Veterinary Treatment of Llamas and Alpacas

Veterinary Treatment of Llamas and Alpacas

2nd Edition

I would like to dedicate this book to all the veterinary surgeons who are mothers and have to juggle looking after their families with practicing veterinary surgery in all its many forms.

‘Taking your daughter to work’.

Lissie Gercke - A mother of four who has completed the Royal College of Veterinary Surgeons Certificate in Camelid Medicine and Surgery which I was proud to write and develop.

Veterinary Treatment of Llamas and Alpacas

2nd Edition

Graham R. Duncanson

Blackthorn Lodge, Crostwick, Norwich, Norfolk NR12 7BG

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Library of Congress Cataloging-in-Publication Data

Names: Duncanson, Graham R., author.

Title: Veterinary treatment of llamas and alpacas / Graham R Duncanson.

Description: 2nd edition. | Wallingford, Oxfordshire ; Boston : CAB International, [2023] | Includes bibliographical references and index. | Summary: This book provides practical veterinary advice for llamas and alpacas. The new edition covers husbandry, nutrition, examination, vaccines, analgesia, anaesthesia, dermatology and poisons, as well as expanding on zoonotic diseases coverage, biosecurity, handling, and advances in treatment options and surgical techniques-- Provided by publisher.

Identifiers: LCCN 2023019013 (print) | LCCN 2023019014 (ebook) | ISBN 9781800623552 (hardback) | ISBN 9781800623569 (ebook) | ISBN 9781800623576 (epub)

Subjects: LCSH: Llamas--Diseases. | Alpaca--Diseases. | Llamas--Surgery. | Alpaca--Surgery.

Classification: LCC SF997.5.C3 D86 2023 (print) | LCC SF997.5.C3 (ebook) | DDC 636.2/966--dc23/eng/20230627

LC record available at https://lccn.loc.gov/2023019013

LC ebook record available at https://lccn.loc.gov/2023019014

ISBN-13: 9781800623552 (hardback)

9781800623569 (ePDF)

9781800623576 (ePub)

DOI: 10.1079/9781800623576.0000

Commissioning Editor: Alexandra Lainsbury

Editorial Assistant: Lauren Davies

Production Editor: Rosie Hayden

Typeset by Straive, Pondicherry, India

Printed and bound in the USA by Integrated Books International, Dulles, Virginia

Contents

Foreword

Acknowledgements

Glossary

Abbreviations

1Animal Husbandry

2Nutrition and Metabolic Diseases

3Examination

4Sample Taking and Simple Diagnostic Tests

5Veterinary Equipment

6Veterinary Medicines

7Vaccines

8Sedation, Anaesthesia, Surgical Conditions and Euthanasia

9Medicine and Surgery of the Gastroenteric System

10 Medicine and Surgery of the Respiratory and Circulatory Systems

11 Medicine and Surgery of the Urino-Genital System

12 Medicine and Surgery of the Neurological System

13 Medicine and Surgery of the Locomotory System

14 Skin Conditions

15 Cause of Sudden Death and Post-Mortem Technique

16 Poisons

17 Zoonotic Diseases

References

Index

Foreword

The New World camelids are a collective group inclusive of llamas, alpacas, guanacos and vicunas, all originating in Central America and forming the Camelidae family. I am delighted to be writing the foreword for the second edition of this book, demonstrating our need to keep our veterinary knowledge up to date with the growing popularity of camelids in the UK. While guanacos and vicunas are still scarce in the UK, alpacas and llamas are becoming increasingly popular whether as pets, show animals or farmed for their sought-after fleeces. This unusual book should give the reader the confidence to take on any camelid-related case.

Camelids are of increasing interest not only as farmed or companion animals but because of their unique contribution to science. After an accidental discovery in the 1980s, it became known that members of the camelid family produce a special class of antibody, known as a nanobody. This has allowed scientists to study previously inaccessible body proteins and understand how those proteins malfunction in disease. Structural biologists can select a nanobody to lock in place their protein of interest. This secure bond allows the protein’s atomic structure to be tested, allowing more precise drug development than previously with antibodies. Virologists have discovered these nanobodies have the potential to form better receptor bonds with human cells than current HIV vaccines, stimulating further interest into these specialist cells.

