Breeding Soundness Examination of the Dog



  • The identification is not only important for the medical records, but is essential in the case of a pre-purchase examination.
  • Failure to positively identify an animal could cause legal problems in the future.
  • Has the dog ever been bred?
  • Has he ever sired a litter? If has bred, but never sired a litter, you may consider congenital infertility.
  • If he has sired litters, and is now infertile you may consider acquired infertility.
  • Frequency of use
  • Every other day breeding is usually acceptable.
  • Breeding more than that may be overusing the dog.
  • Has there been any exogenous drug therapy (testosterone etc.)?
  • What is the dog's habitat?
  • Is he in a kennel?
  • Is he housed with bitch? If so, the bitch may be dominant.
  • Is he 'mommies little boy', who has not had any canine contact?
  • Has he had any exposure to sex?
  • Has he been punished for showing sexual interest?
  • Has his libido changed?
  • Has he ever been shown?
  • Does he have any endocrine disease?
Physical Exam
General exam
  • Look for signs of endocrine problems.
  • Check for any congenital disorders that would make him an unsuitable potential breeder.
  • Reproductive Exam
  • Check for shape, size, and consistency.

A bad way to measure dog testes.

A good way to measure dog testes.

  • Testicular asymmetry can be indicative of testicular degeneration.
  • The normal size of the testes can be estimated using the equation:
    • log Scrotal Width = 0.324(log Body Weight) + 1.249
  • Check to make sure he is not cryptorchid. 
    • The testes should be present by 16 weeks. 
    • You can give them 6 months, but they probably will not descend. 
    • There is generally no acceptable treatment, but hCG is cited to help (100-1000 IU 2 times/week for 2 weeks) at less than 16 weeks of age
  • Check this link out about testicular prostheses for those of you who are unscrupulous!
  • Check for abnormalities, including:
  • Blood
  • Trauma
  • Tumors
  • Paraphimosis
  • Short Sheath
  • Phimosis
  • Short Penis
  • Stricture
  • Priapism - Seen with Spinal Injury
  • Os Penis -Fractures, Congenital Abnormalities
  • B. canis - covered in bitch notes. The Brucella canis status of the male should be ascertained. The rapid slide agglutination test has many false positives and a true positive titer may wane over time.
Semen collection
  • It is recommended that the dog have five days of sexual rest before obtaining a semen sample for evaluation. 
  • Conversely, if the dog has not ejaculated within ten days, a higher than normal number of detached heads and distal droplets will be seen because of prolonged storage. 
  • This problem will normally resolve if a second ejaculate is collected.



Hand collection or manual stimulation

Click to see 'semen collection'


  • Use a rubber cone and collection tube or a disposable plastic cone with end sealed.

  • Slide the prepuce over the bulbous glandis. (Erection normally occurs after intromission into the vagina.) 
  • Slide the cone over penis and apply a gentle 'stoke' pressure to penis, bulbous.

  • Three portions to ejaculate
    • Pre-sperm is the clear, first portion seen during the initial thrusts.
    • Sperm rich - White portion seen during thrusts.
    • Prostatic portion - Clear portion seen when thrusting is done. It may be seen after the 'stepover', when the dogs are rear to rear.
    • The prostatic portion is not needed for fertility. It can be collected to evaluate the prostate.

Problems with collection
No interest by male
  • An estrus bitch is helpful for collection.

  • Sperm numbers have been found to be greater if an estrual bitch is present.
  • You can give estrogen to ovariectomized bitch, but there are potential problems doing this.
  • You can use the dog pheromone, hydroxy benzoic acid, or ICG's 'Eau d' Estrus', or frozen swabs from an estrual bitch.
  • Recent work from VPI shows that 0.1 mg/kg PGF2alpha 15 minutes prior to semen collection significantly increased sperm output over that of saline or GnRH or oxytocin treated males. No comparisons were made with estrual bitches.

