General Pathology and Important terminologies

1. Pathology of Female Reproductive System

3.  FEMALE GENITAL SYSTEM
 DEVELOPMENTALANOMALIES
Agenesis
• Absence of ovary, uterus, oviduct and cervix in females. It may be unilateral or
bilateral.
Hypoplasia
• Complete or partial lack of germ cells in ovaries. Hypoplasia of uterus is related with
agenesis of gonads. Ovaries of freemartin are also hypoplastic. Hermaphrodite
animal has ovary and testicular tissue both in the gonads.
Freemartin
• A freemartin or free-martin (sometimes martin heifer) is an infertile female
mammal with masculinized behavior and non-functioning ovaries.
• The animal originates as a female (XX), but acquires the male (XY) component in
utero by exchange of some cellular material from a male twin, via vascular
connections between placentas.
•Externally, the animal appears female, but various aspects of female reproductive
development are altered due to acquisition of anti-Müllerian hormone from the
male twin.
•Freemartinism is the normal outcome of mixed-sex twins in all cattle species that
have been studied, and it also occurs occasionally in other mammals including sheep,
goats and pigs.

4. Placenta, twin fetuses. Placental vascular anastomoses, which allow exchange of blood between fetuses, are a
requirement for the occurrence of a freemartin. These anastomoses occur most often in the bovine species

5. Segmental Aplasia of the Paramesonephric Ducts:
• The paramesonephric ducts are paired embryonic ducts that develop into the anterior
vagina, cervix, uterus, and uterine tube. Segmental aplasia of the paramesonephric
ducts results in anomalies of those organs.
• The aplasia may be located in a segment of the uterine tube, uterine horn, cervix, or
vagina. Ovarian development is normal.
• Obstruction: Accumulation of secretions proximal to the obstruction occurs
secondarily (hydrosalpinx, hydrometra, mucometra).
• Segmental aplasia of the uterus may involve one horn (resulting in a condition called
uterus unicornis),
• Uterus unicornis has been described in several domestic animal species. The
condition seems to be relatively common in camelids. These females can become
pregnant and carry the pregnancy to term. Cervical aplasia has been described in a
few cases but is not as common.
• True persistence of the hymen or imperforation of the hymen is the most commonly
reported paramesonephric duct anomaly in domestic animals.
• Fluid accumulates in the vagina and uterus, resulting in protrusion of the hymen at
the vulva when the animal is lying down or straining. Hymenal defects are most
common in white Shorthorn cattle (white heifer disease).

6. Segmental aplasia of a uterine horn, uterus, pig. The right uterine horn is
completely missing

7. Hermaphroditism
• In hermaphrodites, there is presence of organs of both sexes in same
individual animal. Both ovarian and testicular tissue occur in one
animal leads to sterility in animal (true hermaphrodite)
• while in pseudohermaphrodite the gonadal tissue of only one sex is
present but there is some degree of development of opposite sex organs.
Uterus unicornis
• Uterus unicornis is presence of only one horn of uterus instead of two, seen
in animals with white heifer disease.
White heifer disease
• White heifer disease occurs due to a single sex linked gene defect
responsible for white coat colour. In such animals, there are normal ovaries,
oviduct but uterus is incomplete and may lack communication with cervix.
There is hypoplasia of cervix and vagina.
 Uterus didelphys
• Uterus didelphys is the occurrence of two cervix with two uterine bodies
and single or double vagina. It occurs due to failure of ducts to fuse at
their distal end. Sometimes failure of fusion may affect only cervix and there
is two cervix which is termed as Cervix bifida.

8. True hermaphrodite, reproductive tract, gilt. An ovotestis is on the left and a testis on the right.
Note the well-developed uterus, cervix, and vagina.

9. Male pseudohermaphrodite, reproductive tract. A, Pig. A testis and epididymis are
present on each side. Note the well-developed uterus, cervix, and vagina. No ovarian
tissue is present.
A B

10. SALPINGITIS
• Salpingitis is the inflammation of oviduct or fallopian tube characterized by
congestion, catarrhal or purulent exudate leading to distended lumen.
Etiology
• Mycoplasma
• Streptococci
• Tuberculosis (Mycobacterium tuberculosis)
• Trichomoniasis (Trichomonas foetus)
Macroscopic and microscopic features
• Congestion, abscess formation
• Distension of oviduct lumen due to accumulation of serous exudate which is known
as Hydrosalpinx.
• Accumulation of pus in oviduct is termed as Pyosalpinx.
• Occlusion of lumen due to inflammatory exudate resulting in sterility.
• Inflammatory exudate is toxic to ova as well as sperms leading to sterility.
• Suppurative inflammation
• Infiltration of neutrophils, macrophages and lymphocytes
• Proliferation of fibrous tissue, hardness

