Skip to main content
Doctoral thesis, 2015

Bacterial infections in dogs with special reference to urinary tract infections, surgical site infections and methicillin-resistant Staphylococcus pseudintermedius

Windahl, Ulrika


An increase in antimicrobial resistance in canine bacterial pathogens, including multidrug-resistance, has been reported worldwide. Increasing antimicrobial resistance is of concern, not only as it complicates therapy in dogs, but also as it is a public health problem when the pathogens are zoonotic, or the location of resistance genes enables transfer between bacteria of animal and human origin. The overall aims of this thesis were to gain knowledge of bacterial infections in dogs with special reference to urinary tract infections (UTI), surgical site infections (SSI) and their antimicrobial susceptibility patterns, and of carriage of methicillin-resistant Staphylococcus pseudintermedius (MRSP). The results were intended to aid in choice of antimicrobial treatment of canine UTI and SSI, and in designing recommendations on prevention and control of carriage of MRSP. First-line antimicrobials were found to be a rational empirical antimicrobial therapy for the studied dog population. In total three percent of detected Escherichia coli isolates were resistant to extended-spectrum cephalosporins. Less than 3% of S. pseudintermedius isolates were methicillin resistant. No methicillin-resistant Staphylococcus aureus (MRSA) isolates were found. Dogs carried MRSP for several months without clinical signs. Systemic treatment for three weeks or longer with antimicrobials to which the bacterium was resistant was associated with prolonged carriage compared to shorter treatment periods. Three of five dogs treated with an antimicrobial to which the MRSP-isolates were susceptible remained MRSP-carriers. These findings support restricted use of systemic antimicrobial treatment in dogs with possible or confirmed MRSP carriage or infection. The risk of MRSP-colonization in dogs living in a household with an MRSP-infected dog might be lowered if the clinically infected dog (index dog) becomes MRSP -negative. Furthermore, all contact dogs in the family might not carry MRSP continuously during the time the index dog is MRSP-positive. The results of the evaluation of five body sites for MRSP carriage screening suggests that simultaneous sampling of pharynx, perineum and the corner of the mouth, as well as wounds when present, should be recommended. Furthermore, the results suggest that sampling of nostrils is not a priority when screening dogs for MRSP.


bacterial infections; canine; antimicrobial resistance

Published in

Acta Universitatis Agriculturae Sueciae
2015, number: 2015:56
ISBN: 978-91-576-8310-6, eISBN: 978-91-576-8311-3
Publisher: Department of Clinical Sciences, Swedish University of Agricultural Sciences

Authors' information

Windahl, Ulrika
Swedish University of Agricultural Sciences, Department of Clinical Sciences

UKÄ Subject classification

Microbiology in the medical area
Infectious Medicine
Clinical Science

URI (permanent link to this page)