Sperm abnormalities in the dog

265 Pages·2017·14.6 MB·English

SPERM ABNORMALITIES IN THE DOG: A LIGHT AND ELECTRON
MICROSCOPIC STUDY
Edmund Eric oettl~
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A thesis submitted to the Faculty of Medicine, University of
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Cape Town, in fulfilment of the requirements for the degree
of Doctor of Philosophy.
Cape Town, 1990
The University of C pe Town ha been given
the right to reproduce this thesis In whole
or In part. Copyright Is held by the author.
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The copyright of this thesis vests in the author. No
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quotation from it or information derived from it is to be

published without full acknowledgeement of the source.
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The thesis is to be used for private study or non-
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commercial research purposes only.

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Published by the Universit y of Cape Town (UCT) in terms
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of the non-exclusive license granted to UCT by the author.
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ABSTRACT
OETTLE, Edmund Eric, Ph.D thesis (1990). Department of
Anatomy and Cell Biology, Medical School, University of Cape
Town.
SPERM ABNORMALITIES IN THE DOG: A LIGHT AND ELECTRON
MICROSCOPIC STUDY
This thesis is a systematic description of normal and
abnormal dog spermatozoa by means of bright field light and
transmission electron microscopy, and an investigation into
the effect that abnormal sperm have on canine fertility. A
total of 101 ejaculates were collected from 88 dogs, of 34
different breeds. Sperm samples were examined
macroscopically for volume, colour, consistency, and pH.
Microscopic evaluation of sperm motility was conducted on
all samples. Morphological evaluation using light microscopy
was conducted on 71 of the samples. Samples from 10 of the
dogs were examined ultrastructurally. A novel classification
for abnormal dog sperm is presented. Abnormal sperm were
classified into one of the following groups: Acrosomal
defects, head defects, midpiece defects, tail defects and
other abnormalities. Abnormalities were further sub-divided
into major and minor defects. The most common abnormalities
encountered were major sperm head defects. The abnormalities
are compared with those described for other species, in
particular the bull and man.
The association between the percentage abnormal sperm in the
ejaculate and the fertility of the dog was statistically
evaluated. On this basis, the dogs were divided into normal
and sub-normal groups. The percentage normal morphology
below which fertility was adversely affected was found to be
sixty percent. The fertility of dogs with greater than or
equal to 60 percent normal morphology was 61 percent, while
the fertility of dogs with · less than 60 percent normal
morphology was 13 percent. There was no statistical
difference between the ages of the dogs in the two groups;
from this it was concluded that sub-fertility may affect a
dog at any age. A means of evaluating dogs for reproductive
potential is discussed.
DECLARATION
I declatrhea tt hist hesiiss m yo wn,u naidweodr kI.t i s
beinsgu bmitftoerdt hed egreoef D octoorf P hilosoipnh y
theU niversoift Cya pe ToIwtn h.a sn ot beseunb mitted
beforfeo r any degreoer examinatiino na ny other
University.
Signarteu mRoeved
EdmunEdr iOce ttl�
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,1 99,o
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In Memory of my Father
Alfred George Oettl~
22.6.1919 - 8.11.1967
ACKNOWLEDGEMENTS
The encouragement and guidance offered by my supervisor,
Professor B. B. Rawdon, are greatly appreciated. The study
was supported by financial assistance from the Medical
Research Council of South Africa. Thanks are extended to
Professor M. Henneberg and Dr D. O. Chalton for advice on
the statistical methods employed. I would like to thank
Professor R. I. Coubrough for introducing me to the field of
spermatology. The technical assistance given by Mr J. Soley
in the preparation of specimens for electron microscopy is
