Mammary Path

Front 1

Relevance of mammary dz

Back 1

- Milk production- economic and health

- Ab prouction for neonates

- Substinance for neonates

- Comparative studies

Front 2

Structure-

Back 2

- Modified sweat gland
- Cuboidal epithelium

- From outside
1) Teat sphincter
2) Teat canal
3) Fustenberg's rosette
4) Teat cistern
5) Gland cystern
6) Milk duct
7) Alveolus

Front 3

Defences of the mammary gland-

Back 3

- Physical-
- Teat canal/ ductus papillaris- long and thin
- Keratin plug
- Sphincter and rosette
- Flushing of milk through teat

- Soluble-
- Lactoferrin- iron binding- keeps Fe from bacteria
- C'- MAC and opsonisation
- Cytokines- soluble protein messengers
- Lysozymes- lysis of bact. cell wall

- Cellular
- MP- resident
- Neutrophils- attracted by leukotrienes- main phag.

- Humoral-
- Low Ig count in normal milk (IgG from plasma)
- Dz- Inc. IgG, production of IgA and IgM
- IgA prevents adhesion
- IgG and IgM- opsonisation

Front 4

Congenital pathologies of the mam. gland-
(x3)

Back 4

- Supernumary teats

- Malformation- Aplasia/ hypoplasia, non patency

- Pigmentation- Melanosis esp. P

Front 5

Inflammation of the mammary gland-

Back 5

Mastitis- Inflam. of mammary gland

Mammillitis- Inflam of teat

Glactophoritis- Inflam of milk duct system

Front 6

Mastitis definitions-

Back 6

- Clinical mastitis- visable signs
- Mild- flakes/ clots in milk, slight swelling of 1/4
- Severe- secretion abnormal, hot, swollen 1/4, pyrexia..

- Subclinical-
- Somatic Cell count- normal= < 200,000 leuko./ml milk
- Bacterial culture of milk

Front 7

Bovine Mastitis-
Causes-

Pathogenesis
Sequence
Changes

Back 7

- Causes-
- Infection-
- Contagious- eg. Strep. agalactictiae, Staph. aureus
- Cow-cow, 10 udder pathogens, streps and staphs
- Environ.- eg. E.coli, Pseudomonas, strep. uberis
- Contam. of teat end
- Part of systemic infection- Leptospira, Myco. TB
- Trauma- injury

- Routes of infection
- Ascending
- Haematogenous
- Percutaneous

- Pathogenesis
- Penetration
- Infection of milk sinus and ducts
- Invasion of glandular tissue---> Immune response.
- Healing- may be complete resolution/ fibrosis in more severe cases

Pathological changes-
- Squamous metaplasia of epithelium
- Fibrosis
- Inflammation
- Glandular atrophy
- (Spp Variation)

Front 8

Mastitis in other spp-
Sheep-

Goats-

Sheep and goats-

Pigs-

Back 8

- Staph Areus, Manheimmia Haemolytica
- Acute, gangrenous, necrotising mastitis
- Per acute toxaemia and sudden death

- Mycoplasma agalactiae, M mycoides mycoides

- Lentivirus (Maedi-Visna, Caprine Arthritis Encephalititis)
- Systemic lymphoproliferative dz

- Mastitis- Metritis- Agalactia syndrom
- 24-48hrs post partum
- Hypo/agalactica- piglets starve
- From endotoxaemia due to E.coli endotoxin

Front 9

Bovine mastitis
Staphs-

Back 9

- Staph aglactiae/ dsygalactiae-
- Continual challenge with occas. flare ups
- Invade a short distance into gland
- Cause oedema, inflam., exudate

- Staph Aureus-
- Deep glandular penetration
- Toxins damage BV---> Thombosis, infarction and gangrenous necrosis
- Tissue sloughing
- Pockets of persistent infect---> granuloma formation
- Depends on virulence of strain
- Coagulase and haemolysin good indicator of path.
- Death from toxaemia

Front 10

Coliforms-
E.coli

A. Pyogenes

Back 10

- E.coli
- Acute, haemorrhagic, necrotising mastitis
- Due to effect of endotoxin prod by E.coli on BV
- Causes-
- Subcutaneous serous inflam. c severe oedema
- Necrosis and sloughing
- Lesions centred around ducts- fibrinous exudate
- Often post partum

