Respiratory affections are important clinical problems recorded in dogs and cats affecting their health condition. This study was carried out on a total of 84 animals including 32 dogs and 52 cats of both sexes and different breeds suffering from different respiratory affections including pneumonia, aspiration pneumonia, Feline upper respiratory diseases(FURD) and Canine infectious respiratory disease(CIRD). Clinical, hematological, biochemical and radiographic changes during these affections were evaluated. In addition the most common incriminated bacteria was isolated and identified. The affected cases showed variable respiratory signs including dyspnea, nasal and ocular discharge, sneezing, cough, abnormal respiratory sound and abnormal lung sound. Hematological changes showed inflammatory leukogram represented by increasing in WBCs and neutrophil count Serum analysis showed marked increase in CRP, SAA and HP levels, with hyperproteinemia and hypoalbuminemia compared to reference value. The most common bacteria isolated from pneumonic cases were Klebsiella(29.1%), E.coli (20.8%), Staph. (16.6%), Pseudomonas (21.5%), Pasteurella (21.5%) Proteus and Serratia(8.3%). Radiographic examinations revealed abnormal radiographic patterns associated with the different affections. The present study concluded that clinical, hematological, biochemical combined with chest radiographic findings are essential for precise diagnosis of different respiratory affections in dogs and cats and the early diagnosis facilitate the prescription of relevant therapy and follow up procedures.