Förekomst av salmonella spp hos katter i Sverige
Salmonella in cats has been documented for many years. Infection with S. Typhimurium,which is often referred to as Songbird fever, is believed to be caused by birds whoinadvertently infect cats. The disease is often seen during the springtime when songbirdsreturn from their winter habitats, while other birds who have stayed during the winter are intheir weakest condition of health. In the spring of 1999 an epidemic of S. Typhimurium incats was recorded in Karlstad in Sweden and the National Veterinary Institute in Uppsala,Sweden has in addition documented hundreds of cases of S. Typhimurium in cats over the lastcouple of years.Two studies were performed to look at Salmonella in cats in Sweden. The first study included56 cats, some were privately owned outdoor cats and some were homeless cats recentlyadopted into shelters. Fecal samples were collected in March 2007 in the Stockholm andUppsala areas. The laboratory tests showed that one of the 56 cats was positive forSalmonella. This cat which was staying at an animal shelter excreted S. Typhimurium but itdid not show any symptoms of disease. All of the cats included in the study had beenoutdoors for a period of time shortly before being testing.The second study was done retrospectively. It included all of the samples from cats sent to theSwedish National Veterinary Institute for Salmonella testing during the year 2006. This studyshowed that 46 % (68 of 148) of the samples were positive for Salmonella spp. All of thepositive samples but one were identified as S. Typhimurium. Furthermore one S.Typhimurium was typed as DT40 and the last Salmonella spp. was identified as being S.Enteritidis NST.The time of infection supports the theory that the cats carrying S. Typhimurium were infectedby songbirds. All of the samples that were positive for S. Typhimurium were collectedbetween January and June 2006. The majority of the positive samples (90 %) were collectedbetween January and April. The largest number (43 %) of infected cats was documented inApril.Symptoms shown by infected cats agree with the results of studies concerning Songbird fever.The most common symptoms in ascending order were; fever, vomiting, depression, anorexia,diarrhea and abdominal pain.The distribution of cases of Songbird fever was unevenly distributed in Sweden. StockholmCounty, which has the largest insured population of cats in Sweden, according to Agriastatistics, had the largest number of cases. It appears that Uppsala and Gävleborg County hada larger number of cases than expected when compared to the distribution of insured cats inSweden. The reasons for this can be many. Maybe the distribution of the bacteria varies. It isalso possible that cat owners´ motivation for going to the vet varies. Routines involved insample testing and levels of knowledge may also vary between different parts of the country.The number of unrecorded cases of Salmonella in cats in Sweden could very well be quitehigh.