While having an extraordinary immune system, camelids too are vulnerable to infectious and non-infectious diseases, which we need to be prepared to diagnose and treat. The zoonotic potential of tuberculosis has become a growing concern in this family of animals, meaning owners and veterinary surgeons need to be armed with the knowledge necessary to recommend precautions for the herd as well as address the individual.

My father can’t help but demonstrate his persistent enthusiasm for life which is again captured in this book making it an invigorating read. I continue to admire my dad’s dogged commitment to professional development and support of the veterinary community. I hope I have the energy to do half as good a job!

Amelia Shanklin MRCVS

Acknowledgements

I would like to thank two camelid associations, The British Llama Society (BLS) and the British Camelids Ltd (BCL), for their permission to include their information sheets and forms for agreement of owners.

I am very grateful to my veterinary friend and colleague Bob Broadbent MRCVS for his input on tuberculosis in camelids.

Glossary

Abortion: the premature birth of young.Annual: a plant that grows from seed, flowers and dies within a year.Anthelmintics: drugs that expel parasitic worms from the body, generally by paralysing or starving them.Antigen: a molecule or part of a molecule that is recognised by components of the host immune system.Awn: a bristle or hair-like appendage to a fruit or to a glume, as in barley and some other grasses.Bacteraemia: bacteria in the blood.Biennial: a plant that flowers and dies in the second year after growing from a seed.Bradycardia: decrease in heart rate.Bruxism: grinding of teeth.Calculi: stones formed in the urinary system.Cerebral: relating to the cerebrum, the largest part of the brain.Cestodes: parasitic flatworms, commonly called tapeworms, which usually live in the digestive tract of vertebrates as adults and in bodies of various intermediate hosts as juvenile stages.Colitis: inflammation of the colon, often used to describe an inflammation of the large intestine.Coma: profound unconsciousness from which the patient cannot be roused.Congestion: the presence of an abnormal amount of blood in an organ or part.Contusions: severe bruises.Convulsion: a violent involuntary contraction of muscles.Corm: underground bulbous root.Cria: a young SAC in its first year.Cryptorchid: rig.Cystitis: inflammation of the bladder.Deciduous plants: those that shed all their leaves annually.Detoxicate: to render a poison harmless.Distension: the filling of a hollow organ to more than its usual capacity.Diuresis: excessive urination.DNA fingerprinting: much like the fingerprint used in human identification, but done with unique DNA characters for each individual animal. Utilizes PCR to replicate small samples.Drenching: giving an anthelmintic dose by mouth.Dysentery: an illness characterized by diarrhoea with blood in the faeces.Dysphagia: difficulty in swallowing. Dysphonia: hoarseness heard when vocalizing.Dyspnoea: difficulty in breathing.Dystocia: difficulty at parturition.Egg reappearance period: the time taken (usually expressed in weeks) for eggs to reappear in faeces after anthelmintic treatment. Usually this is described for drug-sensitive worm populations at the time of product licensing.ELISA (enzyme-linked immunosorbent assay): a technique used primarily in immunology to detect the presence of an antibody or an antigen in a sample. Basically, an unknown amount of antigen is bound to the surface of a plastic well, then a specific antibody is added and if specific will bind the antigen. This antibody is linked to an enzyme or is detected by incubation with a second antibody that is linked to an enzyme. In the final step a substance is added that the enzyme can convert to some detectable signal (usually a colour change that is detectable by a spectrophotometer).Emaciation: excessive body wasting.Emesis: vomiting.Emetic: a substance that causes vomiting.Emphysema: air or gas in the interstices of a tissue.Enema: rectal injection.Epidemiology: the study of factors affecting the health of populations and often how diseases are transmitted.FECRT (faecal egg count reduction test): a test that measures the effect on faecal egg output of anthelmintic treatment. Generally, efficacy is assessed by comparing FECs obtained on the day of treatment with those obtained 14 days after treatment. This is an important tool in detecting anthelmintic resistance in the field.Gelding: castrated SAC.Gene mapping: the gene on a given chromosome.Genome: an organism’s entire hereditary information, encoded either in DNA or, for some types of virus, in RNA. The genome includes the genes that code the proteins and non-coding sequences of the