- Arcanobacterium pyogenes
- "summer mastitis"
- Caused by damaged teats and bacterial penetration
- Aided by flies
- Occurs in all cattle, inc. males
- Characterised by abscess formation and fistulae
- Necrotising suppurative galactophoritis c early fibroplasia

Front 11

Factors influencing mastitis-

Back 11

- Management-
- Hygiene
- Dipping
- Contaminated bedding
- Dry peroid tx
- Faulty palour machinery

- Pathogen-
- Virulence
- Resistance
- Toxin production

- Cow-
- Genetics- udder and teat conformation/ immune syst.
- Teat injury

Front 12

Lesions of the teat-
(x4)

Back 12

1) Pseudocowpox- parapoxvirus- zoonotic
- Common and endemic in cattle
- Erythematous macules and papules
- "Milker's nodule" in people

2) Cowpox- orthopoxvirus- zoonotic
- Uncommon in cattle, resevoir in small rodents

3) Bovine papillomavirus
- Warts

4) Bovine herpes V- bullous and ulcerative mammilitis
- Common dz of lactating cows
- Swollen teat c ulcers/ erosions (ruptured bullae)
- Epithelial syncytia containing intranuclear inclusion bodies

Front 13

Canine mammary neoplasia-
Describe-

Back 13

- Represent about 1/4 canine neoplasm, 50% of those in the b*tch
- 40-70% are benign epithelial tumours
- Metastasise to LN- then commonly to lungs and bone

Front 14

Risk factors for canine neoplasia

Back 14

- Age- peak at 10 y.o., rare below 5.

- Breed- No predisp., pedigree>mixed

- Site- 70% occur in 4th and 5th glands, 40% of animals have multiple gland involvement

Front 15

Causes of canine neoplasia

Back 15

- Hormones- Oestrogen, Progesterone, ProL, GF
- Significantly reduced by ovariectomy
- Pre 1st Oest.- 0.5% of expected incidence
- Pre 2nd Oest.- <10% of expected incidence
- After 2-3 years- Ovariectomy has no effect on rate
- Exogen. progestagens inc. incidence of hyperP and benign neoplasms.

Front 16

Prognosis for canine neoplasia-

Back 16

- Prognosis- depends on
- Clinical stage

- Tumour size

Front 17

Properties of canine mammary tumours-

Benign-
Eg.
Clinical features
Histology

Malignant
Eg.
Clinical features
Histology

Back 17

- Benign-
- Papilloma, adenoma, fibroadenoma
- Slow growing, clearly demarcated, easy to excise
- Uniform, well diff, good margins, no invasion

- Malignant-
- Adenocarcinoma, other...
- Less demarc., infiltrate skin, lymph. spread, metast.
- Anaplasia, infiltration, high mitotic rate, pleomorphic

Front 18

Feline neoplasia-
Describe-

Back 18

- Incidence < B*itch, but 90% are malig- :. poor prog.
- Higher incidence in intact female and siamese

-Presentation-
- Large tumour bulk
- Ulceration
- Metastasis to lungs, LN and skin

- Causes-
- Prolonged Prog. therapy

Front 19

Non- neoplastic enlargement-

Back 19

- Fibroadenomatous hyperplasia
- Uncommon dz of adolescent femal cats-
- Progesterone linked? Exog/ endog.
- Presents as firm, painless swellings of mam. glands
- Micro- Ducts prolif. c Inc. CT and oedema
- May be higher mitotic rate

- Cystic hyperplasia

- Duct ectasia (dilation)
- E.g. after blockage

- Gynecomastia- male enlargement c sertoli cell tumours

- Pregnancy/ pseudopregnancy

- Hernia, skin tumours, abscesses, fat necrosis

Front 20

Epithelial tumour classification-

Back 20

- Gladular?
- No - Malignant= Carcinoma, Benign= papilloma
- Yes- Malig.= adenocarcinoma, Benign= adenoma

- Histology and classification-
- Epithelial only- "Simple"
- Epithelial + myoepithelial- "complex"
- Complex + CT- bone, cartilage, fibrous- "Mixed"