# Breeding Soundness Examination of the Canine Male


## Key Takeaways

- The Canine Breeding Soundness Examination (BSE) is a multi-component assessment to predict a male dog's fertility potential by evaluating history, physical condition, semen quality, and reproductive tract health.
- Semen evaluation includes gross assessment of volume, color, and consistency, followed by microscopic analysis of mass and individual motility, sperm morphology (identifying primary vs. secondary defects), and sperm concentration using methods like hemocytometry or spectrophotometry.
- The spermatogenic cycle in dogs takes approximately 62 days, meaning seminal deterioration from insults like febrile illness or glucocorticoid therapy will manifest 2-3 months post-event, necessitating interpretation of results in this temporal context.
- Testicular ultrasound and Doppler velocimetry can provide adjunctive information on testicular volume, symmetry, parenchymal echogenicity, and blood flow, but their predictive value for future semen quality in dogs remains uncertain and they are not essential for routine BSE.
- Interpretation of BSE results integrates all findings, often using a scoring system, to classify fertility as satisfactory, marginal, or unsatisfactory, acknowledging that conception is multifactorial and influenced by the female, timing, and management.
- Common errors in BSE include unreliable morphology assessment due to insufficient cell counts or improper staining, misinterpreting motility due to temperature shock or delayed evaluation, and overinterpreting single abnormal findings without repeat collections.

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The breeding soundness examination (BSE) of the canine male is a structured, repeatable assessment intended to estimate the probability that a dog will achieve conception when bred to a fertile female under appropriate management. This article provides a practical framework for performing the examination in general practice, covering history taking, physical examination, semen collection, laboratory evaluation, and interpretation of results. It is written for the practicing veterinarian who performs canine breeding evaluations and needs a defensible, evidence-informed approach to case management.

The BSE answers a specific clinical question: does this male have the anatomical, physiological, and seminal characteriztics compatible with fertility? It does not guarantee conception, because fertility is a multifactorial trait involving the female, timing, and breeding management. The examination identifies males with obvious or probable impairment and provides a baseline for monitoring individual dogs over time. This article covers the complete examination procedure and interpretation, excluding detailed artificial insemination techniques.

## At a Glance

| Parameter | What to Assess | Clinical Relevance |
|---|---|---|
| History | Prior conceptions, libido, mating behavior, illness, medications | Identifies acquired causes of infertility |
| Physical examination | Testicular size, symmetry, consistency, prostate, penis, prepuce | Detects structural or inflammatory disease |
| Testicular volume | Caliper or ultrasound measurement | Correlates with spermatogenic mass |
| Sperm concentration | Hemocytometer or spectrophotometer | Total sperm output per ejaculate |
| Sperm motility | Subjective or computer-assisted | Reflects viability and flagellar function |
| Sperm morphology | Stained smear, 100 to 200 cells | Identifies primary versus secondary defects |
| White blood cells | Semen smear or cytology | Suggests inflammation or infection |
| Libido and mounting | Observed during collection | Required for natural breeding or collection |

## Physiology of Canine Spermatogenesis and Ejaculation

Spermatogenesis in the dog occurs within the seminiferous tubules, which constitute approximately 70% to 80% of testicular mass. The process from spermatogonial stem cell to mature spermatozoon takes approximately 62 days in the dog, followed by transit through the epididymis for an additional 1 to 2 weeks. This timeline matters clinically: a dog exposed to a febrile illness, glucocorticoid therapy, or testicular insult will show seminal deterioration 2 to 3 months after the event, not immediately. The clinician must therefore interpret a poor ejaculate in the context of events from the preceding 8 to 10 weeks.

Testicular blood flow is the delivery pathway for oxygen, nutrients, and regulatory hormones. The high metabolic demand of the seminiferous epithelium and the relatively low oxygen tension within the tubules make the testis vulnerable to ischemic and thermal injury. Color Doppler ultrasonography has been investigated as a non-invasive method to assess testicular perfusion in domestic animals, with pulsed-wave Doppler velocimetric parameters showing associations with seminal quality across species [New Approaches to Assess Fertility in Domestic Animals: Relationship between Arterial Blood Flow to the Testicles and Seminal Quality](https://pubmed.ncbi.nlm.nih.gov/33374860/). In dogs specifically, testicular artery resistance index and pulsatility index have been measured, but their predictive value for future semen quality remains uncertain [Canine reproductive ultrasound examination for predicting future sperm quality](https://pubmed.ncbi.nlm.nih.gov/27807899/). These techniques are adjunctive instead of essential for the routine BSE.

