Short- and long-term effects of amoxicillin/clavulanic acid or doxycycline on the gastrointestinal microbiome of growing cats

Abstract

Antibiotic treatment in early life influences gastrointestinal (GI) microbial composition and function. In humans, the resultant intestinal dysbiosis is associated with an increased risk for certain diseases later in life. The objective of this study was to determine the temporal effects of antibiotic treatment on the GI microbiome of young cats. Fecal samples were collected from cats randomly allocated to receive either amoxicillin/clavulanic acid (20 mg/kg q12h) for 20 days (AMC group; 15 cats) or doxycycline (10 mg/kg q24h) for 28 days (DOX group;15 cats) as part of the standard treatment of upper respiratory tract infection. In addition, feces were collected from healthy control cats (CON group;15 cats). All cats were approximately two months of age at enrolment. Samples were collected on days 0 (baseline), 20 or 28 (AMC and DOX, respectively; last day of treatment), 60, 120, and 300. DNA was extracted and sequencing of the 16S rRNA gene and qPCR assays were performed. Fecal microbial composition was different on the last day of treatment for AMC cats, and 1 month after the end of antibiotic treatment for DOX cats, compared to CON cats. Species richness was significantly greater in DOX cats compared to CON cats on the last day of treatment. Abundance of Enterobacteriales was increased, and that of Erysipelotrichi was decreased in cats of the AMC group on the last day of treatment compared to CON cats. The abundance of the phylum Proteobacteria was increased in cats of the DOX group on days 60 and 120 compared to cats of the CON group. Only minor differences in abundances between the treatment groups and the control group were present on day 300. Both antibiotics appear to delay the developmental progression of the microbiome, and this effect is more profound during treatment with amoxicillin/clavulanic acid and one month after treatment with doxycycline. Future studies are required to determine if these changes influence microbiome function and whether they have possible effects on disease susceptibility in cats.

Environmental risk factors in puppies and kittens for developing chronic disorders in adulthood: A call for research on developmental programming

“…The long-term effects of such treatment in puppies still establishing a normal gut microbiota needs to be explored in studies on developmental programming. A course of antibiotic treatment (20 or 28 days) in 2-month old cats with upper respiratory tract disease was shown to delay the maturation of their gut microbiota compared to healthy untreated cats (166). The duration of effects differed between antibiotics; the impact of amoxicillin-clavulanate on the microbiome occurred mainly during treatment, whereas the impact of doxycycline was observed from 1 to 3 months after antibiotic withdrawal (166).…”

The morbidity and the spectrum of applied drugs in shelter cats in the Czech Republic

“…A suitable choice of therapy is amoxicillin with clavulanic acid in combination with marbofloxacin ( 64 ). According to the available literature on the treatment of gastrointestinal diseases, it is generally appropriate to use, among others, amoxicillin with clavulanic acid, furthermore also doxycycline ( 65 ). The use of amoxicillin with clavulonic acid in the treatment of acute diarrhea was discussed by Werner et al ( 66 ) in dogs.…”

“…The results of their study showed that the effect of these antibiotics on the treatment of acute diarrhea has no benefit and increases the risk of Escherichia coli resistance. Stavroulaki et al ( 65 ) reported negative effect on the microbiome of cats when using amoxicillin/clavulanic acid or doxycycline. These antibiotics also slowed the development of the microbiome in growing cats.…”

Comparative Analyses of the Gut Microbiota in Growing Ragdoll Cats and Felinae Cats

“…At the initial enrollment, all the cats were observed for one week for any developing gastrointestinal diseases; all the cats were normally vaccinated and did not receive any antibiotic treatment. Additionally, no probiotics were provided to any of these cats prior to the study [ 22 ].…”