Introduction

With the popularity of first llamas (Lama glama) and then alpacas (Lama pacos) New World camelid (NWC) species are frequently encountered by practitioners. There are a few vicuña (Vicugna vicugna) and guanaco (Lama guanicoe) in private hands however the majority of these animals will be found in zoological institutions. Old World camels (OWC) dromedary (Camelus dromedarius) and Bactrian (Camelus bactrianus) are also popular as pets and exhibit animals. There is even a dromedary camel dairy in southern California and camel races are held at a number of annual festivals.

Anatomy, Physiology and Physical Assessment

Camelids are pseudo-ruminants and have a 3 chambered forestomach. Chamber 1 (C1) is divided by a strong transverse muscular ridge creating a cranial and caudal half. The dorsal portion of C1 consists of squamous, keratin epithelium similar to the rumen of a cow. The ventral portion of C1 and the smaller C2 are divided into sac like glandular areas that are superficially lined by columnar epithelium and also contain deep, tubular glands. C3 is analogous to the abomasum but structurally is a long tubular organ. The distal portion is the only area that contains hydrochloric acid secreting glands and the remainder of C3 has a similar cell and glandular structure to the ventral portion of C1 and C2.¹¹ Camelids are considered intermediate in their feeding strategy and have the ability to slow their digestion time as quality of fiber decreases. As with the true ruminants, diet changes should be done slowly over 1-2 weeks. Lactic acidosis and endotoxemia has been reported in racing, dromedary camels that have been switched from poor quality feed to a high concentrate diet.¹³ Similar to ruminants, camelids also have a spiral colon which in NWC is often the sight of impactions. The contractions of C1 are much more subtle and difficult to hear in NWC as compared to sheep and goats and it is often easier to observe the contractions. They should be uniform in strength and occur 3 - 4 times per minute.

Llamas and alpacas have a different glucose utilization and regulation physiology than cattle. In NWC there is a higher resting blood glucose concentration and they have considerably greater insulin resistance than cattle. Metabolic abnormalities related to glucose metabolism are not uncommon in sick NWC and often complicate a primary disease condition.⁵

In camelids there are 3 sets of lower incisors that in the normal animal will grow to replace the worn portion that contacts the dental pad. Mild to moderate superior brachygnathism is not uncommon in llamas and alpacas and the incisor teeth may need to be trimmed. Male camelids have 3 sets of fighting teeth (2 upper [canine and incisor] and 1 lower [canine]) that erupt at approximately 2-3.5 years. These teeth are extremely sharp and commonly cut in NWC to prevent injury to herd mates. Retained deciduous incisors are not uncommon in NWC's. They may be removed for cosmetic purposes.

For NW camelids in full fleece, the physical exam must include palpation for body condition. Weights are ideal however body condition scores have been described for llamas and alpacas and this is a useful tool if a scale is not available.

Temperature Pulse and Respiration

For llamas and alpacas normal rectal temperature is 99.5-101.5°F, heart rate 48-68 b/min and respiratory rate 10-30 b/min. In camels the normal rectal temperature is 96.2-102°F, heart rate 35-50 b/min and respiratory rate 7-10 b/min.

Preventative Care

Toe nail trimming: The foot of the camelid contains 2 toes with a ventral pad that contacts the ground and is referred to as the "slipper". In NWC the nail is trimmed flush with the plantar surface of the slipper.

Vaccination programs should at a minimum include an annual combination, clostridial vaccine which includes tetanus. Illness and deaths caused by West Nile Virus and Eastern Equine Encephalitis Virus have been reported in NWC. Vaccination recommendations have utilized equine products but require 3 doses, 3 weeks to 1 month apart, followed by annual boosters to establish and maintain adequate titer levels.^3,10

Alpacas and some heavily fleeced llamas require annual shearing prevent heat stress, especially in climates with excessive heat and humidity. Shear in spring when night time temperatures will remain above 50° F. Camels shed their hair coats.

