Optimizing cryptosporidium treatment in neonatal calves

Cryptosporidiosis, a parasitic disease frequently affecting neonatal calves, presents a significant challenge for both animal health and economic productivity on farms [1]. Characterized by diarrhoea and reduced growth rates [2, 3], it poses ongoing concerns for cattle farmers worldwide [4]. While paromomycin has been recognized as a cryptosporidium treatment option, the optimal dosage for effectively combating the disease has been unclear. A recent study by Ceva Santé Animale and the University of Veterinary Sciences Brno provides valuable insights into this question [5].

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How does dosage influence cryptosporidium treatment effectiveness? 

This study examined the effects of three doses of paromomycin administered to 35 Holstein calves experimentally infected with Cryptosporidium parvum. The calves were divided into four groups: 

• One untreated control group (9 calves)
• Three groups treated with doses of 75 mg/kg (9 calves), 100 mg/kg (8 calves), and 150 mg/kg of paromomycin daily for five days (9 calves)

Researchers tracked clinical signs, fecal consistency, hydration, weight gain, and oocyst counts over a 21-day period to evaluate the treatment’s effectiveness.

Key findings: higher dosages improve cryptosporidium treatment outcomes

The results indicated that dosage significantly affects treatment outcomes:

• Clinical recovery: at 24 hours post-treatment, 88.9% of calves receiving 150 mg/kg were classified as clinically cured, compared to 62.5% in the 100 mg/kg group and 44.4% in the 75 mg/kg group. None of the untreated calves achieved recovery during the same timeframe.
• Reduction in diarrhea: calves treated with 150 mg/kg exhibited the most substantial reduction in diarrhea, with odds ratios indicating they were over five times less likely to display symptoms compared to the control group. Lower doses showed diminishing effects, with the 75 mg/kg dose having no measurable impact on diarrhea rates.
• Improved growth: weight gain was another key metric. The group treated with 150 mg/kg achieved a mean daily body weight gain (MDBWG) of 0.67 kg/day, compared to 0.53 kg/day in untreated calves. Lower doses did not result in significant improvements

Implications for farm management

This study reinforces the importance of using an appropriate neodosage for effective treatment. The highest dose of 150 mg/kg demonstrated superior benefits, including clinical recovery, reduced diarrhea, and better growth rates. These findings suggest that a higher dose of paromomycin can play a pivotal role in managing cryptosporidiosis, contributing to improved animal welfare and farm productivity.

Take-home messages

• Cryptosporidiosis remains a leading neonatal disease, affecting calf health, growth, and farm sustainability.
• Paromomycin at 150 mg/kg for five days showed the best outcomes for recovery, diarrhea reduction, and growth performance.
• Correct dosing and early intervention are essential for effective cryptosporidium treatment and animal welfare.
• Integrating optimized therapy with good hygiene and management strengthens overall herd resilience.

References

[1] Roblin M, Canniere E, Barbier A, Daandels Y, Dellevoet-Groenewegen M, Pinto P, Tsaousis A, Leruste H, Brainard J, Hunter PR, Follet J. Study of the economic impact of cryptosporidiosis in calves after implementing good practices to manage the disease on dairy farms in Belgium, France, and the Netherlands. Curr Res Parasitol Vector Borne Dis. 2023 Oct 10;4:100149. https://doi.org/10.1016/j.crpvbd.2023.100149

[2] Shaw HJ, Innes EA, Morrison LJ, Katzer F, Wells B. Long-term production effects of clinical cryptosporidiosis in neonatal calves. Int J Parasitol. 2020 May;50(5):371-376. https://doi.org/10.1016/j.ijpara.2020.03.002

[3] Renaud DL, Rot C, Marshall J, Steele MA. The effect of Cryptosporidium parvum, rotavirus, and coronavirus infection on the health and performance of male dairy calves. J Dairy Sci. 2021 Feb;104(2):2151-2163. https://doi.org/10.3168/jds.2020-19215

[4] Buchanan R, Wieckowski P, Matechou E, Katzer F, Tsaousis AD, Farré M. Global prevalence of Cryptosporidium infections in cattle: A meta-analysis. Curr Res Parasitol Vector Borne Dis. 2025 May 8;7:100264. https://doi.org/10.1016/j.crpvbd.2025.100264

[5]. D. Achard N. Isaka M. Cron A. Goujas T. Blondel J-F. Collin J. Smola B. Koudela. Comparative efficacy of three different doses of paromomycin administered orally to treat cryptosporidiosis in experimentally infected dairy calves. XXII World Buiatric Congress, Cancun, 2024.