A disease of adult sheep, first recognised in South Africa. (See PULMONARY ADENOMATOSIS.)
A male donkey.
Jack Beans may cause poisoning if fed raw. (See LEGUME POISONING.)
A small, lively dog, having a white coat with brown or black patches. Originally a crossbreed, it now breeds true. Jack Russell Terriers were formerly recognised as a type, but have now been accepted by the Kennel Club as a breed. There are three varieties of this terrier breed. The original hunting terrier is the Jack Russell bred by the Reverend John Russell in the East Midlands in the 19th century. This is a long-legged working terrier similar to a fox terrier. The second is a popular, extremely active smaller variety with slightly bowed front legs and is a popular pet in non-hunting circles. Another version is called the Parson Russell terrier. The breed is always white (to distinguish from the quarry in the days when it was bred exclusively for fox hunting) with various black and tan markings. It is generally a healthy breed but it is prone to LENS LUXATION, PATELLAR LUXATION and it may inherit ATAXIA and LEGG-CALVÉ-PERTHES DISEASE.
A breed of sheep which is piebald (black and white). They are small: ewes weigh 35 kg to 40 kg (75 lb to 90 lb), polycerate (multihorned, with two, four or six horns). They are used for meat, wool and hides. Although still considered rare, it is a very popular breed on smallholdings.
Also known as the vomeronasal organ, this is associated with the detection of flavours such as those of food, but is thought also to be able to detect pheromones. The organ has 2 small tubes which extend from the floor of the nasal cavity to the level of the 2nd/4th cheek tooth. It is active in most mammals, but even more highly developed in certain reptiles, especially snakes.
A combination of the Macaulay Land Use Research Institute and Scottish Crop Research Institute, it is a research institute dealing with crop, soils, land use and environment. Addresses: The James Hutton Research Institute, Craigiebuckler, Aberdeen AB15 8QH; The James Hutton Institute, Invergowrie, Dundee DD2 5DA. Telephone: 0844 928 5428.
A female mule.
A breed also called Akita inu, originating from Japan. It is a large strong dog with a thick coat, prick ears and a tail curling over its back. It can suffer from UVEO-DERMATOLOGICAL SYNDROME.
This disease is present in Nepal and other regions of Asia. The virus can be carried by imported monkeys of various strains and from various parts of the world. It is a ZOONOSIS and a cause of human death. A vaccine has been used against human infection.
Cause A flavivirus. The disease is transmitted by mosquitoes from avian species which act as reservoirs of infection but are themselves asymptomatic.
Signs In horses, the sight is affected first. Later they become drowsy. Many die, and the recovery of others is seldom complete. Pigs are also susceptible; abortion and stillbirths result from infection.
A breed of cat of ‘foreign’ conformation with a rudimentary tail, linked to a recessive gene. The hind-legs are longer than the fore-legs but are kept angled so that the back is level. There are similarities with the Manx, but there does not appear to be the same frequency of defects as occurs in that breed.
A small ‘toy’ dog, weighing 2 kg to 7 kg (4 lb to 15 lb) and 20 cm to 27.5 cm (8 in to 11 in) high with a long silky coat. The colour is black and white, lemon and white, red and white, and black and white with tan points. The head is DOLICHOCEPHALIC. The tail is feathered and curls up over the back.
(See SCRUB TYPHUS.)
A breed of dog raised in Japan for fighting. Importation into the UK is banned under the Dangerous Dogs Act 1991.
Jaundice is a yellowish discoloration of the visible mucous membranes of the body (eye, nose, mouth and genital organs). The discoloration is caused by bilirubin, an orange-yellow pigment produced following the breakdown of erythrocytes in the blood (haemolytic jaundice), due to liver disease (non-haemolytic jaundice), or due to obstruction of the bile flow from the liver and gall-bladder.
The clinical sign of jaundice (icterus) may also follow the destruction of red blood cells by parasites, such as may occur in cases of biliary fever and surra in the horse; red-water in cattle; malignant jaundice (canine babesiosis); it is seen also in leptospiral jaundice (see LEPTOSPIROSIS) and canine viral hepatitis.
In cats, jaundice is seen in many diseases, including the dry form of FELINE INFECTIOUS PERITONITIS, TOXOPLASMOSIS.
Jaundice may indicate an incompatibility between the blood of sire and dam causing haemolytic jaundice of the newborn foal or piglet.
When bile cannot enter the small intestine by the bile-duct from the liver in the usual way, it is absorbed by the lymphatics and the blood vessels, carried into the general circulation, and some of its constituents are deposited in the tissues. (See GALLSTONES, also under CIRRHOSIS; LIVER, DISEASES OF; EQUINE BILIARY FEVER; GALL-BLADDER.)
