Case 8: Asthenozoospermia in a dog

CASE 8. Asthenozoospermia in a dog

Case Information: You see a 3-year-old intact male Bloodhound for a routine breeding soundness examination. The dog is normal on physical examination and his libido is excellent. You collect 5 ml of opalescent semen. Concentration is 72 million spermatozoa per ml. Percentage progressive motility is 0%. Percentage morphologically normal spermatozoa can be estimated from the image below.

Question:

What is the total number of spermatozoa in the ejaculate? Is this normal?

Answer:

Concentration (72 million per ml) times volume (5 ml) = total number (72 x 5 = 360 million spermatozoa). This is in the normal range (300 million to 2 billion spermatozoa in the ejaculate) but is not very impressive for a Bloodhound, who should have enough testicular mass to generate many more spermatozoa than this in each ejaculate. Low number of spermatozoa may be due to absence of a teaser bitch, inexperience or apprehension of the male, or pain.

Question:

What is the percent morphologically normal spermatozoa? Is this normal?

Answer:

The majority of the spermatozoa visible in this field are normal. Normal percentage morphologically normal spermatozoa is 80% and this dog meets those criteria.

Question:

Why does this dog have asthenozoospermia (lack of motile spermatozoa in his ejaculate)? What diagnostics would you like to perform?

Answer:

In the absence of morphologic defects that could affect motility, other possible causes include infection, improper collection technique and immotile cilia syndrome (primary ciliary dyskinesia). Initial diagnostics should include culture and cytology of semen; semen collection using different equipment and ensuring there are no contaminants, including soap or other chemical residues, in the equipment used; and brucellosis testing. The definitive diagnostic test for primary ciliary dyskinesia is electron microscopy of ejaculated spermatozoa; this condition is unlikely in a dog of this age with no history of recurrent respiratory disease.