An allergy to bites from Culicoides (Diptera: Ceratopogonidae) occurs because of a hypersensitivity reaction caused by the inoculation of insect salivary antigens during the bite, resulting in immune-mediated dermatitis. To the best of our knowledge, no previous studies have focused on allergic dermatitis in donkeys in Brazil. Therefore, this study aimed to describe the epidemiological, clinicopathological, and therapeutic aspects of allergic dermatitis in donkeys and to identify the insects involved in its epidemiology. This study reported the occurrence of dermatitis in 17 animals. The clinical signs were restlessness and severe itching. Skin lesions were found on the head, depigmented areas of the muzzle and cheeks, flanks, pelvic and thoracic limbs, and the scrotal sac. The lesions were characterized by areas of alopecia with crusts accompanied by serosanguineous exudates. Histologically, the lesions were characterized as moderate superficial dermatitis with irregular epidermal acanthosis and pronounced diffuse orthokeratotic hyperkeratosis. In total, 378 Culicoides specimens were collected, with Culicoides ocumarensis Ortiz being the most abundant species. The combined application of copaiba oil and a multivitamin emulsion exhibited potential for topical treatment of allergic dermatitis caused by insect bites in donkeys. Our study revealed an association between allergic dermatitis in donkeys and Culicoides.

Leucoderma is a condition that affects the skin and hair of animals, causing depigmentation and acromotrichia. In buffaloes, this condition results in significant economic losses for the production chain due to its impact on the leather trade. This study aimed to investigate the epidemiological and clinicopathological aspects of leucoderma in buffaloes in the Amazon biome and describe the prophylactic treatment to control the disease. The study included 40 buffaloes, 16 males and 24 females, aged between 1 and 10 years, and were of the Murrah, Jafarabadi, Mediterranean, and Murrah × Mediterranean crossbreed breeds. The animals were raised without mineral supplementation. The clinical signs observed in the animals included acromotrichia and depigmentation, with varying degrees and distribution of skin lesions. Histological examination of the epidermis showed interrupted melanin production, mild dermal fibrosis, mild perivascular mononuclear inflammatory infiltrate, and pigmentary incontinence. None of the animals had the genotype for albinism. After 120 days of mineral supplementation based on the use of copper sulfate, the clinical signs of leucoderma regressed. There was no predisposition by breed, sex, or age for the occurrence of the disease. The regression of skin lesions after proper mineral supplementation suggests that copper deficiency may be considered an important factor for the occurrence of leucoderma in buffaloes in the Amazon biome.

The study aimed to describe the clinicopathological aspects of 37 cases of pythiosis, 34 in horses and three in mules, from properties located in the Amazon biome of Pará, Brazil. The clinical signs observed in the animals were weakness, poor-to-regular nutritional status, pale mucous membranes, itching at the lesion site, and lameness when the limbs were affected. The lesions were located on the lips, nostrils, rib region, thoracic and abdominal walls, scapular, distal limbs, foreskin, perineum and udder. Macroscopically, ulcerative and granulation-tissue-like masses were observed, with fistulous tracts filled with yellowish and foul-smelling serosanguinous discharges. In the biopsy, it was possible to visualize white and firm areas with foci of yellowish necrotic material and hardened masses, called kunkers. The histopathological examination showed a pyogranulomatous inflammatory reaction with the presence of Pythium insidiosum hyphae, which were impregnated with black, confirming the diagnosis of pythiosis in equids in the Amazon biome, being the first report of the disease in mules in the region.

An investigative and epidemiological study was carried out for equine herpesvirus type 1 (HVE-1) in 10 outbreaks of neurological disease from different farms in the state of Pará, Brazil. 25 horses were studied: six male and 19 females, aged between one and 13 years. A necropsy of six horses was performed, and the others recovered either with or without treatment (T1—vitamin B1 + dexamentasone; T2—vitamin B1 + flunixim meglumine). Animals that received treatment recovered after eight days. The main clinical signs observed were motor incoordination, progressive paresis, thoracic and/or pelvic limbs abducted after induction of clinical examination, knuckling of the hind fetlocks, sagging and swaying of the hindquarters while standing or walking and paresis. All animals were positive: 88% (22/25) in nested PCR and 72% (18/25) in serum neutralization (including three negatives in serology). Focal brownish areas compatible with hemorrhage were found in the white and gray matter of the spinal cord of two animals. On histological analysis, there were perivasculitis and neutrophilic vasculitis in the gray matter of the spinal cord and brain. Based on the evidence, this work proves the circulation of HVE-1 in the Amazon biome, mainly in the state of Pará, Brazil.

This study aims to describe the clinical signs and ultrasonographic and necropsy findings of the first cases of proximal (Buffalo 1) and distal (Buffalo 2) vagal indigestion in two Bubalus bubalis in the Brazilian Amazon biome. The clinical histories of the buffaloes were characterized by progressive weight loss, recurrent tympany, abdominal distention (apple and pear shapes), anorexia, and scant feces. Buffalo 1 was submitted to orogastric intubation, and due to the recurrent tympany, an exploratory laparotomy. Buffalo 2 was submitted to ultrasound examination, and a segment of the pylorus was shown to be adhered to the eventration by ultrasonography. Both animals produced positive results for the atropine test. In the necropsy evaluation, Buffalo 1 was shown to have dilation of the esophagus, rumen, and reticulum; the ruminal contents of animal 1 were olive green and foamy with bubbles within the ingesta. On the other hand, Buffalo 2 was shown to have distention of the forestomach and abomasum; the complex rumen–reticulum and omasum contents were semi-liquid and had a yellowish color. In animal 2, in the eventration region, there was adherence to the pyloric region. The diagnosis of vagal indigestion was based on the history, clinical signs, and ultrasound and necropsy findings, in addition to the results of the atropine test.

This is the first description of cutaneous mucormycosis in buffalo in the Brazilian Amazon biome. All buffalo showed apathy, inappetence, weight loss, reluctance to move, and prolonged sternal decubitus. Of the four affected animals, two died 15 and 30 days after the appearance of clinical signs. In the initial phase, the skin lesions were rounded areas with dry central regions, sensitive to palpation, with protruding edges and diameters ranging from 8 cm to 15 cm. These areas of necrosis were isolated or coalescing and present mainly on the limbs and sides. In an advanced stage of the disease, there was detachment of the skin from the necrotic areas with extensive wound formation, which sometimes exposed the subcutaneous tissue. The histopathology of the skin showed a multifocal inflammatory infiltrate composed of intact and degenerated eosinophils surrounded by epithelioid macrophages. At the center of these areas was a focally extensive area of epidermal ulceration characterized by intact and degenerated neutrophils, the necrosis of epithelial cells, and the accumulation of fibrin and erythrocytes. The mycological culture was positive for Rhizopus sp. The diagnosis of cutaneous dermatitis caused by Rhizopus sp. was based on clinical signs, macroscopic and histopathological findings, and the identification of the fungus by mycological and molecular techniques.