It may be seen during poisoning with copper, mercury, phosphorus, chloroform or lead, and after some snakebites. Aflatoxins may cause jaundice.
(See also BILIARY FEVER; FOALS, DISEASES OF; JAUNDICE; LEPTOSPIROSIS.)
(See under LEPTOSPIROSIS for the appropriate animal.)
The Java beans, Phaseolus lunatus, were once imported in large amounts. The beans are of varying origin, and differ in colour, thus: Java beans are as a rule reddish-brown, but they may be almost black; Rangoon or Burmah beans are smaller, plumper, and lighter in colour (so-called ‘red-Rangoons’ are pinkish with small purple splashes).
The active poisonous agent in the beans is a substance called phaseolunatin, which is a member of a group of cyanogenetic glucosides.
Signs These are exactly the same as those given under HYDROCYANIC ACID.
The upper jawbones are two in number and are firmly united to the other bones of the face. The lower jaw – mandible or coronoid process – is composed of a single bone in horse, pig, dog and cat, but in the ruminants the fusion between right and left sides does not occur until old age. Each of the jaws presents a number of deep sockets or ‘alveoli’ which contain the teeth. (See DISLOCATIONS; FRACTURES - THE FACE BONES; TEETH; also MUSCLES, DISEASES OF; ACTINOMYCOSIS (LUMPY JAW).
For overshot and undershot jaws, see under TEETH, DISEASES OF.
‘Lion jaw’ (CRANIOMANDIBULAR OSTEOPATHY): a disease seen mostly in WEST HIGHLAND TERRIERS. Eating becomes difficult; mouth-opening, painful. Diagnosis is by radiography of the craniomandibular joints. The condition is self-limiting.
(See ‘BOTTLE-JAW’.)
Other synonyms include Haemorrhagic Bowel Syndrome (HBS), Haemorrhagic Gut Syndrome (HGS) or ‘bloody gut’. An uncommon condition of adult cattle, mainly seen in dairy cows. Signs are acute in onset and involve rapid general malaise without pyrexia and usually without MELAENA signs of pain. Diagnosis is difficult but distended small intestinal loops may be palpated and there is a suggestion of intestinal obstruction. Most die and show jejunal haemorrhage at post mortem. The cause is debatable but may be Clostridium perfringens type A, but fungi have been found such as Aspergillus fumigatus and Mucor types. (See MUCORMYCOSIS.)
Jejunum is the central portion of the small INTESTINE.
(See COCKER RAGE SYNDROME.)
A female ass.
This is caused by the red and black seeds of the climbing plant Abrus precatorius, which grows in Australia, Asia and South America. It gives rise to cyanosis and pinpoint-sized haemorrhages from the skin, as well as diarrhoea.
A Channel Island breed of cattle originating from Jersey which produces milk with a high fat and solids content. It has a very female dished face and is relatively small. It has black pigmentation in the mouth and skin. It is a very economic converter of feed into milk. Cattle can suffer MILK ALLERGY and ALLERGIC NASAL GRANULOMA.
Also known as an F–J hybrid, this is a beef cross obtained from a Jersey bull on a Friesian cow. (In New Zealand, the reverse cross is used.)
Jetting is a technique developed in Australia, involving the application of insecticide under pressure by means of a jetting gun – a handpiece with 4 needle jets for combing through the wool. The pressure used is 10 to 14 kg/cm2 (60 to 80 lb per sq in), which can be achieved by an ordinary medium/high-volume agricultural sprayer.
Jetting has not displaced dipping to any extent in the UK, where spraying has been found inefficient in the control of sheep scab.
See JEJUNAL HAEMORRHAGIC SYNDROME in Cattle.
(See under FLEAS – Tunga penetrans.)
A female donkey, ferret or hare.
Johne’s Disease (Paratuberculosis) is a chronic infection, involving the small and large intestines. It affects cattle particularly, but sometimes sheep, goats, camelids and deer, and is characterised by the appearance of a persistent diarrhoea, gradual emaciation and great weakness. A post-mortem examination usually reveals a characteristic ‘corrugated cardboard’ appearance of the large intestine. In other species the main sign is weight loss, sometimes diarrhoea (but usually not), leading eventually to CACHEXIA. The intestinal thickening characteristic of the disease in the bovine is rarely seen and often the changes are a slight enlargement of the mesenteric LYMPH NODES. Lymph tissue disease is confirmed by a positive ZIEHL-NEELSEN STAIN. There are PCR, ELISA and CFT tests for Johne’s disease but often they do not detect infection until the disease is well established. Infection can occur in the rabbit and in the pig, when post-mortem findings may at first suggest tuberculosis. There is a possible association with some cases of Crohn’s Disease in man.
