Dental Fluorosis in Ruminants and Fluoride Concentrations in Animal Feeds, Faeces, and Cattle Milk in Nakuru County, Kenya

Nakuru County in Kenya is a known fluoride endemic area. The region is neighboured by fluoridated water bodies such as Lake Nakuru, Lake Naivasha, Lake Elementaita, and other underground water sources. Unfortunately, these water resources are frequently utilized by farmers as drinking water for their cattle and sheep. However, there is hardly any information concerning fluoride toxicity in these livestock. This gap informed this study to assess the prevalence of dental fluorosis in cattle and sheep, grade the severity of teeth mottling, and assess the fluoride concentration in assorted livestock feeds, faeces, and cattle milk in Nakuru County. A cross-sectional survey involving on-site clinical examination of the cattle and sheep for dental fluorosis was conducted in Gilgil, Njoro, Egerton, Naivasha, and Nakuru areas of the Nakuru County. Grading was done according to Dean's dental fluorosis index. A total of 549 animals was sampled, consisting of 242 cattle and 307 sheep. In addition, samples of feeds, farm water, faeces, and cattle milk were collected alongside the dental survey. The fluoride concentration estimation was determined using an ion selective electrode. The data were statistically analyzed using SPSS, version 25, to get the prevalence rate and the sample means. The findings showed that 86% of all the sampled cattle and sheep had dental fluorosis. Of this, 1.5% were severe, 8.4% moderate, 45% mild, 31% very mild, and 14.1% questionable based on Dean's dental fluorosis index. The range of the mean fluoride concentrations were: farm water 0.3-5.3 mg/L, feeds 21.6-26.9 mg/kg, cattle milk 0.01-0.15 mg/L, and faeces 14.1-18.6 mg/kg. There were statistically significant (p0.05) in the feed and faecal samples. It was further established that most animals were affected during the early stages of their growth and were likely to progress to higher dental fluorosis scores. It is therefore important to work on mitigation measures aimed at reducing the effects of fluorosis in the livestock reared in this region