Experimental haemonchosis in white-tailed deer.

Area of Science:

• Veterinary Parasitology
• Wildlife Health
• Infectious Diseases

Background:

• Haemonchus contortus is a significant gastrointestinal nematode affecting livestock, primarily sheep.
• Understanding parasite transmission dynamics between domestic animals and wildlife is crucial for disease management.

Purpose of the Study:

• To investigate the susceptibility of white-tailed deer (Odocoileus virginianus) to Haemonchus contortus originating from sheep.
• To characterize the clinical and hematological responses of deer to varying doses of H. contortus infection.

Main Methods:

• White-tailed deer were experimentally infected with three different doses of H. contortus larvae (0, 25,000, and 100,000).
• Clinical signs, body condition, and hematological parameters (hemoglobin, packed cell volume, total serum protein) were monitored.
• Larval development and egg production were assessed in infected deer.

Main Results:

• Successful infection of white-tailed deer with sheep-origin H. contortus was confirmed.
• Infection severity correlated with the larval dose, with higher doses causing more pronounced clinical signs like weakness, emaciation, and anemia.
• Hematological values (hemoglobin, packed cell volume, total serum protein) were significantly reduced in infected deer compared to controls.
• Inhibition of larval growth and egg production was observed, particularly in deer infected with the highest larval dose.

Conclusions:

• White-tailed deer are susceptible to H. contortus, exhibiting clinical signs similar to infected sheep.
• The parasite's larval development and reproductive capacity can be inhibited in deer.
• H. contortus poses a potential threat to white-tailed deer populations, warranting further investigation into its epidemiological significance.