Pathologies of Medieval Horses of the Netherlands – An Analysis of the Pathologies of the Medieval Horses from De Hoge Hof Ronny Kost Pathological phalanges (R. Kost) Pathologies of Medieval Horses of the Netherlands – An Analysis of the Pathologies of the Medieval Horses from De Hoge Hof Ronny Kost, S1431900 Master Thesis – Archaeological Science Supervisor: Dr. L. Llorente Rodriguez University of Leiden, Faculty of Archaeology Leiden, 01-07-2020, Final Version 2 Table of Contents 1. Introduction 5 2. An Overview of Animal Pathology 9 2.1. General Overview of Animal Pathology 9 2.1.1. Abnormalities of Skeletal Development 9 2.1.2. Diseases of the Immature Skeleton 10 2.1.3. Inflammation and Infection 11 2.1.4. Traumatic Injuries 12 2.1.5. Neoplasia 13 2.1.6. Diseases of the Joints 13 2.2. Overview of Paleopathology of Horses 15 2.2.1. Cranial and Dental Pathology 15 2.2.2. Vertebral Pathology 16 2.2.3. Pathology of the Limb Bones 18 3. Archaeological background of De Hoge Hof 20 3.1. Preliminary Results 21 3.1.1. Roman Period 22 3.1.2. Medieval Period 24 3.1.3. Modern Age 26 3.1.4. Archaeozoological Remains 26 4. Materials and Methods 28 5. Results 31 5.1. General Results 31 5.1.1. Preservation condition of the Material 33 5.1.2. Age 33 5.1.3. Anthropic and Biological Marks 33 5.2. Pathologies 36 5.2.1. Exostoses 37 5.2.2. Lesions 40 5.2.3. Ossified Haematoma 46 5.2.4. Vertebrae 48 5.2.5. Pelvic Bones 50 5.2.6. Phalanges 55 5.2.7. Splints 58 3 5.2.8. Other 58 5.2.9. Special Finds 59 5.2.10. Pathlogies described by Archeoplan Eco 64 5.3. Overview of the typology and skeletal distribution of pathologies 66 6. Discussion 68 6.1. The unique horse assemblage at De Hoge Hof 68 6.2. De Hoge Hof horse pathologies as a case study: a first insight into typological categorization present in the early medieval period in the Netherlands 69 6.3. De Hoge Hof pathologies and anthropic activities: a related matter? 72 6.4. Horse pathologies: advantages and challenges of study 73 7. Conclusion 75 8. Abstract 77 9. Bibliography 79 10. Figures and Tables 83 4 1. Introduction (Osteo)Pathology is the study of the origin and effects of abnormal structural and functional changes in the body, which usually result from either trauma or disease (Reitz and Wing 2008, 170). Pathologies can yield significant insight into the relation between humans and animals. Osteopathologies in particular can evidence how animals were treated, the way they were kept, or the way they were used. Bone is a dynamic material that reacts to external influences like trauma or diseases. There are two ways bone can react to trauma and disease (excluding some abnormalities in skeletal development): the forming of new bone, or the resorption of bone. In order to identify the possible cause, the spread of the pathological changes throughout the skeleton is of great importance. However, this is a difficult task for archaeozoological materials since most of the materials consist of individual or fragmented bones that are rarely articulated or associated to one single individual (Groot 2010, 92). Making a diagnosis based on a single fragment is very hard, which is why paleopathology for archaeozoological remains is still very underdeveloped (Groot 2010, 89- 92). Unlike the investigation of paleopathology in humans, literature on the analysis of paleopathology in animal remains has been rare so far (Janeczek et al. 2010, 331). Paleopathology, to this day, is still mainly based on the classical publication of Baker and Brothwell in 1980 based on macroscopic pathological changes in archaeozoology. There is still no definitive and detailed system or nomenclature for animal paleopathology, often leading to different terms used by different publications (Markovic et al. 2014, 83). There has been both optimism on the use paleopathology in archaeozoology as well as caution and pessimism. The diagnosis and interpretation of paleopathologies can be very difficult and even in modern clinical situations after a post-mortem pathologists are not always able to make a reliable diagnosis (Siegel 1976, 350). In bones from archaeological contexts, after all manner of taphonomic processes, this will be even harder and coming to a diagnosis can be problematic (Siegel 1976, 350). From both human and animal sources, it has been stated that there are difficulties with distinguishing between pathological changes and pseudopathological changes. These are changes to the bone that are caused post-mortem by edaphic factors, physicochemical decomposition, insect action, or animal gnawing (Wells 1967 in Siegel 1976, 350). Other issues are the possibilities of inaccurate identification of pathologies due to a general lack of knowledge of the parameters of normal variation. This is especially true for wild forms due to the 5 lack of knowledge regarding the occurrence and nature of diseases in wild