Experimental trichophytosis in calves caused by cultures of Trichophyton verrucosum and Trichophyton equinum

Tests were performed on 130 one-month-old calves. In 16 animals, treatment with a suspension of Trichophyton verrucosum culture at the dosage of 5 mil. conidia for an area of 10 x 10 of the clipped skin caused clinical trichophytic changes. The length of the incubation time was shorter in the calves scarified before inoculation of the infecting culture (10 to 13 days), as compared with the group of calves without scarification of the skin (11 to 19 days). Only 3 in 6 calves, infected by the same dose into non clipped skin, did contract trichophytosis, manifesting themselves as separate mycotic deposits, which appeared 26 to 35 days after inoculation. Trichophytic changes lasted longest in the group with scarification of the infected area. The ID50 in T. verrucosum and T. equinum cultures was about 1500 conidia per one calf in the case of the method of infecting into clipped scarified skin (area 100 sq cm). A 10 times lower dose (150 conidia per one calf) of the T. verrucosum suspension did not induce visible mycotic changes, but the T. equinum inoculation produced infection in one of 10 calves.     

An outbreak of ringworm in sheep in Ireland caused by Trichophyton verrucosum

An outbreak of ringworm in sheep in Ireland caused by Trichophyton verrucosum is described. The flock consisted of 110 sheep and two separate groups within the flock were affected. Eleven of the first group of 23 sheep and five of the second group of 25 sheep showed lesions. Contact with infected cattle and fomites contaminated by the cattle are believed to have caused the outbreak. An excellent response was obtained in both infected groups by treatment with griseofulvin at a dose rate of 7.5 mg/kg daily for seven days.     

Chitin synthase 1 (Chs1) gene sequences of Microsporum equinum and Trichophyton equinum

Chitin synthase 1 (Chs1) genes from Microsporum equinum and Trichophyton equinum were compared with those of the other dermatophytes. The Chs1 nucleotide sequences of these dermatophytes from horses showed more than 80% similarity to those of Arthroderma benhamiae, A. fulvum, A. grubyi, A. gypseum, A. incruvatum, A. otae, A. simii, A. vanbreuseghemii, Epidermophyton floccosum, T. mentagrophytes var. interdigitale (T. interdigitale), T. rubrum and T. violaceum. Especially high degree of nucleotide sequence similarity of more than 99% was noted between the Chs1 gene fragments of M. equinum and A. otae, and those of T. equinum, T. interdigitale and A. vanbreuseghemii, respectively. The phylogenetic analysis of their sequences revealed that M. equinum was genetically very close to A. otae and T. equinum to A. vanbreuseghemii. A molecular analysis of Chs1 genes will provide useful information for the genetic relatedness of M. equinum and T. equinum and confirm the value of DNA sequencing in identification of these two dermatophytes.     

Experimental medication of equine ringworm due to Trichophyton equinum var. autotrophkum

SUMMARY Twelve medicaments were tested for their efficacy in the treatment of Trichophyton equinum var. autotrophicum; povidone iodine, thiabendazole ointment, captan ointment and Burroughs Wellcome Ringworm Ointment gave satisfactory results but their usefulness may be limited for treatment of large numbers of horses. Aqueous washes containing 0.5% hexetidine or 0.3% chloramine-T did not prevent fungi being isolated from lesions for up to 7 days after treatment. Similarly neither etisazole nor thiabendazole suspension prevented fungi from being isolated from lesions for up to 15 days after treatment. Commonly used aqueous solution of 2.5% lime sulphur and 2% captan were least successful, as fungi could still be isolated from lesions for up to 30 days after treatment. The need to treat large numbers of horses may dictate the use of such solutions rather than ointments because of ease of application and cost factors. Treatments consisting of 10% nystatin ointment, 10% iodine fortis, 10% Medol and a proprietary ointment, Queensland Itch Dressing, were not satisfactory. Clinical appraisal and a scratch test must be used together to evaluate progress of treatment. Mass medication of large numbers of horses should be primarily aimed at reduction of spread of infection; normal hair growth should not be used as an indication of the removal of infective agents in the hair as regrowth was altered very little by medication. Hence assessments of cure on the basis of regrowth of hair alone are of dubious value.     