DNA.Genotype: The inherited instructions organisms carry in their genetic code.Granules: small grains.Gravid: the pregnant horn of a uterus.Haematuria: blood in the urine.Haemoglobinuria: haemoglobin in the urine.Haemolytic: a substance that causes breakdown of red blood corpuscles.Helminths: a group of eukaryotic parasites that live inside their host. They are worm-like and live and feed off animals.Hembra: female SAC.Hepatitis: inflammation of the liver.Herbaceous perennials: plants in which the greater part dies after flowering, leaving only the rootstock to produce next year’s growth.Herd: the collective word for a group of SACs.Iatrogenic: resulting from treatment.Ileus: failure of peristalsis.In cria: pregnant SAC.In vitro: in the test tube.In vivo: in the living body.Jaundice: a disease in which bile pigments stain the mucous membranes.Larvae: juvenile forms that many animals undergo before they mature to an adult stage. Larvae are frequently adapted to environments different to those adult stages live in.Leucocytosis: increase in WBC in the blood.Leucopenia: decrease in WBC in the blood. Linear leaves: those that are long and narrow.Lumen: the inner space of a tubular structure, such as the intestine.Macho: entire male SAC.Markers: a short tandem repeat (STR) that may be used to aid in the identification of a trait.Melena: dark tarry faeces indicating bleeding high in the intestinal tract.Metritis: inflammation of the uterus.Myiasis: fly strike.Nematodes: roundworms, one of the most diverse phyla of all animals.Nodule: a small round lump.Paracentesis: the technique of puncturing a body cavity.Pathogenicity: the ability of a pathogen to produce signs of disease in an organism.Pathognomic: a single specific sign of a disease.Phenotype: any observable characteristic or trait of an organism, such as its morphology, development, biochemical or physiological properties, or behaviour. Phenotypes result from the expression of an organism’s genes as well as the influence of environmental factors and possible interactions between the two.Polydactyly: having an extra limb.Polydipsia: drinking excessive amounts of water.Polymerase chain reaction (PCR): a technique to amplify a single or a few copies of a piece of DNA by several orders of magnitude generating thousands to millions of copies of a particular sequence. Polymerase chain reaction relies on cycles of repeated heating and cooling of DNA melting and enzymatic replication of DNA. Primers (short DNA fragments) containing sequences complementary to the target region along with a DNA polymerase (after which the method is named) are key components to enable selective and repeated amplification. As PCR progresses, DNA generated is used as a template for replication, setting in motion a chain reaction in which the template is exponentially amplified.Polyphagia: eating an excessive amount.Premix: medicine available in a concentrated form to be added to food.Primer: several thousand copies of short sequences of DNA that are complementary to part of the DNA to be sequenced.Ptyalism: excess saliva production.Purgative: a strong laxative.Pyrexia: raised rectal temperature.Recumbency: unable to get up.Rhinitis: inflammation of the structures in the nose.Rig: a male in which one or both testicles have not descended into the scrotum.Rostral: towards the nose.Rye grass: a commonly grown grass Lolium perenne.Schistosomus reflexus: a deformity of a fetus in which the spine is bent backwards.Septicaemia: pathogenic bacteria in the blood.Short tandem reprints (STR): sections of DNA arranged in back to back repetition.Slough: dead tissue that drops away from living tissue.Spasm: involuntary contraction of a muscle.Staggers: an erratic gait.Stomatitis: inflammation of the mouth and gums.Stricture: a narrowing of a tubular organ.Subclinical: when the symptoms are not evident.Syndrome: a group of symptoms.Tachycardia: increased heart rate.Tachypnoea: increased respiratory rate.Tenesmus: straining to pass urine or faeces.Teratoma: a developmental embryological deformity. Tourniquet: an appliance for temporary stoppage of the circulation in a limb.Tympanic: distended with gas.Ubiquitous: everywhere.Udder: mammary gland.Ureter: the tube connecting the kidney to the bladder.Urethra: the tube leading from the bladder to outside.Urethritis: inflammation of the urethra.Urine scald: inflammation of the skin caused by persistent wetting with urine.Urolithiasis: the formation of stones in the urinary system.Vagus: tenth cranial nerve.Vesicle: a collection of fluid in the surface layers of the skin or of a mucous membrane.Viraemia: virus particles in the blood.Volatile: a substance that evaporates rapidly.Wether: a castrated SAC.Zoonoses: diseases communicable between animals and man.