  • The swabs usually give a better response than synthetic chemicals. These attempts may help, or may not.
  • There may be technique problems in the collectors performance, such as being too vigorous or not vigorous enough.
  • The dog may be in an unfamiliar environment, such as a clinic. The distractions at a clinic include the smells, noise, and 'gapers'.
  • It may be better to not have the owner present, or it may be better to have the owner present, or it may make difference at all.
  • Poor sexual experience, pain with sex resulting from orchitis, prostatitis, lumbar and stifle pain may hinder collection.
Semen evaluation
  • At the 1992 Annual Meeting of the Society for Theriogenology, guidelines for the breeding soundness examination of the dog and a canine semen evaluation form were introduced.
  • The first step in semen evaluation is to examine the color of the different fractions (Fraction 1 - F1, Fraction 2 - F2 and Fraction 3 - F3). F1 and F3 should be clear, whereas F2 should be cloudy.
  • Yellow, brown or red samples may indicate the presence of urine or blood, respectively.
  • Always remember to use warm slides and equipment when examining semen samples for motility.
  • A cytologic examination of the non-sperm cells (F2 and F3) can be made by smearing a drop of semen and staining it with modified Wright's (e.g. DiffQuick). White cells indicate an inflammatory process and a culture may be indicated.
  • RBC
  • WBC
  • Macrophage - associated with azoospermia
  Whole Ejaculate F1 F2 F3
Color Opaque/White Clear White Clear
Volume (mL) < 35 0.25-3.0 0.4 - 3.0 1.0 - 2.0
pH 6.1 - 7.0 8.2 - 8.4 6.1 - 8.9 6.5 - 8.7
Conc (106/mL) 65 (10-200)      
Total Sperm (106) 390 (200 acceptable)      
Total Motility > 70%      
Progressive Motility > 80%      
Velocity Fast      
Normal cells (%) >80%      
  • The standards set forth by the Society for Theriogenology are not absolute and do not guarantee fertility or sterility, but are set forth as guidelines for the practicing veterinarian to use as a standard method to evaluate a dog's potential fertility.
  • Canine semen evaluation forms are available from the Society for Theriogenology.

Breeding with Fresh Semen

  • Artificial Insemination requires no special treatment of the semen

    • Always examine the ejaculate

      • Some dogs have grossly good looking semen that has no sperm cells!

    • The prostatic portion is not needed - you may want it to increase the volume

    • You may want to extend to have an easier volume to handle (usually do not want more that 5 to 6 cc.

    • Volumes as low as 2.2 ml and up to 3.6-3.9 ml  have been reported to yield good pregnancy rates.

    • Conception rates should be around 90% if the bitch is bred every other day while in estrus

      • At least  220 x 106cells need to be inseminated to achieve optimum fertility.

      • Vaginal AI on 3 consecutive days after acceptance of the male by the female using 50 x 106 spermatozoa in fresh semen extended 1:4 for each breeding resulted in lower fertility (20%) than AI on 3 consecutive days with 200 x 106  cells of fresh semen extended 1:1 (80%) or natural mating (80 %).

    • Vaginal AI is suffcient

    • It has been shown that if AI is performed twice, rather than once, around the time of best fertility conception rate is significantly improved.

    • There also appeared to be a trend toward increasing pregnancy rates when the number of inseminations increased

    • Transcervical breeding when the dogs have normal fertility is not needed

    • Transcervical breeding has been shown to help when fertility is low

    Breeding with Chilled Semen

  • AKC requires the proper paperwork to be completed, as well as DNA identification of the stud and the bitch before a litter can be registered.

  • Ovulation timing in the bitch is critical

  • It may take 1-2 weeks to train a male to ejaculate in a veterinary office without an estrual bitch present. Therefore, it is ideal for the dog to have had semen collected and to be familiar with the collection procedure long before any semen is actually needed. 

  • It is also advisable to prepare a “test shipment” in advance. 

    • A semen sample should be extended, stored a minimum of 24 hours in the container that will be used for transport, and evaluated after 24 hours to ensure that extension and storage do not have detrimental effects on the semen quality. 

    • Not all males’ semen  will respond to extending, cooling and storage in a similar fashion, and this ‘test shipment’ will determine the viability of the sperm after extension and cooling. 

  • Not only must the male be trained, but also shipping company schedules and venues to which they ship need to be carefully assessed well before the need arises.

    • Some destinations are serviced by shipping companies and some are best served by counter-to-counter airline shipments. 

    • In some cases shipments cannot be sent out on the appropriate day and in others shipments cannot be delivered on the appropriate day. 

