A careful, complete neurologic examination is important in determining a correct anatomic diagnosis of any neuromuscular condition. The attitude and alertness, gait and posture, muscle tone, sensation, and various reflexes for the cranial and spinal nerves will be tested by systematic standardized examination. The neurologic examination is not painful or distressing to the dog, and takes about 20 minutes.

Impaired swallowing function can increase the risk of aspiration pneumonia, and a swallowing test (esophagram) should be routinely performed before laryngeal surgery in GOLPP dogs. It is valuable to know if your dog has a swallowing problem, and how it may be progressing over time. Swallowing function is evaluated by feeding your dog in a standing position, using fluoroscopy (real-time x-ray) to view food moving from the mouth, through the esophagus, and into the stomach. Any reflux from the stomach is also noted. Although we know that most GOLPP dogs have a degree of esophageal dysfunction when presented for surgery, no one has evaluated how it changes over time. Our goal is to document your dog’s swallowing function three times over the next year. This test does not require sedation and dogs typically participate enthusiastically by eating the offered food. We do not anticipate any increased risks with the additional esophagrams at 6 and 12 months, although there is always a risk of aspiration pneumonia in dogs with esophageal dysfunction.

Biopsies are vital for us to understand exactly how the nerves and muscles are degenerating in GOLPP dogs. Nerve and muscle biopsies are performed as routine diagnostic tests and are not experimental procedures. The biopsies will be performed at the same time and by the same board-certified surgeon doing the laryngeal “tie-back” surgery. Two sets of biopsies will be taken. The first set (dorsal cricoarytenoideus muscle & caudal laryngeal nerve) will be taken directly from the surgery site. The second set (cranial tibialis muscle & peroneal nerve) will be taken through a 2 cm (1 inch) incision in the left hind leg, just below the knee. These samples will undergo special preparation and will be shipped to the Comparative Neuromuscular Laboratory in California for processing and interpretation. Risks associated with this procedure are low, but include the possibility of a small fluid swelling (seroma) forming at the surgery site.

Electromyography (EMG) and nerve conduction studies (NCS) provide valuable information on the extent and severity of changes within the nerves and muscles of GOLPP dogs. EMGs and NCSs are routine diagnostic tests and not experimental procedures. Our goal is to record EMGs and NCSs in your dog, and document any changes over the course of one year. These tests are very important in the characterization of GOLPP, and will give you an idea of how quickly your dog’s condition is progressing. Electrodiagnostics will be performed under general anesthesia, either during surgery (0 months), or during a free-of-charge dental cleaning (6 and 12 months). An EMG requires the insertion of a very fine needle into various muscles to record each muscle’s electrical activity. For NCS, a small electrical impulse is applied to a nerve and the electrical response generated by the nerve is recorded. We will perform EMGs on four muscles in the throat, four in the right forelimb, and four in the right hind limb. We will perform NCSs on two nerves. Risks associated with this procedure are negligible.