Cause Mycobacterium avium subspecies paratuberculosis (MAP), formerly M. johnei and then M. paratuberculosis.
Experimentally, sheep can be infected with as few as 1000 MAP bacilli. These then multiply in the intestinal mucosa for the first two or three months after infection. Some animals are able to overcome the infection completely; others become carriers, with the bacilli remaining in the intestinal mucosa and lymph nodes. Some of the carriers eventually become clinically ill with Johne’s disease.
Signs The disease is very slow in onset. Cattle that have become infected may not show signs for as long as two years after the last case occurred on that farm.
Pointers to the disease are an unexplained drop in milk yield (often months before other signs appear) and diarrhoea in an individual adult animal.
Loss of condition, general unthriftiness, a harsh, staring coat are then seen, with diarrhoea. The temperature fluctuates a degree or two above normal. Appetite is variable. In the last stages emaciation becomes very marked, and the animal becomes progressively weaker.
In sheep, goats and camelids diarrhoea is not a major sign.
Treatment When well established, Johne’s disease is invariably fatal, and no treatment is effective or worthwhile.
Prevention Attention should be paid to the prevention of infection in other animals, especially calves. Pastures that are suspected of being heavily infected should be left without stock for four or five months. All infected litter should be stored in a dung-pit which is not accessible to other animals, and should be used for cultivated land. Loose-boxes, sheds, etc., that have housed a case should be carefully disinfected and diseased animals should be fed after healthy ones. Ponds and water-courses should be fenced to prevent fouling by faeces, water for drinking being pumped out.
Calfhood vaccination may prevent clinical disease but interferes with subsequent tuberculin tests. The vaccine is registered for goats but can be used under the ‘CASCADE’ for calves.
Kids are vaccinated at the age of two to four weeks.
Diagnosis The disease can usually be diagnosed on clinical evidence, with some confirmation afforded by microscopic examination of the faeces. Typical clumps of acid-fast bacilli may be found, and the complement fixation test is positive in about 90 per cent of cattle with advanced disease. The fluorescent antibody test is equally useful.
Diagnosis of the carrier state is not possible with any certainty. There is no single test which can conclusively detect the presence or absence of MAP, although laboratory tests can identify the presence of Mycobacteria spp. The COMPLEMENT FIXATION TEST is positive in only a small proportion of carriers and can give false positive results.
The difficulty in identifying ‘carriers’ makes Johne’s disease difficult to control and eradicate. However there are schemes being undertaken to reduce or remove the infection.
A diagnostic agent derived from M. paratuberculosis used for JOHNE’S DISEASE. Cutaneous injection results in thickening of the skin in positive cases. While insufficiently sensitive for individual diagnosis, the test is useful for identifying infected herds.
Also called NAVEL-ILL or POLYARTHRITIS, this is a disease of foals, lambs, and calves, in which abscesses form at the umbilicus and in some of the joints of the limbs, due, in the majority of cases, to the entrance of organisms into the body by way of the unclosed navel; infection can also be through the tonsils. There are numerous organisms associated with the disease, the commonest of which are streptococci, staphylococci, Pasteurella, E. coli, the necrosis bacillus, and see under FOALS, DISEASES OF.
Signs Usually the young animal becomes dull, takes no interest in its dam, refuses to suckle; the breathing is hurried; the temperature rises from 0.6° C to 1.2° C (2° F to 4° F) above normal; the foal prefers to lie stretched out on its side, and may have attacks of either diarrhoea or constipation. If the navel is examined it is found to be wet and oozing bloodstained serous material, or it may be dry, swollen, painful to the touch, and hard, owing to abscess formation within. In cases that appear later in life there may be no umbilical signs. Within a day or so, one or more of the joints swells up. The joints most commonly attacked are the stifle, hip, knee, hock, shoulder and elbow, but it may be seen in any of the others. The swelling is tense, painful, hot, and oedematous. There is the danger of a fatal septicaemia.
A chronic form of infection resulting in internal umbilical abscesses is sometimes seen. The primary infection occurs at, or soon after, birth; but once the umbilicus has sealed over, external signs are not evident, and the umbilical remnant appears normal.
Calves are usually presented as unthrifty, depressed and slow in their movements. Their temperature invariably normal.
