What can cause sperm abnormalities in dogs and cats?

Sperm abnormalities can have many causes, including infection, hormonal imbalance, genetic factors, or environmental influences. The specific cause needs to be identified through veterinary examination and testing — speak to your vet for a full assessment.

What tests are needed to assess sperm health?

Common tests include semen analysis, palpation of the testes and reproductive organs, blood hormone panels, and a basic blood biochemistry panel. These help identify the likely cause and assess fertility.

What information should I bring to the vet?

It is helpful to bring a record of when symptoms started, notes on dietary and weight changes, photos or videos of any discharge, a list of current medications, and any previous test reports to aid the vet's assessment.

Can sperm abnormalities affect breeding?

Sperm abnormalities may reduce the likelihood of conception or affect breeding outcomes, but the specific impact depends on semen analysis results and specialist evaluation. Consult your vet or a reproductive specialist for guidance.

How much do the tests and treatment for this condition usually cost?

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

Disease Guide

Sperm Abnormalities in Dogs & Cats: Symptoms, Testing & Care Guide [2025]

Sperm morphology abnormalities affecting fertility in dogs and cats

Take 1 minute to check the symptoms first

Last updated: 2026/01/06

Pethealthmap Editorial Team

Sources: AVMA, ACVIM, National Taiwan University Veterinary Hospital

When to See a Vet

Seek emergency care immediately

•Visible bloody discharge from the penis or scrotum
•Persistent high fever or severe lethargy with refusal to eat
•Difficulty urinating or frequent heavy hematuria

Schedule a clinic visit soon (within 24–72 hours)

•Noticeably reduced energy or activity lasting more than two days
•Decreased appetite or change in eating habits for more than 24 hours
•Abnormal discharge present but pet is otherwise alert and can be monitored

01What symptoms indicate something is wrong?

When dogs or cats have sperm abnormalities, they often show non-specific changes such as lethargy, reduced appetite, and altered elimination habits. Some cases also present with genital discharge or blood-tinged secretions that require further veterinary investigation.

Lethargy or noticeably reduced activity level
Decreased appetite or changes in eating habits
Changes in the frequency or character of urination or defecation
Abnormal discharge or blood-tinged fluid from the penis or scrotum
Unexplained weight change over a short period

Seek emergency care immediately if you notice the following symptoms:

⚠️ Obvious blood-tinged discharge from the penis or scrotum
⚠️ Persistent high fever, extreme lethargy, or refusal to eat
⚠️ Difficulty urinating or frequent, heavy blood in the urine

02How to assess the situation at home: key observations and when to seek emergency care

Systematic home observation and recording of key information before your appointment helps the vet make a faster assessment and arrange the right tests.

Note changes in alertness and activity level, including when they started
Measure and record food and water intake daily
Track the timing, frequency, and character of urination and defecation
If semen or discharge is present, note the amount, colour, and frequency
Use a phone to record videos of any abnormal behaviour or discharge
Keep a symptom diary and arrange a clinic visit as soon as possible

03How will the vet diagnose the condition? Common diagnostic tests

The vet will begin with a physical examination and combine it with laboratory tests and imaging to evaluate sperm quality and reproductive organ function.

Semen analysis

evaluating sperm count, morphology, and motility

Reproductive palpation

examining the penis, scrotum, and testes

Hormone blood panel

assessing endocrine function and reproductive hormones

Complete blood count and biochemistry

evaluating overall health and underlying disease

Urinalysis

ruling out urinary tract infection or haematuria

Imaging (X-ray or CT scan)

assessing the pelvis or any suspected masses

04Post-diagnosis treatment and care: medications, dietary adjustments, and home care

Treatment depends on the test findings and may include medication, lifestyle adjustments, and regular monitoring to assess progress.

A treatment plan — which may include medication or other interventions — will be tailored to the test results
Attend scheduled follow-up visits for repeat semen and blood tests
Improve diet and manage body weight to support overall health
Minimise stress and avoid excessive exercise during home recovery
Arrange follow-up imaging or lab tests to monitor treatment response
If breeding is desired, seek a specialist referral for further reproductive evaluation

05What to prepare before your vet visit: key information to help your vet reach a diagnosis

Note when symptoms began, how they have progressed, and how often they occur

List recent changes in diet, water intake, and body weight

Record the amount, colour, and timing of urination, defecation, and any semen or discharge

Bring a list of current medications and supplements

Bring any previous test reports or video recordings of abnormal behaviour

Contact a clinic that offers semen analysis in advance to book an appointment

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.

Related Symptoms (You May Also Be Looking For)

Lethargy

Decreased activity

Anorexia

Loss of appetite

Infertility

Inability to reproduce