Boar Problems 'Down Below' (Penis, Impaction, Testicles & Neutering, Mammary Tumours & Grease Gland)

[Wiebke]

Overview
1 Penis and Semen Fluid
- Penis (Prongs, 'cauliflower willy, strangled and prolapsed penis)
- Semen fluid (Semen rods and 'boar glue')
- Smegma
2 Perianal Sac and Impaction
- White paste in anal sac
- Impaction
- Fly strike
3 Testicles and Neutering Post-op Complications
- Testicles (descending, undescended and swellings in the area)
- Neutering post-op complications
4 Nipples and Mammary Tumours
- Nipples and belly button
- Mammary tumours
5 Grease Gland

This guide is a collection of information that addresses boar specific problems of mainly the reproductive tract and anal sac. It will hopefully make it easier for you to work out what is going on and when to see a vet.

We strongly recommend to get into the habit of a weekly weigh-in, body check and any necessary grooming. Some boars can be very messy and may need more frequent attention (especially with impaction or as teenagers) while others only need a thorough check once a month. We do however recomment that you have a weekly feel of the penis area of any hard bits (smegma or rods) as well as checking the the anal sac (which in neutered boars is much smaller), grease gland and the usual cuddling body feel that gently covers the whole body when feeling for lumps or anything unusual.

Our Boar Care guide with lots of pictures is there to help with the regular care side of boar maintenance: https://www.theguineapigforum.co.uk/threads/boar-care-bits-bums-baths.135661/

We also recommend to take reference pictures once a year to save in a special so you can look up how your boy's 'normal' looks when you have concerns about any body part.



1 Penis and semen fluid
The penis is surrounded and protected by the internal tissue of the penis shaft. The round 'button' you see when you look at the genitalia is actually sac tissue and not the penis itself. In order to look at the penis, you need to express it fully by gently pushing on the hard penis shaft under the skin from the belly side towards the opening. Because it is a proteced place, semen fluid, grease and dirt can build up. In never checked boars this can build up to the degree that an rather nasty infection/abscess can come up. Any swelling in the groin area needs to be vet checked.

Penis
Prongs
- Guinea pig boars have two protrusions on their penis, like horns. This is another variation of ‘normal’ so is nothing to worry about!
- They are very often not visible upon penis inspection, but boars use them to keep hold of a moving sow when they mate.
- Some boars have only got one or no prongs at all.
However, the absence of prongs is NOT an indication of a boar's infertility, as veterinary textbooks maintain without substantion. There is some rather happily wheeking verifiable proof that says otherwise.
Picture from Stewybus showing one penis prong


Cauliflower willy'
-‘Cauliflower willy’ is the term used when the foreskin isn’t as tidy and is more ‘frilly’ in appearance. This may (or may not) mean that it is trickier to keep clean and occasionally the penis itself protrudes which can cause it to get caught or damaged unintentionally.
- In this case your boar would need more frequent checks (at least daily) to make sure everything is safe and healthy.
- Also see a vet if you notice changes to the willy (infection).
Picture from MintyandGary


Merrypip's Angus showing debris & hair around the penis


Strangled Penis
Please always check for problems if your boy seems to be constantly fussing about his penis. Boars do masturbate but nonstop attention can be a sign that there is a problem/pain issue in the penis shaft.

Make sure there is nothing caught around the shaft that could interfere with blood flow; especially if you have long-haired piggies in the same cage. The penis will show a blueish colour past the obstruction if the circulation is compromised. The consequences of a cut-off circulation are dire.
See a vet asap if you cannot remove any tightly looped hair yourself! This is an emergency.
The normal colour for a penis tip is dark ruby into maroon (see Hywel's picture above).

Prolapsed penis
-The penis can sometimes not retract properly. Generally the problem rights itself. With a boar with a more persistent retraction problem, a lubricating human gel like KY gel can help.
- In some cases the penis cannot retract itself and hangs out permanently. It needs stitching back by a vet to prevent the risk of injuries and infection. It is a minor procedure and not a full-blown operation.