  • Semen is analyzed 

  • Extension 

    • Appropriate semen extender is added to the ejaculate, usually 1:1. 

    • Semen extenders provide an energy source and buffers that enhance the survival of chilled sperm cells. 

    • Extenders can be obtained from commercial sources that are manufactured exclusively for extending canine semen (Synbiotics, San Diego, CA 92127; CLONE, Chester Springs, PA 19425; Camelot Farms, College Station, TX 77842; International Canine Semen Bank, P.O. Box 651,Sandy, OR  97055), 

    • Equine semen (Lane Mfg., Denver, CO 80231; IMV Intl, Minneapolis, MN 55430) work well and are much cheaper.

    • Homemade semen extenders can also be prepared, however proper laboratory techniques

    • The extender must be pre-warmed before adding it to the semen or the spermatozoa will suffer cold-shock. 

    • The prostatic portion of the ejaculate may have detrimental effects on the storage of canine sperm cells,

    • We found no detrimental effects on pregnancy rate or fecundity when whole ejaculates were extended 1:1 and inseminated after 24 or 48 hours of storage.

    • If the entire prostatic portion of the ejaculate is collected and the semen is extended, the volume of the resulting extended semen may be such that it cannot be completely inseminated without some vaginal reflux.

    • LSU research (EVSSAR 2007 Estoril, Portugal)

      • Semen collected from 6 dogs and extended in INRA 96 for horses

      • Diluted 1:1 and:

        • Not centrifuged

        • Centrifuged at 900 x g 10 min.

        • Stored in Bioflite 24 hr

        • Non-centrifuged sample centrifuged after storage

      • Prostatic fluid and centrifugation have no effect on the membrane integrity of the cells when semen is extended in a commercial equine extender.

      • Semen extended should have the prostatic fluid removed before storage and it should be stored at a relatively high concentration.

      • If a sample does arrive that has a large volume because the prostatic portion was included in the extended semen, centrifugation to remove the prostatic fluid yields progressive motility that is not different from removing the prostatic fluid before extension.

  • Containers

    • Containers designed to ship semen can be obtained from many of the same sources that provide canine semen extenders. (Synbiotics, San Diego, CA 92127; CLONE, Chester Springs, PA 19425; Camelot Farms, College Station, TX 77842; Bio-Flite, Anaheim Hills, CA 92807; International Canine Semen Bank, P.O. Box 651, Sandy, OR  97055). 

    • The containers usually consist of a Styrofoam box, an ice pack, and container for the semen.

    • These commercially available semen containers maintain semen well enough that acceptable pregnancy rates result. 

    • Commercially available shipping containers offer a predictable, attractive and easy way to ship semen. 

    • Many of these containers are relatively expensive when compared to the disposable equine shipping containers. 

      • A commercially available (although no longer marketed) disposable equine shipping container allowed storage of extended canine semen for up to 48 hours and the resulting pregnancy rates were equivalent to AI with fresh semen.

      • We have used other brands of  disposable equine semen  shippers and have had good success in maintaining semen viability. 

      • The advantage of the equine shippers is their lower cost than the canine semen shippers

  • The semen need not be warmed prior to AI. 

  • It is recommended to save a small aliquot of the semen for evaluation.

  • Results

    • Same as natural breeding if sufficient spermatozoa are inseminated at the proper time. 

    • Vaginal AI on 3 consecutive days  with 200 x 106  cells/breeding with semen extended 1:1 and stored for 24 hours gave the same pregnancy rates as natural mating using the same breeding schedule (80%),

    • Using  50 x 106 cells extended 1:4 and stored for 24 hours resulted in lower fertility (20%).

    • Reports from Sweden that summarized data from chilled semen inseminations show pregnancy rates can vary from 28-60% depending upon the type of extender used.

    • Pregnancy rates are lower when ovulation is timed and the number of breedings is limited compared to the 90-100% conception rates when an average of 3.9 breedings of 250-350 x 106  cells/breeding were used by us.

Frozen Semen 

  • AKC requires the proper paperwork to be completed, as well as DNA identification of the stud and the bitch before a litter can be registered.

  • Semen FreezingA simple method to freeze canine semen that is currently used by the authors’ laboratory is as follows:

    •  After the semen is collected, a complete analysis is performed. 