The dog ejaculates in three fractions. The first fraction is a small volume of clear, prostatic fluid that flushes the urethra. The second fraction is the sperm-rich ejaculate, which in most dogs is produced during active pelvic thrusting. The third fraction is a larger volume of prostatic fluid that follows. Collection technique must separate these fractions to obtain an accurate sperm count, because the third fraction can dilute the ejaculate substantially without adding spermatozoa.

## Indications for Breeding Soundness Examination

The BSE is indicated in several clinical scenarios. Pre-purchase or pre-breeding evaluation of an untested male is the most common indication. A male with a known or suspected fertility problem, such as failure to conceive bitches, poor libido, or abnormal ejaculate, requires a diagnostic BSE. A male that has recovered from illness or injury affecting the reproductive tract should be re-evaluated after one full spermatogenic cycle. Finally, a baseline BSE in a young male intended for breeding provides a reference for future comparisons.

The examination is also used in the context of assisted reproductive technologies. Semen cryopreservation requires a pre-freeze assessment to determine whether the ejaculate is likely to withstand the freeze-thaw process. Males with poor initial motility or high morphological defect rates are poor candidates for freezing, and the BSE identifies these individuals before resources are committed.

## Components of the Examination

The complete BSE consists of four integrated components: history, physical examination, semen collection and evaluation, and additional diagnostic testing when indicated. Each component contributes independent information, and the final interpretation integrates all findings. A male with excellent semen quality but severe hip pain that prevents mounting is not a satisfactory breeder. Conversely, a male with normal libido and mating behavior but azoospermia is clearly unsatisfactory. The Society for Theriogenology provides professional resources and guidelines for breeding soundness evaluation that practitioners should consult for current recommendations [Society for Theriogenology Resources](https://www.therio.org/).

The history should include the dog's age, breed, prior breeding history, number of litters sired, conception rates, and any known infertility in bitches bred to this male. Current and recent medications are relevant because glucocorticoids, ketoconazole, and some antibiotics can impair spermatogenesis. A history of trauma, surgery, or disease involving the reproductive tract or hindquarters should be elicited. The owner should also report observed libido, mounting behavior, and any difficulty with intromission or ejaculation.

The physical examination begins with general body condition and locomotion. The reproductive examination includes inspection of the penis and prepuce for lesions, discharge, or phimosis. The testes are palpated for size, symmetry, and consistency, and the epididymides are assessed for enlargement or pain. The prostate is evaluated by rectal palpation in larger dogs. Testicular volume can be estimated using calipers or ultrasonography, and it correlates with daily sperm production. Scrotal circumference measurement, while standard in bulls, is less commonly used in dogs because of breed variation in testicular size [Associations between sperm abnormalities, breed, age, and scrotal circumference in beef bulls](https://pubmed.ncbi.nlm.nih.gov/22468020/). The clinician should note that breed-specific norms for testicular dimensions are not well established in the dog, so serial measurements in an individual are more informative than comparison to a population standard.

## Semen Collection Technique

Semen is collected by manual stimulation in the presence of a teaser bitch, ideally one in standing estrus. The clinician or trained technician grasps the penis cranial to the bulbus glandis through the prepuce and applies rhythmic pressure. Once erection and pelvic thrusting begin, the penis is rotated caudally and the prepuce is pushed back to expose the bulbus. The sperm-rich second fraction is collected into a warmed, graduated collection vial or a latex cone attached to a centrifuge tube. The third fraction is collected separately if total ejaculate volume or prostatic function is being assessed.

Collection conditions affect semen quality. The collection area should be quiet, non-slippery, and free of distractions. The teaser bitch should be restrained to prevent injury to the male. If the male fails to ejaculate, the clinician should distinguish between lack of libido, inadequate stimulation, and a physical inability to ejaculate. A second collection attempt after a short rest is sometimes successful. Two ejaculates collected 1 hour apart can be evaluated if the first is poor, because the second ejaculate in dogs often has higher sperm concentration.

