Eutrombicula cochinocaensis infestation in llamas (Lama glama) in the Puna region of Argentina.

This paper aims to describe a case of trombiculosis in llamas from the Puna region of Argentina caused by Eutrombicula cochinocaensis. Trombiculosis is a parasitic infestation caused by the larval form of trombiculid mites, commonly known as chigger mites. Six adult llamas out of eighteen (33%) were infested and showed dermatitis, hyperemia, and crusts together with an orange-dotted pattern. The chigger mites were found mainly in the hind limbs and the abdomen. Microscopic identification of E. cochinocaensis was made by phase-contrast microscopy. Then, a histopathological study of the affected animals' skin was performed. Histological findings included dermatitis withmainly lymphocytic infiltrate, pustules, crusts, hyperkeratosis, and the mites' stylostomes in the dermis and epidermis. This is the first report of trombiculosis caused by E. cochinocaensis in llamas from Argentina. Mites of the family Trombiculidae are vectors of certain diseases to humans and animals and are therefore of sanitary and productive importance.

Characterization of lesions of nutritional congenital goitre in cattle.

There are few studies that classify and characterize the morphometric and immunohistochemical features of goitre in bovine thyroid glands (TGs). We investigated 39 bovine TGs (fetuses [9], stillbirths [18], neonates [12]) born to dams with low T4 hormone levels and no iodine supplementation and 10 (fetuses [3], stillbirths [3], neonates [4]) born to dams with normal T4 levels and supplemented with iodine. Body weight (BW), TG weight (TGW), TGW:BW ratio and histological lesions were determined. The TGs were classified histopathologically as normal gland (G0), mild goitre (G1), moderate goitre (G2) or severe goitre (G3). Various morphological and morphometric parameters were calculated from microscopic images using image analysis software. Immunohistochemistry was performed to detect proliferating cell nuclear antigen (PCNA). There were significant differences in the TGW:BW ratio among groups (P <0.05): 0.3 ± 0.1 in G0, 0.5 ± 0.3 in G1, 0.8 ± 0.3 in G2 and 1.3 ± 0.7 in G3. In G0, large homogeneous follicles with eosinophilic colloid were seen. In the groups with lesions (G1, G2 and G3), heterogeneity in follicle shape and size, height and area of thyroid follicular cells, height of thyroid follicular epithelium and PCNA immunolabelling were directly related to histopathological grade, with significant differences among groups (P <0.001), gradually increasing from G1 to G3 compared with G0. The TGW:BW ratio and histological grade were positively correlated (P = 0.008).

Determination of ptaquiloside in ten species of Pteris in northwestern Argentina.

The toxic effect of ferns of the genus of Pteris in bovines is caused by ptaquiloside, the main carcinogenic toxin. In this study, ten species of Pteris fern in different phenologic stages and plant conditions were collected in northwest Argentina. The phytochemical analysis showed the presence of Pt in the recent collected samples (adults and young plants) but not in the herbarium specimens. The results show a great variation of Pt concentration that depends on the phenologic stage, plant condition, and collection site. Pt was measured in 6-4326 µg/g concentration, with a mean concentration of 644 µg/g. No Pt was detected in eight species of Pteris collected from herbarium samples; such results may be a false negative. It is important to notice that analysis of herbarium samples for Pt may not be a reliable method to determine its presence. It is important to further understand the potential toxicity caused by these ferns because of their effect on animals, public health, and the environment.

Pascalia glauca poisoning in ruminants: Report of 12 outbreaks in northwestern Argentina.

Pascalia glauca, a perennial herb known for its toxicity in ruminants, is one of the most important toxic plants in northwestern Argentina. This work describes several outbreaks of natural intoxication with P. glauca from different sources affecting cattle, sheep and goats in different production systems, with morbidity varying between 1% and 100%. Clinical signs included tremors in the hindquarters, recumbency and death. The liver showed swelling, congestion and a mottled appearance. Histopathologic findings included centrilobular hepatocellular necrosis with hemorrhage.

Retrospective analysis of hairy vetch (Vicia villosa roth) poisoning in Argentina (2004-2019).

Hairy vetch (Vicia villosa) poisoning in cattle is characterized by a systemic granulomatous inflammatory response that resembles a type-IV hypersensitivity reaction. Hairy vetch toxicity has been described in cattle worldwide. The aim of this paper was to describe 10 outbreaks of hairy vetch poisoning in cattle studied at INTA EEA Salta and INTA EEA Balcarce, Argentina, from 2004 to 2019. Clinical signs included weakness, pyrexia, dermatitis, alopecia, and progressive weight loss, which leads to death over a clinical course of approximately two weeks. A total of 12 necropsies were performed and tissue samples were collected for histopathology. The main gross changes were observed in skin, lymph nodes, liver, heart, spleen and kidneys. Other tissues, such as pancreas, thyroid, and adrenal glands, were also affected. Histological lesions consisted of multifocal to diffuse granulomatous inflammation in those organs. The toxicity of hairy vetch has been described in several countries of the world. In Argentina, the use of hairy vetch as a cover crop has become common in some regions during the past years. The data suggest that hairy vetch poisoning is an important disease in cattle. More studies are needed to contribute with further information.

