Choanal Atresia in Llamas: Congenital Nasal Obstruction in Crias

Choanal atresia is a birth defect in which the choanae, the internal openings between the nasal passages and the throat, do not form normally. The blockage may affect one side or both sides, and it may be partial or complete. In camelids, this defect is recognized as one of the more common congenital abnormalities.

This matters because llamas are obligate nasal breathers. A cria with severe blockage cannot move enough air through the nose, so breathing becomes much harder during excitement, handling, or nursing. Some crias gasp, cough milk from the nose, or stop nursing because they cannot breathe and swallow well at the same time.

Bilateral choanal atresia is the most urgent form. These crias may show respiratory distress very soon after birth and can decline quickly without airway support. Unilateral or partial defects can be harder to spot at first, but they may still cause chronic noisy breathing, poor growth, repeated milk aspiration, or recurrent respiratory problems.

Your vet can help confirm whether the problem is choanal atresia or another cause of upper airway obstruction. Early evaluation gives your cria the best chance for a workable care plan.

Choanal atresia is congenital, which means the cria is born with it. The defect develops during fetal growth when the back of the nasal passages fails to open normally into the nasopharynx. The obstruction may be bony, membranous, or mixed.

In llamas and alpacas, choanal atresia is widely considered to have a heritable component, even though the exact genetics are not fully worked out. Merck Veterinary Manual notes that congenital defects are relatively common in camelids, likely related in part to a historically narrow gene pool, and affected animals may have more than one defect.

Some camelids with choanal atresia also have other congenital abnormalities, including kidney, facial, ear, or cardiac defects. Research in alpacas has explored genes linked to similar syndromes in people, but no single routine screening test currently prevents all cases.

For pet parents and breeders, the practical takeaway is that this is not caused by routine newborn care. It is a developmental defect present before birth. Because inheritance is suspected, affected animals are generally not considered good breeding candidates, and close relatives may warrant careful review with your vet and breeding advisor.

Diagnosis starts with the history and physical exam. Your vet may notice respiratory distress in a newborn cria, especially distress that worsens during nursing. A common bedside clue is failure to pass a small red rubber catheter or feeding tube through the nostril into the throat.

From there, your vet may recommend airway-focused diagnostics. These can include endoscopic examination, contrast studies, skull radiographs, or CT if referral imaging is available. CT is especially useful for defining whether the blockage is bony, membranous, unilateral, or bilateral, which helps with treatment planning.

Your vet may also check for complications and related defects. That can include bloodwork, oxygen assessment, chest imaging if aspiration pneumonia is suspected, and evaluation for other congenital abnormalities such as renal or cardiac defects.

Because crias can deteriorate quickly, stabilization often happens at the same time as diagnosis. Oxygen, careful feeding support, and in severe cases a temporary airway procedure may be needed before a full treatment decision is made.

There is no guaranteed way to prevent choanal atresia in an individual pregnancy, because the defect forms during fetal development and is thought to have a genetic basis in camelids. Good prenatal herd care still matters, but it cannot reliably stop this specific defect from occurring.

The most practical prevention step is thoughtful breeding management. Because choanal atresia is considered heritable, affected llamas should generally not be bred. It is also wise to review family history, avoid repeating pairings that produced affected crias, and work with your vet or breeding advisor if congenital defects appear in a bloodline.

Careful newborn observation is also part of prevention in a broader sense. Watching every cria closely during the first hours of life can help catch breathing trouble before aspiration and exhaustion develop. Early recognition does not prevent the defect, but it can prevent some of the most serious complications.

If you breed llamas, ask your vet to help you build a herd health and breeding plan that includes congenital defect tracking, neonatal exams, and clear criteria for when a cria needs emergency evaluation.