Hello and welcome. Hope you are doing well. If you want to learn comparative anatomy of male genital organs from different animals, then you are right place now. Here in this article, I am going to discuss on comparative anatomy of male genital organs from different animals (especially ox, sheep, goat, horse, and dog).
If you want to learn about the comparative anatomy of female genital organs, then you may visit this article entitled – Comparative Anatomy of Female genital Organs from Different Animals. If you have already read it, then you may skip. Let’s start to learn and identify the most important differences in the organs of the male genital system of different animals.
“I am going to compare these organs from the male genital system based on the most important features. Please try to compare with more anatomical features.”
Comparative anatomy of male genital organs
We will learn comparative anatomy from the following organs from different animals like ox, sheep, goat, horse, and dog –
- Comparative anatomy of the testis
- Comparative anatomy of the penis
- Comparative anatomy of the seminal vesicle
- Comparative anatomy of the prostate gland
- Comparative anatomy of the bulbourethral gland
Okay, let’s start to learn and compare.
Comparative anatomy of the testis
We will consider the following most important feature to compare the anatomy of the testis from different animals like ox, sheep, goat, horse, and dog –
Shape of the testis
- Elongated, oval, and medial surface flattened in ox, sheep, and goat.
- In a horse, it is ovoid and compressed side to side.
- In a dog, it is a round oval form.
Mediastinum testis
- Axial strand of connective tissue (mediastinum testis) is well developed in the ox, sheep, and goat.
- Not well developed in the horse
- Well developed and central in position in the dog
Attachment of the epididymis
- Closely attached to its caudo-lateral part in ox, sheep, and goat
- In the case of a horse, it is closely attached to its lateral surface.
- Closely attached along the dorsal part of the lateral surface of the testicle in the dog
Okay, let’s learn from the table below –
| Features | Ox, sheep and goat | Horse | Dog |
| Location | Prepubic (somewhat further craniad than horse) | Prepubic region | Half way between inguinal region and anusIn cat, perianal |
| Shaped | Elongated, oval medial surface flattened | Ovoid and compressed side to side | Round oval form |
| Position | Long axis verticle, attached border is caudal | Long axis obliquely longitudinal | Long axis oblique and directed dorsally and caudally |
| Mediastinum testis | 5 mm thick and well developed | Not well developed | Central and well developed |
| Difference between right and left | Left – bigger | Unequal | Left –larger |
| Attachment of epididymis | Closely attached its caudo-lateral part | Closely to lateral surface | Closely along dorsal part of lateral surface of testicle |
| Head, body, tail of epididymis | Head – long Body – narrow (lies along lateral part of caudal border of testicle)Tail – larger, closely attached at ventral extremity of testicle | Head – enlargeBody – narrowTail – enlogated (slightly) | Body – lies along dorso-lateral surface of testicle |
Comparative anatomy of the penis
We will consider the following most important features to compare the anatomy of the penis from different animals like ox, sheep, goat, horse, and dog –
Sigmoid flexure
- S-shaped curved sigmoid flexure is present in ox, sheep, and goat.
- Sigmoid flexure is absent in the horse and the dog.
Os penis
- Only present in dogs
It is better to learn from the table below. Okay, let’s start to learn –
| Features | Ox, sheep and goat | Horse | Dog |
| Shape and size | Cylindrical, longer and smaller diameter 90 cm long (30 cm is folded up in sigmoid flexure – ox) | Cylindrical 50 cm long (15 – 20 cm free in prepuse) | Cylindrical 24 cm long |
| Sigmoid flexure | S shaped curved caudal to scrotum | Absent | Absent |
| Os –penis | Absent | Absent | Present |
| Glands | Flattened dorso-ventrally Pointed and twisted (extremities) | Enlarge free endsPresence of corona glandis and fossa glandis | Long Cranial part – cylindrical Caudal end – pointed |
| Structures | 2 erectile bodies Corpus cavernosum Corpus spongiosum | 2 erectile bodies Corpus cavernosum Corpus spongiosum | Cranial portion of body – bone (os –penis)Caudal to glans – rounded enlargement bulb of glands (present) |
Comparative anatomy of the seminal vesicle
We need to consider the following most important features to compare the seminal vesicle from different species. There is no seminal vesicle in a dog.
