Serum anti-GM2 and anti-GalNAc-GD1a IgG antibodies are biomarkers for acute canine polyradiculoneuritis.

OBJECTIVES: A previous single-country pilot study indicated serum anti-GM2 and anti-GA1 anti-glycolipid antibodies as potential biomarkers for acute canine polyradiculoneuritis. This study aims to validate these findings in a large geographically heterogenous cohort. MATERIALS AND METHODS: Sera from 175 dogs clinically diagnosed with acute canine polyradiculoneuritis, 112 dogs with other peripheral nerve, cranial nerve or neuromuscular disorders and 226 neurologically normal dogs were screened for anti-glycolipid antibodies against 11 common glycolipid targets to determine the immunoglobulin G anti-glycolipid antibodies with the highest combined sensitivity and specificity for acute canine polyradiculoneuritis. RESULTS: Anti-GM2 anti-glycolipid antibodies reached the highest combined sensitivity and specificity (sensitivity: 65.1%, 95% confidence interval 57.6 to 72.2%; specificity: 90.2%, 95% confidence interval 83.1 to 95.0%), followed by anti-GalNAc-GD1a anti-glycolipid antibodies (sensitivity: 61.7%, 95% confidence interval 54.1 to 68.9%; specificity: 89.3%, 95% confidence interval 82.0 to 94.3%) and these anti-glycolipid antibodies were frequently present concomitantly. Anti-GA1 anti-glycolipid antibodies were detected in both acute canine polyradiculoneuritis and control animals. Both for anti-GM2 and anti-GalNAc-GD1a anti-glycolipid antibodies, sex was found a significantly associated factor with a female to male odds ratio of 2.55 (1.27 to 5.31) and 3.00 (1.22 to 7.89), respectively. Anti-GalNAc-GD1a anti-glycolipid antibodies were more commonly observed in dogs unable to walk (OR 4.56, 1.56 to 14.87). CLINICAL SIGNIFICANCE: Anti-GM2 and anti-GalNAc-GD1a immunoglobulin G anti-glycolipid antibodies represent serum biomarkers for acute canine polyradiculoneuritis.

Morphometric parameters of peripheral nerves in calves correlated with conduction velocity.

BACKGROUND: Peripheral nerve injuries are the most frequent neurologic disorder in cattle. So far, no physiologic values have been established for the motor nerve conduction velocity (mNCV) in this precocial species. OBJECTIVES: The electrophysiologic and morphometric reference values of peripheral nerves in calves were determined. It was hypothesized that these parameters would correlate to the high degree of maturity in the first days of life in this species compared to other species. ANIMALS: Twenty-six healthy calves were used in this study. METHODS: The mNCV of the radial and the sciatic/common peroneal nerve was measured in all 26 calves. Nerve biopsies from a group of 6 calves were taken to correlate the obtained electrophysiologic data with morphological parameters. RESULTS: The mean mNCV of the radial nerve was 48.3 ± 10.6 m/s, whereas the mean mNCV of the sciatic/peroneal nerve was with 83.8 ± 5.9 m/s significantly faster (P < .0001). The average fiber diameter was 8.40 ± 2.80 µm (range, 1.98-17.90 µm) and the average g-ratio was 0.61 ± 0.04 SD. CONCLUSION AND CLINICAL IMPORTANCE: The established reference values for mNCV in calves correlate well with the evaluated morphometric parameters. Attributable to their comparably fast mNCV and high fiber diameters, juvenile calves appear to be much more mature individuals than other mammals. Electrophysiologic characterization of peripheral nerve injury now is feasible in this species.

[Measurement of thiamine concentration in the cat using high pressure liquid chromatography]. / Thiaminbestimmung bei der Katze mittels HPLC.

OBJECTIVE: Thiamine deficiency in cats frequently leads to a dysfunction of the central nervous system including vestibular signs with fatal outcome in untreated cases. The aim of the present study was to directly measure thiamine concentrations using high pressure liquid chromatography (HPLC) in feline blood samples and to evaluate values in healthy and diseased cats. MATERIAL AND METHODS: Blood samples (1 ml EDTA-whole blood) from 193 cats were analysed for total thiamine and thiamine diphosphate using HPLC. For the interpretation of the results cats were retrospectively assigned to six groups: A) healthy cats, B) cats with diseases of the gastrointestinal tract, C) cats with different traumas not affecting the gastrointestinal tract, D) cats with inappetence, cats with central vestibular signs and normal (E) or low values of thiamine (F), respectively. RESULTS: In animals of group F no obvious cause for the vestibular signs was found and spontaneous recovery after thiamine application occurred in three cats. Therefore thiamine deficiency was a highly likely clinical diagnosis. Total thiamine concentration (mean 48.2 µg/l, standard deviation ± 22.6) of group F significantly differered from the other groups (group A-D: p<0.01, group E: p<0.001). Comparable results were obtained for thiamine diphosphate. However, low total thiamine values were also found in cats with inappetence without any neurological signs. CONCLUSION AND CLINICAL RELEVANCE: In the present study a method for direct measurement of thiamine formerly established for ruminants was evaluated for cats. A more accurate and objective clinical diagnosis of thiamine deficiency is feasible in cats with values less than 50 µg/l and typical clinical signs. In animals with values of total thiamine levels between 50-70 µg/l a prophylactic substitution of thiamine can be discussed.

Immunohistochemical characterization of inflammatory and glial responses in a case of necrotizing leucoencephalitis in a French bulldog.

A 3-year-old male French bulldog was presented with blindness, staggering and ataxia and was humanely destroyed due to worsening of the neurological signs. At post-mortem examination a non-suppurative leucoencephalitis with extensive malacia within the forebrain was found. In addition, a bilateral necrotizing optic neuritis and focal retinitis was detected. Immunohistochemistry revealed a CD3(+) T-cell dominated inflammatory response with intralesional reactive astrocytes expressing glial fibrillary acidic protein. Astroglia-like cells expressing vimentin, which is characteristic of immature astrocytes, were found within the malacic lesions. The pathological findings are similar to those described in idiopathic necrotizing leucoencephalitis (NLE) of Yorkshire terriers and substantiate the hypothesis that NLE is not a breed-specific disorder that exclusively affects Yorkshire terriers, but also the French bulldog.