Sinuses and horn

Question 1

what are the paranasal sinuses

Answer 1

• air filled diverticula of nasal cavity
• lined by respiratory epithelium
• innervated from opthalmic and maxillary branches of the trigeminal nerve
• considerable species variation but all have frontal and maxillary systems (divided into many smaller connecting sinuses)
• separate on left and right side of the head

Question 2

what are the functions of the sinuses

Answer 2

• resonte voice within cavities
• insulation/cooling of the brain
• reduces weight of the skull
• increases insertion surfaces
• provides space for teeth

Question 3

what is important to remember about the sinuses in the cow

Answer 3

the frontal sinus extends into the horn

Question 4

describe the locations of the frontal and maxillary sinuses

Answer 4

Question 5

what are the 6 different sinuses of the horse

Answer 5

2 frontal sinuses:
1. frontal
2. dorsal conchal

4 maxillary sinuses
1. rostral maxillary
2. caudal maxillary
3. ventral conchal
4. sphenopalatine

Question 6

describe the pathway of sinus drainage in the horse

Answer 6

Question 7

what is the likely cause of maxillary sinusitis and why

Answer 7

tooth root issues because the maxillary sinuses are often where tooth roots are stores (especially in young horses)

Question 8

how does sinus disease usually present

Answer 8

chronic unilateral purulent nasal discharge +/- facial swelling
- primary sinusitis (bacterial) or secondary sinusitis (due to dental issues, cysts or neoplasia)

Question 9

how does fluid in the sinuses present on a radiograph

Answer 9

fluid shows as a horizontal grey line (fluid more radiopaque than air) within dark areas of air in the sinuses

Question 10

what is sinus trephination and what is it used for (what do you need to avoid)

Answer 10

drilling a hole into the sinuses. useful for flushing sinuses
careful to avoid nasolacrimal duct

Question 11

describe the horns and how the sinuses are important when dehorning

Answer 11

• made of keratin
• frontal sinus extends into base of horn
• opened during dehorning adult cattle allowing animal to breath through the horn. this predisposes them to sinus infection as debris can reach the sinuses
• important to disbud within 1 week of age to prevent horn from developing

Question 12

describe the innervation of the horn

Answer 12

nerves branch from trigeminal nerve
- cornual nerve (halfway between lateral canthus and horn base (along ridge of frontal bone)
- cornual branch of infratrochlear nerve (located between medial canthus and medial horn base
- frontal nerve
- branches from C1 and C2`

Question 13

what nerve blocks do you need to use in calves

Answer 13

cornual nerve block only
burn off bud

Question 14

what nerve blocks do you need to use in cattle and goats and how do you remove the horn

Answer 14

• cornual and cornual branch of infratrochlear nerve blocks
• may also need to block region caudal to horn

fetotomy wire helps cauterise blood vessels as you move through, but still need iron to close sinus as it is opened when the horn is removed

Question 15

what do you need to be careful about when disbudding kids

Answer 15

frontal sinus is very small and too much heat can damage the brain

Question 16

what is the blood supply to the horns

Answer 16

ruminants:
- branch off maxillary artery
- superficial temporal artery
- cornual artery