Small Ani. Sx- Ortho- Bone Diseases in Small Animals

drraythe's version from 2016-04-29 14:43


Question Answer
what is Panosteitis?inflammatory condition of the bones. Includes Periostitis, Ostitis, Osteomyelitis (all the bone is affected- inflammation of the bone cortex, medulla, and bone marrow common condition in large breeds, young dogs long bones)
what is the common signalment of a dog with panosteitis (breed, age, gender)Large breeds of young dogs (German Shepherd, Basset hound) usually 5- 20 months age (WONT SEE past 2yr), Male > females
what are possible etiologies of panosteitis?Infection, Metabolic disease, Allergy, Parasitism, Autoimmune, ****Idiopathic
explain the Pathogenesis of panosteitis. How long does it take the pathogenesis to run its coursE?Necrosis of adipose tissue around nutrient foramen--> Fibroblastic & osteoblastic activity--> Osteoclastic activity--> New adipose tissue. This takes 90d!!! (so, 3mo for one bone, but can start at diff times and in diff bones so condition can last longer than 3mo in general) (N= normal. P=panosteitis)
how does panosteitis appear radiographically, and why?you will see differences in opacity, the cortex cannot be differentiated from the endosteal cavity. (cortex and medullary cavity hard to tell apart bc everything full of bone due to osteoblastic activity)
if you see a young animal with a bone that is painful upon palpation and looks cloudy on rads....what are you thinking? prolly panosteitis
what is the prognosis of panosteitis?Good, because it is self-limiting and usually is gone by 2yrs old
what are the clinical signs of panosteitis?Lameness, fever, Pain on bone palpation (bc of periosteal rxn) (**make sure pressing bone not soft tissue!!!), Shifting leg lameness (2-3 wks) (ie, first limping on L leg, then R, then back R, etc)
(he said don't memorize bc all bones are affected but just put this here to read it once) most to least affected bones by panosteitis?Ulna > Radius > Humerus > Femur > Tibia
how do you tx panosteitis?Symptomatic... Pain medication (NSAIDS during worst time periods- dont keep them on it for 2yr (not good for them) just give as much as they need when they really need it ), Exercise restriction

Bone tumors

Question Answer
MOST COMMON BONE TUMOR? what are some other tumors that can affect bone?Osteosarcoma (OSA) (85%). Others: Chondrosarcoma, Hemangiosarcoma, Metastasis, Benign Tumors
(said in class) what can look like bone cancer that you need to R/O?fungal infection
how might you be able to tell if it's a osteosarc or a diff bone tumor?osteosarcs DONT CROSS JOINTS, others can
whats a big radiographic sign that might indicate bone tumor?see lysis AND prolif
age usually affected by bone tumors?old dogs
breeds usually affected by bone tumors?large breeds
which area of the bone is most often affected by bone tumors?metaphysis
what is the saying that tells you where bone tumors are most likely going to be if they are in the arm versus the leg?“Away from elbow, close to stifle” (so, distal radius, prox humerus, prox tibia and distal femur)
are bone tumors usually benign or malig?Quite aggressive (1 year survival), Metastases (98% lung mets at diagnosis) (can start to see chest mets at 1cm)
(said in class) how many rads to look for lung mets?at least THREE. need to be at least 1cm to wanna do a DV and then TWO laterals, one on each side, bc the father from the plate, the bigger the tumor will appear (think: casting shadows) so want both sides to try to catch anything.
what usually causes the pain that you see with bone tumors?the pathological fractures they cause
clinical signs of bone tumor?Lameness, swelling
WHY do you wanna take a bx if you see a bone mass, and WHERE do you take the bx from?want to R/O Fungal osteomyelitis and Bacterial osteomyelitis. You will need to take At least 2 probes from centrum (not many tumor cells in the periphery)
what are these arrows pointing out that is a good radiographic indicator you are dealing with bone tumors? periosteum is elevated by bone turmos forming underneath. quite typical of bone tumors.
what therapy can you provide to pts with bone neoplasia? (basically 2 options- prog for each?)Palliative (Prognosis 3-5 Months), Amputation & Chemotherapy or Limb sparing surgery (Prognosis 1 year (Cat: > 4 years))
what is limb sparing surgery?used to tx neoplasia- cut out tumor, replace it with piece of bone or metal, and then bridge the gap. usually distal see tube replacing tumor in rads
what is a big risk with limb sparing sx?implants getting loose-- can be very painful. then starts to fistulate and get infections and skin necrosis

Hypertrophic Osteodystrophy (HOD)

Question Answer
what is happening in HOD?Disruption of metaphyseal bone leading to necrosis. Unknown etiology.
common signalment of who suffers from HOD? (age, breed)usually Young, rapidly growing dogs- often large breeds at 3-5mo old
what is this pic trying to tell you about HOD? how BVs move in the distal bone. can get infarcts here, stop blood supply close to growth plates, no blood supply--> bone death= HOD
what are the clinical signs of HOD?Acute onset of lameness, Bilateral swelling distal radius/ulna, Pain on palpation, Refusal to stand /walk
what does HOD look like on rads? what is the PATHOGNOMONIC SIGN?Radiolucent line (Pseudophysis) is PATHOGNOMONIC. you will also see Periosteal new bone formation
therapy for HOD?NSAIDs, Fluid support, Recovery 10 days
prognosis of HOD? any persistent problems?good prog, Persistent Malformation

Hypertrophic Pulmonary Osteopathy + Craniomandibular Osteopathy

Question Answer
what IS Hypertrophic pulmonary Osteopathy? what is happening?This is a paraneoplastic syndrome where there are LUNG tumors which cause Diffuse bone proliferation in distal extremities which leads to Lameness, swelling, pain. Cause unknown
what IS Craniomandibular Osteopathy? which bones are often affected?this is a Proliferative bone disease which affects the Occipital bone, tympanic bullae, mandibular rami
what age of dogs is usually affected by craniomandibular osteopathy?immature dogs, 3-7 Months of age
what is the Pathogenesis of craniomandibular osteopathy?Etiology unknown! Breed dispositions lead us to believe it is genetic
which breeds are predisposed to craniomandibular osteopathy?West Highland White Terrier, Cairn terrier, Scottish terrier (so....terriers)
what are the clinical signs of craniomandibular osteopathy?Reduced general status, Enlarged mandibles, Pain, fever, reluctant to eat
one way to dx craniomandibular osteopathy?Radiographs
therapy you can provide for craniomandibular osteopathy?USually Conservative, wait till maturity. can provide analgesics and corticosteroids...if the problem is bad enough, might need feeding tubes to make sure they can get nutrition as it is painful
prognosis of craniomandibular osteopathy?Self-limiting, usually problem resolves by 1yr