Laurel L. Tovrea, Veterinary Student
David E Anderson, DVM, MS, DACVS
Head and Associate Professor of Farm Animal Surgery
Director, International Camelid Initiative
Ohio State University
College of Veterinary Medicine
Columbus, Ohio 43210

Dentition and Eruption Schedules

Llamas and alpacas both have deciduous teeth, or baby teeth, which are present at or shortly after birth and will eventually be replaced by permanent teeth. The deciduous tooth will usually fall out revealing an erupting permanent tooth behind it. Llamas and alpacas have three pairs of deciduous lower incisors (Id1, Id2, Id3), which occlude with the dental pad, and three to five pairs of deciduous premolars (Pd1, Pd2, Pd3, Pd4, Pd5), with two to three pairs on top and one to two pairs on the bottom. There are no deciduous molars. All deciduous incisors and premolars are present at birth unless the cria is born prematurely. Premature birth could delay the eruption of deciduous incisors but I1 is expected to erupt within days after birth. Premature birth delays the eruption of premolars and molars also but the length of the delay is unsure. In addition to the deciduous lower incisors and deciduous premolars lamoids also have one pair of upper and one pair of lower deciduous canines (Cd1) and one pair of upper deciduous incisors (Id3) that are present in all animals but only visibly erupt in about 5% of males.

Permanent teeth have eruption times that vary slightly with each animal but generally fall within the permanent eruption schedule seen below. Llamas and alpacas have one pair of upper incisors (I3), three pairs of lower incisors (I1, I2, I3), one pair each of upper and lower canines (C1), one to two pairs each of upper and lower premolars (PM1, PM2), and three pairs each of upper and lower molars (M1, M2, M3). Because of the fairly consistent eruption schedule of some of the permanent teeth, it is possible to accurately age llamas and alpacas by their teeth until about 3 to 5 years of age. After this time age can only be estimated by the amount of wear that has occurred on fully erupted teeth, and even then is variable between llamas and alpacas due to continuous growth of alpaca incisors well into maturity and the relative deficiency in the amount of enamel on the lingual surface of the lower incisors of alpacas.

The canine teeth of adult camelids are especially well developed in the male and along with the upper incisors, which are similar in shape and function to the canine teeth, are considered to be the fighting teeth. The fighting teeth are sharp and angled towards the back of the mouth. Male llamas and alpacas use these teeth to defend territory and obtain dominance, particularly during the breeding season. This behavior is not especially desirable in a pet or breeding animal. Fighting among males can result in serious injury to the forelimbs and scrotal area of other males and there is also a danger to anyone handling the male such as owners and veterinarians.

The molars and premolars, or cheek teeth, of the llama and alpaca are selenodont, meaning they have longitudinal, crescent-shaped ridges. The cheek teeth generally exhibit sharp ridges and points typical of herbivores that eat tough grasses and shrubs. Even though the lower cheek teeth are slightly narrower than the uppers, the cheek teeth of llamas and alpacas do not have sharp enamel points on the lingual surfaces of the lowers and the labial surfaces of the uppers to the same degree that equines do. This is because lamoids chew in a lateral motion that keeps wear even. The roots of the cheek teeth are also closed so there is not continuous growth as in the equine. This means that llamas and alpacas will rarely need their cheek teeth filed, or "floated".

Eruption schedules

Deciduous: Id1 at birth
Id2 at birth
Id3 at birth
Cd1 variable present in all animals but
visible in only about 5% of males at 9 months
Pd3 at birth not present in all animals
Pd4 at birth present in all animals, retained by many after 5 years of age

Permanent: I1 2 - 2.5 years
I2 3 - 3.25 years
I3 3.1 - 6 years
C1 2 - 7 years average 2.5 - 3.5 years
P3 3.5 - 5 years absent in males and many females
P4 3.5 - 5 years
M1 6 - 9 months
M2 1.5 - 2 years
M3 2.75 - 3.75 years

Dental Health and Preventive Care

As in all other domesticated species, maintaining good dental health should be a concern of both llama and alpaca owners. Dental problems are, however, one of the most common reasons camelids are presented to the veterinarian. Signs of possible dental problems necessitating a dental examination by a veterinarian are weight loss, quidding or dropping feed during eating, pain when chewing, partially chewed fibers in fecal pellets, sensitivity to cold drinking water, swellings on the mandible or over the maxillary tooth roots, protrusion of incisors beyond the dental pad or lip, and visibly worn or deformed teeth. Some of the dental problems and procedures typically encountered in llamas and alpacas will be discussed.