    • During the evaluation process, the semen is diluted 1:1 using a commercially available semen refrigeration extender (Refrigeration Media - TEST Yolk Buffer (TYB) - 9972 - Irvine Scientific, Santa Ana, CA 92705-5588) and centrifuged for 10 minutes at 900 x gravity. 

    • After centrifugation the supernatant is removed and the pellet is resuspended to a concentration of 400 x 106 cells/ml using the same refrigeration extender. 

    • This standardized semen sample is then placed in a 5o C refrigerator for one hour. 

    • During the hour of cooling, an appropriate number of 0.5 ml French straws are labeled with all the data required by the dog’s registry (name, registration number, breed, date, collection facility, etc.). 

    • After one hour, a commercial freezing extender containing 12% glycerol (Freezing Medium - TEST Yolk Buffer (TYB) with Glycerol - 9971 - Irvine Scientific, 92705-5588) that has also been kept at 5o C is added to the cooled semen solution  at 1:1, v:v, to make a final concentration of  200 x 106 cells/ml containing 6% glycerol. 

    • In a 5o C cold box, the 0.5 ml straws are then filled and the ends are sealed. 

    • The straws are then placed on a screen that is attached to a 3 cm thick Styrofoam frame, which is floating in liquid nitrogen. 

    • After 10 minutes, the straws are plunged into the liquid nitrogen before storage. 


  • Frozen semen storage

    • Semen is stored at -196o C in commercially available liquid nitrogen tanks.

    • Storage and inventory are critical aspects of frozen semen use. Meticulous records must be kept as to the location and number of straws frozen from each male. 

    • The liquid nitrogen must be routinely monitored to ensure that there is sufficient liquid nitrogen to maintain the temperature at  -196o C. If frost starts to accumulate on the tank, the semen should be transferred immediately to a new tank and the damaged tank discarded.

    • Most dog breed associations are not as concerned about the quality of the frozen semen as they are about identification of the semen. The quality control of the final product is dependent upon on the integrity of the freezing facility. 

    • Frozen semen is usually shipped in ‘dry dewars’. 

      • These are small tanks that do not contain any liquid nitrogen, but keep the sample at -196o C for a short (e.g. 1 to 2 weeks) period of time.

      • Since there is no liquid in the tanks, the airlines and shipping companies will allow their shipment, unlike liquid nitrogen tanks. 

      • If a liquid nitrogen tank is available at the shipping destination, the semen may be shipped well in advance and transferred to the liquid nitrogen tank upon arrival. 

      • If, however, a liquid nitrogen tank is not available at the insemination site, shipment should be timed in accordance with the intended date of insemination.

  • Thawing

    • Thawing procedures for frozen semen vary as much as freezing protocols. 

    • We thaw straws at 50o C for 10 seconds. 

    • Some facilities recommend thawing at lower temperatures for a longer time

    • Some recommend adding thawing media during the thaw. 

    • Best to use the freezing facility’s recommendation

  • Insemination technique

    • Vaginal

    • Laparotomy

    • Lapasoscopy

    • Norwegian

    • New Zealand transcervical

  • Fertility

    • Vaginal

      • Repeated days during the estrous cycle with adequate numbers of sperm cells conception rates of 50 and 60% 

        • 1-12 breedings with 9-300 x 106 cells/insemination,

        • 2 breedings with 132 x 106 cells/breeding,

        • 2 breedings with 200 x 106 cells/breeding

        • 1-6 breedings with 183 x 106 cells/breeding.

        • 100%  when as few as 21 x 106 cells or up to 105 x 106 cells were vaginally inseminated daily during cytologic estrus.

        • Increasing the number of breedings from 1 to 2 increased conception rate and fecundity from 34% to 60%, but a third insemination had no additive effect.

      •  Conception rates with frozen semen using vaginal AI have been less than or equal to those using intrauterine insemination.

