Staphylococcus pseudintermedius septicemia in puppies after elective cesarean section: confirmed transmission via dam’s milk

Abstract

BackgroundIn humans, transmission of bacteria causing fatal sepsis in the neonates through mother’s milk has been reported. In dogs, it is believed that bacteria from canine milk are not the primary cause of neonatal infections. Staphylococcus pseudintermedius is colonizing the skin and mucocutaneous junctions in adult dogs and can act as an opportunistic pathogen. This bacterium was previously isolated from the canine milk and, although, its transmission from the dam’s milk to the newborn puppies causing a neonatal sepsis was suggested, this hypothesis has not been confirmed.Case presentationA 4.5-year-old healthy Boston terrier dam had an elective cesarean section, delivering five normal puppies and one dead runt. Next day, two puppies developed pustules on their legs and around the muzzle. After two more days, strings of blood were noticed in the stool of the biggest puppy that suddenly died later that night. The same day, blood became visible in the feces of all other puppies. Necropsy of the dead puppy revealed a distended abdomen, catarrhal gastroenteritis with lymphadenopathy, dark red and slightly firm lung, mild dilatation of the right heart chamber and congestion of the liver, spleen, pancreas and meninges. The thoracic cavity contained white-yellow slightly opaque exudate, and there was transudate in the abdominal cavity. Histopathology revealed an acute interstitial pneumonia and multifocal myocardial necrosis with mineralization. Bacteriology of the internal organs, body cavity effusions of the dead puppy and dam’s milk revealed a diffuse growth of S. pseudintermedius in pure culture. Whole genome sequencing (WGS) revealed that all isolates belonged to the sequence type 241 and differed in 2–5 single nucleotide polymorphisms; thus, the epidemiological link between the outbreak-associated isolates was confirmed.ConclusionsThis is the first report of a confirmed transmission of S. pseudintermedius through dam’s milk causing a neonatal sepsis in a puppy after an elective cesarean section. The epidemiological link between S. pseudintermedius isolates obtained from dam’s milk and internal organs of the affected puppy was confirmed by WGS. Our findings indicate that milk of healthy dams can serve as a reservoir of bacteria that can cause fatal sepsis in the newborn puppies.

Lactation‐related mammary gland pathologies—A neglected emergency in the bitch

“…As pathogens responsible for septicaemia in pups are seldom responsible for mammary gland infections (Root Kustritz, 2010), early weaning is not advised since it promotes galactostasis (Davidson, 2017). However, some reports show that puppies can be affected due to the ingesta of infected milk (Schäfer‐Somi et al., 2003; Vasiu, Pop, Chirilă, et al., 2017; Zakošek Pipan et al., 2019). Keeping in mind the age of the neonates, puppies should only be removed and hand raised, with milk replacers, if the mammary glands and health status of the bitch are deteriorating, if the bitches are nervous or present pain, or if other side effects, from antibiotic‐treated milk, like transient diarrhoea in pups, are present (Barsanti, 2012; Bassu, 2017; Biddle & Macintire, 2000; Kirk, 2008).…”

The Complex Diseases of Staphylococcus pseudintermedius in Canines: Where to Next?

“…While, in many cases, such transmission results in the healthy colonisation of commensal S. pseudintermedius , in the puppies, it has been shown that the transmission of S. pseudintermedius , specifically MRSP, has been associated with premature death within the first 2–3 weeks of life, also known as neonatal mortality [ 66 , 79 , 80 , 81 ]. Multiple studies have reported outbreaks of neonatal mortality due to septicaemia, with S. pseudintermedius or MRSP isolated from the blood or organs of all deceased puppies [ 66 , 79 , 82 ]. Interestingly, it was found that S. pseudintermedius strains collected from the organs of puppies were found to be linked to isolates from the mother’s milk and vaginal samples, therefore indicating that the vertical transmission of pathogenic S. pseudintermedius can result in fatal sepsis in puppies [ 79 , 82 ].…”

“…Multiple studies have reported outbreaks of neonatal mortality due to septicaemia, with S. pseudintermedius or MRSP isolated from the blood or organs of all deceased puppies [ 66 , 79 , 82 ]. Interestingly, it was found that S. pseudintermedius strains collected from the organs of puppies were found to be linked to isolates from the mother’s milk and vaginal samples, therefore indicating that the vertical transmission of pathogenic S. pseudintermedius can result in fatal sepsis in puppies [ 79 , 82 ]. However, the cause of neonatal mortality is multifactorial and, in addition to infections, congenital defects and low birth weight may also contribute to neonatal mortality [ 83 ].…”

A Review on Bacterial Infectious Diseases of Dogs

“…S. pseudintermedius spreads to neonates through dam's milk that has undergone cesarean section and causes neonatal septicemia resulting in mortality. Lesions are usually present on the omentum, footpad, and dermatitis called black spot disease [18].…”