Equine Oncology

Question 1

Which breeds are more likely to get ocular SCC?

Answer 1

Shire and Clydesdale

Question 2

Excessive UV exposure is a risk factor for which tumour?

Answer 2

SCC

Question 3

What are the 4 main groups of paraneoplastic syndromes in horses?

Answer 3

1) Mucocutaneous and skin syndromes: paraneoplastic pemphigus, pruritus
2) Neurological syndromes
3) Haematological syndromes: anaemia, polycytaemia, granulocytosis
4) Endocrine and metabolic syndromes: cachexia (wasting), hypercalcaemia (rare), hypertrophic (pulmonary), osteopathy (Marie’s disease)

Question 4

What are the 3 major treatment options for tumours?

Answer 4

Ablative (surgery, laser/diathermy, cryotherapy, hyperthermia)
Cytotoxic (chemotherapy, radiotherapy: brachy/tele, phototherapy, electrochemotherapy)
Biological (immunotherapy, vaccines, cytokine therapy, gene therapy)

Question 5

What is the most common haematopoietic neoplasm in horses?

Answer 5

Lymphoma

Question 6

What are the 4 main forms of lymphoma?

Answer 6

Multicentric (most common)
Alimentary
Mediastinal/thoracic/thymic
Cutaneous

Question 7

Multicentric lymphoma affects horses of which age?

Answer 7

4-12 years

Question 8

Give some clinical signs of multicentric lymphoma

Answer 8

Weight loss, depression, ventral oedema, recurrent fever (signs are vague so cases only tend to present when advanced)

Question 9

How do you diagnose multicentric lymphoma?

Answer 9

Cytology or biopsy

Question 10

What is the treatment for multicentric lymphoma?

What is the prognosis?

Answer 10

Surgical removal if solitary lesions, chemotherapy? (expensive)
Prognosis depends on stage of disease

Question 11

What is the most common intestinal neoplasm of horses?

Answer 11

Alimentary lymphoma

Question 12

What age of horses are affected by alimentary lymphoma?

Answer 12

> 12 years

Question 13

What are the clinical signs of alimentary lymphoma?

Answer 13

Malabsorption, weight loss, colic (uncommon)

Question 14

How do you diagnose alimentary lymphoma?

Answer 14

Cytology (peritoneal fluid), biopsy

Question 15

How do you treat alimentary lymphoma?

What is the prognosis?

Answer 15

Surgical removal if solitary lesions, chemo?

Poor prognosis, depends on stage of disease

Question 16

What is the most common thoracic neoplasm in horses?

Answer 16

Lymphoma

Question 17

Give the clinical signs of mediastinal/thoracic/thymic lymphoma

Answer 17

Weight loss, depression, ventral and limb oedema, pleural effusion

Question 18

How do you diagnose mediastinal/thoracic/thymic lymphoma?

Answer 18

Cytology (pleural effusion), biopsy

Question 19

How do you treat mediastinal/thoracic/thymic lymphoma?

What is the prognosis?

Answer 19

Palliative

Very bad prognosis. Fluid can refill within hours of drainage.

Question 20

What age of horses are affected by cutaneous lymphoma?

Answer 20

Older horses

Question 21

How do you diagnose cutaneous lymphoma?

Answer 21

Biopsy

Question 22

How do you treat cutaneous lymphoma?

What is the prognosis?

Answer 22

Surgical removal if solitary masses

Less aggressive than other forms; may become static for years or even regress

Question 23

What age of horses are affected by haemangiosarcoma?

Answer 23

Middle-aged to older (all ages possible)

Question 24

What are the clinical signs of haemangiosarcoma?

Answer 24

Depends on body system affected
Resp and musculoskeletal most common
Haemorrhage: haemoabdomen, haemothorax etc

Question 25

How do you diagnose haemangiosarcoma?

Answer 25

Cytology, biopsy

Question 26

How do you treat haemangiosarcoma?

What is the prognosis?

Answer 26

Palliative

Very poor prognosis

Question 27

What is the most common oral neoplasm in horses?

Answer 27

SCC

Question 28

Which breed is more likely to get melanomas?

Answer 28

Lipizzaner

Question 29

How does a granulosa cell tumour of the ovary appear on US?

Answer 29

Large

Honeycomb appearance