Pathology Flashcards
What are the portals of entry for pathogens?
Ascending infection - at oestrus, postpartum infections, equine placenta during pregnancy
Haematogenous infection - specific infections
Descending from ovary - rare
Transneural - rare
What defense mechanisms are present in the reproductive tract ?
Innate immunity - vaginal epithelium, cervical barrier, conformation external genitalia, myometrial tone and uterine contraction, drainage of secretions, neutrophils, macrophages, complement, cytokines
Adaptive immunity - humoral, cellular
When is the uterus more susceptible to infection?
Progestational or luteal phase
Pregnancy
What does oestrogen influence in immunity?
Disease resistance - upregulation of T and B lymphocytes in ruminants
What does inflammation with epithelial and mucosal surface loss in the uterus result in?
Decreased PGF2alpha production
No lysis of CL
What are the five types of sexual ambiguity/developmental anomalies that can affect the uterus?
True hermaphrodism Pseudohermaphrodism Chimerism Tract anomaly Ovarian anomaly
What ovarian anomalies can occur?
Agenesis
Hypoplasia
Duplication
Developmental cysts
What are the three types of acquire ovarian lesion cysts?
Follicular cysts
Anovulatory luteinised cysts
Cystic corpora lutea
Describe follicular cysts
Failure of mature follicle to ovulate
>2.5cm in cow, >1cm in sow
Persistence for more than 10 days without functional CL
Anovulation without luteinisation due to abnormality in hypothalamo-hypophyseal-ovarian axis
Lack of LH peak due to low GnRH or receptors
Can be stress/infection associated
Anoestrus or nymphomania
Describe anovulatory luteinised cysts
Anovulation with luteinisation of theca
Likely delayed or insufficient LH peak
Mostly anoestrus
Treatment is different
Describe cystic corpora lutea
Normal ovulation
Ovulation papilla on surface
No infertility
Can be confused with luteal cysts
What are the four types of acquired ovarian lesions?
Cysts
Haemorrhages
Adhesions
Inflammation
What are the four types of ovarian neoplasm?
Germ cell neoplasm - dysgerminoma, teratoma
Gonadal stromal neoplasm - granulosa cell tumour, thecoma, luteoma
Epithelial neoplasm - cystadenoma, cystadenocarcinoma
Secondary tumours - lymphomas, mammary carcinomas bitch, intestinal carcinomas cow
Describe dysgerminoma
From primitive germ cells Smooth surface Areas of haemorrhage or necrosis Frequent mitotic figures Giant cells Mostly benign and undifferentiated
Describe a teratoma
From totipotential germ cells
Elements of 2-3 germinal layers
Mostly well differentiated
Benign
Describe sex-cord stromal tumours
Granulosa-theca cell tumour Some produce steroids Smooth surface Solid or cystic cut surface Usually benign
Describe epithelial neoplasms
Cystadenoma and cystcarcinoma Often bilateral and shaggy surface Especially in bitch May spread by implantation on peritoneal surfaces May result in ascites
What three things can affect the fallopian tubes?
Hydrosalpinx - water filled
Pyosalpinx - pus filled
Salpingitis - infection/inflammation
What physical changes can occur in the uterus causing problems?
Torsion
Rupture
Prolapse
What can prolapse be associated with?
Prolonged dystocia
Hypocalcaemia
Oestrogen excess
What three things can cause endometrial growth disturbances?
Hyperplasia - cystic endometrial hyperplasia, endometrial hyperplasia due to excessive and prolonged oestrogenic stimulation
Mucometra/Hydrometra - obstruction, excessive fluid production
Pseudopregnancy - exaggerated form of physiologic process
What are the three inflammatory diseases of the uterus?
Endometritis
Metritis
Pyometra
Describe endometritis
Limited to uterine mucosa
Post service
Postpartum in particular when dystocia
Inflammatory infiltrate into mucosa
Mild cases usually self-limiting
Severe cases can become chronic and fibrous
Persistent CL in mare and cow in chronic endometritis
Persistent mating induced endometrits in mares
What are the common endometritis pathogens in cows?
