Page 1390 - Equine Clinical Medicine, Surgery and Reproduction, 2nd Edition

The foal 1365

VetBooks.ir followed by open drainage and lavage, has proven RESPIRATORY DISEASE IN
very successful, but it is expensive and can lead to THE OLDER FOAL
pathological fractures.
Definition/overview
Other treatments Bronchopneumonia is a significant cause of morbid-
NSAIDs are useful in these cases to decrease joint ity and mortality in foals aged 1–8 months. Clinical
inflammation and pain, but the potential for toxic signs are often mild until the disease process is
side-effects should be considered, especially in sys- advanced. Mild cases may resolve spontaneously.
temically ill foals. Low doses of flunixin meglumine Outbreaks of infectious respiratory disease are rela-
may be appropriate for this purpose. The use of pro- tively common.
phylactic antiulcer medication in the foal remains
controversial (see Gastroduodenal ulceration syn- Aetiology/pathophysiology
drome, p. 1351) and should be carefully evaluated on Bacterial causes are the most common in this age
an individual basis to determine whether such use is group. Common pathogens include Streptococcus
warranted; many clinicians currently do not endorse zooepidemicus, Streptococcus equii, Rhodococcus equi
its use. The foal should be box rested and affected (Fig. 14.30), Pasturella spp., Bordetella bronchiseptica,
limbs bandaged. There should be aggressive treat- Pneumocystis jirovecii, E. coli and Actinobacillus spp.
ment of any concurrent systemic problem, careful Viral agents are frequently associated with sec-
monitoring of the foal’s nutrition, and supportive ondary bacterial disease. They may include equine
nursing. The foal should be closely monitored for herpesvirus (EHV)-1 or EHV-4, equine influenza
response to therapy. In cases of septic arthritis, if virus, equine adenovirus and equine rhinovirus.
the lameness fails to improve significantly and the Other less common causes, usually in individu-
synovial white cell count remains increased, repeat als, include: aspiration pneumonia due to cleft pal-
lavage should be carried out. In cases of osteomy- ate or dysphagia; congenital cardiac abnormalities;
elitis, serial measurement of SAA is useful in moni- traumatic conditions such as fractured ribs or dia-
toring the response to selected antibiotics. In cases phragmatic hernia; parasite infestations such as
that respond to the selected treatment, SAA protein hepatopulmonary migration of ascarid larvae; and
levels start to fall over 48–72 hours, often in advance atypical interstitial pneumonia.
of improvement in the lameness.

Prognosis
The prognosis for foals with sepsis within the mus- 14.30
culoskeletal system is dependent on the number of
sites of infection, the degree of damage to the joint(s),
the presence of osteomyelitis, concurrent systemic
disease and the response to therapy. Involvement
of multiple joints and/or bones adversely affects the
likely outcome, as does the presence of systemic ill-
ness. Chronic cases and those poorly responsive to
initial aggressive treatment often require extensive
and prolonged treatment, with a poor prognosis for
a return to full soundness. Acute S type cases treated
quickly and aggressively carry the best prognosis. It
has been reported that Thoroughbred foals treated
for septic arthritis were less likely to start on a race-
course when compared with controls, and they were Fig. 14.30 Post-mortem specimen from a foal with
also older when they first started on a racecourse. R. equi lung abscesses.