quick deterioration of balance/neurogical symptoms and increasing mobility issues before it is time to euthanize.
Please make sure that you can afford the vet fees to at least spare your CBS piggies any unnecessary suffering!

What is causing CBS and what can I do to minimise the risk of it developing?
CBS is very much a human generated problem caused by the current commercial mass breeding and sales practices that provide an ideal breeding ground for bacteria in groups of highly stressed young guinea pigs with a not yet fully developed immune system in close proximity where exposure and contagion is great but medical care is not provided.

While other bacteria can cause the syndrome as well (especially various streptococcus or pneumoccus), CBS is currently typically seen in pet store guinea pigs in North America which have been exposed to respiratory bacteria (URI). By far not all of them will ever develop CBS or show the full symptoms of a URI but even a small load of unrecognised and untreated bacteria can eventually get into the bulla and cause CBS.

CBS can also happen in other countries and continents but it is much less common right now.

If you have newly bought guinea pigs with a constant/frequent sniffle/repeatedly wet nose, raspy or crackly breathing, eyes closed with yellowish/greenish mucus etc., then please see a vet promptly for antibiotic treatment. If symptoms have not disappeared by the end of the course, then ask for another one or a different antibiotic. This is important to make sure that there is no bacterial load left.

What are my customer rights in terms of vet care in newly bought guinea pigs?
If you see a vet with guinea pigs with a potential respiratory infection (URI) within 2-3 weeks (UK) / 30 days (North America) of purchase you can reclaim any vet cost/treatment cost by producing your sales receipt together with the vet bill. This is your right because you have in effect been sold faulty ware.

If necessary insist to see the manager and please DO NOT let yourself be fobbed off in selling your guinea pigs back to the shop for the duration of treatment because that will deprive you of your ownership and any legal standing against the shop to get your purchased guinea pig back. Sadly it is a rather common trick especially in the USA and Canada.
More information in this link here:

Where can I get support for the care of guinea pigs with CBS?
The Guinea Pig Forum can help you with the potential identification of CBS and can support you with ongoing practical care tips for your particular symptoms and friendly moral support once it has been diagnosed, but if you want more experienced help, please join Saskia’s USA-based Wheekers! group on Facebook.
Wheekers! Guinea Pig Group Saskia, volunteers and Friends of LAGPR

For practical support care at home and ethical end of life/euthanizing considerations please see the last chapter of this guide.

 

[Wiebke]

2 Leaflet with list of symptoms and comparison x-ray

We have included the text of her own leaflet below as well as reference x-rays courtesy of Los Angeles Guinea Pig Rescue (which is run by Saskia Chiesa) in this guide so that you can show the medical information to your vet since they will most likely not have heard of it.
This leaflet and the reference x-ray pictures are shared with the express permission of Saskia Chiesa.


Calcified Bulla Syndrome (CBS): Medical Information
This is the paper I hand out with Dr Nenn’s blessing as she has read it and has been beside me with every discovery we have made this past year.

Reference x-rays for comparison
The walled-off bullae are very distinctive on an x-ray of the head and can be quite easily (if not cheaply) diagnosed this way. They appear as bright blobs behind the eye sockets instead of as healthy rings. The difference is very striking, even in guinea pigs with only mild symptoms.

Healthy transparent bullae vs. walled-off diseased bullae (middle ear capsules)


Symptoms
Not all these symptoms have to present for the syndrome to be diagnosed.
One or two symptoms are often enough to create a suspicion and a simple head x-ray will confirm the diagnosis. The more symptoms your guinea pigs presents with, the higher the chance the animal will be a special needs patient.

Frequent or chronic Upper Respiratory Infections (seemingly antibiotic resistant)
Pneumonia
Runny Nose - One or both nostrils
Head tilt
Drooping lips on one side
Missing blink reflex
Involuntary twitching of the ear
Extreme sensitivity of the ears

Overactive production of white grooming liquid – usually in one eye

Ulcerated eye
Blindness one or both eyes
Deafness one or both ears (Do the clap test right behind your pig so they can’t see you doing it)
Vertigo
Wobbling
Going in circles
Sneezing
Ear twitches
Weak bite strength (often characterized by the inability to put food in the mouth despite trying)
Leaky eye, one or both sides
Falling over
Molar issues – recurring dental work
Loose stool from recurring antibiotic use, including permanent damage

Causes
The cause appears to come from untreated URI’s or URI’s not treated on time.
A lot of babies for instance purchased from one of the big name pet stores suffer from URI that do not always get immediate treatment or receive treatment when it is too late. Owners may think the URI symptoms are an allergy for instance.

