Female Reproductive System

Dr. Bikash Puri

M.V.Sc (Vet. Pathology)

Developmental Anamolies

Segmental aplasia of uterine horn�

• Uterus unicornis is presence of only one horn of uterus instead of two.
• Occurrence: Short horn cattle (“White Heifer Disease”) Sows
• Causes: associated with the recessive gene for white coat color.

​

Gross Findings:

• Segment of horns absent or consist of thin cords
• Lumen of uterus proximal to affected segment thin-walled
• Lesion may be unilateral (“Uterus unicornis”) or bilateral

Segmental Aplasia of uterine horn (Uterus unicornis)

Freemartin

• A congenital disease seen when female born co-twin with male
• In more than 90% cases such females have sever hypoplastic genital tract and are subsequently sterile.

Pathogenesis:

• Male and female co-twin shares a common placental circulation in utero.
• Male gonads develops faster than the female gonads.
• Androgenic hormones produce by testicles of male fetus may enter the circulation and suppress the development of the female genitalia.

​

Gross findings

• Hypoplasia of ovaries and tubular organs of mullerian duct origin
• Absence of communication between uterus and vagina
• Vagina is hypoplastic or non-patent with a complete hymen.
• Hypoplasia of vestibule and vulva
• Seminal vesicles present
• Clitoris is enlarged.
• Mammary gland fail to reach the normal size.
• Male co-twin may be sterile or fertility may be reduced.

​

The clitoris enlarge and protrudes between the labia of the vulva and is visible on the ventral floor of the vulva. Note: The formation of a bifid scrotum ventral to the vulva.

Pathology of ovary

• Ovarian hypoplasia
• Inflammation
• Cystic ovarian condition

HYPOPLASIA OF OVARIES:�

• Normal in young animals but fail to reach the normal size and functional states after maturity (remain in infantile form).
• Occurs mostly commonly in cow (Swedish Highland Cattle) and to a lesser extent in other species.
• Usually the left ovary is more frequently and severely hypoplastic than the right.

CAUSES:

• Congenital
• MALNUTRITION
• Other form of debility.

Hypoplasia of ovaries:�

Gross findings:

• Affected organ are smaller than normal
• Absence of follicles and luteal scars.
• Tubular genitalia are also under-developed.

​

Microscopic findings:

• Ovary mainly composed of medullary connective tissue and blood vessels.
• Absence of cortical stroma
• Absence of ova.

​

Oophoritis

• It is the inflammation of ovary characterized by granulomatous or lymphocytic inflammation.
• Very rare and if occur it is usually pyogenic.

Etiology:

• Infectious: Bscteria (Salmonella pullorum (Chickens); Tuberculosis- rare); Viral (BHV-1)
• Trauma
• Secoundary to salpingitis, metritis, perimetritis

Macroscopic findings:

• Hard, nodular lesion in ovary encapsulated with fibrous tissue
• Haemorrhage in corpus luteum
• Presence of cloudy fibrinous fluid in some follicles.

Microscopic findings

• Infiltration of lymphocytes leading to lymphofollicular reaction in follicles
• In chronic cases proliferation of fibroblast leading to fibrosis and atrophy of ovary.

​

Cystic ovaries

• It is the clinical term used to refer to one or more cyst in ovary
• May occur in all species (Cattle and swine)

Types of cysts:

1. Cystic grafian follicles:
• Most common form of cystic ovarian condition in cow and sow
• Arising form failure of the mature follicles to rupture.
• Causes: Deficiency of LH or LH receptor in the ovary, stress, or high level of progesterone.

Gross findings:

• Presence of one or more large follicles in one or both ovaries
• Absence of corpus luteum in ovaries
• Uterus and vulva are edematous and flabby
• Cervix is enlarged and produces a tough gray-white mucus
• Enlarged clitoris

Follicular cysts are larger than normal follicules and usually greater than 2.5 cm in diameter.

Microscopic findings:

• Absence of ovum
• Degeneration of the granulosa cells.

2. Luteinized cyst

• Occurs due to delayed or insufficient production of luteinizing harmones during estrus.
• In this case the ovulation fails to occur and theca interna undergoes luteinization.

Pathogenesis:

​

Gross findings:

• Absence of ovulation papilla
• The luteal mass is smooth and rounded
• Cyst cavity is spherical and lined by a layer of fibrous connective tissue.

