How Big are Dog Ovaries?

The dog ovaries are paired organs attached by the mesovarium to the body wall and mesosalpinx. They are comparatively smaller than the ovaries of the cow. Here, you will know the answer to the question – ‘How big are dog ovaries?’

Quick answer: the average length of the dog’s ovaries is 1.5 centimeters. Meanwhile, the average width and thickness of the dog ovaries are 0.7 and 0.5 centimeters, respectively.

Here, I will inform you of the variation in the size of a dog’s right and left ovaries. You will also find a comparative study on dog ovaries with other animals at the end of this article.

What do dog ovaries look like?

The dog’s ovaries look like small, elongated, oval, flattened organs. Each of the ovaries is completely enclosed in a peritoneal pouch. This peritoneal pouch is known as the bursa ovarii, which possesses a slit–like opening ventrally.

What do Dog Ovaries Look Like
What do Dog Ovaries Look Like

However, the shape of other animals’ ovaries (right and left) varies compared to the dogs. Here, Table 1 shows the shape of the ovaries of the different animals, including the dogs, cows, ewes, and horses –

Ovaries of different animalsShape of the ovaries
Dog ovariesSmall, elongated – oval, and flattened
Cows ovariesOval shaped
Horse ovariesLarger and bean-shaped
Ewe ovariesAlmond shaped
Pig ovariesMore rounded than the dogs
Ovaries of Different Animals with Their Shape

Here, the diagram shows the ovaries of the different animals. You will find the detailed diagram of the dog ovaries in the next section of this article.

Ovaries in Different Animals
Ovaries in Different Animals

How big are dog ovaries?

The size of the dog’s ovaries varies with the age and size of the female dogs. According to Miller et al. l., the average size of the dog ovaries is as follows –

  • Length of the dog oavries = 1.5 centimeters,
  • Width of the dog ovaries = 0.7 centimeters,
  • Thickness of the dog ovaries = 0.5 centimeters,

Again, the average weight of the dog’s ovaries is 0.3 grams. These measurements of the dog’s ovaries are appropriate for the 25-pound dog.

According to Session et al., the average length of the dog’s ovaries is less than an inch (2 centimeters). Different authors examine the diameter of the dog ovaries by sonographic imaging technique. Authors like Conze and Wehrend found a maximum diameter of 6 – 9 millimeters by sonographic imaging of physiological ovaries in dogs.

Table 2 shows the average measurements of the ovaries of different animals like dogs, horses, pigs, and cows –

Ovaries sizeLength (cm)Width (cm)Thickness (cm)
Dog ovaries1.50.70.5
Horse ovaries7 – 853 – 4
Sow ovaries21.51
Cow ovaries3.5 – 432.5
Ewe ovaries1.810.8
Ovaries Size in Dogs, Horses, Pigs, Cows, and Ewes

Here, cm = centimeters, and all measurements are performed by different authors on average-sized animals.

A dog ovary has the following typical features –

  • Tubal and uterine extremities,
  • A free and attached border, and
  • The lateral and medial surfaces,

Here, the tubal extremity of the dog ovary is nearest to the infundibulum. Meanwhile, the uterine extremity is the end that attaches to the uterus by the proper ovarian ligament.

Suggested article: dog uterus anatomy – the location, parts, and ligaments with a labeled diagram,

Which ovary is larger in a dog?

Answer: the left ovary is usually larger in a multiparous dog. However, the dogs aged between 6 and 9 months show almost similar sizes.

At this time (6 – 9 months), the surface of the dog ovaries becomes rough and contains nodular structures. The female dog that gives several litters has rougher and nodular ovaries.

So, after 6 or 9 months, the ovaries of the dog go dissimilar in size.

Where are the ovaries on a dog?

Answer: each ovary of a dog is commonly located a short distance behind or in contact with the caudal extremity of the corresponding kidney. Thus, the ovary lies opposite to the third or fourth lumbar vertebra or about halfway between the last rib and crest of the ilium.

Where are Ovaries on a Dog
Where are Ovaries on a Dog

Right ovary of a dog: it is located approximately 10 centimeters caudal to the last rib of the right side. Here, the ventral border and medial surface of the dog’s right ovary contact with the mesovarium. It lies ventral to the capsule of the right kidney and dorsal to the descending duodenum in a young dog.

Left ovary of a dog: it is located 12 – 14 centimeters caudal to the middle of the last rib and a few centimeters caudal to the left kidney. This left kidney of the dog lies between the abdominal wall and the descending colon. It is also laterally related to the spleen.


So, the size of the dog’s ovaries is smaller compared to other animals. It measures 1.5 centimeters in length, 07 centimeters in width, and 0.5 centimeters in thickness. The ovaries of horses, ewes, pigs, and cows are bigger than the dogs.