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Wiebke's Guide to Poops

Wiebke

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Overview
1 How the Digestive System Works
2 Poo Eating (Coprophagy)
3 Health Monitoring: Weighing vs. Poos Watching

- What does weighing do?
- What does the poop output tell you?
4 Minor Poop Issues
- How to deal with a minor tummy upset
- Funny poops: What do they mean?
- Caked on poops

5 Serious Diarrhoea
6 Impaction
7 Worming: Yes or no?


Wiebke's Guides are a series of articles I have written for Guinea Pig Magazine in 2023 and 2024.
They are there to help you understand how the urinary tract works, learn to spot what is normal and what not and what are the most common health issues connected with it.



1 How the Digestive System Works

Guinea pigs are truly mainly a gut with a big food wheek attached. The digestive system takes up the most space inside the body with a comparatively very small respiratory system tucked into the rather small chest together with the heart.

The caecum part of the gut where the fermentation happens makes by far the largest part of the gastro-intestinal tract: it takes up about two thirds of the whole gut, so it is the part where the food stays longest and where you will find most of the eaten food at any given time. Because the digestive system in guinea pigs is not as effective, the gut is overall comparatively larger and heavier than that of rabbits and makes them less agile.

New research has shown that it takes about 8-30 hours from mouth to anus – it takes about 2 hours for any intake to pass the stomach into the small intestine (duodenum, jejunum and ileum) where it is broken down into smaller particles. But it takes around 20 hours in the large fermentation part of the gut, the caecum, for any nutrition to be passed on towards the exit via the colon and the anus, where it is formed into poos; the latter form together the large intestine.

Most bloating happens in the caecum when the fermentation process derails (the classic bloat) but bloating can affect other parts of the gut, even the stomach as I know from a personal experience.

Some vets now think that the rather ineffective way oral medication is absorbed (meaning that they need comparatively much higher dosages than other animals of comparative weight) could lie in the way food is processed in the caecum. More research will be needed but we will hopefully get some answers in the not too far future.

The gut microbiome is retained by a mucus trap in a groove in the colon. This accounts for the occasional bits of mucus in and around poos or as baffling mucus blobs on the bedding – they are parts of the barrier that have slipped through. A one-off appearance is not to worry (unless your piggy is clearly unwell) but if you see mucus several times within a matter of days, a trip to the vet may be advised; the latter case is however rare.

On the whole, it takes about a whole day (ca. 24 hours) for any food from one end to the other. Food passes fastest with runny diarrhoea (when the fermentation and especially the firming up doesn’t happen) and is usually slowest after GI stasis, heat stroke or severe illness without much food intake for several days.


2 Poo Eating (Coprophagy)

Like a number of other species, guinea pigs eat some of their poos; usually directly from the bum as fresh as possible for a second run through the gut in order to break down further the highly nutritious but tough grass/hay fibre, which makes over three quarters of their daily food intake.

New research has shown that unlike rabbits guinea pigs are coprophages. This means literally ‘poo eaters’. Guinea pigs just eat some of their normal poos for a normal second run through the gut to better their overall fibre, vitamin and trace elements uptake. These re-digested second run poos are officially called coprotrophs in order to distinguish them from those that rabbits and their fellow lagomorphs make. Their special bundles of small fibres that are formed in the caecum are called caecotrophs but are more advanced and effective compared to what guinea pigs produce.

The second run through the gut improves the nutrient absorption from the hay/grass fibre and is crucial for long term health. That is why you see many older piggies that are no longer mobile enough to pick up the poos straight from the anus turn quickly around to pick them up from the floor; they can become rather upset when they cannot find them. The longer a poop is outside the body, the less use it becomes. This happens very quickly and is also the reason why poo soup can only be made from just dropped healthy poos, not ones lying around the cage.

Guinea pigs that are not able to eat their poos, like more majorly impacted boars, guinea pigs with back leg paralysis, very ill guinea pigs or piggies unable to pick up food can experience a decrease in weight, a diminished fibre uptake and a loos of minerals, especially over longer periods.

Coprotrophs (poos from the second run) are usually a touch harder than the no longer needed freshly excreted poos from the first run.

However, this means that some poos that come out at the other end have taken a full two days to get there, not just one day – and that is in a normally working gut. When poo monitoring, this is important to know.
 
3 Health Monitoring: Weighing vs Poop Watching

Watching the poo output and health monitoring by regular weighing are both integral parts for spotting potentially developing illnesses but they do very different thing and you cannot just practice the one and not the other.

What does weighing do?
Firstly, you want to know whether your guinea pig is a healthy weight or not since individual sizes and healthy weight vary a lot more than the relevant literature suggests. By mathematical definition, an average weight only ever includes 50% of the considered subject. This does however not mean that the other half is unhealthy or under-/overweight, as too many owners and sadly also quite a few vets assume that go strictly by average weight but do not take the genetically determined size and natural variation or the differing breed related body shapes into account.