Semen fluid
'Boar glue' (Ejaculated semen fluid)
- Boars can ejaculate both when humping and on other occasions. The semen they leave behind is a very sticky substance and dries solid, hence the term ‘boar glue’. You will often find blobs of shiny white dried boar glue on a boar's or their companion's noses or stuck to the fur.
- If it has not yet dried, it is possible to remove it by washing or a damp cloth but once dried (especially into fur) then removal is difficult and often using scissors to carefully cut the offending lump out of the fur is the best bet; if that is not possible, you may have to wait for it to fall off on it own!

Sperm rods (Dried semen fluid in the penis shaft)
- Semen can also dry into a thin rod inside penis, known as a ‘sperm rod’. The ends of these are often protruding from the external part of the penis.
- Small sperm rods can be carefully removed, just as you would with a stray piece of hay or bedding.
- For removing a large sperm rod (which can be very painful and may have caused some infection) please see a vet! Large sperm rods can even cause loss of appetite.
Furryfriends' Monty's large sperm rod



Smegma
- The penis is often covered in a creamy/white/greyish material called smegma. This shouldn’t be excessive or particularly smelly.
If excessive smegma is left to build up for too long, it can dry out and form a hard crust around the penis.
- Any stray hairs, hay or other material should be removed as they could loop around the shaft or scratch it and cause an infection.
Wiebke's Hywel with an exressed penis showing smegma and the usual stray bits of hay and hair in the tip of the penis as you are likely to find with your own boars when checking on them.


Merrypip's Angus showing debris & hair around the penis

 

[Wiebke]

2 Perianal Sac and Impaction

White paste in anal sac
- The perianal sack of a guinea pig is the external part of his bottom that you can see. Since the tiny scent glad is sitting just in front of the genitalia, boars tend to pick up a lot of debris and dirt from the ground while scent marking their territory regularly.
- The perianal sac is stretched and much extended when the testicles descend. It contracts again when the testicles are removed in a neutering operation. This is the reason why adult boar poos are a lot longer and curved compared to the poos of sows and neutered boars.
- This area is important in the process of producing faeces. It often has a whitish substance inside which is part of the process.
- Please have your boar vet checked if there is there is a sudden overproduction of that white fluid. It is comparatively rare but could be candida (a fungal infection).

Impaction
- Some older boars particularly and some who may have medical conditions can struggle with impaction. Impaction affects about 10% of all boars.
- As a boar gets older, the muscles that keep his anus tight (a bit like a drawstring) get looser and he may struggle to expel poops correctly. The faeces can then collect inside his perianal sac in an ever growing ball. This can get very uncomfortable and can cause problems.
- Neutered males do get impaction just as often as full boars but it is often missed because heir anal sac is a lot smaller. Their impaction volume is about the size of a large pea or small bean. This is not on its own a reason to neuter, as impaction only affects a minority of boars!
- The clearing frequency can from twice weekly in the mildest to 2-3 times a day in the most severe cases.
- More information on how to check and care for impaction in this guide with several videos plus an impaction carer's practical diet tips and experiences: Impaction - How To Help Your Guinea Pig.

Fly strike (flesh eating maggots typically around the genitalia)
If there are small red raised dots or white dots in that area in summer or you see tiny white maggots wiggling around the increasingly swollwn genitalia, please race your piggy to vets or out-of-hours vets at any time of the day or night as a matter of life and death - this is fly strike and one of the most awful things a piggy can die from! The dots you see is flesh eating maggots.
A piggy (or other pet) can be saved if the maggots are removed in time, otherwise it will die horribly and will need to be euthanised as the kindest thing you can do. Please note that flesh-laying flies can occasionally make their way indoors and affect especially the frail and elderly that struggle to keep their genitalia clean.
More information on fly strike and what to do: Fly Strike

 

[Wiebke]

