Understanding Swollen Anus in Dogs: Causes, Symptoms, and Treatment

Have you noticed that your dog's anus is swollen? If you notice that the appearance of your dog's anal area is not the usual one and you are worried about his health, the first thing we recommend is to take him to the vet for a check-up and help.

This part of the body of dogs is one of the most delicate, as it is susceptible to injuries and infections, as well as other problems related to the mucosa and anal glands.

At Dogalyo, we want to help you provide the best care for your faithful companion and to inform you better about aspects of his health. For this reason, we have prepared this article to explain the causes that answer your question "Why does my dog have a swollen anus?" as well as the possible treatments for each cause and several tips.

Anal sac disease in dogs

Swollen anus in dogs symptoms

Among the main symptoms of anal inflammation in dogs and related problems, we highlight the following:

  • Swelling in the anal and/or perianal area.
  • Irritated anus
  • Itching and scratching against the floor
  • Clear discharge
  • Pink or red discharge or bleeding
  • Yellow or green discharge.
  • Lump in the perianal or anal area
  • Sores in the anal area

These are the main signs that something is wrong with this delicate part of a canine's body, but other symptoms that often accompany these are nervousness, irritability, fever, more sensitivity to touching the particular area as well as the tail and thighs, listlessness, and so on.

Why does my dog have a swollen anus and what should I do? The causes and treatments

If according to the symptoms you observe, you think, or your veterinarian has already confirmed, that your furry friend has anal inflammation, pay attention because in the following lines we inform you about the main causes of anal inflammation in dogs, which the veterinarian will have to shuffle and make the necessary tests to detect the origin and treat it. Also, in each of the causes, we explain the possible treatment for inflamed anus in dogs:

Swollen anal glands in dogs

Dogs have glands on either side of the rectum and anus known as anal glands or anal sacs. These secrete a fluid that helps lubricate the stool and serves as each dog's distinctive odor. These glands sometimes malfunction, become inflamed, infected or collapse when the fluid is retained and thickens. There are dogs that become inflamed or collapse more easily than others, and we can help them by emptying their anal sacs, something we can learn to do at home but is best done by a veterinarian.

When there are swollen anal glands, swelling in the anus can become noticeable. When these glands become obstructed, anal or perianal fistulas, lumps, and abscesses can develop, and, of course, all of these conditions include swelling as a symptom. If these potential problems are not taken care of, an anal infection can develop and become complicated in a short time.

If the swelling is severe or there is collapse, it is the veterinarian who will have to do the treatment; normally he will do a cleaning and anti-inflammatory, but if the collapse is severe, surgery may be necessary. In the case of an operation, the specialist will most likely prescribe a series of cures, as well as the use of an ointment for anal glands in dogs that is antibiotic and will help prevent infections.


The difficulty of expelling feces makes the mucous membranes and other tissues of the digestive tract between the intestines and the anus suffer overexertion. For this reason, it is very common that in cases of constipation in dogs, the anal area and the belly become inflamed. This occurs most often in cases of chronic or severe constipation.

Apart from following the treatment for constipation in dogs that the veterinarian gives you, discuss with him the compatibility of this with some of the best home remedies for constipation in dogs. If you are wondering how to cure a dog's irritated anus, because it is one of the main problems that appear with this condition, we recommend that you follow the vet's advice, regulate your dog's diet and apply these same remedies, as well as some type of ointment or moisturizing cream for dogs.

Perianal fistula

A perianal fistula is an opening or communication that opens between a body cavity, in this case the rectum, and the surface of the skin or the outside, and is an abnormal tunnel-shaped opening, so it has occurred because something is not right in this area, as an escape route for secretions. In this area, it can be due to abscesses, lumps with fluid, with or without infection, as well as problems in the anal glands, although it is not the usual cause. When they suffer from it, dogs try to bite the rear area while circling or chasing their tails, and when they get there they usually nibble the base of the tail and drag the butt on the floor, where a wound can be observed.

Treatment for a perianal fistula in dogs requires surgery as well as antibiotics after surgery.

Anal sores

In addition to swelling, you may see some open or crusty wounds. Injuries in the anal or perianal area of dogs may be due to excessive scratching, which in turn can happen for various reasons, as well as constipation, a blow or a fight. Thus, an injury of this type in this part easily causes inflammation in the anus.

The treatment of anal and perianal wounds in dogs includes cures with saline and iodine, the use of antibiotics in the form of ointment, cream, pills or injections, and even anti-inflammatory drugs, depending on the case.


