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More To Bull Problems Than Semen

When examining young bulls for the first time we as veterinarians watch out for many conditions that may affect breeding ability besides semen quality. Many conditions can be corrected and others result in bulls being eliminated from the gene pool.

Young bulls more commonly are detected with seminal vesiculitis and other infections involving the secondary sex organs. This is detected upon palpation rectally and the veterinarian can advise whether treatment, time, or culling is the best option based on the severity of the infection. Seminal vesiculitis results from being excessively ridden or can be do to old infections such as navel infections, which seed out into this area. Pus is then discharged in the semen reducing fertility.


Several common conditions can be encountered when the penis is protruded during semen collection and testing. A persistent frenulum is a ligamentous attachment between the sheath and penis. This will cause the penis to bend on full erection making intromission when breeding very difficult. It can also be the cause of a broken penis if not corrected. The already bent penis becomes suddenly bent over on impacting the cow. This ligament (frenulum) can be identified and incised just after the semen sample is collected. Sexual rest is necessary until this heals and should be rechecked to insure scarring has not occurred. Occasionally the two will be present on the same bull. If not detected, attempted breeding may also result in ripping with lots of bleeding. Blood is very detrimental to semen quality and fertility suffers. The bull cannot get the rest in the breeding season to allow the rip to heal. With each erection the bleeding continues. Persistent frenulums are highly heritable so purebred breeders should closely scrutinize breeding forms when purchasing their herd sires. Commercial breeders steer all bulls so it would be inconsequential to them.

Warts are another commonly encountered condition on a bull’s penis. Often these can be surgically removed as long as they are not involving the vital structures on the tip of the penis or extend into the urethra (duct that transports urine or semen). Veterinarians may remove, cauterize the bleeding or if necessary suture where appropriate and recheck later for reoccurrence. Warts are invariably very rough and can rip or tear causing bleeding during breeding. Again fertility is impaired. Very large warts near the tip of the penis can impair nerve supply making it impossible for bulls to hit the mark during copulation. I have not tried making an attenuated wart vaccine on herds with a high incidence but have been tempted to. There seems there is not a lot of correlation between body warts and penile warts. Most bulls I’ve encountered with penile warts have no evidence of warts on other locations. Two to three weeks is generally enough time for most wart removals to completely heal.


Cuts and abrasions are easy to diagnose on visual examination of the penis. Treatment may be necessary, but in most cases rest for varying lengths of time solves these conditions. With severe cuts, scarring may occur whereby full penile extension is impossible. This is a definite cull candidate. All the above problems clearly identify the need for veterinarians to fully examine the extended penis of the bull during semen evaluation. Most problems found here can be treated provided adequate time is available until the breeding season.

In young bulls, before puberty, the prepuce is tightly adherent to the penis. This pulls away as the young bulls erections progress. With this comes some bleeding and any time there is blood fertility may be impaired! If we see this adherence at evaluation time it tells us the bull may be immature and has never become completely erect. We must insure this before allowing this young bull out into the breeding herd.

Hair rings strangulating the penis occur from bulls mounting others and having the hair from the back forming a tight ring around the penis. Most are easily removed but the worst case I’ve seen is the tip of the penis half cut off from a constricting hair ring. This rendered a potentially good bull useless as a breeder. Warts near the tip of the penis also allow the hair to more easily wrap around.

As can be noted from all the above examples many potential problems can be corrected by carefully paying attention during a young bull’s first semen evaluation. Almost all purebred breeders now have semen evaluations performed so any of these abnormalities can be detected ahead of time. And the Murphy’s Law of semen evaluation is any of these problems always happen to the most expensive and sought after bulls. Take heed.

RoyLewisisapracticinglargeanimal veterinarianattheWestlockVeterinaryCenter, northofEdmonton,AB.Hismaininterestsare bovinereproductionandherdhealth


Sale Results Crowfoot Cattle Co. 19th Annual Bull &Commercial Female Sale April 7, 2011, Standard, Alta.

37 two-year-old Black &Red Angus bulls, av. $3,654

81 yearling Black &Red Angus bulls, av. $3,318.

67 commercial yearling heifers, av. $1,166

53 commercial cows, av. $1,557

31 commercial cow-calf pairs, av. $1,629

About the author


Roy Lewis is an Alberta-based veterinarian specializing in large-animal practice. He is also a part-time technical services vet for Merck Animal Health.



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