Herpesvirus Tritrichomonas foetus Campylobacter foetus spp venerealis Pyogenic cocci Coliformes T. pyogenes
What are the common endometritis pathogens in the mare?
Alpha-haemolytic streptococci Klebsiella pneumonia E. coli Taylorella equigenitalis (CEM) Pseudomonas aeruginosa
Describe metritis
Inflammation of all layers of the uterine wall
More severe and advanced than endometritis
Potentially life threatening due to toxaemia/septicaemia
Commonly dull congested serosa
Paintbrush haemorrhages
Thickened oedematous friable uterine wall
Yellowish-dark red exudate
Foul odour
Describe pyometra in the bitch
Infection supervening upon Cystic Endometrial Hyperplasia
Mainly in older nulliparous bitches
Usually a dew weeks after oestrus under progesterone exposure following oestrogen priming
Bacterial infection of the endometrium
Urinary tract infections can predispose
Variation in gross appearance
Common pathogens involved - E. coli (brownish viscous exudate), Strep spp. (creamy yellowish exudate)
Cervix closure important for outcome
Toxaemia/bacteraemia common - widespread extra-medullary haematopoiesis, immune-complex glomerulopathy
Describe pyometra in the cow
Uterine disease predisposes
Mostly early postpartum
Various time after breeding
Persisting CL and high progesterone levels
Functional cervix closure but usually some discharge
Few ml to litres of pus
Thick, mucinous, cream or grey coloured pus
Rarely systemic signs
What are the commonly involved pathogens in pyometra in cows?
Haemolytic streptococci Staphylococci Coliforms Trueperella pyogenes Pseudomonas sp Tritichomonas foetus
What is usually the cause of pyometra in the sow?
Trueperella pyogenes
Describe pyometra in the mare
Some cases follow difficult parturitions with infections Mares continue cycling during disease Hormonal influences less important Mostly no cervical closure Seldom evidence of systemic disease
What are the common pathogens involved in pyometra in the mare?
Streptococcus zooepidemicus E.coli Actinomyces spp. Pasteurella spp. Pseudomonas spp.
Describe leiomyoma
Mostly in bitch
Benign
Often multiple also affecting cervix and vagina
Oestrogens likely involved in provoking and maintaining in bitch
Usually firm, pink or white
Whorled smooth muscle cells
Describe carcinoma
Mainly in cow Mainly in uterine horns Scirrhous response Firm neoplasm Metastases to regional lymph nodes, lungs and seeding in peritoneum
Describe lymphosarcoma
Enzootic Bovine Leukosis in the cow - notifiable
Tetrad of affected organs - heart, abomasum, lymph nodes, uterus
Light yellow
Slightly friable
What non-inflammtory diseases are there of the vulva and vagina?
Persistent hymen Vaginal septum Ruptures Stricture/stenosis Abnormal tumefaction Vaginal hyperplasia/hypertrophy and/or prolapse Vaginal cysts Vaginal polyps - common in older bitches
What inflammatory diseases are there of the vulva and vagina?
Post partum trauma Granular vaginitis/vulvitis IPV CHV-1 EHV-3 - coital exanthema Dourine - notifiable
What neoplasms can affect the vulva and vagina?
Leiomyoma
Transmissible venereal tumour
Fibropapilloma
Squamous cell carcinoma of vulva
Describe transmissible venereal tumours
TVT cells have 59 chromosomes instead of normal 78
Transmission by transfer of neoplastic cells during coitus
Nodule formation beneath vaginal mucosa that enlarges
Large, round neoplastic cells
Occasional large bizarre nuclei
Vincristine responsive
Metastases in dogs with poor health
Which animals are CL dependent during pregnancy?
All of pregnancy - cattle, goats, pigs, dogs
Early pregnancy - horse, sheep, cats
Describe how parturition occurs
Foetal stress Foetal ACTH Foetal glucocorticoid Placental oestrogens increase Myometrial oxytocin receptors increased and endometrial PGF2alpha Myometrial contraction, luteolysis and progesterone decrease Relaxin secretion Placental separation from endometrium Fresh non-autolysed foetus
What are the five mechanisms of embryonic/foetal loss?
