Cryptorchidism / undescended testicles in dogs


  • Cryptorchidism is when one or both testicles fail to drop down into the scrotum.
  • Undescended testicles can become cancerous and/or twisted, so it’s important to have them removed while your dog is young.
  • Contact your vet if your dog’s testicles aren’t both in the scrotum by the time they are 6 months old. It’s likely that they will recommend an operation to remove them.

General information

Cryptorchidism is when one or both testicles fail to drop into the scrotum (ball sack). To begin with, when a male puppy born, his testicles are inside his body. Then over a period of approximately two weeks, they start dropping into the scrotum through a narrow channel called the ‘inguinal canal’. The process can take a little longer in some dogs, but if both testicles haven’t dropped by 6 months old it’s very unlikely that they will.

Retained testicles can cause problems such as becoming cancerous or twisted (both potentially life-threatening conditions), so it’s important to have them removed while your dog is young.

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When to contact your vet

Contact your vet for advice if you are unable to feel both testicles in your dog’s scrotum by the time they are 6 months old. If they haven’t dropped by this time, it’s extremely unlikely that they will. Your vet will probably recommend an operation to remove them to stop them causing problems.


Fortunately, it’s possible to remove most undescended testicles surgically, however, the exact operation your dog needs will depend on where his testicles(s) are sitting. If they are in his abdomen (tummy), your vet will need to open him up to find and remove them (similar to speying a female dog), but if they’re stuck in the inguinal canal (in the groin), your vet may decide to remove them through the skin. Removing retained testicles is more complex and usually takes longer than a normal castration, especially if they are difficult to find.

If your dog has one retained and one normal testicle, it’s important that your vet removes both of them - this means that your dog may have more than one wound after their operation.

Natural treatments

Unfortunately there is no other way to treat a retained testicle other than by removing it surgically.

Cryptorchid dog being prepared for surgery - only one testicle in the scrotum

Recovery and aftercare

As with any operation, your dog will need to be monitored closely while they recover.

Pain relief

Your dog is likely to be a bit tender after their operation so your vet will send them home with pain relief.


When your dog first comes home, they might be a bit sleepy and disorientated. This can last for several hours, but they will start to feel much better as the anaesthetic drugs wear-off (usually within 24-48 hours). Once your dog is feeling brighter and more energetic, it’s likely that they will want to run around as normal, but it’s important to rest them for 7-10 days to prevent any complications with their wound(s) and stitches. If necessary, you may need to keep your dog on a lead, crate them, or confine them to one room. Once your dog has recovered you will need to return them to exercise gradually.

Protecting the wound

It’s likely that your dog will be given a protective cone/buster collar to stop them licking and nibbling at their wound. Speak to your vet beforehand if you would like a soft buster collar or a body suit for your dog.


Your dog will need a check-up 2-3 days after their operation. Your vet will check they are feeling better after their anaesthetic, and that their wound is healing well. Don’t hesitate to contact your vet if you have concerns before their check-up.

Stitch removal

Dissolvable stitches (usually blue/purple coloured) don’t need removing, but non-dissolvable stitches will need removing 7-14 days after the operation.

Breeds affected

Retained testicles are often hereditary (passed from parent to puppy), and is most common in certain pedigree breeds of dog, such as the:


It’s important not to breed from cryptorchid dogs because it’s very often a genetic problem passed from parent to puppy.


It tends to cost more to castrate a dog with cryptorchidism  than is does to castrate a normal dog because the operation is more complex and takes longer. However, the cost is likely to be much less than treating any problems caused by retained testicles. Speak to your vet practice for exact costs.

Published: November 2020

Written by vets and vet nurses. This advice is for UK pets only. Illustrations by Samantha Elmhurst.