Principles of mammary gland disease

Question 1

What aspects should be examined in a mammary gland assessment?

Answer 1

Skin
Gland structure (size, texture, firmness, evenness)
Teat & teat canal condition (ulceration, discharge)
Milk quality (colour, odour, production levels)

Question 2

What additional tests can be used to assess mammary gland health?

Answer 2

California Mastitis Test, ultrasound, fine needle aspiration

Question 3

What does a positive California Mastitis Test (CMT) indicate?

Answer 3

Presence of somatic cells (WBCs), which suggests mastitis

Question 4

What are the characteristics of a normal mammary gland?

Answer 4

Healthy skin
Normal size
Functional suspensory system
No pain or heat
Even texture
Normal milk production

Question 5

How does progesterone affect the mammary gland?

Answer 5

Causes mammary enlargement in non-pregnant dogs, often leading to pseudo-pregnancy

Question 6

What are common mammary disorders?

Answer 6

Skin diseases (e.g. warts or ulcerative mammillitis (BHV2))
Udder suspensory damage
Teat trauma
Inverted nipples
Mastitis
Hyperplasia
Neoplasia
Agalactia

Question 7

What is mastitis, and how is it classified?

Answer 7

Inflammation of mammary gland

Types include:
- Subclinical
- Clinical
- Acute
- Acute gangrenous (tissue necrosis)
- Chronic

Question 8

What are common causes of mammary hyperplasia?

Answer 8

Normal under progesterone

Due to milk engorgement at weaning

Mammary hyperplasia (e.g hormonally induced in Queen with fibroepithelial hyperplasia)

Question 9

What percentage of mammary tumours are malignant in dogs?

Answer 9

50% (with up to 50% of these metastasising by diagnosis)

Question 10

What percentage of mammary tumours are malignant in cats?

Answer 10

85%

Question 11

How is mammary neoplasia staged using the TNM system?

Answer 11

T (Tumor size)
N (Node involvement)
M (Metastasis presence)

E.g.: 4 cm tumour with no lymph node spread & no lung metastasis = T2, N0, M0 (Stage 2)

Question 12

What are the two types of agalactia?

Answer 12

1. Failure of milk production – Due to inadequate mammary development (e.g. early C-section)
2. Failure of milk letdown – Due to stress-induced adrenaline blocking oxytocin release

Question 13

How is agalactia treated?

Answer 13

Milk production failure: Metoclopramide (prolactin agonist)

Milk letdown failure: Oxytocin administration

Infections causing agalactia (e.g. metritis, mastitis): Treat underlying disease