11. Mastitis
• Inflammation of the mammary gland is called mastitis. It is a very important
disease in cattle.
• Inflammation of the mammary gland is almost always caused by infection.
And most infections occur by organisms moving up the teat canal.
• There are many defense mechanisms within the teat canal such as
keratinization and acquired immunity.
• Normal milking does not cause damage but when the procedures or
equipment are faculty (high vacuum, poor liners, ineffective pulsations, over
milking), there can be abrasions, eversions, and disruptions in normal
bacterial flora that predispose to ascending infection.
• Milk also has many products that help to decrease infection and these
include
• lactoferrin that binds iron, making it harder for bacteria to get the iron they
need lysozyme - kills bacteria
• lactoperoxidase - inhibits Staphylococcus and Streptococcus
immunoglobulins
• phagocytic cells

12. Bovine mastitis
• The normal skin of the mammary gland and teat have regular populations
of bacteria which probably help to maintain an ecologic balance.
• Corynebacterium bovis and coagulase-negative staphylococci live here
normally and in general keep the opportunists at bay.
• However, damage to the teat canal allows organisms access to deeper
structures.
• Staphylococci, streptococci, and the coliforms dominate the picture of
bovine mastitis.

13.  Streptococcus and Staphylococcus enter the mammary gland through
the teat canal and find the glandular tissue a really great place to live and
raise a family.
• Usually the cow is not sick, but the milk tastes are affected and production
is also lowered.
• A big problem with mastitis is that it tends to be permanent, hard to ever
get the gland back to completely normal. So production is never fully
returns.

14. Coliform mastitis
• The organisms in this category that cause mastitis include:
• E. coli, Enterobacter spp.,
• Klebsiella spp., Citrobacter spp.,
• Serratia spp.,
• and Proteus spp.
• All are part of the environmental flora and there is no predilection for
mammary gland. They simply invade because the dirt in the
environment is close to the open teat canal.
• The damage that they induce is related to the endotoxins that they
have (all are Gram negative and so have plenty of LPS).
• The microvasculature is shot and there is infiltration of neutrophils.
• Grossly the gland looks edematous, hemorrhagic, and there may be
fibrin. If it goes on for long enough, there will be pus as well. It is
usually restricted to one quarter but can rapidly destroy that quarter.

15. Mastitis in sheep and goats
• Mastitis in the ewe and doe is usually caused by Staphylococcus
aureus or Mannheimia hemolytica. The latter can be very
necrotizing and affects vasculature resulting in cyanosis and so is
sometimes known as “blue bag”.
• Maedi-visna virus and caprine-arthritis encephalitis virus (CAE),
both retroviruses, will cause mastitis in their respective species
(sheep and goats).
• Lactating goats that eat avocados develop mammary necrosis.
Mastitis in dogs and cats
Mastitis in dogs and cats is uncommon and is usually transient and
due to staphylococci or streptococci.
Mastitis in swine
Mastitis- metritis- agalactia syndrome occurs in postparturient sows
and is caused by a number of bacteria, most often are coliforms.

16. Pathology of Female Reproductive System
Lecture # 2

17. ENDOMETRITIS
• Endometritis is the inflammation of endometrium, the mucosa of
uterus. It may be catarrhal or purulent and may occur after
metritis.
• Animals are not SICK, just can’t support a pregnancy.
Etiology
• Trichomonas foetus
• Campylobacter foetus
• Staphylococci
• Streptococci
• Organism enters in uterus as a result of coitus, artificial
insemination or as a iatrogenic infection (Any illness resulting from
treatment, such as
the side-effects of some drugs)
• Strong chemicals/ medicines administered in uterus.
Macroscopic and microscopic features

18. Macroscopic and microscopic features
• Catarrhal discharge from uterus containing desquamated cells.
• Sterility due to toxic environment of uterus to sperms.
• Congestion.
• Moderate infiltration of lymphocytes, plasma cells and neutrophils in
mucosa.
• Chronic endometritis: The endometrium gets fibrotic, and glands
are often atrophied.
• Periglandular fibrosis may result in cystic glands. Can result in
infertility.
• This is a big problem in MARES. Organisms gain access at the time
of foaling or breeding, and set up a mild reaction in the uterine lining
that causes an insidious fibrosis, making it impossible for the
remaining glandular structures to proliferate sufficiently to support a
successful pregnancy.
• Animals are not clinically ill, and vulvar discharge may be minimal,
but the impact on fertility is substantial.

19. • Metritis:
• Inflammation of the ENTIRE uterine wall, like the muscle
doesn’t work either.
• Metritis might start out as endometritis, but with metritis, the
inflammation has become more severe and now involves not only
the endometrium but also some of the myometrium. uterus is
flaccid.
• Pyometra:
• Pus filled uterus, seen in the dog, cat, and cow and rarely sheep.
• The uterus can be mildly to severely distended and filled with
pus or foul smelling fluid.
• The endometrium is thickened, necrotic, and ulcerated, in
addition to being hyperplastic and cystic. The serosa is
congested. The wall is friable and may rupture.

20. Pyometra, uterus, cow. The uterus is distended and filled with foul-smelling dark brown fluid. The
endometrium was red-black and dull, indicating an endometritis secondary to bacterial infection. This cow
developed a severe pyometra immediately after calving.

