Leiomyosarcoma with widespread metastases in a capybara.

A 10.5-y-old intact female capybara (Hydrochoerus hydrochaeris) with a history of chronic weight loss was euthanized following discovery by palpation of a large intra-abdominal mass. Postmortem examination revealed a large, firm, tan mass expanding the uterine body and extensively adhered to the jejunum and abdominal wall. Numerous pinpoint to 3-cm diameter, tan-to-red, raised masses were present throughout the parietal peritoneum, liver, lungs, and intestinal serosa. Histologic examination of the uterine mass revealed well-differentiated smooth muscle intermixed with abundant collagen, interspersed with a highly anaplastic spindle cell population extending to the serosa; the masses in the lung, liver, and peritoneum were histologically very similar to the anaplastic uterine spindle cells. Immunohistochemical staining of the uterus and lung confirmed smooth muscle origin of the anaplastic cells. To our knowledge, leiomyosarcoma has not been reported previously in a capybara, and the widespread metastases in this case represent an unusually aggressive presentation of this rare malignancy. The animal also had an incidental dermal histiocytoma, a tumor that has also not been reported previously in this species, to our knowledge.

Correlation of subclinical gastrointestinal nematode parasitism with growth and reproductive performance in ewe lambs in Ontario.

Infection with gastrointestinal nematode parasites (GINs) is an important cause of productivity loss on sheep farms in Ontario and worldwide. However, efforts to quantify the effect of GIN infection on growth have demonstrated mixed results. Furthermore, there has been limited investigation of their effect on reproductive performance. This study evaluated the effect of subclinical GIN parasitism on growth and reproductive performance of ewe lambs under Ontario grazing conditions. Rideau cross ewe lambs (n = 140) born in spring 2016 on a farm in central Ontario were followed for two years from before weaning through to November 2017, including their first lambing and lactation. These animals grazed from May to November of each year and were sampled every 6-8 weeks during both grazing seasons and once at mid-gestation in March 2017. At each sampling the ewe lambs were weighed, body condition scores assigned, fecal egg counts (FECs) performed, and pasture samples collected to assess number of infective GIN larvae. Study animals with a FEC of 500 eggs per gram or higher were selectively treated with anthelmintics to prevent morbidity and mortality. Fecal samples were cultured to determine infecting GIN species, and climate data were obtained from a weather station 26 km away from the farm. Precipitation levels and numbers of infective larvae on pasture were low during the first grazing season but were more typical of Ontario conditions in the second grazing season. The three most common GIN species were Haemonchus contortus, Teladorsagia circumcincta, and Trichostrongylus spp. General linear mixed models were generated for weight change over time, litter size at lambing, and weaning weights of offspring. Despite moderate peak GIN burdens in both grazing seasons, FEC was not significantly associated with weight change or litter size, apart from periparturient egg rise in study ewe lambs with larger litters (p = 0.05). Significant positive quadratic and negative linear associations were identified between late lactation FECs and offspring weaning weights; the association between FECs and weaning weights changed from negative to positive at a FEC of 361 eggs per gram. These results indicate that when GIN burdens are moderate as evidenced by fecal egg counts and infection is subclinical, there appears to be low to no impact on growth and reproductive performance in ewe lambs in the first 18 months of life. This suggests that when GIN parasitism is regularly monitored and controlled using targeted selective treatment, animal performance is minimally affected.

Correlation of salivary antibody to carbohydrate larval antigen (CarLA) with health and gastrointestinal nematode parasitism in sheep under Ontario grazing conditions.

