Page 408 - WSAVA2018
P. 408

 25-28 September, 2018 | Singapore
Differential Cell Count
Normal synovial fluid contains > 90% large mononuclear cells and lymphocytes (small mononuclear cells). Lymphocyte numbers reported in normal synovial fluid range from 11% to 44% with the large mononuclear cells representing the majority of normal cells.
Normal joint fluid contains very low numbers of neutrophils. Typically neutrophils are <10% of the total white cell count.
Elevation of the relative proportion or absolute
number of neutrophils in synovial fluid indicates either inflammation of the synovial membrane or contamination with peripheral blood. Elevation of the neutrophil percentage >10% regardless of the total white cell count is significant.
It is also important to assess the morphology of the neutrophils. It is widely reported that neutrophils from
a septic inflammatory arthropathy will usually show evidence of toxic change or degeneration whereas those from an immune-mediated arthropathy will appear more normal. This however has been shown to be unreliable. Joint infection is commonly seen without degenerate neutrophils being present. The presence of intracellular bacteria is indicative of infection.
A case series of dogs with septic arthritis (Marchevsky and Read 1998), would suggest that neutrophils in septic arthropathies are more typically non-degenerate. In a series of 19 dogs with septic arthritis only one dog (5%) had degenerate neutrophils present in a synovial fluid smear. Only 7 of 13 dogs had bacteria visible on cytology.
Protein
As synovial fluid is a dialysate of plasma the protein level in normal synovial fluid is usually low. Normal synovial protein levels in the dog are 20 to 25g/L. Protein
levels can be measured by either a refractometer or biochemical assay. Synovial fluid protein levels are a function of the local vascular permeability, the molecular size of the protein and its plasma concentration.
Synovial fluid protein levels will increase proportional to the degree of inflammation and may approach serum protein levels. Synovial fluid samples with very high protein levels may clot. (This can also happen in the presence of peripheral blood contamination.)
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WSV18-0148
NAVC SHORT TOPICS FROM EXPERTS
HOW I DIAGNOSE CANINE COLLAPSING AIRWAY DISEASES
L. Gaschen1
1Louisiana State University, Veterinary Clinical Sciences, Baton Rouge, USA
HOW I DIAGNOSE CANINE COLLAPSING AIRWAY DISEASE
Lorrie Gaschen, PhD, DVM, Dr.med.vet, DECVDI Louisiana State University, Baton Rouge, LA, USA Introduction
Upper and lower airway disease is common in dogs and cats, which can present with similar signs regardless
of the location. Following stabilization of the patient
with oxygen, radiography plays a very valuable role in determining the cause of airway distress. In addition
to radiography, computed tomography (CT) is a cross- sectional modality for examining pathology when radiography is equivocal. This lecture will provide the participant an overview of how to differentiate upper from lower airway disease in the coughing dog and discuss how to arrive at a practical diagnosis with many case examples.Techniques in Radiography
If the animal is stable enough with its respiratory rate and effort, I advocate a 4-view thoracic radiograph (R and L lateral, VD and DV). A dorsoventral radiograph instead of a ventrodorsal radiograph is often beneficial in dyspneic patients as they are often more comfortable resting on their sternum. If diseases of the upper airways are suspected, a lateral projection of the larynx/pharynx area and cervical trachea is mandatory. A foreign body or mass in this region can be immediately recognized. Thoracic studies should always be obtained during inspiration. An additional exception to the rule is the comparison of diameters of the trachea and main stem bronchi in patients with tracheal collapse, which requires both respiratory phases and even fluoroscopy.Upper Airway Diseases
Larynx und Trachea
Lateral views of the laryngeal and cervical region are usually sufficient. Typical changes in dogs
are increasing mineralization of the laryngeal and tracheal cartilages with age. Mineralization can already be present in dogs as young as 2 years of age, especially in chondrodystrophic breeds. The most commonly diagnosed diseases of the larynx are larynx paralysis, eventration of the ventricle and larynx collapse. These can usually be diagnosed by oral inspection. Radiographic findings are often
43RD WORLD SMALL ANIMAL VETERINARY ASSOCIATION CONGRESS AND 9TH FASAVA CONGRESS





































































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