Abbreviations

1

Animal Husbandry

Introduction

South American camelids (SACs) were a vital part of life in the Andes in the days of the Incas before the arrival of the Spanish Conquistadors. Cattle, sheep and goats took over in the following centuries but now SACs are making a very strong resurgence. The area of greatest rearing of SACs is on the Andean Cordillera in southern Peru, central Bolivia and northern Chile. There are significant populations of SACs in Argentina, Australia, New Zealand, USA, Canada and the UK. Numbers are rising on mainland Europe, particularly in Sweden and Eire.

Evolution

Camelid evolution is traced back to North America 40 million years ago. There were probably several genera. Many became extinct but some crossed the land bridge, which at that stage was across the Bering Strait so North America was linked with Asia. The camelids that evolved in Asia to become the camels we know today are outside the remit of this book. The camelids in North America migrated to South America or died out, leaving the SACs we know today. These are mainly domestic or semi-wild. It is not known whether the wild SACs are feral or whether they are truly wild. Most camels in the old world and Australia are actually feral. The only exceptions are the wild camels of the Gobi Desert found in China and Mongolia. Sadly there are only 600 remaining. Both camels and SACs have the same number of chromosomes and if cross-fertilized can produce fertile young. Obviously, their variation in size prevents natural mating.

SACs evolved from a common ancestor approximately 2 million years ago. There is evidence of domestication 6000 years ago in the central Peruvian Andes at altitudes of over 4000 m. This plateau-type high altitude grassland has extreme variations of daily temperatures. Frosts are frequent as are high winds. The area is extremely dry with very limited rainfall.

Numbers

In 2010 it was estimated that there were 36,000 SACs in the UK. Of these 31,000 were thought to be alpacas and 5000 to be llamas with just a few hundred farmed guanacos and a very small number of vicunas in zoos or private collections. Thirteen years later the numbers have risen to a total of more than 50,000 alpacas and 8000 llamas in the UK. In 2023 there are more than 175,000 SACs in Australia. These all stem from a herd of 250 that was brought into Australia in 1858. In the USA there are over 400,000 SACs after an initial import in 1984. These numbers are very small compared to the 4 million in South America.

Classification

The normal classification is into four types, llama, alpaca, guanaco and vicuna. To be exact the first three are placed in the same genus, Lama, making the species L. glama, L. pacos and L. guanicoe. Vicuna are placed in a separate genus, Vicugna. This genus is divided into two subspecies, V. vicugna mensalis from Peru and V. vicugna vicugna from Argentina. They are all classified in the Lamini tribe, which is part of the Camelidae family. SACs are grouped with camels, both the dromedary and the bactrian, in the suborder Tylopoda. Tylopoda and the suborders Cetruminantia, which includes cattle, sheep, goats, water buffalo, giraffe, deer, antelope and bison, and Suinia, which includes pigs and peccaries, make up the order Artiodactyla.

Tylopoda has some important differences from ruminants of the suborder Cetruminantia. Ruminants have red blood cells (RBCs), which are round and 10 microns in diameter. SACs have elliptical RBCs, which are only 6.5 microns in diameter. Ruminants have feet that have hooves, consisting of a horn wall and sole. SACs have toenails and a soft pad. Their second and third phalanges are horizontal, whereas in ruminants the second and third phalanges are nearly vertical.

Both ruminants and tylopods are foregut fermenters, with regurgitation, rechewing and reswallowing. However, tylopods have only three stomach compartments and are resistant to bloat. Ruminants have four stomach compartments and suffer from bloat.

The teeth in SACs cause real confusion whereas in ruminants they are straightforward. Ruminants have no upper incisors or upper canines. On their lower hemi-mandible, they have three incisors and a canine. This canine has migrated rostrally and resembles an incisor. They therefore appear to have four lower incisors. SACs have on their upper hemi-maxilla one canine and one upper incisor, which have migrated caudally and resemble a canine. So, they appear to have two upper canines on each side. SACs on their hemi-mandible have three incisors and one canine. There are also differences with the cheek teeth. Ruminants have three upper and lower premolars on each side. SACs have one and maybe a second, upper and lower premolar on each side. Both SACs and ruminants have three upper and lower molars on each side.

It is perhaps in the reproductive system where ruminants are at variance the most from SACs. Ruminants have an oestrus cycle, with spontaneous ovulation and no follicular wave cycle. SACs do not have an oestrus cycle and are induced ovulators. They have a follicular wave cycle. Ruminants copulate in the standing position with short and intense ejaculation. SACs copulate in the prone position and have prolonged ejaculation. The male SAC has a cartilaginous projection on the tip of his penis. This is absent in ruminants. SACs have a diffuse placenta, and the fetus is surrounded by an epidermal membrane. Ruminant fetuses do not have such a membrane but have placental cotyledons.

