Male Dog Swollen After Heat

When a male dog is exposed to a female dog in heat, his testicles may become swollen or enlarged. This swelling is a normal reaction but can sometimes indicate more serious medical issues. Understanding the causes, symptoms, and treatments for male dog swelling after a female heat cycle is important for any dog owner.

This article will provide an overview of normal male dog behavior around females in heat, explain the possible causes of testicular swelling, identify where swelling occurs, outline associated health risks, discuss seeing a veterinarian, describe diagnostic testing, review treatment options, summarize the recovery process, and offer tips on prevention. This is an important topic for male dog owners to understand in order to monitor their dog’s health and identify when veterinary attention is required.

Normal Male Behavior

When an intact male dog detects that a female dog is in heat nearby, he will exhibit certain natural behaviors in response. These behaviors are triggered by evolutionary drives to seek out reproductive opportunities.

Some common signs of a male dog sensing a female in heat include:

  • Increased excitation and hyperactivity
  • Restlessness, pacing, and inability to settle down
  • Loss of appetite or lack of interest in food
  • Attempts to dig, chew, or scratch his way out of the house or yard
  • Pulling hard against the leash and trying to escape on walks
  • Howling, whining, and crying
  • Mounting of objects and humping behavior

These behaviors are all driven by the male’s powerful urge to seek out and mate with the female in heat. The behaviors may persist for the entire 2-3 week duration that the female is in heat, and can be stressful and disruptive for both dogs and owners.

Possible Causes

There are several theories for why some male dogs may develop swelling after a female dog goes into heat nearby.

One common cause is hormone changes. The pheromones from the female in heat can cause hormonal fluctuations in male dogs, leading to swelling of the testicles and sheath. This swelling is the male dog’s physical reaction to the presence of a female in estrus.

Bacterial infections like brucellosis are another potential cause of testicular swelling in male dogs after a female goes into heat. Brucellosis is spread through breeding and contact with reproductive fluids. The bacteria attacks the male reproductive system, causing inflammation and swollen testicles.

Orchitis, or inflammation of the testicles themselves, can also lead to swelling. The inflammation may be triggered by hormones, bacteria, viruses, trauma, or cancer. Orchitis will cause swelling, pain, and redness in one or both testicles.

In rare cases, testicular torsion can occur if a male dog is very active during a female heat cycle. This is when the spermatic cord becomes twisted, cutting off blood flow to the testicles and causing them to swell painfully.

Swelling Locations

Swelling from sexual arousal or hormonal changes typically occurs in a few key locations on male dogs:

  • The prepuce or sheath, which is the area of skin surrounding the penis. This area often swells up and becomes enlarged.
  • The scrotum and testicles. The scrotal sac and testicles will swell up and appear enlarged.
  • Around the anus. Some swelling of the skin around the anus and tail base is common.

According to the VCA Animal Hospitals, the first physical sign of an impending heat cycle in female dogs is vulvar swelling, which corresponds to the preputial swelling seen in male dogs.[1] The testicular swelling tends to be more pronounced in older unneutered male dogs.




If the swelling is left untreated, it can lead to some dangerous complications for the male dog. Some of the key risks include:

  • Pain – The swelling and inflammation can be very painful for the dog. This pain may prevent him from normal activities and can significantly impact his quality of life.
  • Infection – Swollen testicles are prone to developing bacterial infections. These can spread quickly and lead to abscesses or the infection entering the bloodstream. Infections need rapid veterinary treatment with antibiotics.
  • Difficulty urinating – Large swollen testicles can press against the urethra and make urination difficult or painful. This can lead to straining, blood in the urine, or even an inability to urinate at all, which is a life-threatening emergency.

Due to the severity of these potential complications, it’s crucial to get veterinary assessment and treatment for any significant testicular swelling in male dogs. Leaving it untreated risks the dog developing a painful infection, urinary issues, and overall reduced welfare. The earlier the vet can examine the dog and treat any underlying cause, the better the outcome will be.

Seeing the Vet

It is very important to take your male dog to the vet if you notice swelling after a female dog’s heat cycle. The vet visit is critical to properly diagnose the cause of swelling and to rule out any serious or life-threatening conditions. Some signs of swelling like redness and inflammation can indicate infection, trauma, or testicular torsion, which all require urgent veterinary attention.