If a while before you see this swelling, your furry friend has been hit in this spot, it is likely that, at least for a while more, he will have inflammation. He may have done it if he has been running and jumping a lot, if he has fallen from somewhere not very high, or if he has been hit in some way, for example during a fight with another dog. Any trauma, no matter how slight, to any part of the body can cause swelling, redness, itching, and bruising, as well as localized and more intense pain when the area is touched.

The treatment for trauma in the anal area of dogs is the use of anti-inflammatory drugs, analgesics, and rest. It is also possible to have surgery according to the case, as well as antibiotics, especially if there is a wound.

Intestinal parasites

Internal parasites, specifically intestinal parasites, produce symptoms such as constant itching in the anal area, which causes the dog to be up all the time trying to nibble the area and dragging the anus on the floor to relieve the discomfort. This, in turn, can lead to inflammation, wounds and secondary infections, mainly bacterial. Other clear symptoms of intestinal parasites in dogs are weight loss, even if the animal eats normally; worms and worm eggs in the feces; as well as diarrhea and even blood in the feces.

The treatment for intestinal parasites in dogs is internal deworming with antiparasitic drugs in the dosage indicated by the veterinarian.

Rectal prolapse

If you are wondering, "Why is my dog's anus red?" In addition to the swelling, it could be irritation from excessive scratching.However, if you notice your dog's anus swollen, red, and you can see it larger or with a lump, another quite likely possibility in the face of these symptoms is rectal prolapse. This means that the animal's rectum has come out through the anal orifice and a part of it has been left outside the body, so the mucosa looks reddish, there may even be blood, you can see a lump which is the displaced rectum itself, and inflammation. The main cause of this issue is chronic constipation.

The treatment of a rectal prolapse in dogs is always surgery, more or less complex depending on the case, but always necessary.

Anal infection

Inflammation of the anal area of a dog may be due to infection both in the internal area, near the sphincter and rectum, and in the external area, i.e., in the anal orifice and perianal area. These infections are usually bacterial but can also be fungal. The main causes are: wounds, fistulas, abscesses, parasites, prolapse, and, in the case of collapsed anal glands, if left untreated.

The treatment of an anal infection in dogs is based on antibiotics, but the main cause must also be treated so that the infection does not recur.

Below, we explain the most common causes of a dog's having a swollen anus along with other more specific symptoms that often accompany this swelling.

My dog has a swollen and bleeding anus

If your dog has a swollen and bleeding anus, then the most likely causes of these symptoms are all those mentioned above, since bleeding is another of the most common symptoms in these conditions, especially when they are already somewhat advanced or, in the case of swollen or collapsed anal glands, when they are treated or if pressure is applied to them to clean them. Therefore, it is necessary that when you see both signs in your dog, you go to a specialist without delay.

My dog has a swollen anus and cannot defecate

Another common symptom along with the swelling in this area is the difficulty of defecating. If you see that your faithful companion has discomfort in this area, has swelling, and you see that he has a hard time defecating, and even if you see that he does not manage to expel the stool in any way, all the above reasons are possible in this case. However, these are the most likely causes of your dog's having a swollen anus and not being able to defecate:

  • Constipation
  • Rectal prolapse
  • Collapsed anal glands
  • Trauma or a blow

My dog is leaking fluid from his anus and has a swollen anus

If the problem is that your dog's anus is swollen and leaking, then he is most likely suffering from one of these causes:

  • Swollen anal glands
  • Blow or trauma
  • Anal fistula
  • Wounds
  • Intestinal parasites
  • Anal infection (especially if the fluid is yellow or green and even a little thick)

My dog has swelling between the anus and testicles

If you have a male dog and you notice that he has swelling between the anus and testicles, it may be due to any of the conditions mentioned as causes so far.

However, it can also be due to a testicular problem or if you have just castrated your dog and he has swelling between the anus and the scrotum or in the scar area. It is normal if the operation is recent, but if it is a few days ago, it is not, and there could be infection in the surgical wound.

On the other hand, in the case of a female dog, this area can also become inflamed when she is in heat if, in her case, the genital area usually swells a lot, because if she rubs or nibbles the genital area, the swelling can pass to the anal or perianal part. However, in the case of spaying or neutering the bitch, this reaction is not normal in the anal area.
Next Post Previous Post
No Comment
Add Comment
comment url