SACs are primarily nasal breathers with an elongated soft palate. Mouth breathing in SACs is an extremely serious sign. Ruminants have a short soft palate and can breathe nasally or orally.

SAC’s kidneys are smooth and elliptical. Some ruminants have smooth kidneys, e.g. the sheep, and some have lobed kidneys, e.g. the ox. Female SACs have a sub-urethral diverticulum at the external urethral orifice. Ruminants have no such diverticulum.

There has been less research carried out on parasites occurring in or on SACs than in or on ruminants. However, this is being rapidly rectified as knowledge is constantly being accrued. SACs have unique internal parasites and protozoa as well as sharing other species of parasite with cattle, sheep and goats. The picture with external parasites is confusing. SACs certainly have unique lice. They may also have unique mange mites, but the classification is not yet confirmed.

The author takes issue with camelid owners and veterinary surgeons who maintain that SACs are minimally susceptible to many infectious diseases. The author does not think this is an exact assessment of the situation. SACs were believed to have some resistance to bovine tuberculosis. The situation in the UK in 2023 makes nonsense of this statement where numbers of infected camelid herds are rising monthly. SACs have also been found to be susceptible to human tuberculosis, and they have been found to be a source of infection of bovine and human tuberculosis to humans. SACs are a definite zoonotic danger. Owing to a high-profile single importation of an alpaca from New Zealand, which after arrival had dubious testing results and was subsequently slaughtered, the testing of SACs is in complete disarray.

The author does agree that there is no evidence of bovine brucellosis in SACs; however, SACs are definitely susceptible to foot-and-mouth disease (FMD) and blue tongue virus (BTV). Further examples will be given in Chapter 17.

There are two lines of alpaca, depending on their fleece types. The more common huacaya has an even fine fleece and the less common suri has a fine crimped fleece. In the USA huacaya outnumber suri by nine to one. They may be bred together freely but the results may not be as predictable as desired. For example: a total of 1980 suri × suri matings produced 278 huacaya and 1702 suri offspring; 145 suri × huacaya matings produced 89 huacaya and 56 suri offspring; 19,637 hyacaya × hyacaya matings produced 19,633 huacaya and 4 suri offspring (Sponenberg, 2010). No linkage or other influence of sex was noticed. These results are consistent with a single autosomal dominant gene controlling suri fleece production, with an additional relatively common genetic mechanism that can suppress the suri phenotype in some animals. These results are especially important in cases where the two fleece types are crossed with one another, as they result in a relative underproduction of suri fleeces.

Colours

There are 22 colours recognized for alpacas, ranging from black to white. Some also produce multicoloured fleeces. In fact alpacas can come in a very wide variety of colours. The main colours, though, are brown, black, white, palomino and grey. In the USA the Alpaca Owners and Breeders Association will allow only one or more of 16 standard colours to be registered. The official colours are:

White;

Beige;

Light Fawn;

Medium Fawn;

Dark Fawn;

Light Brown;

Medium Brown;

Dark Brown;

Bay Black;

True Black;

Light Silver Grey;

Medium Silver Grey;

Dark Silver Grey;

Light Rose Grey;

Medium Rose Grey; and

Dark Rose Grey.

There can also be patterns of several colours.

Llamas are the same, with pinto and appaloosa also being recognized. Guanacos are reddish brown in colour with an under-colouring of white. They often have black marks on the top of their noses and heads. Vicuna are basically a yellowish light brown. There are various bib markings of white.

Terminology

A female SAC is called a hembra and a male a macho. Castrated males are called geldings or wethers. Young animals are called crias.

Fibre

The first SAC fibre known to be imported into the UK was in 1834. Sir Titus Salt found some bales used as ship’s ballast on the docks in Liverpool. Being a wool merchant he realized its potential. Importation increased during the next 50 years, particularly after Queen Victoria was given some garments. At the same time in Australia Sir Charles Ledger imported a herd of 250 SACs.

