The most important laboratory findings were a severe or moderate increase in gammaglobulins, hypoalbuminaemia, hyperproteinemia and anaemia. Another six dogs had severe renal failure without systemic clinical signs of leishmaniasis. The acute form of the disease was diagnosed in only six dogs and was characterised by fever and generalised lymphadenomegaly, and by the absence of skin lesions. Ocular signs were observed in 24 dogs (16 per cent) including 16 cases of keratoconjunctivitis (three with keratoconjunctivitis sicca), six cases of moderate uveitis and two cases of panophthalmitis. Skin abnormalities were very common, and included dry exfoliative dermatitis (56 per cent), ulcers (40 per cent) periorbital alopecia ('lunettes') (18 per cent), diffuse alopecia (14 per cent) and onychogryphosis (24 per cent). They showed generalised (56.7 per cent) or symmetrical (32 per cent) lymphadenomegaly the mucous membranes of 87 of the dogs (58 per cent) were pale and moderate or severe splenomegaly was diagnosed in 80 dogs (53.3 per cent) weight loss was observed in 32 per cent of the animals. The majority of the dogs were mongrels (43.3 per cent), male (64.7 per cent), of medium size (50.6 per cent), three to seven years old (64.7 per cent), and living outdoors (60 per cent). There was a gradual onset of clinical signs and the course of the disease was progressive in almost all the cases. The clinical and laboratory findings observed in 150 dogs naturally infected by Leishmania infantum, from a large endemic area of southern Italy, are described. Conversely, microscopy and conventional serology are frequently negative in asymptomatic infected dogs to identify such dogs, polymerase chain reaction, evaluation of cutaneous delayed-type hypersensitivity, in vitro lymphocyte proliferation test to Leishmania antigen, and Western blotting may be employed. From a diagnostic point of view, although clinical cases are readily identified using microscopy and serology, investigation should not stop at this point and an extensive search for underlying diseases is advised, especially in aged dogs. Resistance or susceptibility is not an all-or-nothing phenomenon and many intermediate phenotypes may be found. Susceptibility may be genetically determined or acquired (advanced age, concurrent diseases) in these dogs, parasite multiplication goes unrestricted and overproduction of specific and nonspecific antibodies occurs, leading to multiple organ pathology. Resistance may be breed-associated it is characterized by low to undetectable antibody production and effective cell-mediated immunity, and is orchestrated by cytokines such as interleukin-2, interferon-gamma and tumour necrosis factor-alpha. The outcome of the infection depends on host factors (genetic background, cell-mediated and humoral immune response, cytokine milieu, concurrent diseases) and parasite virulence. Amastigotes are transported via infected macrophages to the regional lymph nodes and finally dissemination may occur. The interaction between the parasite and skin immune system is influenced by the repeated infectious bites and the simultaneous intradermal injection of sandfly saliva. Parasite transmission occurs via female sandflies that inject promastigotes into the skin of the host. chagasi) is an important zoonosis with a complex pathogenesis. Canine leishmaniosis caused by Leishmania infantum (Syn.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |