A 4-year-old male Miniature Schnauzer was presented for annual vaccinations. Physical examination revealed marked enlargement of lymph nodes and a tumor-like mass in the cranial abdomen. These findings were confirmed with X-ray examination, in which a marked hepatomegaly was seen as well. Serum biochemistry was unremarkable except for slightly elevated alkaline phosphatase and slightly decreased total protein. In hematologic evaluation mild leukocytosis and mild anemia were present. Histopathological evaluation of the prescapular and popliteal lymph nodes revealed marked granulomatous inflammatory reaction composed oflarge macrophages with numerous intracytoplasmic acid-fast bacteria. The dog’s condition worsened dramatically during the following three weeks. It became anemic, lethargic, and anorectic. The owners decided to euthanize the animal because of the poor prognosis. Necropsy findings included marked enlargement of the lymph nodes, tonsils, spleen and liver. The tumor-like mass in the abdomen was in reality markedly enlarged mesenterial lymph nodes. Histopathologically severe granulomatous inflammation composed of macrophages was present in lymph nodes, tonsils, and in the gastrointestinal tract. Similar inflammatory infiltrates were present multifocally in the bone marrow, spleen and liver. Myriads of acid fast bacteria were seen within the cytoplasm of macrophages. The acid fast bacteria were cultured and identified as Mycobacterium avium-intracellulare.
Dogs are considered to be resistant to Mycobacterium avium complex (MAC) infections. As Miniature Schnauzers and Basset Hounds have been over-represented in the cases reported previously, a possibility of a genetic predisposition to MAC infection in these breeds has been suggested. Familial clustering of disseminated MAC infections has been reported in humans as well, and in recent studies a genetic defect of cellular immunity has been found in many of these cases. A possibility of a similar defect in the dogs suffering from disseminated MAC infection is discussed.
The domestication has hardly changed the behaviour of the horse. The living environment is though different from one of its wild ancestors. Difficulties to cope with the changed environment can lead to malbehaviour, such as weaving, crib-biting or self-mutilation,to mention a few. These can be inherited or learned behaviour problems or they can be caused by lack of roughage, exercise, social contacts or an adequate stimuli. Traditionally behaviour problems have been "treated" by physically preventing the unwanted behaviour. A better method would be alteration of the environmental factors causing the behaviour. Providing the horse more roughage, social contacts and adequate exercise usually improves the situation.
Salmonella Typhimurium phage type DT104 causes salmonellosis both in man and animals. Multiresistance to several antibiotics, such as ampicillin, tetracyclin, chloramphenicol, streptomycin, tetracyclin and sulphonamides is usually associated with this phage type. Isolates, which are resistant to trimethoprim and fluorokino-lines, are also commonly isolated. The antibiotic resistance genes are chromosomally integrated in S. Typhimurium DT104. That is why the withdrawal of the antibiotics would have no effect on the resistance of the strain.
Salmonella Typhimurium DT104 has been isolated from many species, for example cattle, pigs, chickens, cats, dogs and wild animals. The DT104 strain is especially the problem of cattle. Humans can get the infection from contaminated foods, such as beef. The infection can also be acquired by contact with infected animals. The DT104 can be more virulent than other S. Typhimurium strains.
Infections caused by S. Typhimurium DT104 strain have increased in last few years. The resistance of the strain has risen and approximately 90% of strains are multiresistant. In Finland, the DT104 strain was first isolated in 1995 from two cattle farms. Most of the infections in humans have been caught from foreign countries, but domestic infections are increasing.