    • Laparotomy

      • 90% when 100-300 x 106 cells inseminated once during the fertile period 

      • 60% conception using one insemination of 200  x 106 cells (The 60% conception rate was not different than the 100% conception rate attained by vaginal AI twice with  310  x 106 cells)

      • Many private facilities in the US currently use surgical insemination and report success rates averaging 83% using a single timed AI,

    • Lapasoscopy - not common

    • Norwegian

      • 67% breeding once or twice with an unstated number of sperm,

      • 74% breeding twice with 132 x 106 cells/breeding,

      • 83% breeding twice with 200 x 106 cells/breeding

      • 84% breeding 1-3 times using 186 x 106 cells/breeding

      •  Increasing the number of breedings from 1 to 3 did not increase the conception rate or fecundity

    • New Zealand transcervical

      • 100% breeding twice with 200 x 106 cells/breeding

      • 85% using as few as 50 x 106 cells/breeding

      • 57% using a total of 452 x106 total cells in 2.4 breedings/cycle

Infertility in the Dog




  • It is a heritable condition (sex limited autosomal recessive....action not really understood).
  • The testes have normally descended by 10 days, but we usually give them 16 weeks.
  • If the condition is bilateral, the increased temperature destroys the germinal cells and there is primary spermatogenesis failure, because the germinal layer disrupted. 
    • This results in inhibin being low, so FSH is high (> 15 picograms). 
    • The Leydig cells are normal, so the testosterone and LH concentrations are normal, which gives normal libido.
  • Diagnosis is by palpation, ultrasound, and blood tests
    • LH testing - Witness LH

      • A small study of intact (n=6) and castrated (n=3) post-pubertal male dogs Samples collected from all of the intact male dogs were ≤1 ng/mL (negative) whereas samples collected from all of the castrated male dogs were >1 ng/mL (positive). No cryptorchids were done and the time from castration was not noted. Interesting, but needs further testing to confirm.
    • Testosterone
      • 0.1-2 ng/ml, whereas adult dogs with one or two scrotal testes usually have serum testosteroue  of 1-5 ng/ml.
    • Challenge tests
      • hCG
        • Draw a pretest blood sample.
        • Administer either hCG (100 IU intramuscularly) or GnRH (50 ug subcutaneously).
        • Draw post test samples 12 and 24 hours later.
        • A twofold to fourfold increase from the baseline value is considered significant.
  • GnRH
    • Administer GnRH (2 ug/kg IM).

    • Draw blood 60 min later.

    • A serum testosterone concentration of 3 ng/ml or greater is considered significant.

  • There is no treatment but:
    • 100-1000 IU hCG IM 4 times in 2 weeks resulted in 85% descending in vs 0% in the controls if the dog was < 16 weeks
    • Should recommend castration as there is an increase incidence of neoplasia in retained testes and the condition is heritable

Nutriceuticals to treat sperm problems

I do not recommend these, but this is information that clients will have and will request that you try. None of this information has been documented. The mechanism of action has not been documented and the effects of many supplements on canine semen quality are currently unsubstantiated. This information was summarized by Milan Hess (Theriogenology 66 (2006) 613-617)

  •  Glyco-Flex® and other glycosaminoglycans

    •  Glyco-Flex® -Vetri-Science (Essex Junction, VT, USA)

      • Supplement containing Perna canaliculus (New Zealand Green-Lipped Mussel), glucosamine, and minerals.

      • Manufacturer states:

        • Source of glycosaminoglycans (GAG)

        • Supports proper joint function.

      • Prescribed by multiple reproductive practitioners to improve semen quality in the dog - not stated exactly what and how.

        • Dr. Roger Kendall, a biochemist with Vetri-Science, cites numerous anecdotal reports of improved semen quality in dogs, horses and bulls.

          • Theorizes it enhances cellular reactions and amino acid uptake, which may improve semen quality and motility.

          • Improvement in sperm motility and in the quality of cryopreserved or chilled semen after supplementation, although not documented.

    • Other GAG Supplements

      • Without methylsulfonylmethane (MSM)

      • Recommended for treatment of subfertility

        • Although commonly advocated by a variety of veterinarians, there is little hard evidence supporting the use of these products.

        • To further confuse the issue, there is no standard protocol for the type of case in which Glyco-Flex* or other GAG Supplements are prescribed.

  • Omega 3 fatty acids and antioxidants

    • Several practitioners suggest a form of Omega 3 fatty acid supplementation to enhanced semen quality.

    • OM3 Gold® (Cepav Laboratories, Säo Paulo, SP, Brazil;

      • Contains linoleic acid, linolenic acid, oleic acid and Vitamin E.

      • Anecedotaly 50% of dogs with a high percentage of proximal droplets will show significant improvement after 6 weeks of treatment with OM3 Gold

  • Vitamins C and E for their potential beneficial effects on semen quality.

  • Docosahex-aenoic acid (DHA)

    • Stallions fed a DHA supplement had improvements in motility following cooling and freezing.

    • PROSPERM* (Minitube America, Inc., Minneapolis, MN, US A)

      • Increase semen concentration, total sperm number in the ejaculate and sperm motility in the boar

      • Contains DHA, Vitamin E and selenium

      • Advocated as a treatment for subfertility in the dog by one clinician

    • Cell Advance® (Vetri-Science)

      • Antioxidant supplement

      • Manufacturer claims protects cells from being altered or destroyed by free radicals

    • Motility Plus* (Platinum Performance, Buellton, CA, USA)

      • Carnitine supplement

      • Prescribed by some to enhance sperm motility




Semen collection


Urinalysis - for sperm cells
Alkaline phosphatase of semen375577

  • The Alkaline phosphatase is normally 5,000-40,000, which indicates the ejaculate came from the epididymis.
  • If it is lower, then the ejaculate may not contain a fraction from the epididymis. This could indicate a blockage of the ductus deferens.




Epididymal aspirate687

  • Using a 25 ga needle you can aspirate the tail of the epididymis to check for the presence of sperm cells.


Testicular biopsy687

  • You can use a Trucut needle, and take a biopsy of the testis.
  • Research at LSU has shown that the epididymal aspirate and testicular biopsy do not decrease sperm output and only cause transient antisperm antibodies.




Retrograde ejaculation
  • This is caused by an internal urethral sphincter failure.
  • You see no cells in the ejaculate, but cells are in the bladder after ejaculation.
  • Do a UA to check for sperm cells in the urine.
  • Treatment includes sympathomimetics
    • pheynylpropylalamine - 3 mg/kg PO BID
    • pseudoephedrine - 4-5 mg/kg PO TID or 1 and 3 hours before collection

  • There may be congenital problems (testicular aplasia, ductus or epididymal aplasia, or a congenital weakness of the sphincter that allows the ejaculate to enter the bladder.
  • Check for chromosome abnormalities.
  • The dog may be an intersex. This is associated with cryptorchidism occasionally.

Testicular hypoplasia

  • The germ cells are absent completely , or the dog may be oligospermic.
  • The Leydig cells are present, so libido is usually normal.


  • Diagnosis
    • Wait until the dog is 2 years of age to condemn him for small testes.
    • Do a testicular biopsy.
    • The prognosis depends on if any germ cells are present.
    • LH  normal to slightly elevated
    • FSH
      • Should be high
      • Release is episodic so take 3 samples at 20 minute intervals 10 minutes after 250 ng/kg GNRH
      • 'Normals' (labs do not readily run this assay)
      • FSH - 62-293
      • BET labs - canine validated? (Send in normal to compare)

Sertoli Cell Only Syndrome

  • In this condition there are only sertoli cells in the tubules.
  • The FSH is high


Ductular Aplasia
  • This may cause testicular degeneration if the blockage is at the head of the epididymis.
  • LH and FSH are normal if there is no degeneration, but the condition needs to be bilateral to cause aspermia.
  • An epididymal aspirate may help confirm the condition.


Hypogonadotrophic hypogonadism
  • This is caused by a pituitary dysfunction.
  • It may be congenital, caused by trauma or neoplasia.
  • The FSH and LH are low.
  • On biopsy all testicular cells are cells present.
  • Treatment may be hCG or androgens.

Marathon syndrome

  • This is seen in hard worked dogs (field trial)
  • There are no cells in the ejaculate.
  • GnRH is low in marathon runners (male and female humans), is it low in dogs ???
  • Treatment is to back off the exercise.


Exogenous testosterone
  • This decreases sperm output via feedback on the hypothalamus.

Senile atrophy
  • If a dog is > 10 years old, litters are not recognized by AKC (unless DVM confirms).
  • may be end product after progression through acquired acute disease and oligospermia

Primary Spermatogenesis Failure
  • You may see some cells if the germinal tissue is on its way out.
  • These dogs may respond to Clomid (a non steroidal estrogen that releases GnRH)

Leydig Cell Failure
  • Plasma testosterone may be normal, but usually libido decreases and LH increases. Since testosterone is needed for spermatogenesis, the sperm cell production goes down.