The ejaculate should be evaluated immediately after collection. Spermatozoa are sensitive to temperature shock, and the collection vessel should be maintained at body temperature. Prolonged exposure to room temperature, lubricants, or water can reduce motility and damage the acrosome. The clinician should record the time of collection and the time of evaluation to document any delay.

## Semen Evaluation: Gross and Microscopic Assessment

Immediately after collection, evaluate the raw ejaculate for volume, color, and consistency. Normal canine semen is opalescent white to pale cream. Yellow discoloration suggests urine contamination, red or brown indicates blood, and a watery appearance often accompanies low sperm concentration. Record the volume of each fraction separately when the three-part collection technique is used. The prostatic fraction typically constitutes the largest volume and is clear and watery.

Microscopic evaluation begins with subjective assessment of mass motility on a warm slide. Place one drop of raw semen on a prewarmed slide and evaluate at 100x to 200x magnification. Mass motility reflects the energy of the sample and is graded on a scale of 0 to 5, where 0 is no motion and 5 is vigorous swirling. A score of 4 or higher is expected in a fertile dog. Samples with poor mass motility require individual sperm motility assessment to distinguish asthenozoospermia from collection artifact.

Individual motility is assessed after diluting semen in an extender or physiologic saline at a ratio of approximately 1:10. Evaluate at 200x to 400x magnification on a warmed stage. Report the percentage of progressively motile spermatozoa and the rate of forward progression on a 0 to 4 scale. Normal dogs typically exceed 70% progressive motility with a rate score of 3 or higher. Sperm velocity and trajectory are subjective but clinically useful. Cold shock, contact with water, or prolonged exposure to latex can rapidly depress motility, so interpret poor motility in light of collection technique before declaring a dog subfertile.

## Sperm Morphology and Concentration

Morphologic evaluation requires stained smears. Eosin-nigrosin stains allow simultaneous assessment of viability and morphology, while Diff-Quik type stains provide superior nuclear detail. Prepare smears from the sperm-rich fraction and allow them to air dry. Count at least 100 spermatozoa under oil immersion and classify defects as primary (head and midpiece abnormalities) or secondary (tail defects). Common abnormalities in the dog include detached heads, proximal and distal cytoplasmic droplets, bent tails, and coiled tails. The percentage of morphologically normal spermatozoa in fertile dogs is generally accepted as greater than 60% to 70%, although published thresholds vary. In bulls, morphology thresholds are more rigorously standardized, with greater than 70% normal sperm and fewer than 20% defective heads required for satisfactory classification, and similar reasoning is often applied to dogs.

Sperm concentration is measured using a hemocytometer, spectrophotometer, or computer-assisted semen analysis system. The hemocytometer remains the reference method. Dilute semen 1:100 in a white blood cell pipette or fixed-volume dilution, load the chamber, and count the appropriate grid squares. Calculate concentration and multiply by ejaculate volume to obtain total sperm output. Normal dogs produce 200 million to over 1 billion spermatozoa per ejaculate, with considerable breed and size variation. Total sperm output is a more meaningful fertility indicator than concentration alone, because a dog with low concentration but high volume may still deliver an adequate insemination dose.

## Testicular Ultrasound and Vascular Assessment

B-mode ultrasonography of the scrotal contents complements semen evaluation. Measure testicular length, height, and width to calculate volume using the ellipsoid formula. Compare the right and left testes, asymmetry exceeding 20% warrants investigation. The normal parenchyma is homogeneous and medium echogenicity. Hyperechoic foci may indicate fibrosis or mineralization, while hypoechoic regions suggest edema, neoplasia, or orchitis. In one study of dogs, mean testicular echogenicity was positively related to future sperm motility, although no ultrasound parameter predicted total sperm output or live normal sperm percentage. This finding supports the use of ultrasound as an adjunct instead of a standalone predictor of fertility.

