Abnormalities of the Mammary Gland

Question 1

Laila is 4 weeks post whelping (and is still suckling) and has developed necrotic mastitis

How will you manage this case?

Answer 1

Necrotic mastitis

Substantial discoloration sloughing of skin abscess like lesions

Need to stop the pups from nursing as will be causing pain and cross contamination

Dog needs to go on antibiotic think about one that does not go in to milk

NSAIDs of key importance

As long as still eating and drinking need NSAIDs, Abs do not suture as it will not close need to encourage the sloughing and let swelling go down

Once lactation has stopped use a prolactin inhibitor to reduce size even more

Regular cleaning and EC on bitch

Question 2

List Common Conditions of the Mammary Gland?

Answer 2

• Galactostasis
• Agalactia
• Mastitis
• Mammary Tumours
• Pseudopregnancy
• Fibro-epithelial hyperplasia in queens

Question 3

Discuss Galactostasis?

Answer 3

• Congestion of the mammary gland
• Seen close to parturition / after weaning / rarely in pseudopregnancy
• Engorgement and pain of the gland
• May lead to failure of milk letdown immediately post-partum
• Treatment is reducing food intake, cold packs and encouraging of sucking or milking
• Condition which occurs just before mastitis

Question 4

Discuss agalactica?

Answer 4

Can be a failure of milk production

–Inadequate mammary development

–Early caesarean

–Treated by administration of metoclopramide

Or, failure of milk letdown

–Seen in nervous bitches where adrenaline blocks oxytocin release

–Treated by administration of oxytocin

N.B. Metritis, systemic infection and mastitis can lead to agalactia and requires treatment of the underlying

cause

Question 5

Discuss mastitis?

Answer 5

• Common and associated with ascending bacterial infection with E.coli, Streps and Staphs
• May be seen with prolonged galastostasis after weaning, following teat trauma and in poor sanitary conditions
• Clinical signs are swelling, heat, pain
• In severe cases abscessation may occur
• Treatment

–Broad spectrum antibiotic

•Should be based on sensitivity but not commonly done

–Bathing / stripping of the gland, or allowing neonates to suck (unless frankly purulent)

Question 6

Discuss mammary tumours?

Answer 6

• Common condition
• Previously discussed
• Key points are

–Protective benefit of neutering

• 0.5% incidence of mammary neoplasia if spayed before 6 months
• 8% if spayed before 6 -18 months
• 26% if spayed after 18 months
• No protection if spay after 2 years

–Rapid diagnosis and removal of masses before they become too large

–Appropriate surgical technique

–Histopathological examination and staging

–Consideration of adjunctive treatments although the benefits of chemotherapy and hormonal treatments are yet to be proven

Question 7

Discuss Pseudopregnancy?

Answer 7

• A common and normal event
• Every non-pregnant dog has signs of pseudopregnancy
• Caused by elevated prolactin which is the principal luteotrophic hormone

Question 8

Discuss pseudopregnancy in all non-pregnant bitches:

Answer 8

–have mammary enlargement

–have some milk production

–have some behavioural changes

Question 9

How can pseudopregnacy be described in non-pregnant bitches?

Answer 9

Described as ‘overt’ or ‘covert’ because:

–may or may not be noticed by the owner

–may or may not be disturbing for the owner

–may or may not be distressing for the bitch

Question 10

What are signs of pseudopregnancy?

Answer 10

–Anorexia

–Nervousness

–Aggression

–Nest making

–Nursing inanimate objects

–Lactation

–Occasionally pseudo-parturition

Question 11

Discuss pseudopregnancy causes ?

Answer 11

Not caused by progesterone

–Progesterone priming causes mammary enlargement

–Pseudopregnancy caused by a decline in progesterone and a rise in PROLACTIN

May be also be caused by sudden withdrawal of progesterone for other reasons

–e.g. Spay within the luteal phase

Question 12

What is the treatment for pseudopregnancy?

Answer 12

Treatment

• Most cases require no treatment
• Initiation of treatment is often related to owner demands
• Treatment more popular since pharmaceutical companies have marketed direct to dog owners

Conservative options:

–Nothing

–Sedatives

•Care if considering using phenothiazines as these are dopamine antagonists which may increase prolactin concentration

–Bathing the mammary glands

•Care as may stimulate further milk production

–Diuretics and reducing fluid and food intake

•Care if bitch already anorexic

Medical options:

–Prolactin inhibitors (e.g. Galastop)

–Progestogens (e.g. Ovarid [megestrol])

Question 13

Discuss treatment of pseudopregnancy with cabergoline?

Answer 13

Treatment with Cabergoline

• Rapid resolution of behavioural changes
• Rapid reduction of milk production
• >80% efficacy

Question 14

Before Administration of Hormonal Preparations for treatment of pseudopregnancy what should you do?

Answer 14

Before treatment ensure that bitch has pseudopregnancy and is not pregnant

–Prolactin inhibitors may/will induce abortion

–Progestogens may inhibit or delay parturition

Therefore make that effort to as question to make sure she has not been mated. Palpate caudal abdomen. Note this in clinical records that you have done this to protect yourself.

Question 15

What can spaying in the luteal phase do?

Answer 15

–Spaying in the luteal phase results in iatrogenic Psuedopregnancy as mechanism for prolactin to fall is thought to come form ovary. Will require extended treatment of galastop to end pseudopregancy.

Question 16

What is Fibroepithelial hyperplasia?

Answer 16

• Mammary acromegaly: under influence of progesterone you get excessive GH. High progesterone could be due to: spontaneous cycle or exogenous progesterone administration.
• Significant mammary enlargement caused by local growth hormone production in response to progesterone (like a local acromegaly)

–Young queens (pregnancy or pseudopregnancy)

–Older queens (exogenous progestagens)

• Glands are very firm and may succumb to secondary mastitis or traumatic ulceration
• Can be massive, oedematous, bilateral, ulcerated

Question 17

Discuss treatment for Fibroepithelial hyperplasia?

Answer 17

Treatment

•Need to remove the progesterone stimulation

Intact female

• Spay
• Administer prolactin inhibitor to remove support for CL (Cabergoline [Galastop])
• Administer progesterone receptor antagonist (Aglepristone [Alizin])
• Or both prolactin inhibitor and progesterone receptor antagonist

Female on oral progestogens

• Stop administration
• Administer prolactin inhibitor (Cabergoline [Galastop])
• Administer progesterone receptor antagonist (Aglepristone [Alizin])

Female on depot progestogens

• Administer prolactin inhibitor (Cabergoline [Galastop])
• Administer progesterone receptor antagonist (Aglepristone [Alizin])

General treatments

–Surgery during acute phase not warranted as the condition normally will subside spontaneously

–Progestogens should be avoided!

–Alizin treatment best indicated as it will displace the progesterone already present

Question 18

• Tara is 8 weeks post whelping (2 weeks after weaning) and has a foul smelling and discoloured milk discharge from one nipple
• How would you manage this case?

Answer 18

• Not systemical ill yet
• Mammary gland is warm and not yet painful
• Does have foul smelling material present

Treatment:

• Need BS Abs that will penetrate mammary gland
• NSAIDs to reduce inflammation
• Strip the mammary glands to try to remove the material and remove bacteria present in mammary gland and if we don’t manage it aggressively may result in swollen necrotic abscessed mammary gland that sloughs.
• The more you strip the mammary glands the more you stimulate more milk production so give galastop concurrently to slowly reduce milk production alongside stripping.