gratefully acknowledged. Colour photographs were processed
by Mrs H. Smit; line drawings were prepared by Mrs E. Fuller
Thanks are extended to Sisters A. E. Botha and D. van Zyl,
whose efficient running of the Genesiology small animal
clinic lightened the task enormously.
TABLE OF CONTENTS
Page
Chapter
1. INTRODUCTION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
2. BACKGROUND INFORMATION ON THE ANATOMY AND
PHYSIOLOGY OF CANINE REPRODUCTION ................. 4
2.1. Testicular development and spermatogenesis. 4
2.2. The blood-testis barrier ................... 12
2.3. The epididymis ... , ., .......... ~ ............ 13
2.4. Factors influencing spermatogenedi~ ........ · 17
2.4.1. Nutrition ........................... 17
2.4.2. Hormones ............................ 19
2.4.3. Temperature ......................... 20
2.4.4. orchitis and epididymitis ........... 22
2.4.5. Other factors .........•............. 23
2 • 5 . Semen • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 2 8
2.5.1. Spermatozoa ........•............... , 28
2.5.1.1. Enzyme systems ...................• 28
2.5.1.2. Sperm respiration and motility .... 30
2.5.1.3. Sperm motility in relation to
axonemal structure ...•...........••........ 30
2.5.2. Seminal plasma ......•......•.•...•.. 35
2.5.3. Whole semen .......................•• 37
3 . MATERIALS AND METHODS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 2
3.1. Physical examination of the dogs ..•........ 42
3.2. Genital examination .............. • ......... 43
3.2.1. Palpation ........................... 43
3.2.2. Semen collection ..•................. 43
3.2.2.1. Semen examination ................. 44
a. Macroscopic examination ................. 45
b. Microscopic examination ................. 46
3.2.3. Libido .............................. 53
3.2.4. Fertility data ...................... 53
4. RESULTS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
4.1. Normal morphology of dog spermatozoa ....... 56
4.2. Acrosome abnormalities ..................... 59
4.2.1. Major acrosomal abnormalities ....... 59
4.2.2. Minor acrosomal abnormalities ....... 61
4.2.2.1. Acrosomal damage .................. 61
4.2.2.2. The acrosome reaction ............. 62
4. 3. Head abnormalities. . . . . . . . . . . . . . . . . . . . . . . . . 6 3
4.3.1. Major head abnormalities ............ 63
4.3.1.1. Macrocephalic •.................... 63
4.3.1.2. Microcephalic ••..••••..•.......... 64
4. 3 .1. 3. Pyriform head..................... 64
4.3.1.4. Diadem defect................... 64
4.3.1.5. Ridged sperm ...................... 65
4.3.1.6. Double forms •.••••••........•..... 66
4.3.1.7. Bizarre forms ..................... 66
4.3.2. Minor head abnormalities ............ 67
4.3.2.1. Narrow heads and small, normal
heads • . . • . . . . . . . . . . . . . . . . . . . . . . . . . 6 7
4.3.2.2. Head-base defects ................. 67
4.3.2.3. Detached heads .................... 67
4.3.2.4. Nuclear decondensation ............ 68
4.4. Midpiece abnormalities ..................... 68
4.4.1. Major midpiece abnormalities . . ...... 68
4.4.1.1. Retention of cytoplasmic droplets. 68
4. 4. 1. 2. Ruptured midpiece. . . . . . . . . . . . . . . . . 69
4.4.1.3. Pseudodroplet defect .............. 69
4.4.1.4. Kinked midpiece ••................. 69
4.4.1.5. Other midpiece defects ............ 70
4.4.2. Minor midpiece abnormalities ........ 71
4.4.2.1. Proximal droplets ................. 71
4.4.2.2. Distal droplets ................... 71
4. 5. Tail abnormalities. . . . . . . . . . . . . . . . . . . . . . . . . 7 2
4.5.1. Major tail abnormalities ............ 72
4.5.1.1. The "Dag" defect .................. 72
4.5.1.2. Double tails ...................... 72
4.5.2. Minor tail abnormalities ............ 73
4.5.2.1. Simple coiling of the tail ........ 73
4.6. Sperm agglutination .......•................ 74
4.7. Foreign cells ••••......•.•••••............. 74
4.7.1. Macrophages and phagocytosis of
sperm. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 4
4.7.2. Sperm precursors .•.................. 74
4 . 7 . 3 . Leucocytes . . . . . . . . . • . . . . . . . . . . . . . . . . 7 5
4.7.4. Epithelial cells •................... 75
4.8. Patient data ..•......•••.•................. 76
4.9. Statistical evaluation .........•.••.....••. 76