Thank heavens, someone figured out which bacteria live on a donkey’s penis.

By Seriously Science | November 3, 2015 6:00 am
Photo: flickr/bagsgroove

Photo: flickr/bagsgroove

Have you ever wondered what kind of bacteria live on a donkey’s penis? You haven’t? Well, these researchers are here to tell you anyway! In an effort to fill this gaping hole in our knowledge of donkey penises and microbiology, they cultured bacterial flora from prepubertal, mature intact, and castrated donkeys. Read on for the titillating results!

Bacterial and fungal microflora on the external genitalia of male donkeys (Equus asinus)

“This study was undertaken to investigate the bacterial and fungal microflora on the external genitalia of a population of healthy male donkeys in the state of Michigan, USA. The aim was to identify and determine the frequency of occurrence of these microorganisms using seven different isolation media and standard microbiological procedures. The sites (urethral fossa [fossa glandis], dorsal diverticulum of the urethral sinus, distal urethra, and penile surface) in the distal reproductive tract were cultured and each isolated microorganism identified. Ten different genera of gram-positive bacteria, eight different genera of gram-negative bacteria, and two genera of fungi were isolated from the external genitalia of the 43 donkeys in this study.All 43 donkeys yielded gram-positive bacteria (2–8 species) from all four sites sampled. Arcanobacterium spp., Corynebacterium spp., and Bacillus spp. were the most frequently isolated gram-positive bacteria. Gram-negative bacteria were cultured from 16 (37.2%) of the 43 donkeys, with Acinetobacterlwoffii (16.3%), Oligella urethralis (11.6%), and Taylorellaasinigenitalis (9.3%), the most frequently isolated. Fungi were cultured from only 5 (11.6%) of the 43 donkeys, with Rhizopus spp. isolated from 3 (7.0%) and Cladosporium spp. from 2 (4.7%) individuals. The testes and epididymides collected from 40 donkeys at time of castration were culture negative. Few differences were found in the bacterial flora between prepubertal and mature intact and castrated donkeys. Of notable interest was the scarcity of known equine pathogens across the population tested and isolation of T. asinigenitalis from normal donkeys, especially prepubertal individuals and previously castrated males.”

Related content:
Nipple, penis, or nostril — what’s the most painful place to be stung by a bee? (The answer might surprise you.)
Snakes are ‘righties’–with their penis, that is.
Nipple, penis, or nostril — what’s the most painful place to be stung by a bee? (The answer might surprise you.)

  • OWilson

    Who ordered that?

    • fdebros

      the democrat party ….fearing their logo is sexually despicable?

      • OWilson

        They want an expanded definition of “marriage” so who knows what they’ll come up with next :)

  • John K

    I wonder if this would be information that donkey breeders might want?
    “Of notable interest was the scarcity of known equine pathogens…” Maybe it’s to assess the results of a donkey hygiene program?

  • Doc Darlin

    The tone of the introduction of this article, the headline, and at least one comment (so far) highlights and illustrates the problem in Donkey Welfare in the USA and worldwide. Had this article been about bacterial counts in the sheaths of valuable Race Horses, everyone would have sagely nodded along, with no ignorant, snarky comments. But, because it’s Donkeys, the general public feels almost compelled to fall into into ridicule. No wonder these wonderful, emotional and highly intelligent (times over smarter than horses) animals are abused, neglected and discarded by the thousands to slaughter in Mexico, where their meat is discarded and the hides shipped to China for the pseudo-pharmaceutical industry.

    • OWilson

      Being kind to your donkey is a good thing :)
      But some of us think that scarce (budget wise)scientific resources, could be prioritized to other more pressing problems.
      Say fo example the 9,500,000 children under 5 that the WHO say die every year from disease and malnutrition.


Seriously, Science?

Seriously, Science?, formerly known as NCBI ROFL, is the brainchild of two prone-to-distraction biologists. We highlight the funniest, oddest, and just plain craziest research from the PubMed research database and beyond. Because nobody said serious science couldn't be silly!
Follow us on Twitter: @srslyscience.
Send us paper suggestions: srslyscience[at]

See More


Discover's Newsletter

Sign up to get the latest science news delivered weekly right to your inbox!

Collapse bottom bar