3 Testicles and Neutering Post-op Complications
Testicles
Baby boar separation rules
Please note that boars start making babies from 3 weeks of age or 250g of weight (whichever is earlier) and need separating from any sows long before their testicles descend. This coincides with the weaning process.
250g is the average weight of a 3 weeks old baby boar at weaning age. The weight qualifier helps with catching the early developers before their mother comes into season again around day 16/17 and allows the smallest baby boys a safe extra week with their mum's milk as it increasingly dries up.
The most developed baby boars can in fact start at just over 2 weeks (we have seen cases of early mother-son pregnancies on here) and the slowest boys at ca. 4-5 weeks - but never count on just their size. 4 weeks is the latest safe cut off time for the smallest boars. 4-6 weeks is the age sows have their first season although the earliest documented sibling pregnancy is 24 days (just over 3 weeks).

Sadly, there is still a lot of misinformation around, including with breeders, pet shop personnel and vets not experienced with guinea pigs. In the case of guinea pigs, sexual maturity (when the testicles are fully decended) does not coincide with procreational maturity (gaining the ability to make babies.

Illustrated Sexing Guide
https://www.theguineapigforum.co.uk/threads/sexing-separating-baby-boars-and-rehoming-babies.109391/

Descending testicles (ca. 4-6 months of age)
Boar testicles start descending around 4 months of age and have fully descended at around 6 month of age. The start and the end of the process are often accompanied by strong testosterone spikes which can lead to fall-outs.
Young Llelo with descending testicles @Wiebke

They manifest first as symmetrical swellings to both sides of the genitalia but the whole area is increasing push out and down. The fully descended testicles can vary enormously in size. As the perianal sac is increasingly stretched and extended between th descending testicles, the poos are changing in shape and become longer and more curved; their ultimate size depends individually on the size of the testicles.

Examples of fully descended testicles
Small (Merlin @Wiebke )


Large (Nye @Wiebke )



Neutered boar with contracted anal sac (Maelog @Wiebke )


Undescended testicle
Fully descended testicles should be roughly same sized. If one testicle has not descended or is noticeably smaller please see a vet.
Warning To Vet Check Irregular Boar Bits

Swollen testicle
A swollen testicle which is suddenly larger and noticeably hotter to the touch than the other one also needs to be seen by a for an infection or abscess in the testicle. Your reference pictures can help.

Hernia
A hernia happens when connective tissue, fat or - in the worst case - small bit of the gut slips through a tiny hole in the muscle wall that separates the intestine from the reproductive tract. Occasionally some of the tissue that has slipped through can reach quite size and feel like a soft large lump in the groin area. I can wax and wane over time and even move into the scrotum (the testicle bag). Please always have a hernia vet checked. Your vet is better poised whether a hernia is operable although any operation in a neutered boar is much more difficult when the physical markers in the body have been removed during the neutering operation.
A bit of gut getting trapped and swelling fast is exruciatingly painful and requires emergency Pts/euthanasia. Otherwise it will lead to an agonising death soon after in a quick decline.


Post-op Neutering Complications
For the full neutering process with all considerations and information and for normal post-op care please see these links here:
A Guide to Boar Neutering Operations (Considerations, Post-op Care & Complications and Success Story)
Tips For Post-operative Care

There are now different ways to access the testicles, via a small incision in ech scrotum from the front or from the back. Go with with what your vet is more confident with.

If there is a problem, please don’t spend valuable time asking online whether you need to see a vet, contact your vet asap if your boy is not right, experiencing lethargy (which is a life and death any time of the day emergency), if any staples/glue/sutures have split or come off and there is an open wound or if there are any swellings in the groin area or sudden loss of appetite.

Please check the groin daily in the first two weeks, then every second day for the next two weeks. After a month, you can go back to a twice weekly check-up and after two months to the normal once weekly health check that we recommend for all guinea pig. There can be a little bleeding in the first day as a reaction to GA drugs. Post complications like abscesses or hernias can happen several months after the operation.