Periodontal disease is seen in llamas and alpacas, and can lead to more serious dental problems. Plaque and tartar accumulate on camelid teeth and can cause gingivitis, which can lead to pain or even tooth loss. A veterinarian can remove dental plaque and tartar if it is interfering with oral function, but this is rarely the case.

Malocclusion is a common problem that occurs in both llamas and alpacas. It describes a condition where abnormal positioning of a tooth or teeth prevents appropriate alignment with teeth of the opposing jaw. This can result in abnormal wear of teeth, such as elongation of the incisors (which can be trimmed) or elongation of the points on the cheek teeth (which can be floated to prevent cheek and tongue lacerations), or excessive pressure and wear on the dental pad. Animals with malocclusion may suffer from difficulty with prehension of food or chewing resulting in malnutrition, weight loss, and poor body condition. Malocclusion can have many different causes including trauma (directly to the teeth or to the bones supporting the teeth), fluorine poisoning (which causes softening of the enamel and therefore uneven wear of the teeth), or a congenital abnormality. A complete oral exam should be performed on any camelid during the pre-purchase exam to ensure that there is no evidence of malocclusion especially if the owner is planning to breed the animal. Elongated incisors may be trimmed using a variety of techniques. We prefer a diamond-edged side cutting Dremel tool because this allows smooth cutting without the risk of cracking or splitting a tooth. Cracking or splitting teeth occurs occasionally when pliers, tin shears, obstetrical wire, or other implements are used to trim teeth. These complications can result in tooth root infection.

Retention of deciduous incisors is another common dental problem. Normally as the permanent teeth erupt they push out the deciduous teeth. Occasionally a permanent tooth will develop in an abnormal position and fail to push out the deciduous tooth, resulting in a double row of incisors. This is readily apparent and can be easily remedied by removing the deciduous teeth after sedation in most cases. The deciduous teeth are rostral, or in front of, the permanent teeth.

The fighting teeth (and their potential for harming other animals and people) have been discussed previously. Disarming the fighting teeth is desirable to prevent injury and is one of the most common dental procedures performed. Extraction is one method of disarming them but is not usually done since the roots are large and curved and may requires deep sedation or anesthesia and specialized equipment. Some veterinarians prefer to cut the crown of the teeth off and cover the root with a gingival flap, but this should not be done on a young animal with permanent teeth still erupting. The fighting teeth are usually disarmed by trimming them 2 to 4 mm above the gum line thus leaving the pulp cavity intact. This procedure requires less time, instrumentation, and fewer materials than the other two methods, and can be done while the teeth are still erupting, as may sometimes be required with a very aggressive young male. Llamas and alpacas generally discontinue growth of their teeth by 7 years old so that life-long trimming is not necessary.

Tooth Root Abscesses

Tooth root abscesses, or periapical abscesses, are usually seen during the period of eruption of the permanent premolars and molars around 5 years of age. The molars are the most commonly infected teeth. This has been attributed to feeding stemy hay during their eruption period. As a result of chewing the overly coarse hay, food particles disrupt the periodontal membrane and become the perfect breeding ground for bacteria. Owners can help prevent this by feeding good quality, more easily chewed feed during this time. Tooth root abscesses can also be caused by disruption of the pulp cavity during routine dental procedures such as trimming the fighting teeth. Tooth abscesses are occasionally seen in very young llamas and alpacas because of septicemia (bacterial infection in blood stream) and in very old animals (patent infundibulum with geriatric dental disease).