Immune Mediated Orchitis


  • This results after damage to the blood testis barrier.
  • Antibodies develop and the testis degenerates.
  • Possibly hereditary in Labs
  • See infiltration of lymphcytes in testicular biopsy 

Sperm Granuloma
  • This results from sperm accumulation in blind pockets and a gradual inflammatory response that results.
  • It resembles duct blockage and signs depend upon the site blocked.

Inguinal Scrotal Hernia
  • Normally seen as a painless swelling in the scrotum.
  • The hernia may impair temperature regulation of the testes so you may see oligospermia.
  • Treatment is to castrate, because the condition is heritable.

Low libido

  • The testosterone may be normal, and exogenous testosterone is harmful.
  • It may be a primary testicular failure.
  • Leydig cells lost (also germinal cells)
  • LH is high.
  • HCG can help differentiate. HCG should stimulate an increase in testosterone output.

Leydig cell failure
  • as above

Testicular degeneration

  • You usually other signs seen first.


Acute problems


  • It is usually caused by trauma, septicemia, or descending infections.
  • B. canis is a ruleout 
  • You see acute pain at first and swollen testes. You eventually see a range of testicular degeneration.
  • It may become a chronic problem.
  • You must rule out Brucella at a semen evaluation. Use the RSAT (may be early false negatives, so culture may be better)
  • Castrate after the animal is stabilized.
  • Unilateral castration.
  • If you do not castrate, use anti-inflammatory drugs and hydrotherapy.

Testicular torsion (actually torsion of the spermatic cord)


  • It is seen in abdominal testes mostly.
  • It is often associated with neoplasia of the retained testes and is rare in scrotal testes.
  • You see a dog with pain in the abdomen.
  • The treatment is exploratory surgery and castration.

Inguinal scrotal hernia
  • This may present as a dog with an acute abdomen.
Penile, testicular, and prepuce problems in the Dog






  • Most dogs with testicular tumors are greater than 10 years if the testis is scrotal. They may be younger if the testis is retained.

Sertoli cell
  • They are in retained abdominal testes mostly. (The heat destroys germinal cells.)
  • About 10 % are malignant.
  • There is estrogen production that causes feminization in about 25% of the cases.
  • There is atrophy of the contralateral testis.
  • There may be bone marrow aplasia from the estrogen.
Interstitial cell
  • Theses are from the Leydig cell.
  • Normally they are benign incidental findings.
  • Again, these are usually benign and in inguinal testes mostly.




Persistent Frenulum 537-538

  • Attachment of the tip of the penis to prepuce

  • See strip of tissue

  • Penis will not extend

  • Usually gone by birth or first months of life

  • Treatment - cut

  • May be hereditary



  • Ventral opening in penile urethera

  • May be caused by exogenous estrogens or progestogens during pregnancy

  • Surgically close

Transmissible Venereal Tumor (TVT)


  • See bitch notes


Posthitis (inflammation of the penis)360546-549
  • Usually have balanoposthitis (inflammation of the penis and prepuce)


  • Cannot get it out preputial orifice
  • Treat by opening the orifice.

Paraphimosis 358550-553
  • Cannot get it in.
  • This is one of the few male genital emergencies.
  • You must get it back in (surgically if needed) and remove the cause.
  • May need to amputate

  • Priapism is erection unrelated to lust.
  • It has only been reported in cases of spinal cord trauma.
  • No reports of dogs successfully breeding after persistent erection.

Urethral prolapse359
  • Generally it is caused by trauma or licking.
  • Treat by replacing or excising the end of the urethra.
  • Some discharge of 'pus' is normal.
  • Urine
  • Urogenital Anomalies Rare
  • Urinary Infections
  • Blood
  • Prostatitis
  • Urinary Infections
  • Trauma
  • Pus

  • Inflamation of penis and prepuce

    Canine Prostatitis covered in medicine
  • No sperm changes were seen experimentally after induced prostatic disease.
  • Semen is probably OK, but dog may refuse to breed.


contributed by Bruce E Eilts and modified on 1 October 2007    


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contributed by Bruce E Eilts on 25 September 2012


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