Open Access
Research (Published online: 19-04-2023)
17. Clinical field trial of parenteral amoxicillin for the treatment of clinical and subclinical mastitis in smallholder dairy farms in the upper region of Northern Thailand
Noppason Pangprasit, Anyaphat Srithanasuwan, Montira Intanon, Witaya Suriyasathaporn, and Wasana Chaisri
Veterinary World, 16(4): 792-798

Noppason Pangprasit: Department of Livestock Clinics, Akkhraratchakumari Veterinary College, Walailak University, Nakhon Si Thamarat 80160, Thailand; Department of Food Animal Clinics , Faculty of Veterinary Medicine, Chiang Mai University, Chiang Mai 50100, Thailand.
Anyaphat Srithanasuwan: Department of Food Animal Clinics , Faculty of Veterinary Medicine, Chiang Mai University, Chiang Mai 50100, Thailand.
Montira Intanon: Research Center of Producing and Development of Products and Innovations for Animal Health, Chiang Mai University, Chiang Mai 50100, Thailand.
Witaya Suriyasathaporn: Department of Food Animal Clinics , Faculty of Veterinary Medicine, Chiang Mai University, Chiang Mai 50100, Thailand; Research Center of Producing and Development of Products and Innovations for Animal Health, Chiang Mai University, Chiang Mai 50100, Thailand.
Wasana Chaisri: Department of Food Animal Clinics , Faculty of Veterinary Medicine, Chiang Mai University, Chiang Mai 50100, Thailand; Research Center of Producing and Development of Products and Innovations for Animal Health, Chiang Mai University, Chiang Mai 50100, Thailand.

doi: 10.14202/vetworld.2023.792-798

Article history: Received: 15-11-2022, Accepted: 09-03-2023, Published online: 19-04-2023

Corresponding authors: Wasana Chaisri

E-mail: wasana.ch@cmu.ac.th/wasana_kosa@hotmail.com

Citation: Pangprasit N, Srithanasuwan A, Intanon M, Suriyasathaporn W, and Chaisri W (2023) Clinical field trial of parenteral amoxicillin for the treatment of clinical and subclinical mastitis in smallholder dairy farms in the upper region of Northern Thailand, Veterinary World, 16(4): 792-798.
Abstract

Background and Aim: Mastitis, primarily caused by intramammary bacterial infection, is the most expensive disease in the global dairy industry due to its negative impact on milk composition and manufacturing properties. This study aimed to evaluate the efficacy of parenteral amoxicillin in the treatment of clinical and subclinical mastitis in smallholder dairy farms in Northern Thailand.

Materials and Methods: A total of 51 cows with clinical and subclinical mastitis from dairy cooperatives in Lamphun and Chiang Mai provinces, Northern Thailand, were enrolled in this study. Conventional bacteriological procedures were applied to identify the causative bacteria in milk samples from these cows before and 7 days after treatment, and antibiotic susceptibility tests were conducted using the disk diffusion method for all bacteria isolated before treatment. All cows with mastitis were administered 15 mg/kg of amoxicillin (LONGAMOX®, Syva Laboratories SA, Spain) intramuscularly every other day for 3 days.

Results: Environmental streptococcal bacteria (Streptococcus uberis and Streptococcus spp.) were commonly isolated from infected quarters and were highly susceptible to amoxicillin (100%). The clinical efficacy of amoxicillin treatment for clinical mastitis cases was 80.43%, and the bacteriological efficacy was 47.82%, with opportunistic staphylococcal bacteria (coagulase-negative staphylococci) and contagious streptococcal bacteria (Streptococcus agalactiae) being the most sensitive microorganisms (100%). In subclinical mastitis cases, the bacteriological efficacy of parenteral amoxicillin was 70.45%, with environmental streptococcal bacteria (S. uberis) being the most (100%) sensitive microorganisms.

Conclusion: Amoxicillin is highly efficacious and can be used to treat clinical and subclinical mastitis in dairy cows, particularly mastitis caused by environmental Streptococcus spp. These findings could be used to guide treatment regimens in veterinary practice in smallholder dairy farms in Thailand.

Keywords: bacteriological cure, clinical cure, dairy cow, mastitis, parenteral amoxicillin.