Subcutaneous abscesses and arthritis caused by a probable bacterial L-form in cats

Three cats in one household developed pyogenic subcutaneous abscesses and arthritis over a period of 9.5 months. Despite vigorous surgical and antibiotic treatment, the infections in each of these cats continued to spread locally and hematogenously to involve other joints and subcutaneous sites. Although the infections did not respond to modern broad-spectrum antibiotics, they were susceptible to tetracycline. In spite of a favorable response to tetracycline, all 3 cats were euthanatized. A causative agent could not be identified by microbiologic culture of tissues obtained prior to death and at necropsy, or with special tissue stains. The infection was transmitted experimentally by sc inoculation with cell-free material from one of the naturally infected cats to a specific-pathogen-free cat. A tissue extract from the experimentally infected cat was, in turn, infectious for another specific-pathogen-free cat. The experimentally induced lesion was a rapidly enlarging necrotizing and pyogenic cellulitis and panniculitis, with no demonstrable causative agent by special tissue stains or microbiologic culture. A probable bacterial L-form was visualized in affected tissues of the experimentally infected cats and propagated in special L-form broth. Like the natural disease, infection in experimentally inoculated cats was progressive in nature, but could be treated successfully with tetracycline.     

Clinical haematology and biochemistry profiles of cattle naturally infected with Theileria orientalis Ikeda type in New Zealand

AIMS: To present the haematology and biochemistry profiles for cattle in New Zealand naturally infected with Theileria orientalis Ikeda type and investigate if the results differed between adult dairy cattle and calves aged <6 months.

METHODS: Haematology and biochemistry results were obtained from blood samples from cattle which tested positive for T. orientalis Ikeda type by PCR, that were submitted to veterinary laboratories in New Zealand between October 2012 and November 2014. Data sets for haematology and biochemistry results were prepared for adult dairy cattle (n=62 and 28, respectively) and calves aged <6 months (n=62 and 28, respectively), which were matched on the basis of individual haematocrit (HCT). Results were compared between age groups when categorised by HCT. Selected variables were plotted against individual HCT, and locally weighted scatterplot smoothing (Loess) curves were fitted to the data for adult dairy cattle and calves <6 months old.

RESULTS: When categorised by HCT, the proportion of samples with HCT <0.15 L/L (severe anaemia) was greater for adult dairy cattle than for beef or dairy calves, for both haematology (p<0.002) and biochemistry (p<0.001) submissions. There were differences (p<0.05) between adult dairy cattle and calves aged <6 months in the relationships between HCT and red blood cell counts, mean corpuscular volume, mean corpuscular haemoglobin, mean corpuscular haemoglobin concentrations, lymphocyte and eosinophil counts, and activities of glutamate dehydrogenase and aspartate aminotransferase. In both age groups anisocytosis was frequently recorded. The proportion of blood smears showing mild and moderate macrocytosis was greater in adults than calves (p=0.01), and mild and moderate poikilocytosis was greater in calves than adults (p=0.005).

CONCLUSIONS AND CLINICAL RELEVANCE: The haematology and biochemistry changes observed in cattle infected with T. orientalis Ikeda type were consistent with extravascular haemolytic anaemia. Adult dairy cattle were more likely to be severely anaemic than calves. There were differences in haematology and biochemistry profiles between adult dairy cattle and calves, but most of these differences likely had a physiological rather than pathological basis. Overall, the haematological changes in calves aged <6 months appeared less severe than in adult dairy cattle.