The nose, throat and ears are all connected. In an animal that does not receive timely antibiotic treatment, the bacteria that cause CBS are free to travel and make their way to the middle ear to settle in the bulla. Once there, antibiotics will not be able to reach and the bulla responds to the invaders by creating a wall of calcium that is very easy to spot on an x-ray.

How does this affect the infected guinea pig?
These symptoms happen because the antibiotics are never quite able to kill the bacteria as they hide in the bulla where they multiply and circulate freely through the nose and throat area. I believe that this is why we see an antibiotic work for just a few months at most before a URI returns.

The raging infection will attack the ears mimicking an ear infection - I say mimicking because a key symptom of a “real” ear infection is not present since the smelly pus coming from the ear and often a head tilt is missing. A “regular” ear infection usually will respond to medication and CBS does not.

The calcium build up in the ear can cause a head tilt. Some tilts are more severe than others. These cause vertigo in some cases where the animal loses balance, sways, goes in circles and falls over. They often learn to live with these symptoms so the severity may decrease in time. Sometimes an animal is observed wobbling its head in an up and down manner and or side to side and also holding its head up high. This is caused by blindness and the pig’s attempt to compensate and cope with the disability.

Eating – Teeth
In extremely severe cases, the facial nerve on the side the head is tilting towards becomes affected and this causes dry eye as the blink reflex is no longer there. An inability to eat properly could result if the jaw muscle is also affected. Hay is likely the first thing the pig will stop eating, as the jaw strength needed to grind the rough hay has is absent. The pig will likely gravitate to softer foods and will have a hard time chewing food. Observe your pig eating. Are they just chewing endlessly or swallowing the food and dipping down for the second bite fairly fast?

This is quite a serious affliction that a lot of guinea pigs are suffering from without their owners being aware.

 

[Wiebke]

Seizures - symptoms and causes
Seizures, usually defined as your guinea pig suddenly falling to one side and becoming unresponsive while making repetitive twitching movements, are a symptom rather than a diagnosis in itself.

Possible causes of seizures are:
- Epilepsy in guinea pigs (rare!)
In humans we often associate seizures with epilepsy, and although guinea pigs may suffer from epilepsy this is rather rare, and other causes of seizures should be explored and ruled out by your vet before this default diagnosis is settled upon. Some of the main causes of seizures are mange mite infestation, heat stroke, and poisoning.

- Mange mites (trixacarus caviae)
Mange mites are the most harmful of all guinea pig skin parasites, burrowing into the skin and causing severe irritation. Mild cases that are identified and treated immediately may resolve with no further problems than skin lesions and fur loss; however, severe cases of mange mites may result in seizures. If you suspect mange mites, a veterinary diagnosis is essential, and the vet will take a skin scrape to confirm the presence of mites in the skin. Mange mites can be treated with ivermectin, either as a spot-on treatment such as Xeno 450 (UK), where 3 doses are given, 2 weeks apart- or, in severe cases of mange mites, ivermectin injections may be your vet’s preferred treatment. It is worth noting that as the mites in the skin die, they may trigger a very dramatic immune response, and symptoms may initially get worse before they get better- this is the stage at which seizures are most likely to occur, especially in heavily infested animals from bad situations often further weakened by other forms of neglect such as poor diet and stress. Do NOT home treat on spec with pet shop products!
More information:
New Guinea Pig Problems: Sexing & Pregnancy; URI, Ringworm & Parasites; Vet Checks & Customer Rights
Guinea Lynx :: Mange Mites

- Heat stroke
Heat stroke may also cause guinea pigs to suffer seizures, as the brain overheats when the animal fails to regulate their body temperature. Guinea pigs are extremely prone to overheating, given their short legs, plump body shape, and inability to sweat. Even in the UK cases of heatstroke occur every summer at comparatively moderate temperatures because even half an hour in an exposed place or a hot room on a summer day can cause a guinea pig to overheat.
If you believe your guinea pig may be suffering from heat stroke, this is a veterinary emergency. The first sign may be lethargy, but this can progress to seizures and death very quickly. Emergency first aid should involve moving the piggy to the shade and a cool place, while gently cooling by sponging them with tepid, not very cold, water- especially the ears and feet, where most heat will be lost from, and offering small amounts of lightly chilled, not very cold or frozen, vegetables and drinking water. An emergency vet check is then essential to ensure no lasting damage has been done.
How to spot heat stroke, what to do and how to best prevent it:
Hot Weather Management, Heat Strokes and Fly Strike

