Neoplasia in the Dromedary camel (Camelus dromedarius): A review

Hassan Abu Damir¹Mohamed H Tageldin²Mahmoud A Ali¹Abdu Adem^1*

• ¹Khalifa University, Abu Dhabi, United Arab Emirates
• ²Sultan Qaboos University College of Agricultural and Marine Sciences, Muscat, Oman

Background: The dromedary camels are source of milk, meat, wool and income in poor societies and of importance in social events. Tumors have devastated effects on the dromedary health, production, reproduction and marketing value. Reviews on neoplasia in dromedaries are scarce, making it pertinent to present this comprehensive study. Aim: The review provides insights into the epidemiology, pathology, future diagnosis and treatment of camel tumors. Methods: Literature of tumors in the dromedary are reviewed with focus on tumor types in different body systems, epidemilogy, risk factors, future diagnosis and treatment. The epidemiological data were collected from different sources, analyzed and presented according to body systems. The relative frequencies of malignant and benign tumors were displayed. Results: The relative frequencies of skin (54.8%), reproductive (23.0%), lymphomic (6.9%) and gastrointestinal (6.3%) tumors were the mostly encountered in camels. The common malignant and benign tumors relative frequencies were on the following order: carcinomas (35.5%), fibromas (11.2%), teratoma (7.8%), lymphomas and leukemia (7.4%), papilloma (6.2%), and adenoma (6.2%). Recent rise of tumor cases was observed. The possible risk factors included contamination of feed with fungal toxins, the grazing areas, water and soil with pesticides, herbicides, hydrocarbons and heavy metals from petroleum industry and gold mining. Other tumor risk factors included environmental changes/famine, some veterinary drugs and hormones, plant carcinogens, ultraviolet light, familial and old age. Contraction of bovine papilloma viruses etc., during movement to new areas with denser animal population is very likely. Conclusion: Different tumor types were reported in different body systems of the dromedary with carcinomas, fibromas, teratomas, lymphomas/leukemia and papillomas' being the most common. More tumor reports in camels are expected due to the recent advancements in camel farming systems, specialized breeding centers, improvement of veterinary services, and disease surveillance. Some skin tumors such as papilloma/fibropapilloma depicted koilocytosis, possibly caused by different PV strains, may warrant further investigation. The abattoir tumor surveys might show bias as dromedaries presented for slaughter were either barren females or young males. Different diagnostic methods were discussed and future advanced technology for tumor diagnosis and treatment in camels including targeted therapy and precision medicine were suggested.