Claw/Hoof Flashcards
Breeds predisposed to subungual SCC
Giant Schnauzer
Gordon Setter
Briard
Kerry Blue Terrier
Rottweiler
Poodle
Amount nails grow per week
0.7-2mm
Damage to ___ part of nail would result in permanent onychodystrophy
It is responsible for making most of the stratum externum and stratum medium
Principle Germinative Region
Where are rete ridges present/prominent in dogs?
Foot pad
Nasal Planum
Scrotum
Where is the stratum lucidum present?
Foot pads
What comprises the stratum lucidum?
Eleidin (hyaline-like refractile keratin layer)
Which side of the nail grows faster?
Dorsal, allows for curve of nail
Most common tumors in cat claws
1) SCC
2) Fibrosarcoma
3) Adenocarcinoma
Most common tumors in dog claws
1) SCC
2) Melanoma
3) Osteosarcoma
4) STS
5) MCT
Breed with special version of symmetric onychodystrophy
Norwegian, English, Gordon Setters
Flare in summer (more activity and trauma?)
Function of stratum externum on hoof
Moisture balance
Thin layer on outside, mostly worn off
Function of stratum medium on hoof
Shock dispersion
Bulk of wall
Pigmented
Function of stratum internum on hoof
Contain laminae in refolded pattern to interdigitate with laminae of corium
Which layer of the hoof fails with laminitis?
Stratum internum (interdigitating with lamella of corium)
What is a bad prognostic factor for laminitis on radiographs?
More distal displacement of P3
What are the 3 phases of laminitis?
Developmental: time between injury and clinical signs
Acute: clinical signs present w/no radiographic evidence
Chronic: radiographs show collapse of foot
3 forms of laminitis
1) Endocrinopathic (MOST COMMON)
-PPID
-Iatrogenic glucocorticoids
2) Sepsis (endotoxins– diarrhea, high carb diet)
3) Supporting limb lameness
Hoof macroanatomy (sole, frog, white line, coronary band, hoof wall)
Hoof microanatomy (stratum externa, medium, internum, coreum)
Claw macroanatomy (ungual crest, clawfold, dermis, ungual process, sole, claw plate, coronary band, digital pad)
Nail microanatomy (hyponichium, nail matrix, germinal matrix)
Gross changes as hoof becomes more laminitic
Treatment laminitis
Treat underlying cause (d/c steroids if iatrogenic)
Antibiotics
NSAIDs (banamine is anti-endotoxic)
Blood flow tx- pentoxifylline, acepromazine
Hoof care (supportive shoeing)
Husbandry (bedding
Surgery
Hoof with most weight bearing in ruminants (lateral vs medial)
Lateral
Difference between hoof laminae in horses and ruminants
Ruminants only have primary laminae
(horses have primary and secondary laminae)
Difference in pig feet
Presence of accessory digits – nonweight bearing
Animals with antlers
Cervids
Animals with horns
Bovids
Animals with pronhorns
Antelope
Animals with ossicones
Giraffes
What structures connect horns to frontal sinuses? Important in dehorning?
Cornual processes
When does horn growth stop?
Continuous for life of animal
What hormone controls horn growth in male goats?
Testosterone
Which sex of goat has horns?
Both M and F
When are horns larger?
During breeding season
How old are cows/sheep, etc when their cornual process of horn invades the frontal sinus?
6 months old
How to stop horn growth in newborn calves
Cauterize germinal epithelium when < 2 months old
T or F: Antlers can regenerate after complete detachment
T
Calamus:
quill, central stalk of the feather
Rachis:
Point where barbs start to emerge
“Blood feather”
Some blood within the calamus
(Can see blood drops within quill when feather is plucked)
Types of feathers on body
Contour feathers
Beak: name of sheath covering maxilla
Rhinotheca
Beak: name of sheath covering mandible
Gnathotheca
Feline lung digit syndrome cancer, progosis
Bronchogenic carcinoma
(initial clinical sign can be long, thin nails)
Prognosis: MST 2 months
Predisposing factors for laminitis
Equine metabolic syndrome (insulin metabolism)
PPID (equine cushings)
Obesity
Systemic inflammation
T or F: Antlers are horns
F: NOT a true horn
Boney proliferation from skull covered in by keratinized epithelium
Shed and regrow each year
Males only, except caribou females
Familial vasculopathy of german shepherd dogs: mode of inheritance, age of onset
Autosomal recessive
4-10 weeks old
Familial vasculopathy of german shepherd dogs: Clinical signs
Paw pads are soft and swollen with variable depigmentation +/- ulcer, bridge of nose is swollen, ulcers on ear margins and tail tip
Are also pyrexic and lethargic with varying lymphadenopathy
Familial vasculopathy of german shepherd dogs: Histopath
Histopath shows nodular to diffuse lymphoplasmacytic dermatitis around degenerated collagen and altered vasculature
Familial vasculopathy of german shepherd dogs: Treatment
If they make it through, they spontaneous recover at 5 to 6 months old with scarring
Cell signal required for nail differentiation
BMP
Human nail diagram (prox nail fold, keratogenous zone, matrix, nail bed, nail plate, hyponychium, eponychium
Which part of the hoof is the strongest?
Intertubular horn
Intertubular horn is responsible for large amount of mechanical strength, stiffness, and fracture toughness
Increase in MMPs can result in ____ in the horse
laminitis
In laminitic horses, there is a destruction of _____ and ______ in the BMZ
Laminin and Collagen IV
Which cytokines increase MMP activity, which can lead to laminitis
IL-1, TNF-alpha
Metabolic diseases associated with onychodystrophy
Zn
Hepatocutaneous syndrome
Location of glands that pigs have to mark territory
carpal glands
Familial/idiopathic footpad hyperkeratosis: breeds
-Irish terrier
-Kerry blue terrier
-Dogues de Bordeaux
-Labrador Retreiver
-Golden Retriever
-MXB
Nasodigital hyperkeratosis in labrador retreiver gene
SUV39H2 -> Low loricrin
Most common dermatophyte in dog claws
Trichophyton mentagraphytes
Most common dermatophyte in cat claws
Microsporum canis
Breeds predisposed to SLO
German shepherd
Gordon Setter
Raynaud’s like syndrome in dogs: clinical signs, age of onset, sex, tx
Onychalgia, onychogryphosis, intermittent acrocyanosis of multiple digits
Age: middle
Sex: F in cold climates
Tx: Vasodilation (isoxsuprine)
What is different about idiopathic onychodystrophy compared to SLO? IO Breeds?
No onychomadesis
Older dogs
Cocker spaniels, Dachshunds, Rhodesians, Husky, Welsh terriers
What is different about idiopathic onychomadesis compared to SLO? IO Breeds?
Claws lost without having prior onycholysis
GSD, whippet, English springer spaniel
Disease associated with plasma cell pododermatitis
FIV
(can be triggered by antigenic stimulation, seasonal changes)
How many germinal centers does the claw have?
At least 4
Tyrosinemia breed, clinical signs, etiology
GSD
Paw pad ulceration/sloughing + eye dz
Build up of tyrosine –> inflammation 2’ to crystals in tissue (Splendore-Hoeppli)
Label this horn
1) Frontal sinus
2) Cornual process
3) Noncornified Epidermis/Dermis/periosteum
4) Horny tubules with intertubular horn