What are the common causes of epididymitis or orchitis?

Common causes include bacterial infection, trauma, or spread of a urinary tract infection to the reproductive organs. Some cases are related to systemic immune conditions or other infections. If the cause is uncertain, a veterinary examination and culture test is recommended to confirm the diagnosis.

How long does it usually take to see improvement with treatment?

With appropriate antibiotic therapy guided by test results, clinical signs such as fever and pain typically improve within a few days. However, the full course of treatment and follow-up may take 2–6 weeks; attend check-ups as directed by your vet.

Can the affected area be cleaned or treated at home?

Keeping the scrotum clean and dry at home is helpful. Prevent your pet from licking or scratching the area. However, do not self-medicate or attempt to drain an abscess; seek veterinary care promptly if the condition is severe or worsening.

Is bacterial culture and sensitivity testing necessary?

If there is discharge or pus, culture and sensitivity testing can help identify the most appropriate antibiotic, improving treatment outcomes and reducing the risk of antibiotic resistance. Discuss with your vet whether sampling is appropriate.

How much do the tests and treatment usually cost?

Costs vary by clinic and region — ask your vet for an estimate before proceeding.

Disease Guide

Epididymitis & Orchitis in Dogs and Cats: Scrotal Swelling, Diagnosis & Treatment Guide [2025]

Epididymitis and orchitis are infections or inflammations of the reproductive organs that cause testicular swelling and pain. Antibiotic treatment is usually effective, but recurrent infections may require neutering.

Take 1 minute to check the symptoms first

Last updated: 2026/01/05

Pethealthmap Editorial Team

Sources: AVMA, WSAVA, National Taiwan University Veterinary Hospital

When to See a Vet

Seek Emergency Care Immediately

•Severe scrotal swelling with skin breakdown or bleeding
•Persistent high fever with significantly impaired alertness or responsiveness
•Prolonged inability to urinate or sudden loss of consciousness

Schedule a Clinic Visit Soon (within 24–72 hours)

•Noticeable scrotal enlargement while still able to walk normally
•Clear flinching or yelping when the scrotum is lightly touched
•Marked decrease in appetite and activity level compared to usual

01What symptoms indicate a problem?

Epididymitis or orchitis can cause localised and systemic signs of pain and discomfort. Below are common visible symptoms and situations that warrant prompt attention.

Noticeably reduced appetite or refusal to eat
Avoidance or pain response when the abdomen or scrotum is touched
Scrotal enlargement, redness or warmth to the touch
Reduced activity, low energy or lethargy
Changes in urination such as increased frequency, blood in urine or difficulty urinating

Seek emergency care immediately if you notice the following symptoms:

⚠️ Severe scrotal swelling with skin breakdown or bleeding
⚠️ Persistent high fever with significantly deteriorated mental status
⚠️ Inability to urinate for an extended period or sudden loss of consciousness

02How to assess the situation at home? Key home observation points and emergency criteria

Observing and recording changes in appetite, elimination and activity at home helps your vet quickly assess the condition and prioritise treatment.

Record when appetite changes began and the daily food intake amount
Note changes in daily water consumption and urination frequency
Observe and record any blood or colour changes in stools
Take photos or short videos of scrotal or abdominal swelling for comparison
If symptoms worsen significantly or become acute, arrange a veterinary assessment as soon as possible

03How will the vet diagnose the condition? Common examination steps

Your vet will combine a physical examination with laboratory and imaging tests to identify the source of inflammation and confirm whether infection or complications are present.

Physical examination

palpation of the scrotum and abdomen to assess pain and swelling

Cytology

sampling scrotal discharge or smears to examine inflammatory cells

Bacterial culture and sensitivity testing

to identify the causative organism and any antibiotic resistance

Blood work, serology or PCR

to evaluate systemic infection or identify specific pathogens

Imaging (scrotal ultrasound or advanced CT scan) to evaluate tissue changes

04How to treat and care for your pet after diagnosis? Medications, dietary adjustments and care guide

Treatment typically focuses on anti-infective therapy and supportive care, with medications adjusted based on test results and regular follow-up of clinical and culture findings.

Antibiotics or other medications selected and adjusted based on test results
Surgical intervention may be required in cases of abscess formation or tissue necrosis
Home care: keep the scrotum clean and dry and prevent your pet from licking or biting the area
Follow up regularly as directed to check wound healing and culture results
Ensure adequate nutrition and hydration throughout the treatment period
If recurrence or slow improvement occurs, seek specialist referral for further follow-up

05What to prepare before your vet visit? Key information to help your vet quickly identify the cause

Record when symptoms started and whether they are continuous or intermittent

Prepare a few days of food intake, water consumption and elimination records

List all current and recent medications or supplements

Take photos or short videos of the affected area for reference

Bring any previous test reports or culture results if available

Consider booking a clinic that has culture and imaging capabilities before your visit

This content is for reference only and cannot replace a professional veterinary diagnosis. If your pet shows signs of illness, please seek veterinary care promptly.