Physical exam of affected llamas and alpacas usually reveals a focal swelling over the affected tooth root. This is also the most common owner complaint. The swelling may or may not have a fistulous tract with purulent drainage (more often not seen as the abscesses often rupture into the oral cavity). The most frequently infected tooth is a lower molar so the swelling would occur on the mandible (>90%) more often than the maxilla (<10%), but can occur with any tooth. Animals may also be presented for reluctance to eat, abnormal chewing behavior, unilateral nasal discharge, hypersalivation, weight loss, and pain. Any of these signs requires further investigation by a veterinarian to correctly diagnose the nature of the problem and correct it. Though physical exam is helpful in diagnosing a periapical abscess, radiographs of the skull under sedation or anesthesia will need to be taken to reach a definitive diagnosis. Radiographs will also determine the amount of damage to the bone and may help determine the cause of the abscess, such as a broken tooth, fractured jaw, or retention of a deciduous tooth.

There are several methods for treating a tooth root abscess. They may be treated with long-term antibiotics alone (30 % success rate), by curettage and antibiotics (60% success rate), by root canal (we have done several successful root canals, but unknown success rate), or by extraction of the infected tooth (90% success rate). Long-term antibiotics for a llama or alpaca may end up costing more than extraction of the tooth and reoccurrence is common, and sometimes curettage and root canal may fail, necessitating repeating the procedure at additional cost to the client and discomfort to the animal. The preferred method for treating periapical abscesses at The Ohio State University Veterinary Teaching Hospital is extraction.

Antibiotics will be prescribed perioperatively and continue for 10-14 days after the surgery. These may be changed based on results of a culture and sensitivity of bone samples obtained during surgery. Bacteria commonly cultured from these abscesses are Bacteroides sp., Actinomyces sp., and Peptostreptococcus sp. Fortunately these infections very rarely, if ever, become systemic. In addition to antibiotics, the wound may be flushed once or twice daily until granulation tissue completely fills the defect, which can take 14-21 days.

Antibiotic Selection

Bacteria: A. pyogenes
Drug % susceptible:  ceftiofur 100 %; penicillin 100 %; tetracycline 82 %; sulfonamides 71%

Bacteria: Actinomyces sp.
Drug % susceptible: Ceftiofur 100%; penicilin 100%; tetracycline 93%; sulfonamides 87%

Bacteria: E. coli
Drug % susceptible: Ceftiofur 83%; penicilin 0%; tetracycline 71%; sulfonamides 65%

Some of the complications associated with the treatment of periapical abscesses are bone sequestra, damage to other teeth or tooth roots, fracture of the jaw, and even aspiration pneumonia. Retaining the services of an experienced veterinarian with the proper facilities and equipment can minimize these complications and ensure optimal treatment and results. You may need to contact your local llama or alpaca association to locate an experienced camelid veterinarian.

Dental problems are a common occurrence in camelids. Owner awareness of normal dentition and common abnormalities, along with continued vigilance for any of the aforementioned signs can help prevent problems or detect them earlier. Early detection facilitates more timely and appropriate treatment by your veterinarian, and less discomfort for your llamas and alpacas.

References

Fowler, ME (ed.): Digestive System, in Medicine and Surgery of South American Camelids. Ames, Iowa State University Press, 1992, pp. 306-312 and 333-334.

Fowler, ME (ed.): Surgery, in Medicine and Surgery of South American Camelids. Ames, Iowa State University Press, 1992, pp. 112-120.

Wheeler, JC. Aging llamas and alpacas by their teeth. Llama World, 1982; Summer: 12-17.

Kock, MD. Canine tooth extraction and pulpotomy in the adult male llama. J Am Vet Med Assoc 1984; 185 (11): 1304-1306

Fowler, ME. Health care of the geriatric llama and alpaca. Veterinary Clinics of North America: Food Animal Practice, 1994; 10: 2, pp. 392-395

Anderson, DE. Periapical tooth root infections in South American camelids. GALA, 1999; 14:5, pp. 39-40

Riviere, HL, EJ Gentz, KL Timm. Presence of enamel on the incisors of the llama (Lama glama) and alpaca (Lama pacos). Anatomical Record, 1997; 249, pp. 441-448

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