Prevention Attention must always be paid to the cleanliness of the foaling-box, the calving-box and the lambing-pen. Where climatic and other conditions are favourable, the pregnant females should be allowed to give birth to their young out of doors. Lambing-pens should without fail be changed to a fresh site every year.
Investigations undertaken by the Animal Health Trust suggest that thoroughbred foals in the UK suffer severe illness as a result of being deprived of a not inconsiderable volume of blood when the navel cord is severed prematurely by attendants. Severance of the cord, it seems, is always best left to the mare. The use of strong disinfectants applied to the stump of the navel cord is likewise deprecated.
An application of a sulphanilamide or other antibiotic dry dressing may be safer than iodine solution.
In those rare cases when it is necessary to cut and tie the umbilical cord, the strictest cleanliness must be maintained. Scissors should be sterilised, and sterile tape used.
Treatment Antibiotics and, if available, antiserum for the causative micro-organisms (not available in the UK) should be administered. Surgically, the umbilicus is opened up, evacuated and disinfected. Isolation and other hygiene measures are needed.
All pails, and other feeding utensils that are liable to get infected, should be thoroughly cleaned using boiling water or steamed before future use, and the pen or box that houses a case should be occasionally washed out with disinfectant. (See also FOALS, DISEASES OF.)
A small loose body within a joint. It is usually made up of cartilage or bone that has separated from one or other of the bones forming the joint.
Joints fall into two great divisions: movable joints and fixed joints. In a movable joint there are four main structures. First, there are the two bones whose junction forms the joint; second, there is a layer of smooth cartilage covering the ends of these bones where they meet, which is called ‘articular’ cartilage; thirdly, there is a sheath of fibrous tissue known as the ‘joint capsule’, which is thickened into bands or ‘ligaments’ which hold the bones together at various points; and finally, there is a closed bladder of membrane, known as the ‘synovial membrane’, which lines the capsule and produces a synovial fluid to lubricate the movements of the joint. Further, the bones are kept in position at the joints by the various muscles passing over them. This type is known as a diarthrodial joint.
Some joints possess subsidiary structures such as discs of fibro-cartilage, which adapt the bones more perfectly to one another where they do not quite correspond, and allow of slightly freer movement, e.g. the stifle-joint. In others, movable pads of fat under the synovial membrane fill up larger cavities and afford additional protection to the joint, e.g. the hock-joint. In some, the edge of one bone is amplified by a margin of cartilage which makes dislocation less of a risk than otherwise, e.g. the hip and the shoulder-joints.
In the fixed joints a layer of cartilage or of fibrous tissue intervenes between the bones and binds them firmly together (synarthrodial joint). This type of joint is exemplified by the ‘sutures’ between the bones that make up the skull. Classified among these fixed joints are the amphi-arthrodial joints of the spinal column, in which there is a thick disc of fibro-cartilage between the bones, so that, although the individual joint is capable of only limited movement, a series of these, like the joints between the bodies of the vertebrae, gives the column, as a whole, a very flexible character. In this connection it is noticeable that the movement in the region of the neck may be much more free than in some of the true movable joints, such as between the small bones of the hock or carpus.
Varieties Apart from the division into fixed and movable joints, those that are movable are further classified. Gliding joints are those in which the bones have flat surfaces capable only of a limited amount of movement, such as the bones of the carpus and tarsus. In hinge-joints like the elbow, fetlock and pastern, movement can take place around one axis only, and is called flexion and extension. In the ball-and-socket joints, such as the shoulder and hip-joints, free movement can occur in any direction. There are other subsidiary varieties, named according to the shape of the bones which enter into the joint.
Arthritis means inflammation which involves all the structures of the joint – viz. synovial membrane, capsular ligaments, cartilages, and the ends of the bones that take part in the formation of the joint. Arthritis is a general term which includes osteoarthritis and rheumatoid arthritis. Arthritis often begins as a SYNOVITIS (see below), but the degree of inflammation is severe enough to extend to the structures around the synovial membrane. Its causes, signs and treatment are similar to those given for synovitis, but it sometimes leads to ankylosis and fixation of the joint. (See CORTISONE.) The joints that are most often affected are the stifle, hock, knee and fetlocks, but the shoulder, hip, elbow and the lower joints of the digit are not infrequently the seat of disease as well. Among diseases that are associated with joints, and which are treated separately, are NAVICULAR DISEASE; ‘SLIPPED SHOULDER’; SLIPPED STIFLE; HYGROMA; CAPPED ELBOW; CAPPED HOCK; KNUCKLING; JOINT-ILL; see also below and BURSITIS; ANKYLOSIS; FRACTURES; DISLOCATIONS; GLÄSSER’S DISEASE; HIP DYSPLASIA IN DOGS; SWINE ERYSIPELAS.