Parasite Control

Deworming strategies should be based on quantitative fecal results utilizing either a sugar centrifugation flotation technique for detection of E macusaniensis, Trichuris spp, Nematodirus spp, and capillarids, or a saline McMasters technique for small coccidia.⁴ All camelids evolved and adapted to a dry and seasonally cold environment. Thus, warm, wet regions with abundant pasture may result in heavy parasite loads. Nematodirus, Trichuris, strongyloides, Capillaria and Haemonchus have caused problems in camelids and resistance to anthelmintics is increasing. Oral treatment with ivermectin or moxidectin at 0.2 mg/kg is generally felt to be the regimen of choice for gastrointestinal helminthes. In NWC fenbendazole at 10-20 mg/kg q 3 - 5 days has been recommended for sensitive parasites. Fasciola species can be a problem regionally. Coccidia (Eimeria sp.), Cryptosporidia and giardia can cause diarrhea in neonates. The coccidian parasite Eimeria macusaniensis (E.mac) has caused clinical disease and death with and without diarrhea in naïve alpacas; primarily in stressed animals (weaning age neonates and females with nursing crias). Amprolium (10 mg/kg) SID, x 5 days or Ponazuril 20 mg/kg, SID x 3 days are currently the recommended treatments for Eimeria macusaniensis. External parasites include spinous ear tick (Otobius megnini), lice and the mite (Chorioptes bovis).⁸ As with small ruminants, in herds where parasites are a chronic problem a holistic approach to management is recommended. An excellent source for information regarding parasites in small ruminants is The Southern Consortium for Small Ruminant Parasite Control (www.scsrpc.org).

Blood collection from the jugular in NWC can be difficult due to the thickness of skin (in males up to 1") and presence of full fleece. The jugular vein is more easily palpated on the right. If pressure is applied against the palpable ventral projection of the transverse processes of the cervical vertebrae then the jugular vein can be felt just medial to this. When administering IV injections I always use an 18 gauge 1" or 2" needle to insure that I am in the vein as accidental injection into the carotid artery is not uncommon. In OWC the jugular vein is easily palpated in the cranial portion of the neck just proximal to the ramus of the mandible. The cephalic vein and lateral thoracic vein can also be utilized in both OWC and NWC.

The majority of injections should be administered SC just in front of the shoulder or in the thin skin behind the elbow.

Handling and Manual Restraint

Most camelids are considered domestic species and should be trained to a halter and lead. Halters should fit snuggly and be tightened high on the nasal bone. New World camelids when restrained may spit, bite, "cow" kick and vocalize. Aggressive, intact males may rear up and chest butt. Due to their long necks controlling the head in NWC gives you a leverage advantage. Chutes specifically designed for NWC are available. Old world camels will also bite, spit and kick. Due to their size it is important to protect yourself when adult camels are displaying these behaviors. OWC can be handled if they are trained to Kush, hobbled standing or in a kush position or worked in a chute system.

Sedation and Anesthesia

See sedation, anesthesia and reversal agent drug dosages Table 1. It is recommended that prior to anesthesia NWC be fasted for 12 hours and OWC for 24 - 36 hours.¹² Neonates should not be fasted. Intubation for gas anesthesia (isoflurane in NWC and halothane in OWC) can be achieved in llamas and alpacas or neonatal camels, with a 12" Miller blade (A.M. Bickford, Inc., Wales Center NY, 14169). A large gauge polypropylene canine urinary catheter can be utilized as a stylet. The catheter is placed in the trachea and the endotracheal tube advanced over the stylet. Nasal-pharyngeal intubation has also been described in camelids. In adult camels through the mouth palpation of the arytenoid cartilages or blind intubation are the usual methods of intubation.¹² Injection of anesthesia drugs should be given in the caudal aspect of the proximal rear leg or the deltoid musculature. Positioning and monitoring is similar to ruminants.

