What material is primarily found in cattle horns?
Click to see answer
Keratin
Click to see question
What material is primarily found in cattle horns?
Keratin
How often do deer antlers regrow?
Deer antlers regrow every year.
What is the growth rate of deer antlers?
The antlers of deer are very rapidly growing.
Where are teeth 110 and 111 located?
Teeth 110 and 111 are found in the caudal maxillary sinus.
What should be avoided when dehorning cattle and goats due to the risk of flies?
Opening the frontal sinus.
Which nerves innervate the paranasal sinuses?
The ophthalmic and maxillary branches of the trigeminal nerve (V).
Have a look at the sinuses in all of the views (round hole bit is NOT eye socket!!)
See image
What is the location of the infraorbital sinus in birds?
It is a triangular cavity under the skin, rostroventral to the eye.
How does the frontal sinus relate to cattle horns?
The frontal sinus extends into the base of the horn.
What are paranasal sinuses?
Air filled diverticula of the nasal cavity that invaginate skull bones.
What type of material are rhinoceros horns made of?
Rhinoceros horns are made of keratin.
What is the primary blood supply to the horns in ruminants?
The primary blood supply to the horns in ruminants branches off the maxillary artery, specifically through the superficial temporal artery and the cornual artery.
What are the four types of maxillary sinuses in horses?
The four types of maxillary sinuses are the Rostral maxillary, Caudal maxillary, Ventral conchal, and Sphenopalatine sinuses.
What type of material are deer antlers made of?
Deer antlers are made of bone, not keratin.
CT image of horse skull showing meatuses. Where is the dorsal conchal sinus? And the ventral conchal sinus?
Within the dorsal conchae. Within the ventral conchae
What are the functions of sinuses in the skull?
Sinuses serve as resonating cavities for voice, provide insulation and cooling for the brain, reduce the weight of the skull, increase insertion surfaces, and create space for teeth.
Do rhinoceros horns have a bony core?
No, rhinoceros horns do not have a bony core.
Which nerve branch is found in 90% of cattle and is located between the medial canthus and medial horn base?
Cornual branch of the infratrochlear nerve (which is branch of trigeminal)
What is a potential consequence of opening the frontal sinus during dehorning?
The animal may 'breathe' through the sinus, which predisposes it to sinus infection.
In which sinus are teeth 108 and 109 found?
Teeth 108 and 109 are located in the rostral maxillary sinus.
Why can dehorning in ruminants produce a lot of bleeding?
Dehorning can produce a lot of bleeding in ruminants because the horns are very vascular, and if the fetotomy wire is not moved quickly, it can lead to significant blood loss.
What are deer antlers covered with during their growth?
Deer antlers are covered with very active cells known as 'velvet', which actively lay down bone.
What type of epithelium lines the paranasal sinuses?
Respiratory epithelium, the same as that of the nasal cavity.
Where does the nasolacrimal duct start?
The nasolacrimal duct starts at the nasal puncta.
What nerve branches from the trigeminal nerve (V) and is present in 100% of cattle?
Cornual nerve, located halfway between the lateral canthus and horn base along the ridge of the frontal bone.
What can cause secondary sinusitis?
Secondary sinusitis can be caused by dental issues, cysts, or neoplasia.
Which paranasal sinuses are identified in the horse's anatomy? See image showing sinuses in the cranial view with the halves hinged apart view (round hole bit is NOT eye socket!!)
See image
Which paranasal sinuses are identified in the horse's anatomy? See image showing sinuses in cranial view (round hole bit is NOT eye socket!!)
See image
What caution should be taken when dehorning goat kids?
Be careful since the frontal sinus is very small and excess heat can damage the brain.
What can be found in the frontal and maxillary sinuses during radiography? How is this seen?
Pus or blood can be present in the frontal and maxillary sinuses. See arrows pointing to fluid lines (esp image on right)
What is primary sinusitis and what is its common cause?
Primary sinusitis is usually bacterial in origin.
What is the percentage of animals that have branches from C1 and C2 for horn innervation?