List of the most common post-op neutering complications
Loss of appetite
- Immediately after the operation/on the day after the operation: Please step in with syringe feeding asap and follow the tips in the post-op and syringe feeding guides. Your boar is either having a bad reaction to the GA or is in major pain because an operative mistake.
- Sudden loss of appetite typically in the second week after the operation: infection or abscess. Please see a vet promptly, ideally on the same or the next day.

Gnawing open the operation scar
If your boy is gnawing open the wound (thankfully much rarer these days due to better operation techniques and small animal experience) it is always a sign of great pain or the fact that the healing process is not happening for some reason resulting in necrotic tissue.

Swellings in the groin area
- Haematoma (a ball of clotted blood in the tissue). This is harmless. See a vet as to whether they think it will dissolve on its own or is better removed.
- Abscesses are the most common neutering post-op complication. They typically appear in the second week after the operation, but can come up in rare cases as late as half a rear after the operation. Initially they can be felt as a hard ball, but as they blow up, they become softer.
Depending on how large the abscess is and where it sits, your vet may just treat with a strong antibiotic (ideally stronger than baytril, which is not all that good at cutting through an abscess), drain a larger abscess close to the surface or surgically remove a stubborn deep sitting abscess that is not reacting to even a stong antibiotic.
- Hernia (rare): Like with human men, the muscle wall in the groin is rather thin and prone to rips when under stress so fatty tissue or even a bit of gut can slip through – the latter is bad news but thankfully very rare.
Hernias are thankfully not very common, but they can happen in the operated area even a year after the operation. Unlike a an abscess or a haematoma, a hernia is a soft, squishy swelling to one side of the groin.
- Band of swelling at the back of groin that can cause gut adhesion: Thankfully extremely rare, but also extremely painful!
My Hywel (RIP 2016) survived it in 2011 thanks to determined round-the-clock care and a strong antibiotic. He is the only guinea pig I have so far come across with this particular complication in nearly 10 years on this forum.

That said, the majority of operations is successful! For an example of a problem-free recovery, I have included Nye's story with pictures and videos in our neutering guide.
Neutered / De-sexed Boars And Neutering Operations: Myths, Facts and Post-op Care

 

[Wiebke]

4 Nipples and Mammary Tumours

Nipples and belly button
Boars have two nipples that look the same as sow nipples, so you cannot use them for sexing. The nipples can have different colours because of skin colour markings but they should be the same size and thickness.
Please see a vet if one of them is suddenly bigger, redder and noticeably warmer to the touch.
Nye (neutered boar) @Wiebke


Mammary tumour
Always check your piggy for lumps directly under a nipple during the weekly health check. Mammary tumours are not all that uncommon. They tend to affect boars more often than sows. Mammary tumours can be both benign as well as malign. Often you will only get one but occasionally a piggy with a genetic disposition can develop them on both nipples.

The problem with mammary tumours is that they never stop growing and that they need operative removal for that reason. Left unattended, they can grow so big that a guinea pig is no longer able to stand on all four legs. The operation has generally a good success rate when done early on as it is not really invasive and pretty quick at that stage.
If a mammary tumour is coming up very suddenly and is soft to the touch please see a vet as an emergency; it is likely that the tumour is filled with blood and will turn septic very quickly, which is not a nice death. This variety is thankfully rare but it happened to my Rhosyn.
Guinea Lynx :: Mammary Tumor

 

[Wiebke]

5 Grease Gland

The more often you clean an overactive grease gland, the more you stimulate grease production. Please wait a couple of days and allow the piggy to deal with it on their own.

Clean the grease gland with coconut oil and a cotton bud. Let the oil dry on the gland overnight and then remove it with a cotton bud. This should also remove any muck from the grease gland.
For tips for bum and fulls baths when really needed:
Boar Care: Bits, Bums & Baths
Angus @Merrypig


Please see a vet if the gland is looking sore, swollen or has crusts that cannot be removed. Infections and - much more rarely - cancer in the gland can occasionally happen but are fairly straight forward to deal with for a vet.