Anovulatory luteinized cyst is single round thick yellow-walled follicular cyst. Here, the cystic cavity is lined by fibrous tissue, surrounded by an adjacent zone of luteinized theca cells.

3. Cystic corpus luteum�

• Occurs following ovulation with formation of a cystic cavity in the central mass of the developing luteal tissue.

Gross findings:

• Presence of ovulation papille
• Presence of irregular round to oval cyst within corpus luteum.

A cystic corpus luteum is a normal corpus luteum complete with an ovulation papilla and a prominent cystic center. There is also a normal Graafian follicle (left) present. �

Salpingitis

• It is the inflammation of the oviduct or fallopian tube.
• Uncommon in domestic species; often bilateral.

Etiology:

• Extension of infection from the uterus example: Mycoplasm, Streptococci, Trichomoniasis

Gross findings:

• Hyperemia and thickening of the mucosa of oviduct
• Distension of oviduct lumen due to accumulation of serous exudates (Hydro salpinx ) or pus (pyosalpinx).
• In chronic cases, fibrosis and hardening of oviduct.

Microscopic findings:

• In early mild lesion there is loss of cilia and desquamation of epithelial cells at the tips of the mucosal folds.
• With time adhesion firm between the denuded areas and adjacent mucosa becomes cystic, reepithelializes or is replaced by granulation tissue..
• Presence of numerous neutrophils along with other inflammatory cells, both within mucosa and mucosal cyst.
• Proliferation of fibroblast

​

Endometritis/Metritis/Perimetritis

• Inflammation of endometrium is called endometritis. If the involvement is in entire uterine wall it is called metritis and inflammation of uterine serosa is called perimetritis.

Etiology:

• Infection: Streptococcus, staphylococcus, E-coli, Actinomyces, Trichomonas, etc.
• Entry of organism in uterus as a result of coitus, artifical insemination or as tatrogenic infection.
• Strong chemical/drugs administration

Macroscopic findings:

• Uterus is enlarged, flabby and friable
• Uterine wall is swolled, edematous and congested.
• Uterine lumen contains chocolate colored lochia, with or without foul odour.

Microscopic findings

• Desquamation of epithelial lining
• Necrotic endometrium is replaced by granulation tissue devoid of glands and ultimately by fibrous tissue
• The best indication of metritis is the presence of infiltrated plasma cells and lymphocytes in the stroma.

Sequelae:

• Mild inflamm. → Healing with regeneration
• Severe inflamm. → Healing with scarring

Pyometra

• It is the acute or chronic suppurative inflammation of uterus resulting in accumulation of pus in the uterus.

Two mechanism are responsible for occurance of pyometra:

• Functional obstruction of uterine discharge:

Example: Retained corpus luteum prolong production of progesterone

​

​

​

Increase susceptibility of uterus to infection

​

Inhibition of myometrial contraction

​

Cervix remain closed

​

Leading to pyometra

Example: Cystic corpus luteum, Pseudopregnancy

2. Pyometra associated with mechanical obstruction to uterus

​

Occurs following infection in which cervix become indurated and stenotic

​

Thereby preventing the expulsion of uterine exudate.

Etiology:

• Extension of infection form cervicitis, vaginitis and endometritis.
• Postpartum infection: e.g. dystocia, retained placenta
• Venereal infection: Campylobacter, Trichomonas, Taylorella
• Hematogenous infection: e.g. Brucella

​

​

Gross findings:

• Uterine wall is thick and doughy or it is thin or fibrosed
• Presence of necrotic, ulcerated and hemorrahagic area in uterine mucosa along with dry, white, thickened, finely cystic areas.
• Uterine horn are distended with purulent exudate
• Cervix is completely or almost completely closed
• Escape of small amount of thick and creamy fetoid pus into the vagina
• Presence of cystic corpus lutem in ovary.

​

Fig: Pyometra.

Pus in the lumen of the uterus was removed during processing of the histologic section

Fig: Endometritis and pyometra. There are large numbers of lymphocytes and plasma cells in the endometrial stroma. The surface epithelium is hyperplastic and papillary. The luminal epithelial cells are highly vacuolated.

