Postmortem diagnoses in South American camelids and factors influencing diagnostic rate in the Upper Midwest USA, 2009-2019

Real-time pathologist-assisted field postmortem examinations of beef cattle

Postmortem examination of deceased production animals with appropriate ancillary testing is fundamental to determining causes of morbidity and mortality. Reaching a definitive diagnosis is crucial to evidence-based herd management and treatment decisions that safeguard animal health and welfare, food safety, and human health. However, for a range of reasons, carcasses sometimes cannot be examined in a veterinary diagnostic laboratory. As a result, postmortem examinations of farmed animals, including cattle, are often performed on-farm by the referring veterinarian (rVet) with tissue samples submitted to a veterinary diagnostic laboratory for ancillary testing. For various reasons, field postmortems can be associated with lower diagnostic rates. We investigated real-time pathologist-assisted field postmortem examination (rtPAP) assistance to beef cattle rVets to gauge any improvement in attaining a final diagnosis. We found that rtPAPs improved the success of reaching a final diagnosis compared to unassisted field postmortem examinations. Both the participating bovine rVets and the pathologists saw benefits to the rtPAPs, with bovine rVets indicating that they would utilize this service in the future if available. Our proof-of-concept study demonstrated the positive role of rtPAPs in diagnosing beef cattle disease and speaks to the need for telepathology services supporting food animal rVets and producers.

Infectious and non-infectious causes for pregnancy loss in South American camelids - A review

South American camelids (SAC) are gaining popularity for various purposes, including fiber production, trekking, and companionship. High abortion rates pose a significant health issue in SAC herds, leading to substantial economic losses for breeders. Often, the causes of these abortions remain unidentified. This review provides a comprehensive summary of the known infectious and non-infectious causes of abortions in SAC.

Clinical and hematological findings in alpacas (Vicugna pacos) with and without Candidatus Mycoplasma haemolamae infection

Anemia is a common problem in South American camelids (SACs). Infections with Candidatus Mycoplasma haemolamae (CMh), a cell-wall free, hemotropic bacterium, are often suspected to be an important cause of anemia, as the pathogen infects the erythrocytes and is found in the blood of up to 30% of SACs. The information on the clinical signs of animals infected with this pathogen vary widely. Most infections are clinically inapparent. Treatment is usually carried out with oxytetracycline. A detailed overview of the clinical and hematological findings in 13 alpacas infected with Candidatus M. haemolamae (CMh+), based on patients from our university clinic and comparing those findings with the results of 22 negative alpacas (CMh-) is provided. Assignment to both groups was based on the PCR result. No relevant clinical or hematological differences between CMh+ and CMh- were found, the clinical signs in CMh+ were usually due to comorbidities. The examination of a blood smear alone proved to be insufficient; a PCR test should be carried out to confirm or rule out an infection. A critical review of the need for antibiotic treatment on the basis of a positive test result alone is recommended.

Pathological findings in South American camelids presented at a farm animal clinic in Northern Germany (2005-2021)

To expand the knowledge about common diseases in llamas and alpacas in Germany, a screening of the cases of South American camelids presented at the Clinic for Swine and Small Ruminants of the University of Veterinary Medicine Hannover, Germany from 2005 to the end of November 2021 was performed. A retrospective evaluation of necropsy reports from this period was conducted. Overall, necropsy reports were evaluated from 187 alpacas, 35 llamas and one vicuña (n = 223). A total of 50.2% of the dissected animals were thin or cachectic. Pathological alterations of the gastrointestinal tract were the most common findings (44.8%). In addition, liver changes were recorded, most frequently in adult animals. In contrast, diseases of the respiratory tract and the nervous system were found more frequently in juvenile animals. This study provides an overview of common pathologies in South American camelids in Germany and thus may help to recognise different disease symptoms at an early stage.

[Choanal atresia in an alpaca cria (Vicugna pacos)]

After birth, an alpaca cria was noticed to exhibit weakness and respiratory distress, particularly when attempting to suckle milk from the dam's udder. Clinical findings indicated the presence of bilateral choanal atresia and the animal was subsequently euthanised. A computed tomography scan and a pathological examination were performed to describe the malformation in detail. Choanal atresia is a common malformation in neonatal South American camelids, surgical treatment is not recommended. This case report provides an overview of the clinical findings as well as the results of imaging and pathologic examinations and may help to raise awareness of this malformation for early recognition.

Anaemia in South American camelids - an overview of clinical and laboratory diagnostics

South American camelids (SACs) play an increasing role in veterinary care in Europe. Many alpacas or llamas presented to veterinarians suffer from anaemia, regularly with a packed cell volume (PCV) below 0.10 l/l, which is a life-threatening condition for the animals. This review article presents clinical and laboratory diagnostic tools for the diagnosis of anaemia in SACs. Clinical identification of anaemic animals can be performed by assessing the FAMACHA© score and the Body Condition Score (BCS), since anaemia in alpacas and llamas correlates with pale mucous membranes and a lowered BCS. Haematological examination of a blood sample can provide a more differentiated diagnosis of anaemia in SACs. A common finding is regenerative anaemia with an increased number of reticulocytes that is often caused by blood loss due to Haemonchus contortus. Changes in a blood smear from an alpaca or llama with regenerative anaemia may include normoblasts (nucleated red blood cells), anisocytosis, poikilocytosis, polychromasia, Howell-Jolly bodies or basophilic stippling. Furthermore, non-regenerative anaemia, often caused by trace element deficiency or cachexia, can also occur.

Hematologic parameters in female alpacas during age progression: a retrospective study

Alpacas, like all camelids, have elliptical red blood cells (RBCs) in contrast to other mammals. This particular shape is important for increased osmotic resistance and stability. Age-related changes in the RBC count are known in other species, with alterations in both red and white blood cells being described. In alpacas, there are few data on age-related changes, and only a comparison of crias with adult animals. We characterized age-related hematologic changes in a study of 21 female alpacas from a research herd. A total of 87 records of clinically healthy alpacas of different ages were statistically analyzed retrospectively from the hematologic records over a nine-year period. Significant positive correlations of age with hemoglobin (Hb), HCT, MCV, MCH, neutrophils, platelet-to-lymphocyte ratio (PLR), and neutrophil-to-lymphocyte ratio (NLR) were found as well as significant negative correlations of age with lymphocytes in addition to lymphocyte-to-monocyte ratio (LMR). A paired comparison of eight older animals in the herd at three different ages also showed significant differences in the parameters Hb, HCT, MCV, MCH, MCHC, lymphocytes, eosinophils and neutrophils. Similar changes in hematologic parameters have been reported in other species and should be taken into account when interpreting hematologic results in alpacas.

[Diaphragmatic hernia in a female alpaca (Vicugna pacos)]

A 3-year-old pregnant female alpaca was noticed due to increased lying and decreased feed intake after shearing. Twelve days after shearing, she aborted an almost completely developed cria. After another two days, the alpaca was recumbent and subsequently died during transport to the clinic. A dissection of the carcass revealed a diaphragmatic hernia. Diaphragmatic hernias have been described in many different species, diagnosis can be made by radiography or ultrasound. Depending on the extent, surgical therapy may be successful.