Experienced and professional animal trainer provide their insights in answering this question :
A. We don’t have much information to go on here, as we don’t know where the pus is coming from. But pus is a sign of infection, so your dog should be seen by a vet, who may prescribe antibiotics among other treatments.

How to Identify Common Pet Problems ?

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

What are the clinical signs of vaginitis in dogs? The most common clinical signs of vaginitis include increased frequency of urination, licking of the vaginal area, vaginal discharges of mucus, pus, or blood (rarely), and scooting or rubbing of the vaginal area. The vagina will often appear red and swollen.
Clinically significant or abnormal vaginal discharge in dogs is a disruption of the natural fluids produced by the body to clean the vagina. This may indicate an infection, injury or foreign body in the vagina. Additionally, it may also signal a secondary infection of the urinary tract. Protect yourself and your pet.
In an open pyometra the pus discharges out of the vagina – as seen by a yellow, green or red/brown copious discharge from the vulva of the dog. The diagnosis of an open pyometra is therefore easier if there is a visible discharge.
What Are the Signs of Pyometra? Pets that have open pyometra may have a foul-smelling white, yellow, or blood-tinged discharge from the vagina. Otherwise, the signs can be somewhat vague, such as: Lethargy (tiredness)
Discharge that is yellow or sticky and pink and comes from a pocket within the skin most commonly indicates an abscess. Abscesses are a collection of pus that can occur anywhere on your dog`s body. They often occur because of a scratch, bite, or wound caused by another animal or some unknown oopsie.
Symptoms of pyometra include early warning signs of the animal feeling unwell, such as vomiting, refusal to eat, lethargy, increased thirst and frequent urination. She may also appear to be uncomfortable, because pyometra is a particularly painful condition for dogs, while being somewhat less so for cats.
This can be accompanied by lethargy, depression, anorexia, and fever. Dogs with closed cervix pyometra typically become severely ill very quickly. They might show signs like severe listlessness, depression, and anorexia, as well as diarrhea, vomiting, and swollen or bloated abdomen.
It may be estral bleeding, cervical mucus during late gestation, fetal fluids at parturition, or lochia for up to 4 weeks after parturition. All other vulvar discharges in intact female dogs and all vulvar discharges in spayed females are abnormal.
Pus appears green due to an antibacterial protein called myeloperoxidase. It`s made by certain white blood cells. Green pus is a potential warning sign of a pseudomonas bacterial infection caused by a bacterium called Pseudomonas aeruginosa. This color of pus is often accompanied by a foul odor.
The initial stage of pyometra usually comes with a slight vaginal discharge with no prominent symptoms. Pets diagnosed with pyometra later show visible signs. Dogs with pyometra also have an increased white blood cell count and globulins in the blood. Some dogs may also have painful, enlarged abdomen.
The chance of successful resolution without surgery or prostaglandin treatment is extremely low. If treatment is not performed quickly, the toxic effects from the bacteria will be fatal in many cases. If the cervix is closed, the uterus can rupture, spilling the infection into the abdominal cavity. This will be fatal.
How quickly does pyometra develop? If it is a closed-cervix pyometra, clinical signs of pyometra can develop very quickly, sometimes within a matter of hours and a few days. If it is an open-cervix pyometra, the clinical signs of pyometra can take days to weeks to reveal.
Purulent drainage is a sign of infection. It`s a white, yellow, or brown fluid and might be slightly thick in texture. It`s made up of white blood cells trying to fight the infection, plus the residue from any bacteria pushed out of the wound. There may be an unpleasant smell to the fluid, as well.
Pus is a natural result of the body fighting infection. Pus can be yellow, green, or brown, and may in some cases have a foul odor. If pus appears after surgery, contact a doctor immediately. Smaller buildups of pus can be self-managed at home.
A wound that`s healing can produce a clear or pink fluid. An infected wound can produce a yellowish, bad-smelling fluid called pus.
Pyometras are most often found in dogs of any breed between the age of 6 and 10, and may be more common in dogs that have never had puppies. They do not occur in spayed animals, since a spay surgery involves removing the uterus. In extremely rare instances pyometras can occur in cats.
SIGNALMENT. It has been suggested that pyometra is a condition of middle aged and older dogs. 22-25 However, pyometra has been reported in dogs as young as 4 months old and as old as 16 years.
Pyometra is a life-threatening womb infection in dogs, which can be prevented by spaying your dog. Early symptoms include licking their back end more, season lasting longer than usual and not eating.
However, most dogs with pyometra are not seen until later in the illness. A very ill female dog that is drinking an increased amount of water and has not been sterilised is always suspected of having pyometra. This is especially true if there is a vaginal discharge or painful, enlarged abdomen.
If pyometra is not caught and treated in the early stages of the infection, the female dog`s uterus will rupture, causing the pus to fill the abdomen. If this happens, the prognosis is poor, and the animal will have only 24 to 48 hours to live if not properly and effectively treated.
A classic sign of open pyometra is purulent, foul-smelling discharge from the vulva. In closed pyometra, the cervix is sealed and the infection is trapped in the uterus.
So, how long do dogs bleed after giving birth? When you continue to see bloody discharge a couple of days after delivery, there is no need to panic as that is completely normal! This discharge is called lochia. According to VCA Hospitals, lochia discharge is normal for three to seven days following birth.
This disorder is often referred to as “spay incontinence” because it appears in female dogs after they have been spayed. The cause of incontinence in these patients is most likely related to decreased estrogen levels associated with removing the ovaries during the spay.
Discharge – If the wound is discharging small amounts of pus, it is a positive sign of healing. However, if there is continuous drainage and you start noticing bad odor or have discoloration, the wound is likely infected.