Microscopic findings:

​

• Cystic hyperplasia and squamous metaplasia of surface epithelium
• Selective bone marrow depression leading to anemia and sever extramedullary hematopoiesis.
• Leukocytosis is observed.

Cervicitis

It is the inflammation of the cervix

Etiology:

• Extension of vaginal or uterine infection
• Inappropriate AI
• Injuries at the time of parturation or correction of dystocia

Macroscopic findings:

• Congestion and hemorrage of cervix
• Enlargement of cervix
• In chronic cases the cervix become hard and fibrosed.

Microscopic findings:

• Catrrhal inflammation of cervical mucosa
• Hyperplasia of mucous glands with tall mucin containing epithelial cells
• Presence of mucin in lumen.

Vaginitis

It is the inflammation of vagina

Etiology:

• Laceration or brusing of vaginal mucosa during parturation
• Malacious injury
• Trichomonas foetus
• BHV-1

Macroscopic findings

• Vagina is painful, congested and edematous
• Granular elevation in vaginal mucosa
• In case of bacterial infection there is necrosis and foetoid discharge is common

Microscopic findings:

• Accumulation of lymphocytes in sub epithelial region.

Foetal death

• Once the foetus die it is handle by body in 3 ways:
• Mummification of foetus
• Maceration of foetus
• Abortion.

Abortion

• Abortion is expulsion of dead embryo or foetus before attaining normal gestation
• Two terms are related to abortion

1. Still birth: expulsion of dead foetus

2. Premature birth: Birth of live foetus before attaining ful gestation peroid.

Etiology

• Faulty rectal palpation
• Infection: Example: Bacterial (Brucellosis, Listeria, Leptospira, Mycoplasma, Campylobacter), Virus (Equine Herpes Virus) , Protozoal (Trichomonas foetus, Toxoplasma, ),etc.
• Toxin and poisions

Findings:

• Expulsion of dead foetus
• Liver of foetus have necrotic foci and are congested
• In some cases there is retaintion of placenta and placenta may be inflammed, edematous and necrotic.

​

Mummification of foetus

Pathogenesis:

>

Death of foetus

​

Death foetus are not expelled as cervix is closed

​

No entry of pathogens from outside

​

Autolysis occur in sterile condition

​

Fetal fluid and liquefied fetal tissue are reabsorbed.

​

Entire foetus becomes shrunken with wrinkled skin and dried as mummy.

Mummification

Findings

• Presence of corpus luteum in ovary
• Closure of cervix
• Entire foetus become brown or black in colour and leathery like with complete absence of exudate or odor.
• Mummified foetus consist of dried wrinkled skin and bones.

Maceration of foetus

• Death and retained foetus that undergoes autolysis in presence of uterine infection.
• In this case corpus luteum is not persistent and cervix may be open
• Discharge of brown colored fetid exudates from the vagina
• On rectal palpation fetal bones can be felt and crepitating sound can be heard.

Hydramnios and hydrallantosis

• Usually, there are 6-15 liter of allantoic fluid and 3-6 lt of amniotic fluid in cow.
• These foetal fluid content reaches maximum in mid gestation and then gradually decreases
• Failure of this leads to the above mention conditions.

i.e:

​

Hydramnios

Hydrallantosis

Accumulation of fetal fluid in amniotic cavity

Accumulation of fetal fluid in allantoic cavity

Mastitis

It is the inflammation of the mammary gland.

This condition is of greatest economic importance in dairy cattle.

Etiology:

• Bacterial infection: Example- staphlyococcus, Streptococcus, Actinomycosis, E-coli, Mycobacterium, etc.
• Viral infection: Example- FMD, Pox virus, BHV-1
• Fungal Infection: Example- Candida, Trichosporon, etc.

Gross findings:

• Oedema and swelling of udder
• Loss of symmetry
• Presence of flakes n milk
• Milk may be watery, grey or dark colour and some time blood mixed milk.
• In chronic cases there is atrophy and shrunken quarter
• Gangrene formation

​

Microscopic findings

• Congestion and haemorrhage of mammary gland & fibrin may be present.
• Infiltration of neutrophils, macrophages and lymphocytes
• Necrosis of alveolar epithelium and hyperplasia of epithelial linings
• Proliferation of fibrous connective tissue
• Leukocytosis is observed i.e increase WBC count i.e > 100/ml of milk

Gangrenous necrosis

Suppurative Mastitis