Glossoplegia in Large Animals

Glossoplegia (paralysis of the tongue) is uncommon in large animals, including horses and cattle.

One cause of glossoplegia in horses is the incorrect placement of obstetric snares in neonates during manual forced extraction (delivery). Other causes include bacterial, viral, or protozoal infections, such as strangles, meningitis, botulism, encephalomyelitis, leukoencephalomalacia, equine protozoal encephalomyelitis, and cerebral abscessation.

Any condition that damages the hypoglossal nerve (cranial nerve XII)—the major motor nerve to the muscles of the tongue—can result in glossoplegia.

Neonatal foals with glossoplegia must be monitored carefully to ensure they are able to eat. If necessary, a nasogastric tube should be placed for supplemental feeding, including administration of colostrum or milk replacer. Similarly, if foals are unable to maintain hydration or nutrition via a nasogastric tube, IV fluids and partial or total parenteral nutrition should be considered.

If bacterial infection, including sepsis, is considered to be the cause of dysphagia, affected foals should be administered systemic broad-spectrum antimicrobials—usually a combination of aminoglycosides and beta-lactam antimicrobials.

Care should be taken when administering aminoglycosides or NSAIDs to dehydrated foals because of the risk of nephrotoxicosis. Frequent monitoring of renal function via biochemical profiles is warranted. Prophylaxis against gastric ulceration is indicated and should be administered. If the condition persists for > 10 days after birth, the prognosis for regaining normal function is guarded.

Inflammatory diseases and trauma can result in transient glossoplegia. Occasionally, horses undergoing prolonged dental procedures that involve excessive traction of the tongue can develop temporary glossoplegia. Tongue lacerations can contribute to glossoplegia. The prognosis of glossoplegia in horses depends on the animal's response to treatment for the primary condition.

In cattle, glossoplegia can accompany severe actinobacillosis or follow laceration of the tongue. There can be complete paralysis of the tongue accompanied by necrosis of the tip. The tongue might be completely paralyzed, and the tip might show necrosis. Outbreaks of such paralysis occasionally occur in feedlot cattle, sometimes after a bout of viral stomatitis.