The vet will perform a full physical exam and palpate the swollen area to check for pain, inflammation, and abnormalities. They may run lab tests like a complete blood count, urinalysis, and blood chemistry panel to assess for infection. Diagnostic imaging such as ultrasound or X-rays can check for fluid buildup, masses, or testicular torsion.

Based on the exam and test findings, the vet will determine the appropriate treatment which may include antibiotics, anti-inflammatories, or surgery. It’s crucial not to delay a veterinary visit if swelling occurs after breeding as certain conditions can quickly become emergencies. Getting an accurate diagnosis and prompt treatment from the vet can help prevent complications and relieve your dog’s discomfort.

Diagnostic Tests

If a vet suspects testicular swelling or infection, they will likely perform several diagnostic tests to determine the cause. Some common tests include:

  • Physical exam – The vet will thoroughly examine the dog’s genital area and perform a rectal exam to check for abnormalities.
  • Urinalysis – A urine sample is analyzed to check for signs of infection, crystals, or other abnormalities.
  • Bloodwork – Blood tests can reveal increased white blood cells if infection is present and look for other systemic issues.
  • Cultures – The vet may take samples from the affected area and grow cultures to identify any bacterial infections present.
  • Ultrasound – An ultrasound of the scrotum can allow the vet to visualize the testicles and surrounding structures.
  • Biopsy – Taking a tissue sample for examination under a microscope can help diagnose testicular cancer.

The results of these tests will enable the vet to determine if the swelling is due to infection, cancer, trauma, or another cause. This will inform the proper treatment approach. Regular testing may be required during treatment to monitor the dog’s response and progress.


The treatment for testicular swelling in male dogs will depend on the underlying cause. Some common treatments may include:

  • Antibiotics like amoxicillin to treat infections causing inflammation and swelling (
  • Anti-inflammatory medication like carprofen to reduce pain and swelling (
  • Cold compresses applied to the testicles and scrotum area to reduce swelling and discomfort (
  • Hormone therapy to reduce testosterone production and swelling if the cause is testicular tumors
  • Surgery to remove infected, damaged, or cancerous testicles if they cannot be treated with medication

Veterinarians may recommend a combination of treatments depending on the specific condition causing the swelling. Quick diagnosis and treatment is important to relieve pain and prevent long-term complications in the dog’s reproductive health.

Recovery Process

The recovery process for male dog swelling after a female dog’s heat cycle can vary depending on the underlying cause. However, most dogs should start to see improvement within 5-7 days after initiating treatment. According to WagWalking, dogs with testicular swelling and inflammation may need 7-10 days of rest along with anti-inflammatory medication and cold compresses to fully recover.

It’s important not to resume normal activity too soon, as this can aggravate the swelling and delay healing. Take short, gradual walks for the first week and avoid strenuous exercise or playtime. Your vet will likely recommend restricting activity for at least 10-14 days. Jumping, climbing stairs, and roughhousing should be avoided during this time.

With proper treatment and rest, most cases of male dog swelling after a female dog’s heat cycle resolve without complications. However, in severe cases like testicular torsion, castration may be necessary. Overall, the prognosis is good if caught and managed early on. Monitor your dog closely during recovery and follow up with your vet to ensure the swelling continues to subside.


There are several ways to help prevent swelling and other problematic behaviors in male dogs when females are in heat:

Limit Exposure – Keep male and female dogs separated during the female’s heat cycle. This may involve keeping them in separate rooms, using baby gates, or boarding one of the dogs elsewhere during this time. Reduce opportunities for the male to be exposed to the female’s scent. source

Neuter the Male Dog – Neutering eliminates the production of male hormones that cause arousal and the desire to mate. According to veterinarians, neutering has a calming effect and can reduce frustration in males when females are in heat. source

Use Odor Reducers – Use scented sprays designed to mask a female dog’s scent while she’s in heat. Washing the female frequently with a mild dog shampoo can also help reduce her scent. source

Provide Physical & Mental Exercise – Give the male dog plenty of exercise and mental stimulation to distract him from the female in heat. Take him on long walks, play fetch, or give him interactive puzzle toys. A tired, mentally stimulated dog is less likely to be fixated on the female.

Scroll to Top