Diseases of the Eyelid

Question 1

What is ectropion and what is the most common causes for it in the horse?

Answer 1

Ectropion is the eversion of the eyelid (lid rolls outward)

It is typically a result of scar tissue (cicatricial) in the horse.

Question 2

What is the most common eyelid neoplasia in the horse?

Answer 2

Squamous cell carcinoma

Question 3

What is the second most common eyelid tumor in the horse?

Answer 3

Sarcoid

Question 4

True or false: Squamous cell carcinomas are highly metastatic

Answer 4

False - they are LOCALLY AGGRESSIVE although they have the potential to metastasize

Question 5

What type of animal is at an increase risk for the development of SCC?

Answer 5

Lightly pigmented animals, animals with high UV exposure, or draft breeds (incidence also increases with age)

Question 6

What is the best way to treat SCC?

Answer 6

Depends on the location, but in general wide surgical excision with adjunctive therapy

Question 7

What is the gold standard adjunctive therapy for many eyelid tumors in the horse?

Answer 7

Radiation

Question 8

A 10 year old Belgian mare has been diagnosed with SCC on her third eyelid and along the medial canthus. Surgical excision of the third eyelid was performed, and intralesional chemotherapy was administered to the remaining parts of the tumor. A few days later, the owner calls and is concerned because the mass looks worse than it did pre-operatively (more ulcerated, slightly larger, etc.), is this normal?

Answer 8

YES because with intralesional chemotherapy, the tumor gets worse before you start to see improvement (same applies for the use of BCG immunotherapy of sarcoids).

Question 9

What type of tumor is a sarcoid?

Answer 9

A fibroblastic tumor of the skin