Department of Veterinary Clinical Medicine Ethics and Jurisprudence, CVAS, RAJUVAS, Bikaner-334001
Canine distemper (Caress diseases) is a viral disease of dogs, caused by a morbilivirus and often associated with diphasic fever and leukopenia among other clinical signs. The canine distemper virus is pantropic and causes immunosuppression. These two features of the disease lead to varied clinical signs. Thus, it is often not easy to differentiate canine distemper from other diseases of dogs with similar symptoms. Haematology is one of the diagnostic methods often employed for both tentative diagnosis and at times it can be used even for confirmation of diagnosis. To investigate the effect of distemper virus on haematology, seven dogs suffering from the diseases were selected. Confirmation of disease was done by Canine Distemper Ag Detection Kit, Intas Animal Health, Ahmedabad. 2.5 ml blood from each dog was collected in EDTA and used to determine the Haemoglobin (Hb), Packed cell volume (PCV), Total white blood cell count (TLC). Smears of blood samples were made on grease-free glass slides and stained with giemsa's stain for 15 minutes to analyze Differential white blood cell count (DLC). The mean values of the haematological parameters of the canine distemper infected groups showed 10.14 ± 2.48 gm % Hb, 30.46 ±4.25% PCV, 10.28 ± 4.68 (103/cub mm) TLC, 3.69 ± 0.90 (lac/cu mm) platelets and 6.21 ± 1.43 TEC(106/cub mm). DLC showed 72± 4.69% neutrophil, 23.14 ± 12.32% lymphocyte, 3.29 ± 1.83% monocytes and 0.71 ± 0.88% eosinophils. The lowering of the values of the total red blood cell count and packed cell volume seen in the canine distemper infected dogs suggests that disease causes anemia. Canine distemper virus is known to persist in bone marrow of infected patients, which may cause erythriod hypoplasia and thus may be the cause of the anemia. Also canine distemper infection causes release of interleukin-6 which causes sequestrating of iron into a less available form, thus iron may not have been available to the developing reticulocytes. Other possible causes of the anaemia observed in the canine distemper infected dogs could be production of inflammatory mediators, which could inhibit erythropoesis and also shorten RBC life span. The viral multiplication in the lymph node may be responsible for the initial lymphopaenia and the consequent leucopaenia. The result also showed that after the initial leucopaenia, there was lymphocytosis and thus leucocytosis. So, both lymphopaenia and lymphocytosis are features of canine distemper. In early cases, lymphopenia could be expected while late cases are characterized by lymphocytos is.