Color and pulsed-wave Doppler evaluation of the testicular artery adds functional information. The testicular artery is imaged at the spermatic cord, marginal, or capsular locations. Resistance index and pulsatility index are calculated from the spectral waveform. In domestic animals, pulsed-wave Doppler velocimetric parameters correlate with seminal quality, and Doppler assessment is gaining relevance for evaluating testicular function. Testicular blood perfusion is critical because the seminiferous tubules have high metabolic demand and low oxygen tension. However, Doppler measurements vary with measurement site, breed, season, and laterality, and reference intervals for dogs are not firmly established. Use Doppler findings as supportive evidence of testicular health instead of as a sole criterion for fertility classification.

## Interpretation and Fertility Classification

Integrate all findings into a fertility classification. No single parameter predicts fertility with certainty. The Society for Theriogenology provides professional resources for breeding soundness evaluation standards and interpretation. The MSD Veterinary Manual offers species-specific reference values for canine semen parameters.

A practical scoring system assigns points across five domains: libido and collection success, total sperm output, progressive motility, morphology, and testicular ultrasound findings. Each domain is scored 0 to 2, with 2 representing satisfactory, 1 marginal, and 0 unsatisfactory. A total score of 8 to 10 supports a satisfactory potential breeder classification. A score of 5 to 7 indicates questionable fertility with recommendation for re-evaluation in 60 days. A score below 5 supports an unsatisfactory classification. This system is a clinical framework, not a validated predictive model, and should be adjusted for breed, age, and intended use.

| Parameter | Satisfactory | Marginal | Unsatisfactory |
|-----------|-------------|----------|----------------|
| Total sperm output | > 300 million | 100 to 300 million | < 100 million |
| Progressive motility | > 70% | 50% to 70% | < 50% |
| Morphologically normal | > 70% | 60% to 70% | < 60% |
| Testicular volume asymmetry | < 10% | 10% to 20% | > 20% |
| Doppler resistance index | Within published range | Borderline | Elevated or absent flow |

## Documentation and Reporting

Record the collection method, any sedation used, ejaculate fractions, and all quantitative results. Note the date and time of collection relative to the last ejaculation, because recent ejaculation lowers sperm output. Include a description of testicular palpation and ultrasound findings. State the fertility classification and the basis for it. Provide a recheck interval when the classification is marginal. Advise the owner that a single satisfactory examination does not guarantee conception, because fertility depends on the female, timing, and breeding management. Where international movement of dogs or semen is planned, consult the World Organization for Animal Health terrestrial standards for applicable health requirements. The American Veterinary Medical Association provides practice resources on professional conduct and client communication that apply to breeding soundness examinations.

Repeat examination timing depends on the spermatogenic cycle. Because canine spermatogenesis and epididymal transit require approximately 60 days, a recheck at 60 days after a marginal or unsatisfactory result allows assessment of a new cohort of spermatozoa. If the initial collection was technically poor, repeat the examination within 7 to 14 days before attributing the findings to testicular dysfunction.

## Complications and Failure Modes

The most common complication of semen collection is failure to ejaculate, usually from inadequate stimulation, a distracting environment, or a bitch not in standing estrus. Less commonly, prostatic fluid may be absent from the third fraction, which does not affect fertility but may complicate evaluation of total ejaculate volume. Hematospermia can follow aggressive prostatic massage or collection technique and usually resolves with rest. Urethral trauma from an overzealous collection cone is rare but should be suspected when fresh blood appears at the start of the ejaculate instead of throughout.

Early detection depends on systematic observation. Record the number of mounts, the time to erection, and the character of each fraction. A dog that mounts readily but produces only the first fraction may have a behavioral or prostatic problem. A dog that ejaculates but shows pain on palpation of the prostate warrants ultrasound and possible culture. Retrograde ejaculation into the bladder is uncommon in dogs but should be considered when the ejaculate volume is unexpectedly small and the post-ejaculatory urine sample contains sperm.

## Common Errors in Examination and Interpretation

Less experienced clinicians most often err in sperm morphology assessment. Counting fewer than 100 sperm per slide, or evaluating only the head region of the smear, produces unreliable percentages. The corrective action is to count at least 100 sperm, ideally 200, and to scan the entire smear systematically. Another frequent error is classifying distal midpiece reflexes or bent tails as primary defects when they are often artifacts of cold shock or improper smear preparation. Warm all slides and stain solutions before use and evaluate a second smear if the first shows an unusual proportion of tail defects.

