Experienced and professional animal trainer provide their insights in answering this question :
A. This may be normal, but it also may be a sign of a prostate problem. You should have your vet examine your dog.

How to Identify Common Pet Problems ?

Our sources include academic articles, blog posts, and personal essays from experienced pet care professionals :

You may see the glans penis make an appearance from time to time, however. This occurs during sexual arousal, but even neutered males may get an erection when excited or overstimulated. During normal canine breeding, after ejaculation occurs the bulbus glandis enlarges.
In male dogs, it may even appear that they still have testicles in the scrotum, but this is due to the swelling and goes away after a few days. This means that it is not a postoperative complication of castration.
Paraphimosis is much more common in unaltered dogs but can still occur in neutered males.
My Neutered Dog Still Humps: Is That Normal? Yes, your dog`s humping can be absolutely normal and natural, whether they`re a neutered male or spayed female. Dogs may hump people, other dogs, or even objects like furniture or toys.
It turns out that dogs can actually pick up on the pheromone chemical that your sweaty private parts produce, and pheromones hold a lot of information about ourselves: our diets, moods, health, even whether a female is pregnant or menstruating.
Early-age neutering does not stunt growth in dogs or cats (a once-held belief), but may alter metabolic rates in cats. The anaesthetic and surgical procedures are apparently safe for young puppies and kittens; morbidity is lower and recovery is faster than in adult animals.
On average, it takes about two to four weeks for testosterone levels to decrease significantly after neutering. However, it can take up to six months for testosterone levels to fully decrease.
Can Neutered Dogs Still Get Stuck? It`s rare, but not impossible for a neutered dog to get stuck when pairing up with a female. “It`s more likely if your dog is recently neutered. That`s because he may still have higher testosterone levels than he will later on,” says Greer.
Most likely he won`t want to. With the lower testosterone levels he won`t have a huge libido. But neutering and the resultant low testosterone doesn`t remove all sexual behaviors. That`s because the circulating testosterone in young puppies causes changes that permanently masculinize the brain.
Male dogs have homosexual sex under a variety of circumstances. They mount each other in dominance displays, and that mounting can involve anal penetration. (This is probably what happened in Tennessee if, in fact, there was even sex involved.)
Licking is a natural part of the male dog`s behavior. Female dogs will lick their vulva quite vigorously sometimes as they derive pleasure from this activity. Licking the vulva from a sexual perspective could be the sign that your female is coming into heat.
They`re exploring. Dogs use their tongue to understand the world through scent and taste. Licking people and objects is their way of touching things like we do.
What is your dog saying when they flick their tongue and lick their lips? “I`m feeling anxious about what`s happening now. I`m a bit uncomfortable.” In the dog world, a quick upward flick of the tongue is a clear and direct signal that he doesn`t like what`s happening.
Is it Too Late? The recommended time to spay or neuter a dog is six to nine months. But if your dog is healthy, there is no specific age limit to having the procedure done.
Neutering, also known as castration, is a surgical procedure performed by a veterinarian to remove the testicles. Neutering is almost always a less invasive procedure than spaying (the “fixing” equivalent for female dogs).
So we must be cautious to take a step back occasionally and consider their lives from the viewpoint of a dog, not from a human. There is little to no evidence that dogs miss their testicles in anyway, emotionally benefit from retaining them and having sex, or lose any `masculinity`.
Yes. While your dog will not feel any pain throughout the surgery because they will be unconscious under anesthesia, they will need medication to alleviate pain after the procedure. At the end of the surgery, pain medications will be administered to your dog through an injection your vet will provide.
Testosterone levels will be lower after neutering, but some testosterone will still be present. This means that some masculine behaviors may still occur, although they will be less pronounced than before neutering. If you are concerned about your dog`s behavior after neutering, talk to your veterinarian.
Health-Related Causes

Humping behavior is normal for whole (sexually intact) male cats. Even after castration surgery, it takes time for the hormones to leave the body, and it`s not unusual for mounting to continue for at least a few weeks after the procedure—if not longer.

It`s a common play gesture.” It`s done by males and females, even by dogs that have been neutered or spayed, he says. “It`s a play behavior that dogs do because no one has told them it`s not acceptable,” Landsberg said. “It can become enjoyable or a normal part of the dog`s day, so it keeps doing it.
Humping behavior is not too terribly uncommon, but it is most frequently seen in intact males. However, both males and females can demonstrate humping, even if they have been neutered or spayed. Humping isn`t necessarily something to worry about, as it is a natural behavior.
When dogs meet for the first time, they will sniff and occasionally lick each other “private areas”. This is how they get to know each other, it`s actually a good sign that they are getting along.
The scrotum is often swollen in the first few days after surgery, leading some people to wonder if the procedure was really performed. If the dog is immature at the time of neutering, the empty scrotum will flatten out as he grows. If he is mature at the time of neuter, the empty scrotum will remain as a flap of skin.