21. Metritis-pyometra-endometrial hyperplasia, uterus, bitch. A, Pyometra occurs several weeks after estrus. Bacteria grow
in the uterus and induce a suppurative response. The uterus fills with pus and is distended. B, Endometritis and pyometra.
There are large numbers of lymphocytes and plasma cells in the endometrial stroma. The luminal epithelial cells are highly
vacuolated. Pus in the lumen of the uterus was removed during processing of the histologic section. H&E stain.

22. NEOPLASMS
• There are three main groups of primary ovarian neoplasia in domesticated
animals: germ cell, sex-cord stromal, and epithelial neoplasms.
Germ cell neoplasms
• The great majority of neoplasms of germ cells are benign and
undifferentiated (dysgerminoma) or benign with somatic differentiation
(teratoma).
• Dysgerminoma is a rare neoplasm of bitches, sows, cows, and mares and is
composed of cells resembling primitive germ cells. The neoplasm is usually
a solid lobulated mass with areas of hemorrhage and necrosis.
• It is analogous to seminoma in the male. Mitotic rate is high, but
metastases are rare.
• Ovarian teratomas are rare, usually well differentiated, and benign. They
arise from totipotential primordial germ cells and have disorganized
elements of at least two of the three embryonic germ layers.
• Skin is often a significant component . Malignant teratomas occur less often,
except in the bitch.

23. Ovarian teratoma, ovary, bitch. These tumors have cells derived from all three germ cell lines:
ectodermal (epithelium, including neuroepithelium), mesodermal (mesenchymal tissue), and endodermal
(intestine and respiratory tissues). The most common tissues seen macroscopically include hair, cartilage,
and bone. This teratoma was 30 cm in diameter and surrounded by a bursa, but residual ovarian tissue was
not found. Hair and bone are the main structures visible.

24. Gonadal stromal neoplasms
• Granulosa cell neoplasms are the most common ovarian
neoplasms in large animals. They are unilateral, smooth surfaced,
and round and can be 20 to 30 cm in diameter. They can be solid,
cystic, or polycystic .
Microscopically the granulosa cells are not different from normal
cells and often are arranged as they would be in normal Graafian
follicles, that is, in single or multiple rows of round to columnar cells
lining fluid-filled spaces. In less differentiated areas, the neoplastic
cells are arranged in sheets.
• Granulosa cell neoplasms are often malignant in the bitch, but in
the cow and mare, sex cord stromal neoplasms are usually benign.
• Many stromal neoplasms produce estrogens or androgens. The
mare can have signs of anestrus, nymphomania, or stallion-like
behavior; the bitch is likely to have prolonged estrus and may
develop pyometra.

25. Granulosa cell tumor, ovary, cow. A, This large, lobulated neoplasm has obliterated the normal structure of the ovary. They
can be solid (as in this case) or multicystic. B, Multiple fluid-filled cysts and solid areas have caused the dramatic ovarian
enlargement. Granulosa cell tumors are part of the group of neoplasms known as gonadal stromal tumors. C, This granulosa
cell tumor has solid and cystic regions. The cysts are lined by cells that resemble granulosa cells of the follicle. H&E stain.
A B C

26. Epithelial neoplasms
• Neoplasms of the ovarian surface epithelium can thus resemble the
several neoplastic types of the endometrium.
• Cystadenoma and cystadenocarcinoma occur commonly in the
bitch.
• They originate from the surface epithelium. The neoplasms are
frequently bilateral.
• Malignant forms spread over the peritoneal.
• Ascites results either from obstruction of the diaphragmatic lymph
vessels, which reabsorb peritoneal fluid, or from excess fluid
secretion by the neoplasm.

27. Leiomyoma:
• This is a benign smooth muscle tumor that occurs in all animal
species but is most common in the dog.
Leiomyosarcomas:
• These are the alignant version of the leiomyoma. Like the
leiomyoma, they can occur in the uterus, cervix, or vagina. They
are less common than their benign counterpart.
Fibropapilloma:
• This tumor affects the vulva of young cows. They are caused by
infection with bovine papillomavirus.
• The masses are sessile and round to cauliflower like, basically
“warts”. Most masses regress in 1 to 6 months.

28. Uterine adenocarcinoma:
• These tumors can occur in all species, but are particularly common in
old domestic rabbits and chickens.
• This tumor can spread hematogenously to the lymph nodes and lung. It
can also spread by implantation (carcinomatosis) to the peritoneum.
• Carcinomatosis results in lymphatic blockage since the peritoneum is
often covered with tumor tissue, impairing resorption of fluid, so
animals will develop severe ascites.
Lymphosarcoma:
• This is the most common uterine neoplasm in the cow. Probably also the
most common neoplasm in cows, period. It can be part of multicentric
bovine lymphosarcoma or of primary uterine origin.
Vulvar squamous cell carcinoma:
• Similar to sunlight induced squamous cell carcinoma, squamous cell
carcinomas of the vulva are most often seen in cows, horses, and ewes.
They are typically locally aggressive, but are slow to metastasize to
regional lymph nodes.