Failure of zygote to attach to endometrium
Early embryonic losses - chromosomal abnormalities, inherited disorders, uterine environmental factors
Late embryonic loss - after dam recognised pregnancy stage
Foetal losses - non-viable, placentitis, foetal death from various causes
Stillbirth - potentially viable stage of gestation
Describe embryonic death
Zygotes and early embryos
15-30% loss can be considered normal in most species
Expulsion or reabsorption
Can return to oestrus at normal interval
May have delayed return to service
Often no diagnostic material available
Chromosomal abnormalities important cause
Infections rarer - Ureaplasma spp., Tritrichomonas foetus, Campylobacter spp.
What is abortion?
Premature expulsion of a non-viable foetus or foetuses
What are the three types of foetal retention?
Mummification
Maceration
Emphysema
What can happen with foetal death in uniparous animals?
Early gestation - may lead to mummification, can be resorption or abortion
Late gestation - usually abortion
What can happen with multiparous foetal death?
Most foetuses die - generally abortion
One or only a few die - retention, foetuses differ in size, differ in degree of mummification (SMEDI)
Describe mummification
Mostly in multiparous animals - sows most commonly
No bacterial infection
Foetal skin developed enough to withstand autolysis
Absorption of placental and foetal fluids
No odour
Closed cervix
Expulsion time varies
Causes include: genetic, twinning mare, viral, protozoan infections, uterine horn torsion queen, placental insufficiencies
Diagnosis on mummified foetus usually not possible
Usually no effect on subsequent breeding
Describe maceration
Foetus becomes liquified
Presence ofbacterial uterine infection required
Reabsorption or expulsion with purulent exudate
If foetal bones developed only incomplete maceration
Foetid odour
Common with venereal infections - Campylobacter foetus venerealis, Tritrichomonas foetus, non-specific endometrial infections
Consequence often pyometra or endometritis
Perforation of uterine wall by foetal bones possible
Describe foetal emphysema
Putrefactive organisms ascending from the vagina
Patent cervix
Mostly associated with dystocia at or near term and incomplete abortion
Putrefaction of foetus - distends with foul gas and crepitates
Advanced uterine lesions
Oten fatal to dam due to toxaemia
What are the two main classification of abortion causes?
Non-infectious
Infectious
What are the three infectious causes of abortion?
Haematogenous infection of placenta and foetus - pathogens with affinity of reproductive tract
Bacterial and fungal abortions in mares mostly ascending
Venereal infections - Tritrichomonas foetus, Campylobacter foetus venerealis
Describe laboratory abortion investigations
Mostly detect infectious causes of abortion
Diagnostic success rates vary between 8 and 50%
Better success if investigating outbreaks
Conditions in the dam can cause abortion
Cooperation between owner, clinician, pathologist and lab essential
Dam, placenta and foetus should be examined and sampled
Beware of zoonotic potential of many abortion pathogens
What are the majority of sheep abortions diagnosed from?
Placental examination alone
When should sheep, cattle and pigs be investigated with abortion?
Sheep - more than 1-2% of sheep aborting
Cattle - more than 3-5% of cows aborting, cluster of abortions
Pigs - only investigate outbreaks, otherwise diagnosis unlikely
What should be looked for with abortion investigations?
Foetal distress - meconium staining, meconium in trachea/lung or oesophagus/stomach
Degree of autolysis
Foetus and placenta are appropriate size, weight and stage of development
Give some examples of non-infectious abortions?
Dystocia Twinning in mares and cows Umbilical cord anomalies Placental insufficiencies esp. mare Congenital/Genetic Aplasia/hypoplasia adrenal gland Anomalies with aterior pituitary Husbandry Seasonal indertility esp. sows Toxins Nutritional Stress Induced Spontaneous
What are the four infectious causes of abortion?
