Distemper is a contagious, highly lethal, and almost incurable viral disease in dogs and other terrestrial carnivores. This study aimed to treat distemper in dogs with a novel method. Two healthy 10 and 12- month male dogs of mixed breed and weighed 31 and 33 Kg were prepared. A 1000-dose vial of Newcastle disease vaccine (Lasota strain) was then diluted in 6 ml normal saline and 3 ml of it was injected into the cephalic vein of each dog. Eleven hours later, the dogs were anesthetized and 20% of their blood volume was collected. Blood sera were separated and used as anti- Newcastle disease vaccine serum (ANDVS) to treat dogs suspected to have canine distemper. Dogs whose distemper was finally diagnosed by RT-PCR were grouped in the following seven treatment groups: 1- ANDVS; 2- ANDVS+ Cotrimoxazole; 3- ANDVS+ Penicillin-Gentamicin; 4- ANDVS+ Cefazolin-Amikacin; 5- Cotrimoxazole; 6- Penicillin-Gentamycin; 7- Cefazolin-Amikacin. Then the mortality rate of dogs, correlation between distemper and sex, breed, and age, and effects of distemper on hematological factors and vital signs were evaluated. The recovery rate in the ANDVS+ Cotrimoxazole and the ANDVS+ Cefazolin-Amikacin groups were higher than the ANDVS group (P<0.05). There was also a significant difference between the mortality rate in distemper positive and negative dogs. It is concluded that although ANDVS alone has no effect on the treatment of distemper, along with some antibiotics such as cotrimoxazole or cefazolin+ amikacin significantly improved the recovery rate compared to antibiotics used alone.