Distribution of Alaria spp. mesocercariae in waterfrogs.

The distribution of Alaria-spp.-mesocercariae within the host is relevant for the examination via Alaria spp. mesocercariae migration technique (AMT) regarding predilection sites and may indicate an interaction between parasite and host. Naturally Alaria-exposed frogs of Pelophylax species (n = 13) were examined for systemic distribution and localization-specific parasite density of Alaria spp. mesocercariae. The frogs were necropsied and their body was divided into the following localizations: inner organs, head, torso, forelimbs, and hind limbs. The localizations were analyzed individually and in toto using Alaria spp. mesocercariae migration technique. Our results showed neither statistical differences concerning the number of mesocercariae in the different localizations nor in respect of the rate of positive localizations. Therefore, an accumulation in a particular predilection site seems unlikely. Further research on a representative sample is necessary before final conclusions can be drawn.

Amiodarone and itraconazole improve the activity of pentavalent antimonial in the treatment of experimental cutaneous leishmaniasis.

Leishmaniasis affect millions of people, causing morbidity and mortality, especially in developing tropical and subtropical countries. Unfortunately, the possibilities of treatment for these infections are still quite limited and most of the available drugs present serious side effects. The objective of this paper was to evaluate the therapeutic role of amiodarone and itraconazole in the treatment of cutaneous leishmaniasis caused by Leishmania (Leishmania) amazonensis. In order to perform this evaluation, hamsters were infected with 1 × 106 metaciclic promastigotes of the parasite in the hind footpad and, after the onset of the lesions, were treated with glucantime, amiodarone, itraconazole, glucantime and amiodarone, glucantime and itraconazole or amiodarone and itraconazole. The treatments' efficacy was evaluated per analysis of the size of the cutaneous lesions and by parasitic investigation of the infected foot (by histopathological examination and PCR) and possible side effects were analyzed taking into account the weight of the animals and some biochemical and metabolic parameters (glucose, urea, creatinine, AST, ALT and ALP). The results have shown that, in hamsters, amiodarone and itraconazole, either used isolated or in combination, are unable to stop the development of cutaneous lesions caused by L. (L.) amazonensis, but improve the activity of glucantime in the treatment of these lesions and seem to present no evident side effects. More studies are necessary in order to investigate the clinical potential of these combinations, so there can be the possibility of broadening the therapeutic options available, especially in resistant cases.

The first report of Knemidocoptes intermedius Fain et Macfarlane, 1967 (Acari: Astigmata) in naturally infected European birds.

According to the latest taxonomical review, the genus Knemidocoptes (Epidermoptidae: Knemidocoptinae) comprises 15 species of mites responsible for skin lesions on the face, legs, or body of various wild and domestic birds. A number of 54 common ravens, Corvus corax (Aves: Passeriformes: Corvidae) were found dead (accidental poisoning) in March 2009, in Târgu Mures, Romania. One individual presented bilateral symptoms of scaly leg disease. Microscopic examination revealed the presence of Knemidocoptes intermedius (Epidermoptidae, Knemidocoptinae) in one bird. The lesions were present on both feet (bilateral) and consisted of moderate hypertrophic crusts on the dorsal and ventral part of the toes as well as the distal part of the tarsometatarsal region. It is the first reliable record of K. intermedius in Europe and also the first record of this species in the common raven. The host range and specificity of this parasite is discussed, along with a revision of occurrences in wild birds.

Pathological findings associated with experimental infection by Trypanosoma evansi in cats.