Behaviour and Behaviour Problems

Introduction

The single dominant male controls the family group (Fig. 1.1). He decides its size and its territory and he spends most of his time patrolling and protecting the group. It is because of this trait that male llamas have been used with sheep flocks to protect young lambs from foxes (Fig. 1.2). His period of dominance only lasts until he is deposed by another male. Under him there is a strong hierarchy, with the oldest female in top position with the other females ranking below her. Crias tend to have the rank of their mothers so young weaned animals tend to be at the bottom of the pecking order.

Fig. 1.1. A dominant male on the altiplano.

Fig 1.2. A single animal stands guard.

In the wild a group will consist of one male with up to 20 females and their babies. The adolescents are driven away. Young females soon go to join another male’s family group. The young males and the deposed males tend to live in large groups of up to 200.

In the wild, groups stay well away from each other and travel great distances (Fig. 1.3). SACs are very aware of their limitations so that they will drive off small predators but run away from large predators or packs of smaller predators. They depend on body language for communication. In the wild the normal age at death is 12, but under domestication they may well live on into their early twenties. There are no toxic plants on the altiplano and so SACs are very sensitive to poisoning.

Fig. 1.3. Wild groups travel great distances.

SACs even in the wild tend to defecate in a pile. This is used by the male to smell for strangers and for receptive females. It is also useful as it is a natural way to reduce intestinal parasites. Overcrowding should be avoided at all costs because all types of disease will flourish. Disease control, particularly the control of internal and external parasites, will be very difficult if there is overstocking.

Heat stress is a real problem for SACs. Temperatures over 26°C and humidity of over 80% need to be avoided, so fans, shade and ponds need to be provided in hot climates. However, liver fluke is becoming a major parasite in the UK so ponds should be avoided. SACs will also defecate in water and so pollute it and increase the risk of coccidiosis. SACs are excellent swimmers and so ditches, dykes and rivers will not contain them.

Vocalization by humming is the most common sound used by SACs. It is probably used to confirm contact as it will become louder on separation. A lack of humming may be a cause for concern. Groaning or bruxism is a real cause for alarm for the keeper as it indicates pain. Veterinary attention should be sought. Snorting denotes mild aggression. This will turn to screeching in males if being handled or meeting other males. The position of the ears and tail denotes status. Males may spit and kick. They may even charge and bite. Submission will be shown by a drooping of the upper eyelid and imitation mouth breathing. Males make an ogling sound before and during mating.

Behavioural problems

A number of behavioural problems have been found in captive SACs, but to date there has been little research carried out into their causality. The two most common ‘vices’ are spitting at people and the Berserk Male Syndrome (this syndrome is not actually exclusively in males) where SACs respond aggressively to people.

SACs have a largely unfair reputation for spitting, since they will rarely spit at people unless they have become overfamiliarized. The activity is part of the animal’s natural defensive mechanism, and is usually a response to the invasion of personal space. An unwary person can be caught in the cross fire of two spitting animals. An animal that commonly spits at people is extremely rare. The actual contents of the spit can take three forms, food, saliva or stomach contents, the latter is the so-called green spit. Adults and more commonly crias will spit food and/or saliva when they are eating to warn other animals to back off and give them space. The green spit, which is much more unpleasant both to humans and other SACs, is used in more severe confrontations. It is used by SACs to establish dominance. Most animals will pre-warn the challenger by pinning its ears back very tightly and tilting its head back so that the nose is pointing up in the air. If this warning is ignored then the animal will spit.

The more serious problem involving human–camelid interaction is the Berserk Male Syndrome, which, like spitting at people, is likely to have a root cause in overfamiliarization with people at a young age. It is extremely common in orphaned animals that have had to be hand reared. The syndrome may slowly develop until eventually the animal will pace a fence line, screaming and spitting, when anyone approaches. Such animals become highly dangerous and should be destroyed. However, the syndrome can be avoided by not bottle feeding animals unless absolutely necessary and then only handling the animal at feeding time, leaving it with other crias for the rest of the time.

Wild South American camelids

The wild vicuna (Vicugna vicugna) in southern Chile were pushed to near extinction by poachers who shot and skinned the animals for their very valuable fleece, until by the 1970s only 6000 were left in the wild. A ban on trade in wild vicuna products has allowed the population to recover to over a quarter of a million. In the 15th century the Incas used a system called ‘Chaku’ to round up, shear and release the vicuna annually. This system has been revived recently by the Aymara Indians. It involves stretching a rope, decorated with brightly coloured ribbons, up to a mile long, across a hillside and ‘walking’ the vicuna down. Eventually the animals are driven into a corral which is made like a labyrinth. The vicunas once caught are blindfolded before being shorn and then are released back into the wild.

