Hypersensitivity pneumonitis associated with inhalation of Lycoperdon spores (lycoperdonosis) in a 3-month-old English setter dog in Quebec.

A 3-month-old female English setter dog was presented to the Faculty of Veterinary Medicine of the Université de Montréal (Quebec) with acute respiratory distress. The dog had moderately increased C-reactive protein concentrations, and thoracic radiographs revealed a moderate, caudodorsal, nodular-to-miliary alveolo-interstitial pulmonary pattern that was worse in the perihilar region. Initial differential diagnoses included a fungal pneumonia (e.g., blastomycosis or histoplasmosis). Cytology of the bronchoalveolar lavage revealed several round, green structures ~2 µm in diameter, consistent with fungal spores. The dog was hospitalized, but within 24 h the respiratory condition deteriorated and euthanasia was elected. Post-mortem panfungal PCR and sequencing tests identified the spores as Lycoperdon sp. Retrospectively, the owners recalled that the dog had played in a wood pile with mushrooms and had sneezed in a cloud of spores, implying inhalation of Lycoperdon spores. This is the first report of a confirmed case of canine lycoperdonosis in eastern Canada (Quebec), and the radiographic features in this case differed slightly from previous reports. Diagnosis before bronchoalveolar lavage analysis was challenging, as spore inhalation was not initially reported. Although the disease is infrequently reported in dogs, this case report reminds veterinarians to consider lycoperdonosis as a differential diagnosis when addressing animals presented with acute dyspnea with similar radiographic lesions, and highlights the importance of history and cytology in diagnosing this condition. Key clinical message: Hypersensitivity pneumonitis secondary to inhalation of Lycoperdon spores must be included in differential diagnoses for a dog with acute onset of respiratory signs and a nodular-to-miliary interstitial pulmonary pattern coalescing in patchy perihilar alveolar pulmonary lesions, and should prompt clinicians to question owners regarding inhalation of mushroom spores.Although cytological examination of a bronchoalveolar lavage reveals the presence of fungal spores, panfungal PCR and sequencing tests are needed to pinpoint the species involved.

Pneumopathie d'hypersensibilité associée à l'inhalation de spores de Lycoperdon (lycoperdonose) chez un chien setter anglais de 3 mois au Québec. Une chienne setter anglais âgée de 3 mois a été présentée à la Faculté de médecine vétérinaire de l'Université de Montréal (Québec) avec une détresse respiratoire aiguë. Le chien présentait des concentrations de protéine C-réactive modérément augmentées et les radiographies thoraciques ont révélé un schéma pulmonaire alvéolo-interstitiel modéré, caudodorsal, nodulaire à miliaire, pire dans la région périhilaire. Les diagnostics différentiels initiaux incluaient une pneumonie fongique (par exemple, blastomycose ou histoplasmose). La cytologie du lavage broncho-alvéolaire a révélé plusieurs structures rondes et vertes d'environ 2 µm de diamètre, compatibles avec des spores fongiques. Le chien a été hospitalisé, mais en 24 heures, l'état respiratoire s'est détérioré et l'euthanasie a été décidée. Les tests panfongiques PCR et de séquençage post-mortem ont identifié les spores comme étant Lycoperdon sp. Rétrospectivement, les propriétaires ont mentionné que le chien avait joué dans un tas de bois avec des champignons et avait éternué dans un nuage de spores, ce qui implique une inhalation de spores de Lycoperdon. Il s'agit du premier rapport d'un cas confirmé de lycoperdonose canine dans l'est du Canada (Québec), et les caractéristiques radiographiques de ce cas différaient légèrement des rapports précédents. Le diagnostic avant l'analyse du lavage broncho-alvéolaire était difficile, car l'inhalation de spores n'avait pas été initialement signalée. Bien que la maladie soit rarement rapportée chez les chiens, ce rapport de cas rappelle aux vétérinaires de considérer la lycoperdonose comme un diagnostic différentiel lorsqu'ils traitent des animaux présentant une dyspnée aiguë avec des lésions radiographiques similaires, et souligne l'importance de l'anamnèse et de la cytologie dans le diagnostic de cette affection.Message clinique clé : La pneumopathie d'hypersensibilité secondaire à l'inhalation de spores de Lycoperdon doit être incluse dans les diagnostics différentiels chez un chien présentant un début aigu de signes respiratoires et un schéma pulmonaire interstitiel nodulaire à miliaire fusionnant dans des lésions pulmonaires alvéolaires périhilaires inégales, et devrait inciter les cliniciens à interroger les propriétaires concernant l'inhalation de spores de champignons.Bien que l'examen cytologique d'un lavage broncho-alvéolaire révèle la présence de spores fongiques, des tests panfongiques PCR et de séquençage sont nécessaires pour identifier les espèces impliquées.(Traduit par Dr Serge Messier).

Allergic respiratory disease.

Allergic rhinitis and extrinsic allergic alveolitis are the most common allergic disorders of the bovine respiratory system. Environmental and management factors play significant roles in the pathogenesis of these disorders. When compared to infectious or toxic respiratory disease, allergic respiratory disease is relatively rare and of far less economic importance in North American cattle; however, the environmental and management conditions conducive to these diseases exist in many regions. Therefore, familiarity with the clinical and epidemiologic features of these unique diseases will aid the veterinarian in establishing an accurate diagnosis. Signs of respiratory dysfunction are common to anaphylactic and anaphylactoid reactions. Early recognition of these adverse reactions will provide the practitioner with the greatest chance of successful treatment.

Respiratory disease in adult cattle.

This article discusses the nomenclature of respiratory disease, acute respiratory distress syndromes, hypersensitivity diseases, chronic respiratory disease, and the differential diagnosis of respiratory disease.

"Haysickness" in Icelandic horses: precipitin tests and other studies.

Blood samples were taken from 18 healthy horses (Group A), 15 horses clinically diagnosed to have "haysickness" ("farmer's lung") (Group B), 10 closely related horses (Group C) and 14 inbred horses (Group D). Precipitins in sera were measured by double gel diffusion test against Micropolyspora faeni, Thermoactinomyces vulgaris, Aspergillus fumigatus, Alternaria, Penicillium and Rhizopus species. In Group A, all the horses were precipitin negative except one with a faint reaction to Rhizopus species. In Group B all had precipitin against M faeni. One horse also had precipitins against Rhizopus species and another against A fumigatus. In Group C, seven of the 10 horses had precipitins against M faeni. Of these, five had a history of respiratory signs, but two horses with a faint reaction had no such history. In Group D, four out of 14 horses had positive precipitin tests against M faeni. Of these four horses, three also had a faint reaction to A fumigatus and one a faint reaction to Alternaria species. All were asymptomatic. These results indicate that "farmer's lung" in man and "haysickness" in horses are of the same origin. However, further studies are necessary to substantiate the diagnostic or prognostic value of these precipitin tests in equine practice. The question of whether hereditary factors play a role in causing this disease also warrants further studies.

Hypersensitivity pneumonitis: experimental production in calves with antigens of Micropolyspora faeni.

Pneumonitis was induced in calves by exposure to aerosols of Micropolyspora faeni with or without prior sensitization of the animals by subcutaneous injection of antigen. The pneumonitis primarily involved centrolobular areas and was characterized by alveolar septal thickening and loss of air space by cellular infiltration. Vasculitis and focal haemorrhage occurred in certain individuals and haemoproteinaceous exudate appeared within septa and alveolar lumina. The pneumonitis was compared with human farmer's lung, pneumonitis of housed cattle and other experimental hypersensitivity pneumonitides.