Five cats were experimentally inoculated with Trypanosoma evansi in order to evaluate the pathological changes induced by this protozoan infection. Clinical signs observed included vomiting, diarrhoea, hyperthermia, weight loss, facial oedema, corneal opacity, lymphadenopathy and hindlimb instability. Reduction in hematocrit was observed from 7 days post-infection (dpi) (P<0.05). One cat died at 40 dpi and the other four cats were humanely destroyed. Necropsy examination was performed in two cats at 56 dpi and two cats at 120 dpi. Gross findings in all cats included generalized muscle atrophy, pale mucosae, icterus of the subcutaneous and serosal tissue and the intima of arteries, lymphadenopathy and splenomegaly. Other findings included corneal opacity, subcutaneous oedema (mainly of the head) and hydropericardium. Trypomastigotes of T. evansi were observed in impression smears prepared from the aqueous humor. Microscopically, there was lymphoid hyperplasia of the spleen and lymph nodes. The animals with corneal opacity had mild corneal oedema and accumulation of fibrin and inflammatory cells (neutrophils and plasma cells) in the anterior chamber. Similar inflammatory cells infiltrated the iris, ciliary body, corneoscleral limbus and conjunctiva.

Experimental model of chronic osteomyelitis caused by Leishmania (L) amazonensis.

Experimental animal models have been used for the study of the physiopathogenesis of leishmaniasis, on some occasions with success, while in other situations such as bone alterations that accompany tegumentary leishmaniasis, especially in diffuse cutaneous form (DCL), the mechanisms are still unknown. In the present study, we determined these alterations in an animal model susceptible to Leishmania (L) amazonensis. Amastigotes of L. (L) amazonensis isolated from patients with diffuse cutaneous leishmaniasis (DCL) were inoculated into the hind paws of eight BALB/c mice, macroscopic and histopathological aspects were analyzed. After 90 and 120 days of evolution, histopathological analysis demonstrated a mononuclear cell infiltrate rich in plasma cells and intense parasitism of intra- and extra-medullary macrophages, with areas of bone necrosis and discrete involvement of cartilaginous tissue. The results show that the inflammatory process developed during L. (L) amazonensis infection might cause bone tissue destruction and secondarily affect the joints.

Osteolytic osteomyelitis associated with visceral leishmaniasis in a dog.

A dog was examined with a history of weight loss and lameness of the left hind limb. A painful response to examination of the left hip joint, and lymphadenopathy were noted. Amastigote forms of Leishmania sp. were observed by cytology in samples from the popliteus lymph node, and anti-Leishmania sp. antibodies at a titer of 1:640 were detected in serum by indirect immunofluorescence. Radiological changes included osteolysis and a periosteal proliferative reaction in the left femoral greater trochanter. These changes were histologically characterized as an osteolytic granulomatous osteomyelitis associated with amastigotes within macrophages. Non-decalcified fragments of the periosteum were processed for immunohistochemistry, observed with prominent immunolabelling of amastigotes of Leishmania sp. within macrophages. The diagnosis was further confirmed by positive PCR for Leishmania sp., belonging to the Leishmania donovani complex.

Management of leishmanial osteolytic lesions in a hypothyroid dog by partial tarsal arthrodesis.

A five-year-old male boxer, previously diagnosed with leishmaniasis and hypothyroidism, had gradually become unable to bear weight on its left hindlimb. Physical examination revealed a left popliteal lymphadenopathy, mild crepitus, and severe swelling of the left tarsal joint, a radiographic examination of which revealed severe bone destruction of the talus and a periosteal reaction of the calcaneus. Laboratory findings and serological tests suggested an active leishmanial infection, and a Leishmania species was identified by direct cytology of a sample from the osteolytic area and by indirect immunohistochemistry of a bone biopsy. The dog's condition improved when it was treated with meglumine antimonate and allopurinol. Because of the large osteolytic area and the increased use of the affected leg, a partial tarsal arthrodesis was performed to prevent a fracture. Five months after the surgery, the osteolytic area had healed completely and the calcaneus periosteal reaction had disappeared.

Papillomatous pastern dermatitis with spirochetes and Pelodera strongyloides in a Tennessee Walking Horse.

