Prevalence of Chronic Progressive Lymphedema in the Rhenish German Draught Horse

Abstract

Chronic progressive lymphedema (CPL) is a common disease in Rhenisch German draught horses. The objective of our study was to evaluate the prevalence of this disease and its progression with age in 493 Rhenish German draught horses from different regions in Germany. We employed generalized linear models with binomial, multinomial, and normal distributions to analyse the effects of breeding association, coat colour, sex and age within sex, time of examination, limb on which CPL was recorded, and farm-related factors on disease scores. The occurrence and severity of CPL were significantly influenced by breeding area, sex, coat colour, and interaction of age by sex. Males had significantly higher CPL-scores than geldings (1.92-fold) and females (5.02-fold) as well as a faster (1.85-fold) disease progression per year of life than females (1.44-fold) and geldings (1.25-fold). Regression on age within sex was still significant when age was restricted to a minimum of 7 years in the analysis. Bay horses exhibited 1.77-fold and 2.19-fold higher CPL-scores than chestnut and black horses. Keeping horses on pasture and keeping bedding clean reduced CPL-scores, whereas feeding of hay silage and concentrates during winter increased CPL-scores. Our analysis revealed significant regression coefficients of cannon bone circumference on CPL-scores. Relationships with hoof measures and skinfold diameter at the neck were not found. In conclusion, differences among breeding districts and sexes by age had the largest impact on CPL prevalence and scores. Disease progression was evident up to a mean age of 16 years in males and 20 years in females. The identification of risk factors and their effects on CPL should help to reduce the occurrence and progression of CPL.

Chronic Progressive Lymphedema in Belgian Draft Horses: Understanding and Managing a Challenging Disease

“…The severity of lesions, especially the skinfold thickness, increases for both mares and stallions from the age of 3 years onwards [ 9 ]. Sievers and Distl also confirmed that the first onset of clinical signs starts in horses aged 1–2 years [ 62 ]. The disease progression ceases at a mean age of 16 years in stallions, 18 years in geldings, and 20 years in mares [ 62 ].…”

“…Sievers and Distl also confirmed that the first onset of clinical signs starts in horses aged 1–2 years [ 62 ]. The disease progression ceases at a mean age of 16 years in stallions, 18 years in geldings, and 20 years in mares [ 62 ].…”

“…This implies that its variation in both the disease susceptibility and the development of clinical signs are determined by an interplay of two factors: the genetic variance of an individual (genotype) and the environmental influences. Although no genetic traits associated with CPL have been identified in affected horses, a limited number of studies have identified environmental risk factors for CPL occurrence and the disease severity [ 9 , 13 , 18 , 33 , 61 , 62 ].…”

“…Sex, as well, is significantly associated with the occurrence of lesions, with the disease prevalence being significantly higher in stallions compared with mares [ 18 ]. Indeed, Sievers and Distl reported that males have a fivefold higher risk of developing CPL lesions compared with females [ 62 ]. Furthermore, De Cock et al and Verschooten et al have reported that, in general, stallions are more severely affected than mares [ 6 , 63 ].…”

“…However, sex was not correlated with disease severity in a study by Geburek et al [ 33 ]. Although lesions appear sooner in mares compared with stallions, disease progression is more rapid in stallions [ 9 , 62 ]. The latter may explain the difference in age at which the disease’s progression stabilizes.…”