Synopsis on the 2011 International Camelid Health Conference
Written by Dr. med. vet. Heike Köhler-Aanesen, Oslo, Norway
The 2011 International Camelid Health Conference was held from 3rd-6th of March at the Oregon State University in Corvallis and covered a broad range of camelid related veterinary topics including a presentation of many research projects and retrospective studies to gain more insight into camelid disease.
Thanks to a sponsorship from the British Camelids I was able to attend this wonderful conference.
The conference began with a very interesting overview by Susan Tornquist from Oregon State University on Mycoplasma haemolamae, a bacteria detected in the blood causing symptoms such as fever, mild anemia and chronic weight loss .
Treatment of experimentally-infected camelids with various antibiotics did not effectively clear the infection. Most infected animals appeared to be chronically infected. Transmission over the placenta was proven, but transmission by biting insects is suspected but has not yet been proven. The prevalence rate appears to be 30% of the camelids in the US.
Beth Valentine from Oregon university discussed the question whether camelids can get strokes. Strokes are caused by blood clots in brain vessels and are common to humans but not to animals. Four suspect cases in camelids (3 -15 years of age) causing sudden onset of severe neurologic disease such as blindness, ataxic gait and seizure-like activity were investigated. The pathologic findings in brain tissue suggested clotting in the vessels, but the number of inflammatory cells found in the affected brain areas mimicked infection (encephalitis).
Julie Dechant from Davis reported on oleander intoxication in camelids. At the University of Davis it appears that this intoxication occurs with a high frequency in camelids. All parts of the plant, including leaves, seeds, fruit and the root are toxic with a deadly dose being 225mg/kg equating to 10 leaves.
The diagnosis is made by detecting the oleander toxin “oleandrin” in feed, stomach content, blood or urine of affected animals. Clinical signs include arrhythmia of the heart, diarrhea and renal injury. Intravenous fluid treatment and adsorbents are thought to be the most important treatment options.
Andi Niehaus from Ohio State University gave an update on dental diseases in camelids. He pronounced the importance of radiographs to diagnose and localize dental disease. The most common abnormalities are abscessation around the tooth roots, osteomyelitis affecting the jaw bone and bone sequestra. Lower jaw cheek teeth are particularly prone to abscessation in camelids. The cause of the abscessation is still not known, but theories include chewing of rough and stemy forages leading to abrasions in the mouth and subsequent migration of bacteria into the tooth roots, premature breaking of the juvenile tooth caps when the permanent teeth erupt, fractured teeth and inaccurate trimming of the fighting teeth exposing the pulp cavity of the tooth.
Most organisms cultured from tooth abscesses are in fact part of the normal bacterial flora found in the mouth, with A. pyogenes being the most common bacteria isolated. Camelids with tooth root abscesses present with a hard, bony and often painful swelling over the affected tooth and osteomyelitis may contribute to the swelling. The degree of swelling is generally indicative of the chronicity of the disease. Most animals still eat normally, but pain while chewing leading to anorexia and weight loss can also be observed.
A differential diagnosis for a tooth root abscess is packing of cud within the mouth which may mimic a transitory swelling, as well as impaction of the salivary gland, a generalized osteomyelitis (lumpy jaw), bone sequestra or a neoplastic growth.
The treatment options include both conservative therapy with antibiotics and surgical removal of the tooth and tooth root. Many tooth root abscesses in chronic states do not respond well to medical therapy alone and require a combined medical and surgical treatment.
Interestingly, he also presented findings of a study investigating blood concentrations of florfenicol after intramuscular injection of the recommended dosage. This study concluded with recommending an injection interval of 24 hours based on a drop of the florfenicol blood concentration already right after this time period.
Jane Vaughan from Australia gave a review on common alpaca reproduction issues. She stated that it is a myth that camelids are often regarded as being less fertile than other domestic livestock: At least 50% of matings between fertile males and females result in pregnancy, which is comparable to reproductive rates in cattle, sheep and goats. In contrast to sheep, cattle and goats however, alpaca females are usually not culled upon failure to conceive after three matings due to their value.
The most common cause of female infertility is ovarian hypoplasia (small ovaries).
Jane emphasized the need to not only focus on body confirmation and fiber characteristics when selecting herd sires: testicular size should be included in the selection criteria in order to ensure high fertility and thereby minimize generation intervals. When investigating male infertility it is important to ensure that the male is sexually mature, as the age of puberty onset in alpacas range from less than twelve months to greater than four years of age. Testicular hypoplasia (small testicles) is the most common congenital abnormality in infertile alpaca males whereas degeneration of the testicles due to heat stress, trauma or chronic inflammation secondary to other diseases is the most common cause of acquired male infertility.
Research results also included the establishment of normal computed tomography (CT) of the abdomen giving huge diagnostic benefits in detecting tumors and many other disease states in camelids.
An ongoing study on dropped pasterns in lamas and alpacas in the US found an overall prevalence of 14% in lamas and 0.6% in alpacas (owner survey of 500 breeders). Affected animals showed significantly increased sink levels, decreased copper levels and, surprisingly, increased vitamin D levels in the blood.
Claire Whitehead reported on biosecurity in camelid operations and quality assurance in the UK and gave an excellent overview of use of ultrasound in camelid medicine.
Christopher Cebra from Oregon State University discussed aspects of enteral parasites. He states that until recently coccidial infection had generally been underestimated as a cause of disease and death in favor of more known diseases such as E. coli infections, entertoxemia and Johne’s disease. Moreover there has been inadequate diagnostic testing for coccidia in the past. The largest coccidia, Eimeria macusaniensis, causes colic, weight loss and possibly diarrhea already before eggs are shed in the feces. It appears that this coccidian parasite also creates an environment for Clostridium perfringens related disease (entertoxemia). Due to its size it will not be detected with simple fecal flotation techniques, but requires combined centrifugation-flotation techniques with a flotation solution of high density. As the diagnosis in the period before shedding of eggs in the feces is a very difficult one, new diagnostic techniques are being developed. The fecal PCR test seems fairly promising at this point.
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