populations (Siegel 1976, 350). It is also important to understand that most diseases primarily leave their mark in the soft-tissue. Only in more severe cases do diseases typically leave their mark on the bones as pathological changes. One should keep in mind that pathological changes on the bones represent only the bare minimum of diseases that were present in ancient populations (Siegel 1976, 355). However, regardless of the difficulties and possible problems with the use of paleopathology in archaeozoology, the reporting and describing of pathologies should be encouraged. Research done on pathology in human populations has built up significant amounts of literature (Siegel 1976, 350). A similar base of knowledge should be possible for pathologies in animals. The Animal Palaeopathology Working Group of the ICAZ has already made a commendable start to such a base of knowledge by managing a searchable bibliography of publications on the topic of paleopathology (www.zotero.org). From modern day research it is clear that pathologies can be the result of a variety of factors that include malnutrition or mismanagement as a result of husbandry practices by humans. The research on paleopathologies in archaeozoological contexts could yield insight into the husbandry practices of animals in past societies and the role these animals played in said societies (Siegel 1976, 350-351). The frequency of pathologies in a population and in an archaeozoological assemblage can be influenced by many factors. For example, a low frequency of pathologies might indicate that the population was young and fit, while a high frequency of pathologies might be explained by local inbreeding causing an increase in detrimental genetic traits or by poor husbandry practices (Siegel 1976, 357). But other variables, such as economic factors may be at work as well. For example, animals exploited for meat are often slaughtered at a young age. This could lead to an “increase” in the relative frequency of diseases that develop in young animals such as rickets or neonatal infections. On the other hand diseases that tend to occur in populations of older animals, such as degenerative, senile and infectious changes, are likely less frequent due to the composition of the population because of economic reasons (Siegel 1976, 357). Different forms of pathology occur in differing frequencies throughout the body of different animals. In a research on a British Neolithic to Medieval site, Siegel identified 141 pathologies of which oral pathologies were most common (33%) (Siegel 1976). These were mostly found in oxen with a particularly high frequency of absence of the first lower molar. Arthropathy, here defined as non- infectious degenerative pathologies of the joint, was second in frequency with 20% and were mostly 6 found in the tarsals and metatarsals of horses, likely due to use of the horses as draught animals. Fractures accounted for 10% of the pathologies and were most common in dogs. Finally, hunting game, such as red deer and fowl, had no pathologies, likely due to underrepresentation in the assemblage (Siegel 1976, 357-362). Another research by Dzierzecka et al. regarding pathological changes in Iron Age and medieval horses showed that fractures were the most common condition (Dzierzecka et al. 2008, 693). Because the occurrence and frequency of pathologies differs per species and location, for this research, the choice has been made to focus on pathologies in a single species of animal: horses. Horses have been chosen due to the variety of roles these animals played in past societies, from riding horses to war horses, to draught horses. Horses have been used primarily to ride since the end of the Bronze Age (3500 BC) onwards (Outram et al. 2009, 1332). Horses are somewhat unique as a domesticated ungulate given that they are mostly used for a variety of tasks rather than just for exploitation of food. In the case of medieval horses in the Netherlands, they have typically not been consumed, hence their bones tend to be less fractured compared to food animals of similar size such as cattle. Cutting and chopping marks are also less common, although their radii and metapodia were used for the production of objects (Lauwerier 1997a, 483-484). Their role as riding or draught animals instead of food animals means that the horses should live longer and have more time to develop pathologies that could be used to indicate a particular role. The idea is that different tasks lead to different forms of pathology and to pathologies in different places. Levine et al. pointed out that the stresses on the horse caused by riding and traction differ from natural activities, as well as being distinguishable from each other (Levine et al. 2000, 125). Since most horses are typically used for one task, it would be expected that these different tasks are identifiable (Levine et al.