Concentration estimates from a single drop are unreliable. Use a hemocytometer or a validated spectrophotometric method, and dilute the sample when sperm density is high. Clinicians who skip the motility assessment within 10 minutes of collection may report falsely low motility. Keep the sample at body temperature and evaluate motility before preparing the morphology smear.

A third error is overinterpreting a single abnormal finding. A dog with a low percentage of morphologically normal sperm on one collection may have a transient stress-related decline. Repeat the collection after 7 to 14 days before classifying the dog as unsatisfactory. Conversely, a single normal collection does not guarantee sustained fertility, particularly in older dogs or those with progressive testicular disease.

## Limitations of the Evidence and Areas of Dispute

The evidence base for canine breeding soundness examination is thinner than for bulls or stallions. Most published thresholds for normal sperm morphology and motility in dogs derive from expert consensus instead of large prospective fertility trials. The Society for Theriogenology provides professional resources and examination guidelines, but the canine standards lack the formal, widely adopted classification system used in bovine practice [Society for Theriogenology professional resources](https://www.therio.org/).

Testicular ultrasound parameters illustrate the gap. B-mode measurements of testicular volume and echogenicity correlate with semen quality at the time of examination, but one prospective study found that no ultrasound parameter predicted future total sperm output or percentage of live normal sperm, with only mean testicular echogenicity positively related to future sperm motility [canine reproductive ultrasound and future sperm quality](https://pubmed.ncbi.nlm.nih.gov/27807899/). Doppler velocimetric indices of testicular blood flow show promise as objective markers of testicular function in domestic species, but the literature is dominated by farm animal studies, and breed, season, and measurement location affect the values [Doppler assessment of testicular blood flow in domestic animals](https://pubmed.ncbi.nlm.nih.gov/33341504/). Whether these parameters will prove clinically useful in dogs remains an open question.

Expert opinion also differs on the minimum acceptable percentage of morphologically normal sperm. Some clinicians accept 60% normal sperm for breeding, while others require 70% or higher. The dispute reflects the absence of canine fertility trials comparable to those performed in bulls, where abnormal chromatin condensation has been shown to lower fertility and can be compensated by increasing the number of normal spermatozoa in the insemination dose [flow cytometric evaluation of abnormal chromatin condensation in bovine sperm](https://pubmed.ncbi.nlm.nih.gov/7525953/). Until similar data exist for dogs, the clinician should interpret morphology thresholds as guides instead of absolute cutoffs.

## Referral, Consultation, and Reporting

Referral to a theriogenology specialist is appropriate when the examination reveals azoospermia, severe oligospermia, or a high percentage of primary sperm defects that do not improve on repeat collection. A specialist can perform testicular biopsy, hormonal stimulation testing, or advanced imaging. A veterinary diagnostic laboratory should be consulted when a computer-assisted sperm analyzer is needed for objective motility or concentration data, or when sperm chromatin structure assay testing is desired.

Regulatory reporting is rarely required for canine breeding soundness examinations in private practice. However, veterinarians performing examinations for dogs intended for international movement should consult the World Organization for Animal Health terrestrial animal health standards, which address disease surveillance and trade-related health certification [WOAH terrestrial animal health standards](https://www.woah.org/en/what-we-do/standards/codes-and-manuals/terrestrial-code-online-access/). The MSD Veterinary Manual provides additional species-specific clinical reference material for practitioners [MSD Veterinary Manual professional edition](https://www.msdvetmanual.com/).