5% of animals.
Is there variation in the anatomy of paranasal sinuses among species?
Yes, there is considerable species variation, but all have frontal and maxillary systems.
Where are teeth 106 and 107 located?
Teeth 106 and 107 are embedded in the maxilla.
What is the function of the nasolacrimal duct?
The nasolacrimal duct drains excess tears from the medial canthus of the eye to the nasal cavity.
Which sinus extends into the horn of a cow?
The frontal sinus extends into the horn (cutting horn opens sinus in adults)
What are the common clinical signs of sinus disease in veterinary medicine?
Chronic unilateral purulent nasal discharge and possible facial swelling. (note left and right sinuses independent of eachother - bilateral discharge usually to do with chest, unilateral to do with head)
What percentage of animals have the frontal nerve (branch of trigeminal) as a branch for horn innervation?
15% of animals.
Which animals are unique for having antlers?
Antlers are unique to deer, moose, and antelope.
What method is used to dehorn cattle and goats?
Wire (fetotomy wire) or saw.
How does the nasolacrimal duct exit in horses and cattle? And dogs?
In horses and cattle, the nasolacrimal duct exits at the nostril. Nasal cavity in dogs
How does the density of fibers in rhinoceros horns compare to true horns?
The fibers in rhinoceros horns are less densely packed than in true horns.
What are the two types of frontal sinuses in horses?
The two types of frontal sinuses are the Frontal sinus and the Dorsal conchal sinus.
What type of nerve block is used for dehorning calves?
Cornual nerve block only.
What additional nerve blocks may be needed for dehorning cattle and goats?
Cornual and cornual branch of infratrochlear nerve blocks, and possibly a block in the region caudal to the horn.
How are the paranasal sinuses divided?
They are divided into many smaller connecting sinuses. Seperate on left and right side of head
What are hypsodont teeth characterized by? How is this relevant to sinuses?
Hypsodont teeth have long roots, especially in young animals. Teeth grow throughout lifetime. Teeth disease likely also means sinus disease
Through which structure does the nasolacrimal duct run?
The nasolacrimal duct runs within the infra-orbital canal through the maxillary sinus (along the tooth apices). Then continues within maxilla
dog maxillary and frontal sinuses by skull type - name the three skull types in the image (eg brachycephlalic)
Brachycephalic, mesaticephalic, dolichocephalic (longest)
Two bones that the frontal sinus is underneath in the horse
Frontal and nasal bone
How many sinuses are present in horses? What two categories?
There are 6 sinuses altogether in horses. 2 frontal and 4 maxillary
Which paranasal sinuses are identified in the horse's anatomy? See image showing sinuses in lateral view (round hole bit is NOT eye socket!!)
See image
Sinus drainage in horses! Image very important here. Five sinuses which drain into other sinuses rather than have other sinuses drain into them
Frontal, dorsal conchal, sphenopalatine, rostral maxillary, ventro conchal sinus
What do the frontal sinus and dorsal conchal sinuses drain into?
Frontomaxillary apertuire, then into caudal maxillary sinus
Three sinuses (and related structures) that drain into the caudal maxillary sinus
Sphenopalatine sinus, AND both the frontal sinus and dorsal conchal sinus via the frontomaxillary aperture
Three sinuses that drain into the nasomaxillary opening? What does the nasomaxillary opening lead to?
Rostral max. sinus, caudal max. sinus, ventro conchal sinus. THEN to middle miatus
Describe sinus trephination as a procedure done on a horse
Drill hole in frontal / nasal bone (or at border) to access frontal sinus
Five nerves relevant in dehorning (ordered from most to least likely to be present in animals). Which are branches of the trigeminal?
All branch from trigeminal (V). Cornual nerve, cornual branch of infratrochlear nerve, frontal nerve, and branches from C1 and C2
Where does the cornual nerve pass? Where should it be anaesthetised?
From medial canthus of eye, under bony ridge of skull (ridge of frontal bone). Anaesthetise halfway between lateral canthus and base of horn.
