Osteomyelitis and sepsis

Question 1

when can osteomyelitis in foals occur

Answer 1

from birth up to 7 months

Question 2

what is the main risk for osteomyelitis

Answer 2

failure of passive transfer

Question 3

List 5 bacteria that can cause osteomyelitis

Answer 3

E. coli
Actinobacillus
Klebsiella
Staph
Strep
rhodococcus equi

Question 4

How is blood supplied to the metaphysis in the adult horse

Answer 4

through a nutrient artery

Question 5

how is blood supplied to a foals metaphysis

Answer 5

through a vast network of transphyseal vessels supplying the metaphyseal side of the physis (these close within 2 weeks)

Question 6

Describe how osteomyelitis begins in foals

Answer 6

bacteria become trapped in the small peripheral capillaries and this leads to infection by small septic thrombi

Question 7

How many types of osteomyelitis are there

Answer 7

5

Question 8

what is SAPO

Answer 8

septic arthritis, physitis and osteomyelitis

Question 9

describe S-type

Answer 9

infection of synovial membrane

Question 10

describe E-type

Answer 10

infection of the subchondral bone of the epiphysis

Question 11

Decsribe P-type

Answer 11

infection of the physis/metaphysis

Question 12

Describe T-type

Answer 12

infection of cuboidal bones of the tarsus/carpus

Question 13

before blood vessels close, what is the most common types of osteomyelitis

Answer 13

S and E types

Question 14

after closure of the blood vessels, what is the most common type of osteomyelitis

Answer 14

P-type

Question 15

List the clinical signs of osteomyelitis

Answer 15

swollen joints
lameness
impaired movement
altered movement of neck/back
recumbent
unable to nurse
signs of sepsis

Question 16

Decsribe how to diagnose osteomyelitis in the foal

Answer 16

synovial fluid analysis +/- culture

blood analysis +/- culture

diagnostic imaging -> synovial effusion, joint distension, irregularity of the physeal margin

Question 17

Decsribe how we treat osteomyelitis in foals

Answer 17

Antibiotics -> penicillin and gentamycin + C&S
joint lavage
surgery -> debridement
NSAIDs

Question 18

which abnormality is associated with an increased risk of SAPO in a 7-day old foal

Answer 18

omphalophlebitis- inflammation of the umbilical veins

Question 19

which of the following would be the most likely clinical presentation of a 3-day old foal with septic arthritis of the metacarpophalangeal joint

Answer 19

lameness
effusion of the fetlock joint
reluctance to stand
rectal temperature of 37.6C

Question 20

you are presented with 6-week-old foal with lameness and swelling over the right hock.

you obtain a sample of synovial fluid from the tibiotarsal joint. Which of the following would be the clinicopathological data if the foal has type P septic physisitis of the distal tibial physis?

Answer 20

gross colour hazy yellow, total nucleated cell count 7x10^9/L, total protein 35g/L, cytology 80% neutrophils

Question 21

On further examination of the 6 week old foal you find that as well as distension of the tibiotarsal joint, there is heat on the dorsolateral aspect of the limb just proximal to the joint. When you further investigate this, you want to highlight the dorsolateral aspect of the physis.

Which would be the best radiographic projection that will provide the best diagnostic image of this area

Answer 21

45 degree dorsomedial-plantarolateral oblique

Question 22

which would be the most appropriate therapeutic regime for management of spetic physitis in a horse under general anaesthesia

Answer 22

sodium penicillin and gentamycin IV, flunixin IV, clinical reassessment of lameness after 5 days of therapy