Christopher K. Cebra VMD, MA, MS, DACVIM-LA
Several surveys have indicated that digestive disorders are the most common causes of illness and death in New World camelids. In spite of this, there is relatively little scientific information concerning these disorders, and popular discussion has focused on certain ones, such as gastric ulcers, clostridial infections (and Johne’s disease), to a degree disproportionate to their importance. In recent years, we have tried to publicize some of the more important (though often neglected) disorders, including tooth root abscesses, grain overload, gastrointestinal obstructions, and infectious and parasitic diseases or the abdomen. Unlike ulcers and clostridial disease, some of these other disorders have real treatment and survival possibilities, which count of course on correct and early identification of the disorder.
Signs of digestive disease include: facial masses, malaligned teeth, dropping feed from the mouth, salivation, regurgitation, gurgling sounds from the throat or abdomen, a fluid wave in the neck, weight loss, weakness, obtundation, a staggering gait, retroflexion of the head over the back, dehydration, high or low body temperature, high or low heart rate, high or low respiratory rate, labored breathing, congested mucous membranes, sudden death, lack of abdominal fill, abdominal distention, colic, straining, fresh blood in the stool, tarry stool, lack of defecation, and diarrhea.
Some of these signs arise early in the course of the disease, others late. Some are relatively specific to certain disorders or at least gastrointestinal disorders. Others are general findings common to many diseases of different organ systems. Finding any one of the signs warrants further investigation, possibly including a more thorough physical examination, laboratory tests, and other diagnostic modalities.
In some cases, the sign is obvious. In others, it requires careful examination. Observation of the animal and frequent monitoring as discussed above are the best ways to detect problems early.
The most common digestive problems of the head or tooth root abscesses and malocclusion. Tooth root abscesses (impacted teeth) are infections around the base of the tooth and are most common on the cheek teeth of the upper jaw. Hard lumps and occasional drainage are the most common signs. Antibiotic treatment or surgical removal of the infected tooth may lead to resolution of signs. Malocclusion usually relates to how the incisor teeth (lower jaw) interact with the dental pad (upper jaw). Alpacas especially have problems with incisors that are aimed more forward than up. In some cases, a too-short upper jaw is at fault. Malocclusion may affect the animal’s ability to eat, especially on pasture, and is usually treated by corrective trimming.
The most common digestive problems of the neck are choke and megaesophagus. Megaesophagus is a result of ineffective muscular contractions of the esophagus, and is especially important in camelids because of their upright neck and the need to regurgitate cud back up the esophagus. Common clinical signs include salivation, weight loss, abnormal cud spilling, and a fluid wave in the neck. Choke, or esophageal obstruction, causes the same signs and is often the result of megaesophagus. In other cases, a dental abnormality, greedy chewing, inflammation of the esophagus (from Rhododendron family plants), or especially fibrous feedstuffs can lead to choke. Choke is usually relieved by passing a stomach tube. Megaesophagus may be managed by a careful feeding protocol – pellets fed from a height is my preference.
The most common gastric disorders are Grain Overload in the first compartment and Ulcers in the third compartment. Grain overload is the result of over-ingestion of carbohydrate-rich feeds (grains or fruits). We believe that camelids are relatively susceptible, as they involved in environments where nutrients were scarce. Accidental overfeeding, animals escaping into the grain store or orchard, and bullying by certain animals in a group are the greatest risk factors. Signs start as weakness with obtundation,. anorexia, and a staggering gait, and progress to recumbency with the head flopping over the back. Multiple camelids may be affected. Medical treatment with oral and possibly intravenous alkalinizing fluids is usually successful. Ulcers are still a bit of a mystery. They appear to be the result of stressful situations and possibly high-energy feeds (including copious lush pasture). These may slow emptying of the stomach into the intestine and hence promote gastric acid retention. Signs are often very subtle and treatment is controversial.
The third compartment is also the site of infestation by Stomach Worms. These are mainly the same worms that affect sheep and cattle, and hence can be shared between these species. Loss of blood, protein, and weight lead to an unthrifty animal, and diagnosis is made by fecal examination. Treatment is through deworming medication and possibly some pasture management. Resistance to some common dewormers including ivermectin is becoming a problem.
Worms can also affect the intestine, as can Protozoal Parasites. The most commonly reported protozoal parasite is Eimeria spp. or Coccidia. This mainly affects juveniles between about 1 and 18 months of age, but can affect older camelids that have poor immune function or are confronted with a large parasite load (overcrowding). Multiple camelids may be affected. Cryptosporidium can be an important parasite of young crias, and in some areas Giardia is common. The protozoal pathogens cause loss of protein and weight, and frequently also cause diarrhea. They are diagnosed by fecal examination and treated with appropriate medications and pasture management.
The most common Viral Infections of camelids at our practice also affect the intestine. Coronavirus, and to a lesser extent Rotavirus, damage the intestinal lining and cause diarrhea. Dehydration, anorexia, and obtundation may be present in severely affected camelids. Younger camelids are affected most frequently, but Coronavirus at least also affects adults. Outbreaks are common. Diagnosis is by fecal examination by electron microscopy, which should be available at the local veterinary diagnostic laboratory. Treatment consists chiefly of supportive care with fluids, and possibly antibiotics to prevent secondary bacterial infections.
Bacterial Infections of the intestine appear to be less common in camelids in our practice than in other large animal species. Salmonella infections occur sporadically, as to a variety of other bacterial including E. coli, Actinobacillus, and Clostridium. Unfortunately, many of these infections are highly invasive and lead to a rapid demise of the animal. In some cases, we believe the bacteria invade existent lesions, possibly originally created by viruses. Diarrhea is a less consistent finding than signs of sepsis: congested mucous membranes, high heart rate, anorexia, and obtundation. Diagnosis is by clinical signs and blood work. Treatment is a course of antibiotics and usually anti-inflammatory drugs.
Other infections in the abdomen can affect the gastrointestinal tract. Ruptured ulcers are one uncorrectable source. Streptococcus zooepidemicus is another infection that frequently inflames the lining of the abodomen. Affected camelids usually have a fever and a history of exposure to horses. Diagnosis is by cultures of blood or abdominal fluid, and treatment consists chiefly of antibiotics and supportive care.
Intestinal Twists and Obstructions are relatively rare, but a are certainly seen at any large camelid practice. The list of possible lesions is long. As a few general rules, blockages near the end of the stomach cause mild pain signs, but also cause abdominal distention, dehydration, obtundation, and anorexia. Blockages further down the intestine cause more violent pain signs, and possibly straining. Because “gas colics” are rare in camelids, any camelid showing signs of abdominal pain should be examined by a veterinarian. A variety of diagnostic options are available, with treatments depending on the identified lesion.
The above list is not comprehensive, but should address the majority of the digestive ailments. Some items are common, others are more sporadic. Some can be avoided or managed. Regardless, early and correct identification offers the best treatment success, and as the owner or farm manager is the one in most frequent contact and most intimately aware of the individual camelid’s habits, it often falls to that person NOT to make a diagnosis, but to recognize that an abnormality exists, and thereby initiate the process to seek a diagnosis and a cure.