Partial brachial plexus paresis in three calves

Use of Electrodiagnostics in the Diagnosis and Follow-Up of Brachial Plexus Syndrome in a Calf

Electrodiagnostic testing by using electromyography (EMG) and nerve conduction studies (NCS) is essential in the evaluation of patients with traumatic brachial plexus injury as it facilitates the localization of the lesion and the prognosis. In this case report, we present a long-term electrodiagnostic follow-up of a 5-day-old female Holstein calf with brachial plexus syndrome. Electrodiagnostic studies were carried out at 2 weeks, 5 weeks, 7 months and 12 months after admission. Initially, EMG confirmed the damage to the brachial plexus, potentially indicating a condition of neurotmesis or axonotmesis. However, motor NCS and the repeated electrodiagnostic follow-up, along with the evolution of the clinical signs, allowed a more favorable diagnosis of axonotmesis to be made. In fact, EMG showed a slow but gradual reduction and finally the disappearance of spontaneous pathological activity, while motor NCS revealed an increase in the amplitude and areas of the compound muscle action potentials. The animal was deemed fully recovered 12 months after admission. To the authors’ knowledge, this is the first report on the use of motor NCS in bovine medicine and it demonstrates that electrodiagnostics represent a useful and practical tool for the evaluation and prognosis of brachial plexus injury cases in cattle.

Peripheral Nerve Microscopic Changes Related to Study Procedures: Two Nonclinical Case Studies

Peripheral nerves are routinely examined microscopically during the nonclinical safety assessment of therapeutics. In addition to test article-related on- or off-target changes, microscopic changes in peripheral nerves may also be caused by study procedures, such as parenteral test article administration and blood or tissue sampling. We present 2 nonclinical case studies in which nonstandard peripheral nerves had study procedure-related histologic changes. The first case study describes mouse trigeminal nerve changes as a result of blood sampling via retro-orbital sinus puncture. These changes included minimal-to-mild nerve fiber (axonal) degeneration associated with macrophage infiltration. The second case study presents rat brachial plexus changes associated with animal handling and blood sampling. Brachial plexus changes included minimal-to-moderate inflammation, focal hemorrhage, and nerve fiber degeneration. In both cases, the histological changes were morphologically indistinguishable from those that might be due to test article. Therefore, careful consideration of the incidence and severity across groups and a review of study procedures to rule out handling-related nerve damage are essential before identifying a test article-related effect on peripheral nerves. Study design considerations to avoid such procedure-related changes will be discussed, as well as sampling strategies to help distinguish these from test article-related effects.

Retrospective analysis of iatrogenic diseases in cattle requiring admission to a veterinary hospital

Iatrogenic diseases in veterinary medicine are often related to malpractice or lack of skill. For this retrospective study, 4262 clinical records of cattle admitted to the veterinary teaching hospital of the University of Milan between 2005 and 2017 were analysed, and 121 cases (2.8 per cent), referred for an iatrogenic-related disease, were selected. The findings showed that iatrogenic diseases were more often caused by farmers (92.6per cent) than by bovine practitioners (7.4 per cent). Iatrogenic diseases were caused mainly by the improper administration of drugs (43.0 per cent), forced extraction during calving (19.8 per cent), forced milk or colostrum feeding, which was often performed by awkward administration using a nipple bottle (14.9 per cent) or by oral oesophageal tubing (15.7 per cent). Moreover, farmers often performed medical, nursing and zootechnical procedures without adequate training. The role of the practitioner is fundamental in farmer education. Clinicians, especially in some professional branches such as neonatology, should not delegate medical procedures to untrained farmers. Effective tutoring and good communication with farmers play a key role in dairy herd health and consequently in public health. This then can lead to a decrease in improper drug administration, the prevention of antibiotic resistance and the reduction of treatment costs.

Spinal Cord and Peripheral Nerve Abnormalities of the Ruminant

In food animals, spinal cord damage is most commonly associated with infection or trauma. Antemortem diagnosis is based on clinical signs, history, cerebrospinal fluid analysis, and imaging. As clinical signs are often severe, and prognosis is grave, necropsy may provide a postmortem diagnosis. Peripheral nerve abnormalities are most often the result of trauma. Calving paralysis or paresis is the most common condition affecting the sciatic or obturator nerve and often concurrently involves the peroneal branch of the sciatic. Damage to peripheral nerves is often transient and resolves within a few days as long as the nerve is not severed.

[Peripheral limb pareses in cattle. Part 2: Diagnostics, prognosis and therapy]

This two-part review presents an overview of peripheral-limb pareses in cattle, which represent the most frequent bovine neurologic disorder and are mostly caused by trauma of specific peripheral nerves. Occurrence, etiology, diagnosis, prognosis and therapy are presented. The second part of the review describes neuroanatomical details important for diagnostics, localization of the neuronal lesion within the lower motor neuron and classification of the grade of peripheral-nerve injury. Furthermore additional diagnostic tools are presented and prognosis, therapy and prevention of peripheral limb pareses in cattle are discussed.

[Peripheral-limb pareses in cattle. Part 1: General causes and specific pareses of the fore- and hindlimbs]

This two-part review presents an overview of peripheral-limb pareses in cattle, which represent the most frequent bovine neurologic disorder and are mostly caused by trauma of specific peripheral nerves. Occurrence, etiology, diagnosis, prognosis and therapy are presented. The first part of the review describes general causes for peripheral limb pareses in cattle. Furthermore, a detailed overview of specific peripheral nerve damages of the fore- and hindlimbs is presented.