Relevant Questions and Answers :

the most relevant questions and answers related to your specific issue

Q. My pet is suffering eyes discharge, what should I do?
ANSWER : A. Mucus, yellow-green pus, or a watery eye discharge can all be signs of conjunctivitis, which is inflammation of the lining of your dog’s eye.

There is a wide range of causes for conjunctivitis, from allergies, injury, birth defects, and tear duct problems, to foreign bodies, dry eye syndrome, infections or even tumors.

Other signs of conjunctivitis include excessive blinking or keeping the eye closed, squinting and pawing at the eyes.

Treatment of this condition depends on the underlying cause. In most of the cases cleaning, soothing the eye and applying antibiotics eye drops suffice but is some instances further investigation is required to establish the cause of the excessive eye discharge, and this should be performed by a veterinarian.

Q. What can I do if my pet is suffering mucus nasal discharge?
ANSWER : A. Diseases of the nasal cavity, paranasal sinuses or lower respiratory tract typically cause nasal discharge, sneezing and snorting.

Other common causes of nasal discharge include viral, bacterial or fungal infections, foreign bodies, allergies, polyps, neoplasia, and extension of diseases from oral cavity.

In most of instances dogs will require treatment with antibiotics, anti-inflammatory or antihistamine medications and in cases of persistent nasal discharge further investigation like x-ray of the nasal cavity, endoscopy, culture of the nasal mucus is warranted. Therefore, it is strongly advised to have your pet checked by your veterinarian if the discharge persists.

Q. We have a 3 yr old Weiner dog, she is having pus in her eyes, I took her to the vet he gave me derma vet ointment, used it as the doctor prescribed
ANSWER : A. If the pus really isn’t all that bad, and it’s just some discharge, your pup may benefit from a diet change. It could be that the food you’re feeding just isn’t right for your dog, and that’s okay! Dogs grow and change over time, and now that your dog is fully matured, a diet change may be in order. Try something like Taste of the Wild, maybe a grain free dog food, Orijen, or Ziwipeak. These are all really great food options.

If the pus is really bad, and continues to get worse, see your vet again and let them know what’s going on. Maybe you could try a diet change, and then see if there are any improvements.

Remember, you should always gradually change a dogs diet. By gradually, I mean you put a tiny bit of new kibble in with a bowl of the old kibble. Reduce the old kibble by just a few bits of kibble. Throughout the course of at least two weeks (or as long as you want depending on whether or not you want to finish off the old food) you slowly add more of the new kibble while removing some of the old kibble. This makes the process gradual, and won’t cause any tummy-upset in your dog.

Q. My dog keeps licking himself in different areas, what does this mean?
ANSWER : A. Licking and fretting is part of a normal dog’s grooming behavior. It only becomes a problem when your pet does it in excess or carries it to the extreme.

In most of cases excessive nibbling is related to skin diseases. Problems like skin allergy, parasites, infections, anal glands problems usually results in excessive itchiness.

In rare cases skin irritation can be a result of internal disease like liver problems or even a tumor.

Excessive licking and chewing should be promptly treated as dog dogs will self-inflict skin scratches and wounds which could be easily avoided if treatment is not delayed.

Read Full Q/A … : Excessive Dog Licking

Q. Excessive pus discharge
ANSWER : A. We don’t have much information to go on here, as we don’t know where the pus is coming from. But pus is a sign of infection, so your dog should be seen by a vet, who may prescribe antibiotics among other treatments.

Q. What do you do when a cat sneezes all the time.
ANSWER : A. Some cats just sneeze. If you feel it is happening too consistently or there is discharge from eyes or nose have him or her evaluated by vet. Greenish or yellow discharge can be a sign of infection. Also if no discharge is present but sneezing is excessive your cat may have something in the nasal cavity, a foreign body or polyp for example.

Q. My veterinarian says my cat is in kidney failure, can you explain what that means?
ANSWER : A. Chronic kidney failure is persistent azotemia for 3 or more months. Azotemia is an excess of urea nitrogen and/or creatinine. The first ability that is lost with the failing kidney is often the kidney’s ability to concentrate the urine. In a cat, the urine becomes both dilute and excessive when 66% of the kidney function has been lost. This change will precede the rise of metabolic waste in the blood (urea- creatinine) which occurs only when approximately 75% of the kidneys are lost. Kidney disease involves a loss of functional renal tissue due to a progressive process that is irreversible.

The aim of treatment is to slow the progression of the kidney’s inability to remove excess metabolic waste. For more information: http://bit.ly/1A19OJw

Q. My dog has a green colored discharge coming from his penis. It is not all the time, but his licking it a lot so its hard to know when it comes.
ANSWER : A. These sounds like inflammation and infection of the prepuce(spotting, excessive licking, discharge are the symptoms)Treatment involves checking for any foreign bodies and daily flushing with an antiseptic solution.You should take him to your vets to get treatment.