Papillomatous digital dermatitis is a common disease in cattle. The pastern dermatitis observed in a horse shared many of the gross characteristics of papillomatous digital dermatitis in cattle. Lesions included a mixture of proliferative and erosive changes, with a verrucose appearance in some areas. Microscopic similarities included pseudoepitheliomatous and papillomatous epidermal hyperplasia with hyperkeratosis, spongiosis of the epidermis, and intraepidermal spirochetes. The horse was also concurrently infected with Pelodera strongyloides. Papillomatous digital dermatitis in cattle is associated with poor husbandry practices. The environment of the affected horse was heavily contaminated with urine, manure, and other organic debris. Verrucous pododermatitis of horses may be the same as or similar to bovine papillomatous digital dermatitis, and these conditions have similar etiologies.

Morphological clues from multilegged frogs: are retinoids to blame?

Morphological analysis was performed on multilegged deformed frogs representing five species from 12 different localities in California, Oregon, Arizona, and New York. The pattern of duplicated limbs was consistent with mechanical perturbation by trematode infestation but not with the effects of retinoids.

The effect of trematode infection on amphibian limb development and survivorship.

The causes of amphibian deformities and their role in widespread amphibian declines remain conjectural. Severe limb abnormalities were induced at high frequencies in Pacific treefrogs (Hyla regilla) exposed to cercariae of a trematode parasite (Ribeiroia sp.). The abnormalities closely matched those observed at field sites, and an increase in parasite density caused an increase in abnormality frequency and a decline in tadpole survivorship. These findings call for further investigation of parasite infection as a cause of amphibian deformities in other sites and species.

Epizootic podoknemidokoptiasis in American robins.

Epizootics of scaly leg disease caused by infection with the submacroscopic mite Knemidokoptes jamaicensis (Acari: Knemidokoptidae) in migratory American robins (Turdus migratorius) from a residential area of Tulsa (Oklahoma, USA) are documented during the winters (December through February) of 1993-94 and 1994-95. Estimates of 60 to > 80% of the birds in several different flights arriving in the area had lesions consistent with knemidokoptic mange. Epizootic occurrence of K. jamaicensis also is confirmed incidentally in American robins from Georgia (USA) in 1995 and 1998 and in Florida (USA) in 1991. These are the first confirmed epizootics of scaly leg attributed to infections with mites specifically identified as K. jamaicensis in North America. Severity of observed lesions in American robins ranged from scaly hyperkeratosis of the feet and legs to extensive proliferative lesions with loss of digits or the entire foot in some birds. Histologically, there was severe diffuse hyperkeratosis of the epidermis which contained numerous mites and multifocal aggregates of degranulating to degenerating eosinophilic heterophils; there was mild to severe superficial dermatitis with aggregates of eosinophilic heterophils and some mononuclear cells. Based on limited data from affected captive birds in Florida, we questioned the efficacy of ivermectin as an effective acaricide for knemidokoptiasis and propose that conditions associated with captivity may exacerbate transmission of this mite among caged birds. While knemidokoptic mange apparently can result in substantial host morbidity and possibly mortality, the ultimate impact of these epizootics on American robin populations presently is unknown.

A morphological study of the effects of liposomized albendazole on the muscle phase of Trichinella spiralis in mice.

The pathomorphological effects of daily and weekly doses of liposomized albendazole on Trichinella spiralis larvae have been examined and compared during the course of muscle infections in mice. Treatment with three and six daily doses of the drug given by intraperitoneal injection to mice resulted in marked pathological alterations to encapsulated larvae, mainly in the walls of the capsules. There was a 5% efficacy against T. spiralis in mice given three daily doses of albendazole, and 38% efficacy in mice given six daily doses of the drug. The same doses of drug, when administered weekly, did not reduce the numbers of parasite larvae, and the application of drug at 6-weekly intervals resulted in a 5% reduction in numbers.

Recovery, distribution, and development of Acanthocheilonema viteae third- and early fourth-stage larvae in adult jirds.

