Miscellaneous conditions of the equine head.

This research paper explores various conditions affecting the head of horses, with particular emphasis on nutritional secondary hyperparathyroidism, sialoliths, and nasolacrimal duct obstruction.

Nutritional Secondary Hyperparathyroidism (NSH)

• This condition usually affects horses that are fed a diet with an imbalance of calcium and phosphorus, or those that consume foods rich in oxalates.
• NSH manifests as shifting lameness, joint tenderness, reluctance to move, or a stiff, strutting stride.
• Physically, horses might show broadening of the nasal bones, or enlarged maxilla and/or mandible. A ridge over the nasal bones may also be visible.
• The diagnosis is generally made on the basis of physical examination, feed analysis, and clinical pathologic data. The latter may reveal normocalcemia, normal to increased serum phosphorus, and increased fractional excretion of phosphorus.
• The main treatment goal is to correct the imbalance of calcium to phosphorus in the horse’s diet.

Sialoliths

• Sialoliths refer to calcified clumps that form in the salivary gland or duct.
• The standard treatment for sialoliths is surgical removal.
• Complications associated with the condition are uncommon.

Nasolacrimal Duct Obstruction

• Obstruction of the nasolacrimal duct mostly occurs due to intraluminal foreign material, but congenital atresia (absence or closure of a normal body opening or tubular organ) may also cause the condition.
• Signs of nasolacrimal duct obstruction are epiphora (excessive tearing), conjunctivitis, and mucopurulent discharge (thick, greenish yellow discharge).
• The typical treatment involves removing the foreign material, often through retrograde saline flush. Cases of atresia are usually treated surgically.