Leveraging mucosal immunity is a promising method for controlling gastrointestinal nematode (GIN) parasitism in sheep. Salivary antibody to carbohydrate larval antigen (sCarLA), a heritable measure of immunity to third-stage GIN larvae (L3), has been successfully applied to genetic improvement programs in New Zealand. However, sCarLA levels wane in the absence of ongoing GIN exposure. New Zealand's temperate climate permits year-round exposure to L3, but cold winters in boreal regions such as Ontario, Canada interrupt exposure for five months or more. This study investigated associations between sCarLA levels, GIN parasitism, and indicators of overall health in sheep grazing under Ontario conditions. A commercial flock of 140 Rideau cross ewe lambs were followed from approximately 30 days of age in May 2016 until November 2017, including lambing and lactation in the spring of 2017. Every 6-8 weeks during the grazing season and at mid-gestation in March 2017, fecal egg counts were performed, blood collected to assess serum albumin, globulin, and hematocrit, and pasture samples obtained to confirm exposure to infective larvae. Measurements of sCarLA level were performed at the beginning, middle, and end of each grazing season, and at mid-gestation. Spearman's rank correlation coefficients were calculated to compare sCarLA levels over time, and general linear mixed models created to evaluate associations between sCarLA levels, GIN fecal egg count, hematocrit, serum albumin, and serum globulin. Levels of sCarLA followed a similar seasonal pattern to GIN fecal egg counts with a 6-8 week delay; much higher sCarLA levels were observed in the second grazing season. The proportion of the flock with detectable sCarLA (≥ 0.3 units/mL) was 68.3 % by the end of the first grazing season, declined over winter to 43.9 % at lambing, and approached 100 % after 3 months of grazing in the second grazing season. Correlations between sCarLA levels over time were consistently positive, of weak to moderate strength, and significant (p < 0.05). At all time points, sCarLA level was significantly (p < 0.001) and negatively associated with fecal egg counts. The flock displayed minimal variability in hematocrit, serum albumin, and serum globulin; none of which were significantly associated with sCarLA levels. These results suggest that sCarLA can be maintained over winter and is a useful measure of immunity to GINs in sheep under Ontario grazing conditions.

Comparison of ITS-2 rDNA nemabiome sequencing with morphological identification to quantify gastrointestinal nematode community species composition in small ruminant feces.

Mixed gastrointestinal nematode (GIN) infections are a common and significant cause of financial loss for small ruminant producers. Morphologic examination of third-stage larvae (L3) can be used to identify species composition in feces but has limitations due to the requirement for specialized expertise and the extensive time (8-15 d depending on method used) and labour involved. Moreover, differential development and survival of larvae during coproculture to the third stage often occurs. Deep amplicon sequencing of the ITS-2 rDNA locus of first-stage larvae (L1) allows for higher throughput with reduced specialist labour and reduces the risk of misidentification. Harvesting of L1 soon after hatching is also faster and further reduces labour as well as biases that can occur due to differential larval development and survival. This study compares the results of morphologic examination of L3 with those of ITS-2 rDNA deep amplicon sequencing of L1 from a set of pooled fecal samples. The proportions of eggs that were successfully recovered as larvae following culture to L3 and L1 were also compared. Larval recovery rate was significantly lower from L3 cultures than from L1 cultures (p < 0.001); eggs were 238.7 times less likely to develop to L3 than to L1 (95 % confidence interval for odds ratio 80.0-712.0). Significantly lower proportions of Teladorsagia circumcincta (odds ratio = 3.1, p = 0.008) and higher proportions of Trichostrongylus spp. (p = 0.009) were identified using morphologic examination of L3 compared with deep amplicon sequencing of L1 on the same samples. This is consistent with previous reports of differential survival of these species in L3 cultures. These results indicate that deep amplicon sequencing of L1 may reduce bias introduced by differential GIN survival to L3 in small ruminants.

Retropharyngeal abscess with carotid involvement presenting as fever of undetermined origin in a dog.

A young dog was presented with lethargy and pyrexia of 2 days duration, not responding to empirical treatment. Thorough diagnostic investigation failed to determine the cause. A retropharyngeal abscess became apparent when it eroded into the carotid artery 2 days later. This case highlights the challenging nature of fever of undetermined origin (FUO) and the value of close monitoring for diagnosis and prompt intervention.

Abcès rétro-pharyngien avec une atteinte de la carotide et une fièvre d'origine indéterminée chez un chien. Un jeune chien a été présenté pour un abattement et une pyrexie d'une durée de 2 jours et il ne répondait pas au traitement empirique. Une enquête diagnostique complète n'a pas réussi à déterminer la cause. Un abcès rétro-pharyngien est devenu apparent lorsqu'il s'est érodé dans la carotide 2 jours plus tard. Ce cas souligne la nature difficile d'une fièvre d'origine indéterminée et la valeur d'une étroite surveillance pour le diagnostic et une intervention rapide.(Traduit par Isabelle Vallières).