At What Age Does a Jack Russell Terrier Penis Show Through Its Sheath?

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As a dog owner, many habits are gross and embarrassing that you have to live with. One of them is when your dog’s penis, or red rocket or dog lipstick as it is called, starts showing. You may not have noticed this before, so you ask yourself, at what age does a Jack Russell terrier penis show through its sheath?

At What Age Does a Jack Russell Terrier Penis Show Through Its Sheath?

The penis of a Jack Russell starts showing through its sheath between 9 to 12 months. This is around the time that male JRTs become sexually mature. When your furry friend’s penis is showing through its sheath, it means that it is aroused and it is normal.

This arousal is not sexual; it is excitement about something. It can be a treat, playtime, training, or seeing someone it has not seen in a while. The best way to handle this situation is to ignore it. This also ensures that you do not encourage or reward the behavior. After a short while, it will become enclosed in the prepuce.

A white and brown Jack Russell terrier dog with a purple collar digs on the green grass

Things You May Notice With Your Jack’s Penis

Apart from your Jack’s penis showing through its sheath, there are several other things you may observe that may also raise questions.

Inability to Retract Penis

Paraphimosis is a condition where the dog cannot retract its penis, which may cause damage to the exposed tissue. As mentioned above, your dog showing its penis through its sheath is normal. However, if you notice it is showing the penis for a longer time, it means that it is unable to retract it; this is called paraphimosis.

When Jack’s penis stays like this for a long time, it may become dry and irritated, which will cause it to swell and even become infected. If it continues for longer, its ability to urinate will be affected. This is why taking your Jack to the vet as soon as you notice this is important. Your vet will treat the condition depending on what causes the condition. This includes:

  • A deformity or congenital abnormality
  • Tumors
  • Traumatic injury
  • Something physical such as hair

Typically the vet will give your dog anti-inflammatory medicine and lubrication to try and ease the penis back to its sheath. In some cases, your Jack may end up needing to undergo surgery to rectify the condition.

Licking Another Dog’s Private Part

Your Jack showing its penis is one thing; licking another dog’s private part is mortifying. Especially when it has just met the other dog, and you do not know the owner. You probably start wondering how you will explain your dog’s perverted ways.

Vets and dog behavior experts say this is a normal interaction between dogs, although some dogs are more interested in this behavior than others. Most dogs stop at sniffing, and others go overboard. If you notice your dog sniffing and licking another dog, tell it to stop. If it does not, you may have to separate them.

In some instances, you may notice your Jack licking itself. This is common even in dogs that have been neutered, and it is normal. Dogs do it to clean themselves and also because it feels good to them. However, when they do it excessively, it causes pain and makes them lethargic. Subsequently, it can cause an infection that will lead to problems with the urinary or reproductive tract.

A tri-colored Jack Russell terrier wears a black collar and stands on green grass with an orange ball in its mouth

Related Questions

Other questions about your Jack and its penis are answered below.

What Age Do Male Jack Russells Puppies Hump?

Male JRT puppies start humping from the age of three to six weeks. This behavior is natural and instinctive, mostly seen when they are playing. At this age, it is non-sexual and is a way for them to discover their strength and social standing.

Why Is There Blood Coming From My Jack’s Penis?

There is blood coming from your Jack’s penis because of a number of reasons. They include wounds, the prostate gland being sick, especially in unneutered males, and blood clotting disorders. The best action to take when you see your dog bleeding is to take it to the vet as soon as possible.

Why Is My JRT Penis Discharging a Yellow-Greenish Discharge?

The yellow-greenish discharge that your Jack’s penis is discharging is a mix of lubricant and cells that your dog’s body produces to protect the penis in the prepuce. If you start seeing it many times and in large numbers, your dog may not be healthy, and you should see a vet immediately as it indicates a UTI or cancer.


Talking and asking questions about your Jack’s penis may seem a little out of the norm and even embarrassing to some people. However, it is important not to shy away from conversations with fellow dog owners and your vet. This way, you will know when your dog needs help.