Chondrodystrophic breeds of dog can be more prone to intervertebral disc disease. Degeneration of the intervertebral disc occurs when the nucleus pulposus begins to dehydrate. A dehydrated disc no longer functions as a good shock absorber. In chondrodystrophic dogs, degeneration of the intervertebral disc begins at between 2 months and 2 years of age [ 5 ].
Acute non-compressive nucleus pulposus extrusion( ANNPE) can also occur in non-chondrodystrophic breeds as the result of a sudden, high-impact event. In these dogs, the nucleus pulposus is not dehydrated and remains more fluid, similar to a‘ runny’ jam. When a rapid compressive force is applied to the disc, such as during abrupt hyperflexion or high-energy activities like jumping to catch a ball, a small volume of this gelatinous material can be expelled at speed through the annulus fibrosus. Rather than causing sustained compression, the high-velocity impact of this material against the spinal cord produces a focal contusion or bruise.
In these cases, the extruded nucleus pulposus disperses quickly within the epidural space, resulting in a contusive rather than compressive spinal cord injury [ 6 ]. The degree of neurological recovery depends largely on the severity of the initial injury: mild to moderate contusions often improve as the oedema and bruising resolve, whereas more severe impact injuries may lead to persistent deficits despite the absence of ongoing compression.
Intervertebral discs may also protrude into the vertebral canal, resulting in milder compression of the spinal cord. This differs from a herniation, as it arises from thickening of the annulus fibrosus( the tougher outer connective tissue) rather than displacement of the nucleus pulposus. Such cases are more frequently associated with chronic, progressive disease processes rather than acute emergency presentations [ 4 ].
findings can then be used in combination to decide on a suitable pathway of treatment; this may be conservative, in the form of rest in a crate and physiotherapy, or surgical management. The nursing considerations for both pathways are very similar.
Nursing care
Spinal emergencies presented in veterinary practice can be some of the most challenging cases to manage. Although veterinary nurses( VNs) cannot make a diagnosis, they play a crucial role in the diagnostic process, particularly in facilitating imaging procedures and providing anaesthetic monitoring for these patients. VNs also play an extremely important role in the care required for the day-to-day management and recovery of these patients. Although many patients with spinal disorders may need to be referred to neurological specialists for further tests and treatment, the nursing care of these patients starts at the time of admission and continues throughout their stay in the practice.
Patients should be crate-rested on appropriate padded bedding, such as an orthopaedic mattress, with additional use of incontinence sheets and thick, moisture-wicking veterinary bedding. This combination provides comfort, reduces the risk of pressure sores [ 8 ] and helps ensure that any urine is drawn away from the patient ' s skin, thus preventing urine scalding. Softer bedding, such as fleece blankets, can be layered on top; this is particularly important with entire male dogs, where scrotal trauma may occur during efforts to move or reposition themselves( Figure 3). It is important to regularly check the bedding, making sure it is always dry and is providing the support needed. If it is wet with urine, it should be changed straight away.
Acute spinal cord disorders can be categorised as the following:
• Degenerative disc disease
• Traumatic( including ANNPEs and road traffic accidents)
• Vascular( including fibrocartilaginous emboli and haemorrhage)
• Infectious.
Following a neurological examination of the patient, the next steps would be imaging, in the form of either computed tomography( CT) or magnetic resonance imaging( MRI); the latter is currently considered best practice [ 7 ] due to the quality of the images it produces of soft tissue structures such as the spinal cord and discs. The imaging and neurological examination
Figure 3. Sore scrotum in an entire male dog.
Considerations should be made for regular turning( usually every 4 hours) and repositioning of the patient, due to the risk of hypostatic pneumonia or atelectasis( collapse) of the dependent lung lobe [ 8 ]. Regular turning also reduces the risk of pressure sores developing on bony prominences such as the hips and
56 Veterinary Nursing Journal