Restraint

Some practitioners have issues with handling alpacas and llamas. There are some very wide differences in behaviour and hence handling in individual animals and in types of animal varies enormously. Practitioners familiar with cattle should reflect on the differences between handling dairy cattle and suckler cattle that are kept extensively. Alpacas kept in small groups by one quiet kind owner are very different from a large group of semi-wild llamas herded on large areas (Fig. 1.4).

Fig. 1.4. Large groups are herded over a wide area.

Quiet animals can easily be handled by firmly grasping them around the neck having herded them into a small pen or stable with long ropes (horse lunge-lines are ideal) or long white rods. For injecting animals intravenously the author has found getting an assistant to hold both ears and stretch the neck upwards to be useful. It would appear that grasping the ears acts like a twitch in horses. Certain individuals, usually well known by the owners, will kick if the handler is up close to them. This is of little consequence. It is only if the animal is 3 feet away and the kick of the hindleg lands at its full force that it is serious. Llamas may strike forwards with their front legs. However, this does not seem to be a problem if the handler grasps them firmly around the neck. Many males will bite other males but it is very rare for a human to get bitten when holding an animal firmly.

Both llamas and alpacas will ‘kush’ when restrained. They can be made to continue in this position of ventral recumbency if they are held firmly around the neck or if they are ‘chukkered’. This is when a rope is looped around their abdomen in front of their pelvis in a noose. Their hindlegs are brought forward above their fetlocks through this loop. The noose is then tightened when they are on the ground.

Drug Administration

SACs have an inelastic skin, which is thick. There is little subcutaneous space. Most clinicians favour the subcuticular route for injections as there is little muscular development in SACs. The best sites for subcutaneous injections are in front or behind the shoulder. The author prefers the quadriceps muscle as a site for intramuscular injection. However, the triceps and semitendinous/semimembranous can also be used. Intravenous injection is best carried out into the right jugular vein to avoid any danger of penetration of the oesophagus. In adults the skin is too thick for the raised jugular to be visible (Fig 1.5). Some authors (D’Alterio, 2006) prefer to use the lower part of the neck, using the ventral projection of the transverse process of the fifth and sixth cervical vertebrae (laterally) and the trachea (medially) as landmarks. There is some danger of injection into the carotid artery as the carotid artery runs only just deeper to the jugular vein in this site. Therefore the author prefers higher up the neck between the third and fourth cervical vertebrae, where the carotid is deeper. To carry out catheterization it is easier to cut through the skin with a scalpel rather than trying to place the catheter directly into the vein. The hair should be clipped, local anaesthetic should be infiltrated and the skin should be surgically prepared.

Fig. 1.5. The right side is used for venipuncture.

Gastric intubation in SACs can only be accomplished orally. A calf-sized gastric tube or an oral calf rehydration bag and tube is ideal for this procedure. If a soft gastric tube is used the mouth will need to be held open to prevent damage to the tube from the sharp cheek teeth. With good equipment and well-trained staff, SACs can be drenched (Fig 1.6).

Fig. 1.6. Experienced staff are required for drenching.

Reproductive Anatomy and Physiology

Introduction

The reproductive anatomy and physiology of SACs is quite unique, more closely resembling the horse than the ruminant by having a gestation period of 335–350 days, a diffuse placentation, the ability to breed back shortly after parturition, and very rare term twinning occurrence. Induced ovulation, which occurs 24 h after copulation in females with a tertiary follicle in excess of 7 mm, is obviously not comparable to the horse.

Males reach sexual maturity at 2.5 years. They have a fibroelastic penis and sigmoid flexure like ruminants. There is an embryonic preputial adhesion (frenulum), which prevents penile protrusion until repeated sexual stimulation occurs. This normally occurs in the animal’s third year. In a normal size llama the penis when extended is 40 cm, of which half extends beyond the prepuce. There is a very short cartilaginous process that dilates the cervix during prolonged copulation, which occurs with both animals on the ground. In the relaxed state, the prepuce points caudally and urination is in a caudal direction. When sexually aroused the prepuce is directed cranially by the protractor prepuce muscle.

