A bum note

A question I get asked a lot (often during coffee break):

If a dog is on a good diet why does he regularly require his anal glands emptying? And is there any truth in 'once he has had them emptied as a puppy, he will need them emptying for the rest of his life?

Thanks,

Tony C, by email




Alison Logan, vet, advises...

There are two anal sacs, as they should strictly be termed because they do not have a lining of secretory cells. They lie just inside the anus at approximately 4 and 8 o’clock if you were to imagine the anus as the face of a clock. They fill with a foul, often fishy smelly fluid or thicker secretion which should be naturally emptied onto the faeces as they pass through the back passage. They can also be released when frightened, hence the smell you may notice if dogs have a confrontation or are scared.

There are so many stories and myths about anal sacs, and a true, full explanation has not yet materialised as far as I am aware! Certainly, I will always check the anal sacs if a dog presents with an ear infection or skin infection, and they are invariably full. Whether that is coincidence is hard to know. There are vets who boast of having never emptied an anal sac during their professional lives – lucky them! I do seem to have days when most consultations have involved this less than pleasant task. Sometimes there is an infection within the anal sac, indicated by the presence of blood in the material expressed, and occasionally a dog will present in a great deal of pain because of an abscess. Would these have been prevented if the anal sacs had been more regularly emptied? – who can tell?

Dogs who drag their rears across the ground, or scoot, often have full anal sacs. Some poor individuals need their anal sacs emptied on a regular basis, others once in a blue moon. Having the anal sacs emptied as a puppy is not a red light to me for a lifetime of impacted anal sacs – the gut of a puppy is developing, and the faeces are often variable, especially if there is a change in diet (intentional or inadvertent such as through scavenging!). Sometimes, though, the anal sacs are empty and the scooting is a reflection of an itchy backside associated with allergic skin disease, so a young adult showing perineal irritation for the first time may indeed experience this for the rest of his or her life.

I have also noticed that an older dog may start to need the anal sacs emptying, which I attribute to changes in the stance adopted when passing faeces, secondary to joint pain and arthritis.

Increasing the fibre content of the diet may help anal sac impaction. This is achieved by adding bran (not high fibre breakfast cereals which have other ingredients) or a specific canine high fibre formulation.

Cold feet

My three-year-old Pug, Boris, is suffering from blocked anal glands. They become blocked so often that my vet has suggested giving Boris an operation to have them removed. I have been with my vet for 30 years and he has been brilliant with my other dogs so I do trust him but there is some doubt in my mind and I can’t shift it. I suffer from arthritis and find it very difficult to empty them myself, although I have done so and continue to try.

I was a vet nurse for five years and have never hesitated to allow my own dogs to undergo necessary routine teeth removals or for pyometra, for example, but I am worried about this operation. My son has helped me to search internet forums and the overwhelming opinion seems to be that Pug owners should avoid this operation going ahead. The operation is planned for this Thursday, but my vet told me last Friday to ring him today if I still had doubts, and I am thinking about postponing it.

I wonder if changing his diet might help? He is on medium junior Royal Canin and has been since he was a pup – his breeder said it was ok for him to have junior food rather than puppy food as a pup because it’s all dog food. I’m not sure if this is truly the case, but apart from blocked anal glands, he is a very healthy and happy dog in all other respects. I have started adding spinach to his diet too.

Has anyone else had a dog who has had this operation? Is this a common operation? I would love to hear from anyone who has, and even more so if the op was carried out on a Pug. He is clearly stressed by the problem and I think he must be in pain. I do not want to prolong his pain, but I do not want to put him under a stressful operation that may not help.

I really want to make an informed decision on this, because Boris is so much more than just a dog and I love him to bits. I am happy to change his diet – I would cook for him if it made him better. I would be really very grateful for any advice.

Thank you very much

Joan, by phone


Alison Logan, vet, says...

The anal sacs lie just inside the anus, at four and eight o’clock as you look at your dog’s backside. They fill with a fluid which has a smell all of its own, quite fishy but not in a pleasant way. When dogs fight, there is often a fishy smell because the anal sacs have been released during the confrontation.

They are thought to have a role in territorial marking. Under normal circumstances, the fluid they contain passes onto faeces as the bowels are evacuated, marking them as belonging to the dog. Personally, I find it hard to believe that each dog has a unique smell for its anal sac fluid.

If the anal sacs do not empty properly but accumulate this fluid, they can become very full and cause the dog all manner of irritation. This may manifest as:
- Scooting – the characteristic dragging of the rear across the floor, usually when you have visitors of a delicate disposition;
- Biting at the back paws;
- Biting at the tail base;
- Leaping up suddenly as if been stung by an insect;
- Odd behaviour, rushing around for no apparent reason.

Emptying anal sacs is generally a simple matter, either externally or with a gloved finger. Some dogs may find this painful, sometimes needing sedation.

Normal anal sac fluid ranges from a brown liquid to a greeny-white toothpaste-like substance. The fluid being warm, it is not uncommon to detect an infection, usually indicated by the presence of blood in the fluid. Rarely, an abscess may develop which is incredibly painful for the dog, and it may burst through the skin. Antibiotics and pain relief are often sufficient but it may be necessary to flush the infected sacs under sedation.

Recurrent anal sac infections and abscessation are a common reason for removal to be recommended. This is not surgery to be undertaken lightly so you are quite right to be giving this careful thought. Faecal incontinence is the major concern, albeit a rare complication. There is also the need for general anaesthesia so the age and general condition of your dog need to be considered. However, if your dog is suffering from repeated anal sac infections and abscesses then removing the anal sacs will solve that.

If your vet has recommended anal sac removal because of a growth in one or both sacs, then there are other factors to consider.

If you are at all unsure about putting your dog through this procedure, then I would go back to your vet to discuss it with him at greater length. He really will not mind talking it over with you because this is an important decision you are making on your dog’s behalf. Your vet is in the best position to advise you because he knows you and your dog and the history leading up to his recommendation to have the anal sacs removed. He will want to know that you are happy and giving fully informed consent for the procedure before he goes ahead.