The easiest way to roughly work out the cavy BMI out is by feeling around the ribcage. If you can just about feel the ribs, your piggy is a healthy weight. If can feel every single rib, then a piggy is underweight and if you cannot feel any ribs at all, a guinea pig is overweight. This method works for all ages and sizes irrespective of their actual weight or age. Babies and the real oldies are generally bonier while piggies between 2-4 years tend to be at the height of their life long weight curve.
My Pioden was bordering on underweight at 1500g and could have easily packed another 200g without being overweight while my sisters Hedydd and Heulwen were bordering on overweight at 900g. Yet all three rescue adoptees lived to a very respectable age of 8 years.

Once you have worked out whether the weight on the scales is OK or not, the weekly weigh-in on your kitchen scales will then help you monitor the foot intake. Since you are not using your scales for computing medical dosages, cheap scales from a supermarket or online are perfectly fine.

It is worth keeping in mind that the difference between a full and an empty bladder is 10g and the difference between a full and an empty belly 30-40g. That is why a few grams difference do not matter. We are only talking about weight loss from 50g onward.

The body weight also rises and falls over the course of a day. When you switch to weighing daily with an ill guinea or one you have major concerns about, then please always do so first thing in the morning before feeding since the weight is at its lowest for best day to day comparison and to allow you to plan any necessary support (top up or full on syringe feeding) for the coming 24 hours. Please note that the more often you weigh, the more the weight will jump around. If you have anxiety issue, this can turn into a perfect rabbit hole.

However, the scales do not lie and always give you an up to date feedback on your piggy’s food intake. Since most of it is hay, which you cannot control by eye, the scales are your best ally to get your piggy through an illness/operation recovery and to tailor the necessary support according to their current food intake.

Videos and more in-depth information on weighing and weight monitoring, over- and underweight in these links below:
How To Pick Up And Weigh Your Guinea Pigs Safely (videos)
Weight - Monitoring and Management


What does the poo output tell you?
The poos will tell you roughly how much and what your piggies have eaten a day or two before – especially whether a food group has been left out, whether the digestive system is working or whether there could be a pain issue from outside the gut impacting on it. The plumpness and quality of the poos can also tell you whether you are getting enough feed of the right sort into an ill guinea pig or not.

A little guide to 'poopolpogy' comes in the next chapter.
 
4 Minor Poop Issues

I know that there is a whole ‘poopology’ out there but to be honest, for all intents and purposes the majority of changes do come under the heading of minor tummy upsets.

Healthy poops for comparison
Baby - teenage sow - adult neutered boar (examples are not quite fresh)
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Full boar poop 'sausages' (freshly dropped - you can see the moist sheen on them when compared to dried up poops)
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How to deal with a minor tummy upset
Stop feeding any fresh food for a day and things should normalise again within a day or two. You can offer extra probiotic products or ‘poo soup’ from a healthy companion to help with the recovery.
Because of the way the gut works and re-digests poos, it is advisable to wait at least 24 hours or better 48 hours after the poos have normalised again in a more major incident before you reintroduce fresh food again, one by one veg more with each of the first three meals in order to avoid a relapse.


Funny poops – what do they mean?
Each guinea pig has their own individual poop shape. Boars with descended testicles have the longest, sausage shaped poops due to their stretched anal sac. In boar babies and neutered boars the anal sac is contract so their poops resemble those of sows.

Minor tummy trouble
- Darker, softer poos usually mean that a lot of fresh food has been eaten whereas lighter poops point towards a lack of fresh food.

IMG_5908_edited-1.jpg

- Very minor upsets result in pointed poops, poops with coloured bits mean not fully digested veg. Beetroot poops are purple coloured. Not well digested poops can also have little craters. Please keep in mind that poops dry up the longer they are exposed to air.

Poop with undigested inclusions
IMG_3045_edited-1.jpg

Poop with a calcium pee coating next to a normal one
IMG_3056.JPG

- White powder on a poop can mean a calcium pee made on an already dropped poo.

Soft poops that still have texture
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Post-op poos from the day after are reflecting the operation gap and the chemical cocktail - this is normal for this stage
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- Shorter poos are generally caused by a pain issue outside the gut impacting on the anal exit area where poos are formed. This also goes for larger or longer than normal poos.

Major illness alert
- The poos that should make you take note are noticeably thinner poos – they point towards a reduced food intake.
First poos made after a major GI stasis event
IMG_5905_edited-1.jpg

- Small poops on a string point to a more serious tummy upset and potential drinking issue.

- Tiny poops with a dried mucus crust mean that the piggy has not eaten or drunk much or at all a day ago. This counts as an emergency. Please contact n out-of-hours vet clinic at any time if you can.


When mould is getting to a poop mountain in warm, rather humid weather before cleaning day. The purplish poops are from beetroot, by the way.
IMG_3057_edited-1.jpg


Loose poos right down to ‘cowpads’ that are mushy blobs but still have just about texture count as minor issues as long as they firm up noticeably or full within a day off fresh food.
If that doesn’t happen, or if the problem recurs immediately or regularly, please see a vet. Please be aware that the problem could be located outside the gut but radiate into it (pain in the lower spine from arthritis, the bladder or reproductive tract) or by pushing on the anus area.

Constipation is NOT something that guinea pigs suffer from.