Detection and first molecular characterization of bovine papular stomatitis virus in dairy calves in Argentina.

Bovine papular stomatitis virus (BPSV) is a parapoxvirus associated with papular and erosive lesions on the muzzle, lips, and oral mucosa of cattle. BPSV infection occurs worldwide; however, it has still not been unequivocally diagnosed. The present report describes an outbreak of BPSV infection affecting dairy calves in northwestern Argentina and provides the first molecular characterization of this virus in the country. The disease was detected in a dairy farm, affecting 33 calves between 2 and 20 days of age. The signs included reddish papules, ulcers, and scabby proliferative lesions on muzzle, lips, and oral mucosa. The affected calves resisted to being fed due to severe local pain. Two necropsies were performed; papulas and ulcers were observed in ruminal and omasal mucosa. Histologically, the affected areas of the skin showed acanthosis, spongiosis, and parakeratotic hyperkeratosis with adjacent focally extensive ulcers and multifocal inflammatory infiltrate in the epidermis. Eosinophilic inclusion bodies were detected in the cytoplasm of epithelial cells. DNA extracted from scab samples was analyzed by PCR using pan-parapoxvirus primers for the B2L gene. The sequence analysis revealed 99%, 85%, and 84% similarity with BPSV, Pseudocowpox virus, and Orf virus, respectively. A phylogenetic tree constructed using the B2L sequence showed that the virus clustered with BPSV isolates. Although clinical cases compatible with BSPV infection have been frequently described in Argentina, the present report is the first to identify the agent associated with cattle disease in the country.

Acute heart failure in rabbits by avocado leaf poisoning.

The aim of this paper was to report an outbreak of avocado poisoning in rabbits in Salta, Argentina. Fourteen rabbits died of congestive heart failure within 30 h of ingesting fresh avocado leaves from pruned trees. They showed clinical signs of respiratory and cardiac distress. Full necropsies of four rabbits were performed and samples were collected for histopathology. The gross pathological observation included pleural and pericardial effusion, pulmonary oedema, slight ascites; the hearts appeared flabby and markedly pale. In addition, the stomach content consisted mostly of green feed with large amounts of avocado leaves. Epidermal fragments of Persea americana were identified by microhistological analysis of gastric content to get most efficiently to a correct diagnosis. Histopathological examination revealed degeneration and necrosis of myocytes and a mononuclear cellular infiltration mainly involving the myocardium and, to a lesser extent, the liver, lung and kidneys. Our observations indicate that avocado leaves should be avoided in the green diet of rabbits.

Experimental poisoning by Heterophyllaea pustulata Hook. f. (Rubiaceae) in goats. Clinical, biochemical and toxicological aspects.

The aim of this study was to investigate the clinical, biochemical and toxicological findings of the experimentally poisoning induced by Heterophyllaea pustulata in goats. Ten healthy adult female Saanen breed goats were used in the experiment. The goats were randomly assigned to two groups of five individuals: control and experimental group (CG and EG). Both groups were kept in the same enclosure devoid of shade for 8 h daily. The EG received only H. pustulata samples (leaves and thin steam) and water ad libitum. The CG received lucerne hay. Blood samples were taken at different times after oral administration of vegetal samples, and level of hepatic enzymes, total bilirubin, conjugated and non-conjugated bilirubin was measured, together with the detection of anthraquinones (AQs) and phylloerythrin by High Performance Liquid Chromatography with Diode-Array Detector and Mass Spectrometry with Electron Spray Ionization and Quadrupole Time Of Fly analysis. At the same time, skin biopsy samples were collected for AQs determinations. For histopathological examination, hepatic biopsy samples were collected on day 8. Clinically, all goats of the EG revealed photophobia, dermatitis and photosensitization. None of these goats developed jaundice or died during the experiment (15 days). In addition, affected goats exhibited a significant elevation in the serum levels of glutamic oxaloacetic transaminase, direct bilirubin, and total bilirubin. Microscopic examination of the liver samples revealed slight degenerative lesions. Although phylloerythrin was not detected in sera, a high level of two predominant AQs in H. pustulata (rubiadin/soranjidiol) were noted between 24 and 72 h after plant consumption, which coincided with the period in which the clinical signs were more obvious. Since those AQs were not identified in skin samples, the clinical findings were supported by the presence of AQs in sera. Finally, toxicological studies of the AQs are important, since many current works suggest their potential use in the photodynamic therapy.