Cryptosporidiosis, caused by Cryptosporidium parvum, is a pervasive disease in neonatal dairy calves, leading to severe diarrhoea, dehydration, and high mortality rates. The economic impact on the dairy industry is substantial, driven by increased veterinary costs, reduced growth rates, and long-term productivity losses. Effective control strategies are crucial to mitigate these impacts and ensure the health and welfare of affected calves.
One promising approach is the use of paromomycin sulphate, an aminoglycoside, which has shown efficacy in reducing the incidence and severity of cryptosporidiosis when administered to at-risk neonatal calves. By targeting the parasite during the early stages of infection, paromomycin sulphate can significantly improve calf survival and growth outcomes, thereby enhancing overall herd productivity.
The study by Vasquez Flores et al. (2024), performed in Mexico, demonstrates the above benefits in field conditions and compares them with standard alternative treatment protocols.
Materials and methods
A total of 120 newborn female calves were included in the studies from three different private dairy facilities. The study sites were in northern Mexico (S1), central Mexico (S2) and western Mexico (S3; Table 1). Calves were raised in individual crates and randomly assigned at birth to one of the treatment groups. The treatments were as follows (Table 1):
- the control (C) - calves received the antibiotic treatment of choice for scours at the dairy site
- commercial treatment against Cryptosporidium (T1a and T1b - halofuginone)
- paromomycin sulphate (Parofor®) at 50 mg/kg body weight for 7 days (T2)
A daily scoring system was used to record diarrhoea for the first 60 days of life. Faeces were collected at 7 and 14 days of age and analysed morphologically. Calves had their weight measured at birth, 60 days (S2 and S3), 90 days (at S1 and S3), and 120 days (at S2). All calves received pasteurized colostrum, and the total population received pasteurized milk until 55 days of age.
Results
Table 2 summarises the results from the three dairy facilities. Parofor® showed better weight gain and a faster reduction in Cryptosporidium parvum oocyst prevalence.
Figure 1 shows the data collected from S3 relating to weight gain at 30(A) and 60(B) days in both treatment groups. The green line shows the Parofor® treatment group results, and the yellow line shows the halofuginone treatment group results.
Conclusion
In summary, the use of Parofor® (T2) during the peak of cryptosporidiosis infection resulted in a 34-50% reduction in oocyst shedding, supporting the development of local immunity with fewer clinical symptoms, maintained appetite, and a decrease in pneumonia cases.
Calves in the Parofor® (T2) group consistently demonstrated superior weight gain at 60, 90 and 120 days of age compared to those receiving prophylactic treatments for Cryptosporidium spp.
Effective control of cryptosporidiosis is further enhanced by ensuring strong passive immunity, providing higher levels of milk feeding, closely monitoring clinical cases, and implementing biosecurity measures alongside timely treatment interventions.