- Poisoning
Poisoning is another possible cause of guinea pigs suffering from seizures. Pesticide poisoning is the most obvious source of neurological poisoning in many animals, but the most likely source of poisoning is your guinea pig accidentally eating common garden plants which contain toxic compounds. Many garden plants are toxic, and some may cause gut disturbances, affect the heart, or damage the liver- but some are acutely neurotoxic, and even small amounts may cause seizures, disorientation, uncoordinated movements, or paralysis. Some common examples of neurotoxic plants are rhododendron, cycads, horse chestnut, morning glory- but also some plants that are toxic to the liver and kidneys, such as lily plants, may also induce seizures where the liver and kidney damage causes metabolic waste products to accumulate in the blood and affect the brain function.
Suspected poisoning is of course a veterinary emergency, and it should be noted here that guinea pigs cannot vomit, so cannot expel any ingested poisonous food in the same way as other species can.
List Of Life And Death Out-of-hours Emergencies


E.cuniculi (Encephalitozoon cuniculi)

What is e.cuniculi?
E. cuniculi is a tiny single-celled parasite, most commonly affecting pet rabbits. While wild rabbits may carry the disease, they usually do not show symptoms and are less likely to be infected or infectious than pet rabbits. The parasite affects the nervous system, and also the kidneys. Baby rabbits who are born to infected mothers may also show eye damage.

How is it transmitted?
E. cuniculi is spread to guinea pigs primarily by contact with rabbit urine, as infected rabbits shed parasite spores in their urine. The parasite is very difficult to get rid of, so rabbits and guinea pigs should not share play areas, toys, bedding, cages etc. Thoroughly disinfecting potential rabbit urine contaminated items with a veterinary grade product such as F10, or even wiping floors and cages with bleach before rinsing thoroughly, is recommended, and if you have both rabbits and guinea pigs, always handling and feeding the guinea pigs first, and thoroughly washing and disinfecting your hands after feeding, handling or cleaning out rabbits, is also important.

Symptoms
Symptoms of E. cuniculi may be very similar to symptoms of inner ear infections, characterised initially by a head tilt and loss of balance. If the disease progresses untreated, seizures, paralysis and ultimately death may occur. Contact with rabbits is often the only indicator that this parasite may be an issue for guinea pigs.
If your guinea pig shows neurological symptoms and you have rabbits at home, or your guinea pig has boarded with or been cared for by someone who keeps rabbits, you should make your vet aware of this.

Testing for e.cuniculi
Definitive tests for E. cuniculi in rabbits involves blood or urine tests - however due to the invasive nature of blood sampling in guinea pigs, and the fact that they may be infected by the parasite without shedding infective spores, treatment and diagnosis are more likely to be based on the rabbit contact aspect.

Treatment
Treatment for E. cuniculi is fairly experimental and not always effective, but fenbendazole or albendazole, often prescribed as Panacur, is a recommended treatment that may kill the parasites and halt progression of the disease. Panacur comes in a range of formulations and it is very important that your vet prescribes an appropriate formulation for small animals- such as the medicine formulated for rabbits- at an appropriate dosage for the smaller size of guinea pigs. Beware of buying Panacur online and trying to guess the dosage yourself- this product is also available in formulations for sheep, cattle and horses, so please avoid any quick fix home medicating such as less reputable guinea pig websites may recommend, it could easily end in a fatal overdose! It should also be noted that this medicine does not provide any protection against future infections- it is metabolised in a couple of days at the most- the only protection against e. cuniculi infection, or re-infection after treatment, is scrupulous hygiene and avoiding contact with potentially infected rabbits.
Unfortunately, although treatment may kill the parasites and halt progression of the disease, the neurological damage is irreversible and even when recovered, your guinea pig may still have a head tilt and poor balance and co-ordination. It is important here to be honest with yourself, and discuss with your vet, what the quality of life is if the neurological damage is severe.


