Influence of parasitic load, breed, age, housing and season on skin and hair coat condition in horses.

Horses with higher parasitic infections tend to have less glossy hair, and different horse breeds show distinct skin and hair coat characteristics. Other factors such as age, sex, housing, and season showed less clear effects.

Study Objective and Hypothesis

• The study aimed to investigate how various factors affect the skin and hair condition of horses.
• Specifically, researchers focused on parasitic load (strongyles), breed differences, age, housing environment, and seasonal changes.
• The hypothesis was that horses with lower fecal egg counts of parasites would have better hair and skin coat conditions than those with high parasite loads.

Background on Strongyles and Their Impact

• Strongyles are nematode parasites primarily inhabiting the large intestine and cecum of horses.
• They can cause symptoms ranging from poor hair coat appearance to colic, indicating potential health deteriorations.
• These parasites may negatively affect gut health and nutrient absorption, possibly leading to general poor body condition.

Study Population and Methodology

• The research involved 56 horses: 45 Morgan horses and 11 Thoroughbreds.
• Multiple variables were measured including: parasitic load (via fecal egg counts), breed, age, sex (mares vs non-mares), body weight, housing conditions (four different levels), and seasonal effect (spring vs fall).
• Statistical analyses were performed using linear mixed models with random intercepts for each horse to account for repeated measures.
• Hair luster, a key indicator of coat condition, was analyzed using binomial mixed models based on how frequently glossy coats were observed per season.

Main Findings

• Horses with a higher parasitic load had significantly lower odds of exhibiting a glossy hair coat compared to dull coats (P < 0.01).
• There was no significant correlation detected between parasite load and other skin or hair condition outcomes (P > 0.1).
• Breed differences were prominent:
  • Compared to Morgans, Thoroughbreds had thinner skin (P < 0.01).
  • Thoroughbreds had reduced odds of glossy hair (P < 0.01).
  • They displayed less dryness in their tails (P < 0.05).
  • They also shed more (P < 0.05).

Conclusions and Implications

• Parasitic infection level was specifically linked to hair luster, suggesting that parasite control may improve coat shine and appearance.
• Other aspects of skin condition, such as thickness, dryness, and shedding, were more influenced by breed rather than parasite load.
• The lack of association between parasite load and other skin outcomes may imply these factors have multifactorial origins beyond parasitism alone.
• This research highlights the importance of managing parasitic infections to maintain healthy, glossy coats in horses, especially for breeds prone to poorer coat luster.