Living third- and fourth-stage larvae (L3 and L4) of Acanthocheilonema viteae were recovered quantitatively from adult Meriones unguiculatus within the first 10 days after subcutaneous inoculation of 60 arthropod-derived larvae (mL3). The average recovery of the inoculated larvae was about one third (28.5%), and the majority (87.7%) were found in muscular tissues. Seventy-two hours after inoculation, larvae could be isolated from all body locations, although the majority still was found near the site of inoculation. Morphological and biometrical data indicated that, at least until molting, the development of the larval population was not synchronous, with molting occurring over a period of 48 hr on days 7 and 8 postinoculation. The stomatal rings of postinvasive L3's and L4's were distinguishable structurally and could be used as stage-specific determinants. Immediately after infection, L3's showed a linear growth in diameter; rapid longitudinal growth started after the molt, leading to a doubling in the length of L4's within 4 days. The time course of shedding was reconstructed in detail using isolated L3/L4 intermediates.

Pathology and epizootiology of Dirofilaria scapiceps (Leidy, 1886) (Nematoda: Filarioidea) in Sylvilagus floridanus (J.A. Allen) and Lepus americanus erxleben.

Dirofilaria scapiceps was found between the synovial sheath and tendons, i.e., within the tendon sheath, in the ankle region of eastern cottontail rabbits (Sylvilagus floridanus) and snowshoe hares (Lepus americanus). In cottontail rabbits, tendons and sheaths appeared normal and all worms were adults. Only one (4%) of 24 infected rabbits contained dead worms. All female worms were gravid in rabbits killed in late winter or early spring. Microfilaremias in rabbits were high (approximately 30-100 microfilariae/60 microliter blood) and of long duration (at least 8-28 mo), and rabbits were considered normal hosts of D. scapiceps. In some snowshoe hares, tendons and sheaths also appeared normal; however, in other hares a chronic proliferative tenosynovitis, characterized by fibrinous exudate, hyperplasia and hypertrophy of the intima and inflammatory cell (predominantly lymphocytes and plasma cells) infiltration of the intimal and fibrous layers of the synovial sheath led to encapsulation of worms. Dead subadult, dead adult, and live adult worms were found in the ankles of hares; 86 (46%) of 186 infected hares contained some or only dead worms. Fibrosis commonly occurred around dead worms. Dead subadults were also found in subcutaneous connective tissues over the trunk of the body. Degenerate embryos and amorphous material were observed in uteri of some female worms in hares killed in late winter or early spring. Few (1-5 microfilariae/60 microliter blood) or no microfilariae were observed in the peripheral blood of hares and microfilaremias were of short duration (less than 8 mo). Microfilariae in hares are probably trapped and destroyed in the chronic inflammatory lesions in the tendon sheaths since normal, degenerate, and calcified microfilariae were observed in the capsules around adult worms. Some microfilariae might also be destroyed in lymph nodes. Although D. scapiceps can be maintained within snowshoe hare populations, hares are considered abnormal hosts of D. scapiceps. Dirofilaria scapiceps may have spread from cottontail rabbits to snowshoe hares relatively recently.

Maseria vespertilionis n.g., n.sp. (Dorylaimina : Muspiceidae), a nematode from nearctic bats (Vespertilionidae).

Maseria vespertilionis n. g., n. sp. (Dorylaimina : Muspiceidae) is described from nearctic bats (Vespertilionidae). In addition to the type host, Eptesicus fuscus (P. de Beauvois), in Oregon, M. vespertilionis was recorded from Myotis volans (Allen) in Oregon, and from M. lucifugus (Le Conte) in Oregon and Alaska. The nematode was found only in subcutaneous tissues near the plantar surface of the rear feet of the host. The genus Maseria is distinguished from other genera in Muspiceidae by various morphological characteristics, among which the presence of a Demanian system is important. The lesions produced in the feet of the host are described, and other biological characteristics of the nematode are discussed.