Serum, milk and saliva cytokines in canine pseudopregnancy. A pilot study

The measurement of cytokines in serum, milk, and saliva is advancing rapidly, especially for non-invasive health monitoring, stress evaluation, and disease diagnosis in bitches. This study aimed to evaluate the potential of a cytokine panel in serum, milk, and saliva in bitches with pseudopregnancy (PSG; n = 11) and compare their values to those observed in bitches with subclinical mastitis (SM; n = 7) and healthy lactating bitches (n = 6). Results showed that, in serum, only keratinocyte-derived chemokine (KC)-like protein levels differed significantly between groups (P < 0.05), being lower in pseudopregnancy and subclinical mastitis compared to healthy dogs (P < 0.05). Conversely, in milk, bitches with pseudopregnancy had higher levels of GM-CSF, IFNg, IL2, IL7, IL10, IL15, IL18, IP10, and TNFalpha than those with SM or healthy controls. These findings indicate that pseudopregnancy, a common clinical condition, involves a significant localized inflammatory response and should be actively managed rather than regarded as purely physiological.