The study was performed to identify the bacterial causes of tonsillitis in dogs.Twelve clinical cases of dogs (5 males Engine Oil Cooler and 7 females) of different ages and breeds were observed.Tonsils swabs were taken from all the dogs, then cultured on different agars and bacterial smears prepared from all cultures and Gram stains were done.The study confirmed that the most bacterial causes of tonsillitis in dogs were Escherichia coli, Staphylococcus aureus, Staphylococcus Star Wars intermedius, Staphylococcus albus, Streptococcus pyogenes, Klebsiella spp.
and Pasteurella spp.