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