The shape of the kidneys is unique in different animals. Here, I will provide a concise answer to the question – “what is the shape of the kidneys in animals?”. Thus, this article will help you practically identify the kidneys from the different animals in your laboratory.
Quick answer: the ox or bovine has elongated elliptical and lobulated kidneys. But other domestic mammals like horses, sheep, goats, dogs, and cats have bean-shaped, non-lobulated (smooth) kidneys. Finally, the avian species (like chicken) possesses finely lobulated and elongated kidneys with exceptionally three divisions (cranial, middle, and caudal).
Now, let’s get into the article and learn the unique shape of the kidneys from the most common domestic animals.
What is the shape of the bovine kidney?
Both the right and left kidneys of the bovine are elongated and elliptical. But, they possess variation in their surfaces, borders, and extremities.
Superficially, the bovine’s right and left kidneys possess various-sized polygonal lobes. These lobes are separated by fissures that are filled with fat.
They are brownish-red and embedded in large amounts of peritoneal fat. The left kidney of the bovine is larger and heavier than the right one. Again, you will find a little variation in the position of the right and left kidney in the bovine.
Location of the bovine right kidney: ventral to the last rib and first two or three lumbar transverse processes.
Location of the bovine’s left kidney: right side of the median plane, caudally, and little ventral to the bodies of third, fourth, and fifth lumbar vertebrae.
How will you differentiate the right kidney from the left of an ox?
You might know their unique features to differentiate the ox’s right kidney from the left kidney. Thus, let’s know the unique identifying features of the ox’s right (RK) and left kidneys (LK).
Identifying anatomical features of the ox’s right kidney:
Surfaces of the kidney: the right kidney of the ox possesses two surfaces. They are dorsal and ventral surfaces. The dorsal surface is rounded (D) and related to the sublumbar muscles. Again, the ventral surface is less convex and related to the liver, pancreas, duodenum, and colon.
Borders: it possesses two borders (lateral and medial). The lateral border of the right kidney is convex, whereas the medial border is straight and parallel to the caudal vena cava.
Extremities: The right kidney of the ox possesses two extremities – cranial and caudal. Here, the cranial extremity is rounded and thin, occupying the ox liver’s renal impression. Again, the cauda extremity is also rounded but larger and thicker than the cranial extremity.
Location of the hilus of the ox’s right kidney: The hilus is located on the cranial part near the medial border (ventrally).
Identifying anatomical features of the left kidney of the ox:
Surfaces: the left kidney of the ox possesses three surfaces – dorsal, ventral, and ruminal. Here, the dorsal surface is convex, where the ventral surface is flattened and related to the intestine. Again, the minimal surface is less flattened and in contact with the medial surface of the rumen.
Borders: due to the presence of three surfaces, the left kidney possesses three borders – medial, lateral, and ventral. The medial borders are formed between the dorsal and ventral surfaces. It is convex cranially and concave caudally. The lateral border is formed between the ruminal and dorsal surface, which is slightly convex. Finally, the ventral border is formed between the ruminal and ventral surfaces, which are convex.
Extremities: the left kidney of the ox also possesses two extremities – cranial and caudal. The cranial extremity is small, whereas the caudal extremity is large and rounded.
Location of the hilus of the left kidney of the ox: it is located on the dorsal surface that opens cranio-laterally.
Right vs left kidneys of the ox
Now, Table 1 shows the major difference between the right and left kidneys of the ox. These are also the unique identifying features for the right and left kidneys in your laboratory.
What is the shape of the kidneys in sheep and goats?
Both the right and left kidneys of the sheep and goat are bean-shaped. They extrenally possess smooth surfaces.
Shape of the horse’s kidney
The horse has a unique shape in their kidney. Here, the right kidney of a horse is heart or equilateral triangular.
However, the left kidney (LK) of the horse is bean-shaped. Both the right and left kidney of the horse possess a smooth surface.
Location of the hilus of the horse’s kidneys: the hilus is located at the middle of the medial border in both the right and left kidneys.
Location of the horse kidneys
Right kidney of the horse: lies ventral to the dorsal part (vertebral extremity) of the last two or three ribs and first lumbar vertebra.
Left kidney of the horse: lies ventral to the last rib and first two or three lumbar transverse processes.
What is the shape of the kidneys in dogs?
The dogs’ right and left kidneys are bean-shaped and have a smooth surface. Again, the hilus of these kidney are located at the middle of the medial border of the respective kidneys.
Location of the dog’s right kidney: ventral to the bodies of the first three lumbar vertebrae.
Location of the dog’s left kidney: ventral to the bodies of the third to fifth lumbar vertebrae.
In horses, dogs, sheep, and goats, both the right and left kidneys possess two surfaces (dorsal and ventral), two borders (lateral and medial), and two extremities (cranial and caudal).
Shape of the bird’s kidney
The kidneys of the avian species (especially chicken) are finely lobulated. Both the right and left kidneys of the birds are elongated.
They possess three unique divisions – cranial, middle, and caudal- compared to mammal kidneys.
Location of the bird kidney: below pelvis and synsacrum.
Conclusion
So, the elongated elliptical and bean-shaped kidneys are available in common domestic animals. The equine (horse) and bovine (ox) kidneys have the unique shape compared to other domestic animals like dogs, sheep, and goats.