Testicles are small, averaging 24 g for adult llamas and 20 g for adult alpacas. The males have two small paired bulbo-urethral glands and a small prostate gland. The volume of the ejaculate is 3 ml or less.

The gross anatomy of the female SAC’s reproductive tract is very similar to that seen in ruminants. The vagina of a mature female is approximately 25 cm long and 3 cm in diameter. The external os of the cervix protrudes slightly into the vagina. There are two or three rings in the cervix. In the maiden mature female, the uterus has a short body of 2.5 cm × 2.5 cm and two uterine horns of 2 cm × 6 cm. As 98% of pregnancies occur in the left horn this is bigger in the bred female even after involution. The gravid horn is roughly 3 cm × 10 cm and the non-gravid horn 2 cm × 6 cm after involution. Inactive ovaries are roughly 1.5 cm × 1.0 cm × 0.5 cm but will double in size with the development of multiple follicles or a corpus luteum.

From puberty females normally have a 12-day follicular wave pattern with follicles developing alternately on each ovary. Peak sexual activity is reached when the follicles are over 1 cm in size. Ovulation will occur 24 h after copulation, usually due to a luteinizing hormone (LH) surge after the stimulation from the male. The LH surge is not increased by further breeding within 48 h. After ovulation the corpus luteum will develop in a standard cottage loaf form approximately 1.5 cm in size. If the mating is non-fertile it will regress in 13 days with sexual receptivity recurring at 14 to 21 days after the original mating. If the mating is fertile the corpus luteum will remain, as pregnancy depends on the corpus luteum in SACs.

Mating

Mating has been seen in 6-month-old SACs but it is not recommended to breed animals before 18 months. If young females are mated there is a danger of stunted crias and dystocias. There are no significant differences in the reproductive anatomy and physiology among llamas, alpacas, guanacos and vicunas. A non-pregnant sexually mature female will, after a few minutes in the presence of a normal sexually mature male, adopt a sternal recumbent position, called the ‘kush position’. The male will straddle the female to allow penile penetration. Initially semen is deposited in the cervix. However, with prolonged copulation the cervix will dilate enough for the semen to actually be deposited in the uterus. If a tertiary follicle is present ovulation will be induced. The time taken for copulation will vary between 5 and 45 min with an average of 20 min. If the female then refuses the male it is likely that ovulation has occurred. This can be confirmed by a blood test 5–7 days later, which will show a progesterone level greater than 1 ng/ml.

Female SACs show extended periods of sexual receptivity, indicating that the association of oestrogens and sexual receptivity is not quite related as it is in spontaneously ovulating ruminants. In ruminants, females are sexually receptive to the male only for a short period of time, in contrast to 1 to 36 days in SACs.

In SACs pregnancy may result from ovulations originating from either ovary; however, implantation occurs over 95% of the time in the left horn of the bipartite uterus. Implantation starts at approximately 30 days after the successful mating and is complete by 90 days.

Pregnancy cannot be readily seen even in the advanced state in SACs. Mammary development may be observable 1 week prepartum with some enlargement of the four teats. Waxing of the teats is rare as is prepartum milk let-down.

Postpartum females are often receptive to the male soon after birth. It is prudent to withhold the male for 2 weeks or longer if a vulval discharge is seen. SACs are reproductively active for their whole lives, which is often over 20 years.

Breeding strategies

Domestic SAC breeders should reflect that wild vicuna and guanaco manage to reproduce very satisfactorily without human interference. Therefore, it is likely that given sufficient area and adequate fencing herds of alpaca and llama will reproduce very well with minimum interference. Often 350 females are run with ten males on a vast area. However, there are some disadvantages to such a management strategy, which is called stud pasture breeding. The management is in the dark as to the pregnancy status of the females, which, because they are not handled, will be more wild and harder to train. If such management is reduced to one male to 35 females there is a danger that without good and early pregnancy diagnosis an infertile or subfertile male will not be found and pregnancies will be missed. If more than one mature male is run with say a group of 70 females there is a danger that the mature males will tend to fight and injure themselves.

The other end of the spectrum is hand mating, where females are bred to a selected stud at a selected hour at various time intervals. The advantages are that the management knows exactly what the breeding record is for each female, progesterone samples can be taken at the correct times and all the stock become easier to handle. Obviously there is considerably more work required but more importantly there is a danger that breedings may be forced and lead to genital tract trauma and infections.

The ideal system