Stroke

What is a stroke?
A stroke is an event where blood supply to the brain is interrupted, often either by a blood clot, or a burst blood vessel. Symptoms of a mild stroke may be similar to symptoms of an inner ear infection, or E. cuniculi infection. Your guinea pig may have a head tilt, and appear rather uncoordinated and unable to balance.

How can it be diagnosed?
It is possible that a CT scan may be able to show if there is a clot or bleed on the brain, but realistically this may require sedation that could be risky, and facilities at a specialist exotic referral hospital which may be expensive or not immediately available, and as there is little that can be offered in the way of treatment, even if a stroke is confirmed, it is always worth considering how much you and your pet want to pursue a definitive diagnosis if it will not change the clinical outcome.

Stroke recovery and permanent damage
A mild stroke may be survivable, but leave your guinea pig with some mild mobility issues and a permanent head tilt- perhaps if the face is partially paralysed, adjustments to the diet such as chopping veg smaller, and offering recovery food or mushed up pellets in a syringe, may be required; perhaps removing ramps, steps, and any hard edges your guinea pig might fall against if their mobility and balance is affected.
As with humans, it is impossible to say always what caused a stroke, and if another will occur, or how complete the recovery might be. Be guided by your guinea pig’s quality of life, and your vet, and also by how much time you can realistically devote to nursing and syringe feeding long term, if after a couple of weeks you are not seeing your pet regain some independence.
Practical care tips for stroke survivors: Caring for Older Piggies and Facing the End - A practical and supportive information collection

 

[Wiebke]

2 Home care tips, welfare and end of life considerations

Many of the issues in this guide can sadly not be healed or successfully treated, so has to concentrate as much on your support at home and any necessary - if needed regular - veterinary care and medication for symptomatic relief.

Practical home care measures
At home, simple measures can make a big difference for comfort and minimising the risk of secondary problems for guinea pigs with mobility issues - from getting around to lifting their heads, wether that is arthritis or CBS.
These guides here contain lots of practical care tips as well as tips on what to look out for in terms of complications that arise from restricted mobility and staying more in one place:

Cage and comfort adaptions; monitoring for complications:
Looking after guinea pigs with limited or no mobility
Caring for Older Piggies and Facing the End - A practical and supportive information collection

Weight monitoring and feeding support:
Weight and Weight Loss Explained: BMI, Weighing, Poos and Feeding Support
All About Syringe Feeding and Medicating Guinea Pigs with Videos and Pictures

How to Improvise Feeding Support in an Emergency
Emergency and Crisis Care as well as Bridging Care until a Vet Appointment

End of life considerations
Unfortunately, with all uncurable and progressive problems you may have to face end of life decisions as your piggy' quality of life may gradually or suddenly decline.
If in any doubt, please follow your gut feeling and try to see things from your piggy's perspective if needed. The right time to let your piggy go is when they are no longer able to exercise normal behaviours like moving around and eating on their own, don't give clear signs that they still have interest in life and the will to go on, and when they are clearly in distress or pain that cannot be medically alleviated.

Please do not let your own fears of loss get in the way of your piggy's welfare. If you love somebody, then you will always find the strength in yourself to do what is needed, even where you cannot help yourself or you can organise support for yourself during that time and also support for yourself afterwards - it is out there. You can cry as much as you need afterwards but the knowledge that you have done the right thing for a beloved one will help you in the longer term.
The more you allow your fear of loss to rule you and run away with you, the harder and emotionally more devastating will the aftermath of a pet loss be on you. There is sadly no miracle cure that can magically prolong life or heal your piggy when it comes to neurological problems, but your insistence can easily prolong the suffering of your pet. 'Fair' does unfortunately not come into it - not for your piggy and not for you.

You are welcome to open an ongoing support thread in our End of Life and Bereavement Support Section to help you talk through all the issues so you can make any decisions with a clearer mind and support you during and in the wake of a loss or euthanasia/pts.
End of Life and Bereavement Support Corner

The guide link below will talk you in a sensitive and practical way through all the little and large questions that come up in this situation and will provide help during a very daunting time for you:
A Practical and Sensitive Guide to Dying, Terminal Illness and Euthanasia in Guinea Pigs

Support and pet bereavement resource links for adults, children and guinea pig companions after a loss:
Human Bereavement: Grieving, Coping and Support Links for Guinea Pig Owners and Their Children
Looking After a Bereaved Guinea Pig