Bacterial
Viral
Protozoal
Fungal
What are the animals, clinical signs, abortion time of Brucella? Is it zoonotic?
Animals - cows, sheep, pigs, dogs
Clinical presentation - abortion, placentitis, notifiable
Time - late pregnancy
Zoonotic - yes
What are the animals, clinical signs, abortion time of Salmonella? Is it zoonotic?
Animals - horses, cows, sheep, pigs, dogs
Clinical presentation - abortion, placentitis
Time - all stages of pregnancy, usually late
Zoonotic - yes
What are the animals, clinical signs, abortion time of Campylobacter foetus? Is it zoonotic?
Animals - horses, cows, pigs, dogs
Clinical presentation - abortion, endometritis, placentitis
Time - all stages of pregnancy
Zoonotic - yes
What are the animals, clinical signs, abortion time of Leptospira? Is it zoonotic?
Animals - horses, cows, pigs, maybe sheep
Clinical presentation - abortion, placentitis
Time - late pregnancy
Zoonotic - yes
What are the animals, clinical signs, abortion time of Listeria? Is it zoonotic?
Animals - cows, sheep
Clinical presentation - abortion, foetal necrosis, placentitis
Time - late pregnancy
Zoonotic - maybe
What are the animals, clinical signs, abortion time of Chlamydophila? Is it zoonotic?
Animals - sheep, goats, maybe cows
Clinical signs - abortion, placentitis
Time - late pregnancy
Zoonotic - yes
What are the animals, clinical signs, abortion time of Coxiella burnetti? Is it zoonotic?
Animals - cows, sheep, goats
CLinical signs - abortion, placentitis
Time - late pregnancy
Zoonotic - very
What are the animals, clinical signs, abortion time of Bacillus lichenformis? Is it zoonotic?
Animals - cows, maybe sheep
Clinical signs - abortion, placentitis
Time - all stages of pregnancy
Zoonotic - no
What are the animals, clinical signs, abortion time of Trueperella pyogenes? Is it zoonotic?
Animals - cows, maybe sheep
CLinical signs - abortion, placentitis
Time - all stages of pregnancy
Zoonotic - no
What are the animals, clinical signs, abortion time of Streptococcus zooepidemicus? Is it zoonotic?
Animals - horses
Clinical signs - abortion, placentitis, cervical star
Time - all stages of pregnancy, mainly late
Zoonotic - probably not
How are bacterial and fungal diseases diagnosed?
Culture of foetal stomach contents
Selective cultures for: Campylobacter spp., Listeria monocytogenes, Brucella spp., fungi
Macroscopical and histopathological examination of foetal tissues and placenta
Serology - maternal, foetal
Fungal wet preparations of foetal stomach contents
Which bacteria are cultures not possible for?
Leptospira spp. - PCR of kidney tissue
Chlamydophila abortus - impression smears of placenta stained with mZN
Describe mycotic abortions
Mainly Aspergillus fumigatus
In cattle mainly haematogenous
In horses mainly ascending infection
Mostly sporadic outbreaks associated with poor quality feed
THickened leathery placenta covered with exudate
Elevated greyish plaques on foetal skin and eyelid
Diagnose with fungal culture/fungalwet preparation of foetal stomach contents
How can viral abortion be diagnosed?
PCR - PRRS, EHV-1, BVD, Schmallenberg-virus, EVA, FeLV
Virus isolation
Histopathology
Serology - matneral, foetal
Describe Neospora caninum
Persistent infection in cattle
Repeat abortions rare but occur
Dog responsible for horizontal transmission
Vertical transmission most common
Every calf of an infected dam will be Neospora posivie
Diagnose by PCR of brain stem
Can also do histopathology of heartand brain
Describe Tritrichomonas foetus
In cattle Transmitted at coitus Foetal maceration common Endometritis/pyometra Time of abortion: 2-4 months
Describe toxoplasma gondii
In sheep and goats
Timing of infection important
Transmission by cat faeces
Beware of zoonosis