Shape of the seminal vesicle
- Compact glandular, lobulated (unsymmetrical shape and size) in ox, sheep, and goat
- In a horse, it is an elongated and somewhat pyriform sac.
Excretory duct
- Open at the seminal clliculus just lateral to the ductus deferens (in ox, sheep, and goat)
- Open in common with the duct deferens as the ejaculatory duct on the side of the seminal vesicle (in the horse)
You may also learn from the table –
| Features | Ox, sheep and goat | Horse |
| Shape and size | Compact glandular, lobulated (unsymmetrical shape and size | Elongated and somewhat pyriform sac |
| Location | Lies on eash side of caudal part of dorsla surface of urinary bladder | |
| Relation | Dorsal surface is dorsaaly and medially covered by peritoneum partly Ventral surface is opposite direction and non-peritoneal | Related to rectum dorsally Partly enclosed by genital fold |
| Execratory duct | Open at seminal clliculus just lateral to ductus deferens | Open in common with duct deferens as ejaculatory duct on side if seminal vesicle |
Comparative anatomy of the prostate gland
To understand species differences, we will compare key anatomical features of the prostate gland in various animals. Notably, the prostate gland is larger in dogs.
Structure of the gland
- Pale, yellow, and consists of two parts in ox, sheep, and goat.
- Lobulated and having two lateral lobes in a horse
- Yellowish and globular in a dog
Location of the gland
- Lies on the dorsal surface of the neck of the bladder and the origin of the urethra in the ox, sheep, and goat
- Lies on the neck of the bladder and the beginning of the urethra, ventral to the rectum in the horse
- Lies near the cranial border of the penis bone in the dog
You may learn from the table below –
| Features | Ox, sheep and goat | Horse | Dog |
| Structure | Pale, yellow and consist of two part | Lobulated Two lateral lobe | Yellow color Globular |
| Location | Lies on dorsal surface of neck of bladder and origin of urethra | Lies on neck of bladder and beginning of urethra ventral to rectum | Lies at near cranial border of penis bone |
| Prostatic duct | Open into urethra in row | 15 – 20 ducts Perforates urethra and open lateral to seminal colliculus | Numerous ducts Lobes of prostatic tissue found in wall of urethra |
Comparative anatomy of the bulbourethral gland
We need to consider the following important features to compare the anatomy of the bulbourethral gland from different animals –
Duct of the bulbourethral gland
- Ox, sheep, and goat each have a single duct.
- In a horse, there are 6 -8 excretory ducts.
Let’s learn from the table below. There is no bulbourethral gland in a dog.
| Features | Ox, sheep and goat | Horse |
| Location | 2 in number Located on either side of pelvic part if urethra | 2 in number Located on either side of pelvic part of urethra close to ischial arch |
| Relation | Covered by a thick layer of sense fibrous tissue, partlially by bulbospongiosus | They covered by urethralis muscles |
| Shape | Ovoid | Ovoid |
| Ducts | Each has single duct Open into urethra under cover of a fload of mucous membrane | Each has 6-8 excretory ductsOpen into urethra caudal to prostatic ducts |
Conclusion
Hope you got an idea on comparative anatomy of male genital organs from different animals, and will be able to identify the basics of these organs from different animals based on their most important anatomical features.
If you think this information is not enough for you to learn about the comparative anatomy of male genital organs of different animals, I would recommend that you learn from class lectures or from books. And, again, if you want to learn more about veterinary comparative anatomy, I would recommend that you connect with me or follow my upcoming articles. You may also learn from the article below –
Comparative Anatomy of Urinary Organs from Different Animals
“If possible, I will update or enrich information, pictures, and videos on this topic in the future.”
If there is any mistake in the above information or if you have any suggestions for me, please let me know in the comment box. Thank you so much.