## Troubleshooting Guide

| Observation | Likely Cause | Discriminating Check |
| --- | --- | --- |
| No ejaculate after 10 minutes | Inadequate stimulation, estrous bitch not present, or behavioral inhibition | Change teaser bitch, move to quiet area, allow longer foreplay |
| Only first fraction produced | Incomplete ejaculation or prostatic dysfunction | Palpate prostate, assess third fraction on repeat collection |
| Blood in ejaculate | Urethral trauma or prostatic disease | Note timing of blood, perform prostatic ultrasound and cytology |
| Low motility within 10 minutes | Cold shock, delayed evaluation, or testicular disease | Repeat collection with warmed equipment, evaluate immediately |
| High percentage of tail defects | Smear artifact or cold shock | Prepare second smear with warmed stain, compare results |
| Azoospermia | Retrograde ejaculation, obstruction, or testicular failure | Examine post-ejaculatory urine, palpate epididymides, measure testicular volume |

## Frequently Asked Questions

### How Should I Proceed When a Dog Is Difficult to Collect From or Refuses to Ejaculate?

Begin by reassessing the environment. Move the dog to a quiet, non-slippery area with minimal distractions and allow a brief acclimation period. Confirm the teaser bitch is in standing estrus, as proestrus or anestrus females often fail to stimulate mounting. Manual stimulation alone, without a teaser, is effective in many experienced stud dogs. If the dog mounts but fails to achieve penile erection or thrusting, check for pain from orthopedic disease, prostatitis, or preputial adhesions. A calm, patient approach with repeated short sessions over several days is often more productive than prolonged struggling. If collection remains unsuccessful after multiple attempts, perform a full physical examination and testicular ultrasound to rule out structural pathology before considering hormonal or behavioral referral.

### What Minimum Equipment Is Needed for a Reliable Field Assessment of Semen Quality?

A microscope with 100x and 400x magnification, warmed glass slides and coverslips, a graduated collection vial, and a method for warming the ejaculate to 37°C are the minimum requirements. A phase-contrast or bright-field microscope is acceptable for motility estimation and morphology assessment using stained smears. Eosin-nigrosin stain is inexpensive and allows permanent records. A hemocytometer or Makler chamber provides accurate concentration counts. If a spectrophotometer or computer-assisted sperm analyzer is unavailable, subjective motility scoring and manual morphology counting remain clinically valid. Testicular ultrasound, including Doppler assessment of testicular blood flow, adds diagnostic value but is not required for a basic breeding soundness examination [Advances in applications of color Doppler ultrasonography in the](https://pubmed.ncbi.nlm.nih.gov/33341504/). Prioritize consistent technique and standardized handling over equipment sophistication.

### How Do I Interpret a Breeding Soundness Examination in a Young Dog With Poor Semen Quality?

A single poor ejaculate in a dog under 18 months of age does not confirm infertility. Spermatogenesis continues to mature, and ejaculate quality often improves with age and sexual experience. Repeat the collection after a two to four week interval, ensuring a seven day sexual rest period before each attempt. Compare total sperm output, motility, and morphology across collections. If abnormalities persist, investigate for concurrent illness, fever within the past 60 days, recent medication, or heat stress. Testicular ultrasound can identify parenchymal lesions or reduced volume that may explain poor output [Canine reproductive ultrasound examination for predicting future sperm quality](https://pubmed.ncbi.nlm.nih.gov/27807899/). Advise the owner that a single suboptimal result warrants re-evaluation instead of a permanent fertility classification.

### What Records Should I Maintain From a Breeding Soundness Examination?

Document the dog's signalment, body condition score, and testicular measurements including scrotal width and individual testicular length, width, and height. Record the collection method, teaser use, number of mounts, and any behavioral observations. For each ejaculate, note volume, color, concentration, total sperm output, progressive motility percentage, and morphology findings with separate counts for primary and secondary defects. Include ultrasound images and Doppler parameters if performed. Store stained morphology slides for at least one year. Provide the owner with a written report that includes the fertility classification and any recommendations. These records support future comparisons, legal disputes, and breeding management decisions. Professional guidelines from organizations such as the Society for Theriogenology offer standardized reporting templates [Society for Theriogenology Resources](https://www.therio.org/).

### How Does the Canine Breeding Soundness Examination Differ From the Bull Standard?

The bull standard relies heavily on scrotal circumference as a predictor of sperm output and uses defined thresholds for satisfactory classification [Associations between sperm abnormalities, breed, age, and scrotal circumference](https://pubmed.ncbi.nlm.nih.gov/22468020/). Canine examination places greater emphasis on ejaculate collection and individual sperm assessment because breed size variation makes scrotal measurement less standardized. Bulls are typically evaluated for natural service soundness with emphasis on libido and physical conformation. Dogs are often evaluated for artificial insemination with fresh, chilled, or frozen semen, so sperm longevity and post-thaw tolerance become relevant. The canine ejaculate has three fractions, and the sperm-rich second fraction must be collected separately for accurate concentration and total count. There is no universally accepted canine threshold equivalent to the bull's 30% abnormal sperm cutoff, so interpretation relies more heavily on clinical judgment and breed-specific expectations.