Relevant Questions and Answers :

the most relevant questions and answers related to your specific issue

Q. I have a 13 1/2 year old Shih Tzu. How old is he in dog years?
ANSWER : A. It’s used to be that dog years were 7 years to every 1. Now it normally around 5 years to every year as long as your dog is healthy and kept up with vaccines. So he’s about 68ish in dog years.

Read Full Q/A … : Shih Tzu Age

Q. Is neutering a good idea? What are the main aspects to consider?
ANSWER : A. Neutering is a procedure that surgically removes a dog’s testicles for the purpose of canine population control, certain medical health benefits, and behavioral modification.

There are several pros and cons to neutering. The positive aspects of neutering include the following:
1. Reduces the risk of prostate disorders, including prostate infections, prostate cysts, or enlarged prostate tissue. It also reduces the risk of testicular cancer, perineal hernias, and perianal fistulas.
2. Reduces the risk of dominance and aggression in many dogs due to a reduction in the amount of circulating testosterone.
3. Reduces the occurrence of sexual behaviors, such as humping, urine marking, or licking of genital regions.
4. Population control – neutering prevents dogs from creating more litters of puppies that need homes.

The following are possible issues to consider:
1. Neutering is a surgery that requires general anesthesia causing slight risks involved in placing an animal under sedation and anesthesia. Performing bloodwork prior to any anesthetic procedure can help decrease the risk of complications prior to surgery.
2. There is an increased risk of neutered dogs becoming prone to obesity because of a change in hormones and activity level.
3. Neutering your dog at too early of an age can have complications.

Overall, neutering is a good idea for your dog in order to prevent population overgrowth and specific medical issues that can result if your dog remains intact. Consult with your veterinarian on the details of surgery and any risk factors based on your dog’s age and breed.

The AVMA supports the concept of pediatric spay/neuter in dogs and cats in an effort to reduce the number of unwanted animals of these species. Just as for other veterinary medical and surgical procedures, veterinarians should use their best medical judgment in deciding at what age spay/neuter should be performed on individual animals.

Read Full Q/A … : Spay/Neuter Your Pet

Q. is it normal that my 7 year old, neutered Pomeranian has started having erections?
ANSWER : A. This may be normal, but it also may be a sign of a prostate problem. You should have your vet examine your dog.

Read Full Q/A … : Puppy Dog Erection

Q. Does an indoor cat need to be vaccinated every year?
ANSWER : A. In practice, I recommend a feline combo vaccine every year, but will generally start administering every 3 years once they have had their kitten vaccines and 2 additional yearly vaccines. Rabies, is required yearly by law, and if kept up to date can be good for up to three years also. Based on the age of your cat I would give a yearly feline combo and rabies, and then boost the combo again next year.

Q. I was wondering what would be the best dog for a nine-year-old 14-year-old and a nine-year-old that cannot walk
ANSWER : A. You should pick a gentle, no agressive, inteligent dog. some breeds are predisposed to this kind of character but you should always asses the single animal and its behaviour. You can choose from family breeds like labs, shephards, retrievers.

Read Full Q/A … : Caring for an Elderly Dog

Q. My 9 year old lab has tested positive for heart worms. A feed store owner told me I could use Noromectin (ivermectin) to get rid of them? Is it safe?
ANSWER : A. The feed store owner is taking about the “slow kill” method for adult heartworms. This method is the considered an alternate method that has the following disadvantages over the normal immiticide treatment:
1) Takes years (often-times up to 2-4 years) to completely rid heartworms vs immiticide treatment which takes at most 3 months
2) Slowly kills baby worms only in the bloodstream, does not kill adult worms in the heart. Immiticide kills the adult worms that are in the heart directly which is why it is so effective.
3) Higher risk of thromboembolism (clots in the lung artery) than Immiticide treatment.
4) Adult worms will stay in the heart for years and can impede blood flow.
So that is the gist of doing the slow kill method for baby heartworms instead of the fast kill method with Immiticide for adult heartworms. Which is why most veterinarians will recommend the fast kill method as the best choice for your pets care.

Q. I have 8 week old mini Poodles, I wanted to start them out on grain free and to use Innova grain free Natures Table, is this okay?
ANSWER : A. If the food is formulated for puppies, then it should be find to give. There should be an AAFCO statement that states “for growth” or “for all stages of life” to indicate that it is OK to feed puppies during growth. If your puppies are currently on another food, be sure to gradually switch them over a period of about a week to prevent digestive upset. (Starting with a few days of 25new/75 old, then 50/50, then 75/new/25 old before finally all new food) If your puppies are starting on solid food, then moistening larger kibbles can help make it easier for them to eat.

Read Full Q/A … : Dog Feeding Tips

Q. I have a 9 week old kitten. At what age do they start spraying? We have a 12 yr old cat that has sprayed a door, I think. Could it be the kitten?
ANSWER : A. It is not unusual for an established house cat to start acting out once there is a change in his environment. In this case, the new kitten could be a stressor for the older cat as he tries to get used to the new change of an added house member. To answer your question, cats generally do not start spraying until the are around 5-6 months old.