How to remove caked on poos
When poos, especially very soft poos and diarrhea dry up, they become very hard. They can cake onto hairs and skin really tightly.

If they are stuck to hairs, try to cut them off as gently as possible with a pair of scissors. Make sure that the scissors cannot stab into the skin or legs in sudden movements. It is ideally a two person job with one holding the guinea pig and the other performing the operation.

Poos stuck to the skin need softening with water and then careful and gentle scraping off. It may take several rounds of soaking and scraping. With poos stuck under the soles, you may want to stand the piggy in a basin with very shallow baby warm water (5-10mm).
 
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5 Serious Diarrhoea

Any runny output counts as serious diarrhoea and should be ideally seen within a day. UK vets will usually try their best to squeeze in a guinea pig because of the risk of dehydration. Any very apathetic guinea pig with runny diarrhoea counts as a life or death emergency.
If you cannot be seen within that period, please ask what you can do. Electrolyte powder from a pharmacy (dioralyte for the UK, pedialyte for North America) can help. Please follow the instruction on the packet. Please never just squirt any fluid into the mouth or it can go down the wrong way up the nose or into the lungs. A mouthful is about 0.3 – 0.5 ml but a very weak piggy may only cope with a small 0.1 ml sip.

Any dark, stinky fluid combined with apathy and total loss of appetite/thirst counts as a life and death emergency and should be seen at any time of the day or night if you can get to an out-of- hours service for subcutaneous rehydration and round the clock feeding support.
All About Syringe Feeding and Medicating Guinea Pigs with Videos and Pictures
Emergency and Crisis Care as well as Bridging Care until a Vet Appointment
First Aid Kit: Easily available non-medication support products for an emergency
List Of Life And Death Out-of-hours Emergencies

With any serious, persistent or recurring issues, lab tests will be the next step in order to find the culprit so it can be treated appropriately.
Guinea Lynx :: Diarrhea


6 Impaction

About 10% of all ageing boars (neutered or not) will suffer from impaction; i.e. the inability to form poos and to express them properly. It is a progressive issue that is caused by a weakening of the musculature of the back end in the area where the poos are no longer formed and expressed properly.

Impaction can also result in younger boars as one of the rarer neutering operation complications but the most common cause of impaction in younger boars is an unsuitable diet lacking in grass/hay fibre. Thankfully, impaction caused by malnutrition can usually be reversed in younger boars with a correct diet.

Some of the poos from the second run through the gut can still be normal in the earlier stages when only the first run through the gut is affected. The unformed poo mass builds up in the anal sac between the descended testicles and is very stinky. In neutered boars whose testicles have been removed, the mass is just about pea sized and easily dealt with but it is much larger in full boars. Unfortunately, impaction will have to be manually cleared out from every few days to several times a day in the most advanced stages.

Unformed large impaction poops mixed with normal poops
DSCN0247.webp DSCN0268_edited-1.webp
Mild impaction can often be reversed for a time with a very regular, limited and unchanged diet that is mainly hay based. The more clock-like the feeding regime the better. Guinea pigs make use of 12 out of the 15 in the vitamin B complex while rabbits only use 3, so the vitamin B12 supplement should be extended to the whole spectrum. Supplementing with a feeding formula that offers a range of minerals may be considered, especially in the more severe forms.

There are sadly still some horrible impaction care videos making the rounds online. You can find videos showing the correct clearing out procedure in our Impaction Care Guide here: Impaction - How To Help Your Guinea Pig..

The procedure is at first not at all pleasant for you and your boars but the boys will get used to it and will learn to enjoy the relief you are giving them. Connect the session with some petting and a healthy dried forage treat (which is also good for those trace elements).


7 Worming – yes or no?

Worms in guinea pig intestines are actually surprisingly rare. In nearly 15 years on guinea pig forums and with tens of thousands of guinea pigs passing through, there have only been a handful of confirmed cases I have come across since routine worming care in larger pets is generally much better these days and domestic lawns are a pretty safe place.

Panacur can also be used when other bugs are suspected or confirmed as causing digestive and diarrhoea or persistent pooing/bloating issues. I would however recommend discussing the use of it especially in older guinea pigs with a tender digestion with your vet and not just apply it on speculation. It is not an all-heal for gut problems.
Antibiotics may come into play when your vet suspects a gut infection is causing runny diarrhoea, especially the more severe forms.



I hope that this guided tour around all things 'poop' is going to help you in learning what is normal and what not, and when to step in with a trip to the vets and opening a support thread in our specially monitored Health/Illness section for moral and practical support during any treatment.

The sister guide to digestive tract issues deals with all things gassing (bloat) and coming to a screeching halt (GI stasis):

The guides are part of a series called Wiebke's Guides to the Body to learn more about how the body works, what is normal and what the most common health issues to look out for.

Please try to make sure that you know the alert signals but please make also sure that you do not fall into the trap of spending most of your ownership on the lookout for possible symptoms. Most guinea pigs are thankfully perfectly healthy and they are there to brighten up your lives, not feed your mental health issues. Serious runny diarrhoea is thankfully not all that common in well cared for guinea pigs.
Pet Owners Anxiety - Practical Tips For Sufferers and For Supporters
 
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