An outbreak of ringworm in karakul sheep caused by a physiological variant of Trichophyton verrucosum Bodin.

An outbreak of ringworm in Karakul sheep occurred during 1973 among the flocks of at least 14 farmers in South West Africa and the northern Cape Province. Infections spread from one farm to another as a result of introducing infected stud rams. On one farm a few cattle, a goat and a horse developed lesions after being in contact with infected sheep. Some of the attendants handling infected sheep also contracted the disease. Strains recovered from infected animals resembled Trichophyton verrucosum morphologically, but when grown on laboratory media they did not require an exogenous source of vitamins, which was found to be indispensable for strains of this species studied previously.     

Dermatophytosis caused by Trichophyton benhamiae in a dog

Trichophyton benhamiae was diagnosed in a 9-year-old female dog by histopathological evaluation, fungal culture and confirmation by sequencing of the internal transcribed spacer region of ribosomal DNA. Successful therapy was achieved with itraconazole, bathing with miconazole and chlorhexidine shampoo, and topical application of sodium hypochlorite as a rinse.     

Development of an enzyme-linked immunosorbant assay (ELISA) for the serodiagnosis of canine dermatophytosis caused by Microsporum canis

Abstract In dogs, dermatophytosis should be considered in any case of alopecic, papular or pustular lesion. The aim of this study was to develop an enzyme-linked immunosorbant assay (ELISA) as an aid in the diagnosis of canine dermatophytosis. The antigen used was a whole fungal extract obtained from an isolate of Microsporum canis cultured on a liquid medium from the parasitized hair of a cat with patches of alopecia. To assess the ELISA performances, sera from 18 dogs with dermatophytosis caused by M. canis (group A, n = 18), 20 dogs with skin diseases other than dermatophytosis and 22 healthy dogs (group B, n = 42) were tested. Four further animals were tested: three with dermatophytosis caused by M. gypseum and one by T. mentagrophytes. A significant difference (P < 0.01, Wilcoxon's test, w = 364) was found between IgG-specific levels of sera of recently M. canis-infected dogs (infection < 15 days) and controls (although three dogs had negative titres at this stage). A highly significant difference (P < 0.001, w = 462) was noted between controls and dogs with infection of longer duration (> 30 days). All dogs had positive titres at this stage. A highly significant correlation (P < 0.001, Spearman's test, rho = 0.86) between duration of infection and IgG concentration was noted. The test has good sensitivity (83.3%) and high specificity (95.2%) but some dogs retained positive titres after elimination of infection. The sensitivity is higher than that of direct microscopic hair examination and similar to that of fungal culture with DTM (dermatophyte test medium).     

Dermatophyte granulomas caused by Trichophyton mentagrophytes in a dog

Multiple, dermal and subcutaneous nodules developed in a young female Manchester Terrier dog that had a chronic history of superficial dermatophytosis. Skin biopsy specimens of the nodules revealed granulomatous inflammation in the deep dermis and subcutis with branching fungal organisms. Cultures of multiple biopsy specimens from the nodules all yielded Trichophyton mentagrophytes. The lesions in this dog were similar to granulomatous dermatophytosis, a skin disease that has been reported in Persian cats and one Yorkshire Terrier dog.     

Enterocolitis caused by Ehrlichia sp. in the horse (Potomac horse fever)

Potomac horse fever was reproduced in 15 ponies by transfusion of whole blood originally from two natural cases and subsequently from ponies infected by the transfusions. Incubation periods varied from 9 to 15 days. Affected ponies developed varying degrees of fever, diarrhea, anorexia, depression, and leukopenia. Eleven affected ponies were killed, three died in the acute phase of the disease, and one did not show clinical signs. The most consistent post-mortem findings were fluid contents in the cecum and large colon, and areas of hyperemia (of inconstant degree and distribution) in mucosae of both small and large intestines. Multifocal areas of necrosis occurred in mucous membranes. Ehrlichial organisms were most common in the cytoplasm of epithelial cells, macrophages, and mast cells of the large colon.