Analgesia and Pain Management

Many procedures can be accomplished with sedation and the administration of local anesthetics. Non steroidal anti-inflammatory drugs can be utilized as for ruminants. Pain or illness, depending on the location of the lesion or organ system involved, may manifest as restlessness, frequently getting up or down, lying down while other animals are up and eating, frequently going to the dung pile to posture to urinate or defecate, grinding their teeth, lying their head and neck flat on the ground, tail flagging or bending their head and neck over their back. Animals with severe acute abdominal pain may kick at the abdomen, roll and thrash.²

COMMON MEDICAL PROBLEMS

Noninfectious Diseases

Conditions common to NWC include snake bite, heat stress, rickets, metabolism abnormalities and fatty liver syndrome, lymphoma, urolithiasis, gastrointestinal impactions, C3 ulcers, "lumpy jaw" or tooth root abscesses, localized alopecia, angular limb deformities and dystocia.^2,6,7

Surgical procedures most frequently performed in camelids include castration, cesarean section, repair of angular limb deformity and exploratory surgery for abdominal pain resulting from perforated C3 ulcers or intestinal obstruction.²

Infectious Diseases

Infectious diseases are often regional or situational in their occurrence. Infection with Streptococcus zooepidemicus has been documented in alpacas exposed to horses. Coccidioides immitis infections are not uncommon in the south western United States. Parelaphostrongylus tenuis infections are found east of the Rocky Mountains and infections with fascioliasis are only going to be present where the snail intermediate host is found. Other infectious diseases that have been noted in camelids include internal and external parasites, Bovine Virus Diarrhea Virus, West Nile Virus, Eastern Equine Encephalomyelitis, Coronavirus, Mycoplasma haemolamae, clostridial diseases, Johne's disease, tuberculosis, Salmonellosis, and Colibacillosis.^{3,6,7,8,10,13}

In the alpaca industry it is still common to move animals across many states for breeding, shows and sales. Thus a biosecurity program on the farm is a critical component of infectious disease management. When investigating illness in NWC, reviewing the travel history of the animal may considerably expand your list of differential diagnosis.

Table 1 Sedation, Anesthesia and Reversal Agents and Dosages for Camelids^1,6,7,9,12

References

1.  Abrahamsen, E.J. 2004. Sedation and chemical restraint of camelids. In: Proc. Cur. Vet. Care Mang. Llamas and Alpacas. 25-26.

2.  Anderson, D. E. 2005. Camelid anesthesia and surgery. In: Proc West. Vet. Conf. (V488)

3.  Bedenice, D. A., M. Bright, D. D. Pederson and J. Dibb. 2009.Humoral response to an equine encephalitis vaccine in healthy alpacas. J. Am. Vet. Med. Assoc. 234 (4) Pp. 530-534.

4.  Cebra, C. K. and B. V. Stang. 2008. Comparison of methods to detect gastrointestinal parasites in llamas and alpacas. J. Am. Vet. Med. Assoc. 232(5):733-41

5.  Cebra, C. K. 2007. What We Currently Know About Glucose Control in Camelids. In: Proc. Int. Vet. Emerg. Crit. Care Symp.

6.  Fowler, M.E. Camelidae. In: Fowler M.E. and R. E. Miller (eds.) Zoo and Wild Animal Medicine. Elsevier, St. Louis, Missouri. Pp 612-625.

7.  Fowler, M.E. 1998. Medicine and Surgery of South American Camelids, 2^nd ed. Iowa State University Press, Ames, Iowa. Pp.468-497.

8.  Johnson, L.W. 2004. Skin diseases and ectoparasites. In: Proc. Cur. Vet. Care Manag. Llamas and Alpacas. 55-57.

9.  Kreeger, T. J., J. M. Arnemo and J. P. Raath. 2002. Handbook of Wildlife Chemical Immobilization (international edition). Wildlife Pharmaceuticals, Inc. Fort Collins, Colorado, USA.

10. Kutzler, M.A. 2005. West Nile Virus in alpacas and llamas. In: Proc. Int. Camelid Hlth. Conf.

11. Lechner-Doll, M., W. v. Englehardt, A. A. Abbas, and H.M. Housa et al. 1995. Particularities in forestomach anatomy physiology and biochemistry of camelids compared to ruminants. Resource report CIHEAM.org.

12. Mama, K. R. Camelids. In: West, G., D. Heard and N. Caulkett (eds.) Zoo Animal and Wildlife Immobilization and Anesthesia. Blackwell Publishing, Ames, Iowa. Pp. 585-593.

13. Wernery, U. and O.R. Kaaden. 2002 Infectious Disease in Camelids. 2^nd ed. Iowa State University Press, Ames, Iowa. Pp. 36-72.