### How Should I Explain an Unsatisfactory Fertility Classification to the Owner?

Use direct, objective language focused on the measured parameters instead of subjective impressions. State the specific findings, such as total sperm output below the expected range for the breed or a high percentage of morphologically abnormal sperm. Explain that the classification reflects the current ejaculate and does not necessarily mean permanent sterility. Outline the next steps, including repeat evaluation, additional diagnostics such as hormonal testing or testicular ultrasound, and referral to a theriogenologist if needed. Discuss the financial implications of further testing and the realistic prognosis for breeding. Provide written documentation of the findings and recommendations. Avoid guarantees about future fertility and emphasize that the examination estimates breeding potential, not a guarantee of conception.

## Related Clinical & Scientific Guides

* [Diagnostic Approach to Canine Infertility in the Bitch](/knowledge/veterinary-medicine/theriogenology/diagnostic-approach-to-canine-infertility-in-the-bitch)
* [Canine Neonatal Resuscitation: Protocol and Monitoring](/knowledge/veterinary-medicine/theriogenology/canine-neonatal-resuscitation-protocol-monitoring)
* [Equine Breeding Soundness Examination of the Stallion](/knowledge/veterinary-medicine/theriogenology/equine-breeding-soundness-examination-of-the-stallion)


## References and Further Reading

- [New Approaches to Assess Fertility in Domestic Animals: Relationship between Arterial Blood Flow to the Testicles and Seminal Quality.](https://pubmed.ncbi.nlm.nih.gov/33374860/). 2020.
- [Advances in applications of color Doppler ultrasonography in the andrological assessment of domestic animals: A review.](https://pubmed.ncbi.nlm.nih.gov/33341504/). 2021.
- [Flow cytometric and microscopic evaluation and effect on fertility of abnormal chromatin condensation in bovine sperm nuclei.](https://pubmed.ncbi.nlm.nih.gov/7525953/). 1994.
- [Associations between sperm abnormalities, breed, age, and scrotal circumference in beef bulls.](https://pubmed.ncbi.nlm.nih.gov/22468020/). 2011.
- [Canine reproductive ultrasound examination for predicting future sperm quality.](https://pubmed.ncbi.nlm.nih.gov/27807899/). 2017.
- [Diagnostic applications of ultrasonography to stallion's reproductive tract.](https://pubmed.ncbi.nlm.nih.gov/15961150/). 2005.
- [Society for Theriogenology Resources](https://www.therio.org/). Society for Theriogenology.
- [MSD Veterinary Manual, Professional Edition](https://www.msdvetmanual.com/). MSD Veterinary Manual.
- [American Veterinary Medical Association Practice Resources](https://www.avma.org/resources-tools). American Veterinary Medical Association.

## Related Articles

- [Equine Breeding Soundness Examination: Mare Evaluation](/knowledge/veterinary-medicine/theriogenology/equine-breeding-soundness-examination-mare-evaluation)
- [Equine Breeding Soundness Examination of the Stallion](/knowledge/veterinary-medicine/theriogenology/equine-breeding-soundness-examination-of-the-stallion)
- [Breeding Soundness Examination of Bulls: Standards and Interpretation](/knowledge/veterinary-medicine/theriogenology/breeding-soundness-examination-of-bulls-standards-and-interpretation)
- [Progesterone Testing in Canine Breeding Management](/knowledge/veterinary-medicine/theriogenology/progesterone-testing-in-canine-breeding-management)
- [Canine Artificial Insemination: Techniques and Timing](/knowledge/veterinary-medicine/theriogenology/canine-artificial-insemination-techniques-timing)

> This article is educational professional reference material for veterinary audiences. It is not a substitute for veterinary diagnosis, individual clinical judgment, current product labeling, or applicable regulatory requirements.