Rheumatoid arthritis This can be important in the dog, and may occur at any age from eight months to two years. Clinical signs may be vague at first; the animal appears depressed, with a poor appetite and often some degree of fever, but with no lameness. Eventually the latter sign appears, sometimes involving several joints, sometimes affecting only one limb and then shifting to another. There may be crepitus – a grating sound – when the limb is moved.
Diagnosis depends upon radiography and – as in human medicine – there are certain laboratory tests, the results of which provide additional criteria for deciding whether the condition really is rheumatoid arthritis or not.
Intractable arthritis of the hip-joint in dogs, as in human beings, may be overcome by major surgery involving removal of the top of the femur and replacement of the ball part of the ball-and-socket joint with a plastic prosthesis.
Synovitis is the name given to any inflammation of the membrane lining a joint cavity. It may be acute, subacute, or chronic.
Generally this is not a separate condition but occurs during the course of rheumatism, rickets, gout (in poultry), severe sprains and bruises, and in a variety of specific infections such as brucellosis, swine erysipelas, tuberculosis. Tubercular joint disease often produces a chronic synovitis in the neck bones of the horse, which leads to an arthritis later.
Conditions such as wind-galls, curb, bog spavin, etc., are really only synovitis that have become chronic or are complicated with other pathological conditions.
The synovial membrane becomes inflamed, thickened, and secretes an excessive amount of fluid into the joint. As a result the joint becomes hot, swollen and painful. The animal goes lame in greater or lesser degree according to the extent of the inflammation. When at rest, the joint is usually kept flexed with the toe of the affected leg just resting on the ground. If it is a simple condition, such as a mild sprain, these signs last for a few days and then gradually pass off. In more severe cases, such as in joint-ill, there may be pus formation, septicaemia and death. In the chronic type the swelling persists. The animal is able to use its limb as usual, but the accumulated fluid in the cavity does not disappear (e.g. BOG SPAVIN, WIND GALLS, etc.).
Open joint is a condition in which, by accident or other trauma, the inside of the joint is exposed to infection.
The seriousness of an open joint is not so much due to the initial injury as to the danger of infection. This may cause tissue destruction within the joint, and even lead to a fatal SEPTICAEMIA.
The most striking signs of open joint are, first, the excessive degree of pain that seems out of all proportion to the visible amount of damage that has been inflicted; secondly, the great amount of swelling that is usually seen; and thirdly, the discharge of a thin, straw-coloured or bloodstained sticky synovia which has a tendency to coagulate around the skin opening.
Veterinary advice should be sought at once. Prompt treatment with antibiotics, and surgery if required, is necessary to prevent or limit infection.
Dislocations (See main dictionary entry.)
Bursitis, an inflammation of a bursa, commonly occurs in the region of a joint. The prominences of the hock, elbow, knee, stifle, etc., are protected by bursae – lined on their insides by synovial membrane. These sometimes become inflamed and lead to the formation of fluctuating swellings which have a tendency to become chronic. Capped elbow, capped hock and hygroma of the knee are of this nature. (See also BURSAE; OSTEOARTHRITIS; MAST CELLS; OSTEOCHONDROSIS; RHEUMATISM.)
A derived SI unit of metabolisable energy. (See CALORIES and STARCH EQUIVALENT, which it replaced; also SI UNITS.)
Jugular veins carry the blood back to the chest from the head and anterior parts of the neck. The jugular vein is often used for taking blood samples and for intravenous injection. The jugular furrow is the groove between the trachea and the muscles of the neck, in the depths of which lies the jugular vein. The jugular vein on the right side is larger than that on the left in birds and is favoured for venepuncture in cage birds (except pigeons and raptors).
(Gallus gallus) A native of the rain forests of South-East Asia, it is the species from which the domestic fowl originated. In its normal environment it prefers hot, humid, shady conditions with frequent rain showers. A broiler-producing company has replicated the climate found in the rain forest in its broiler houses. Mortality was very low and lameness almost non-existent, although the birds took a little longer to reach market weight.
Also known as ‘puppy strangles’, this condition affects pups between three weeks and four months of age. The cause is unknown but a hypersensitivity reaction may be involved. Clinical signs are CELLULITIS with severe swelling of the face and head, prepuce and anus, accompanied by lethargy, anorexia and, possibly, raised temperature. There may be enlarged LYMPH NODES (adenopathy). Steroid and antibiotic therapy is indicated. Permanent scarring may result.
It is seen in some dog breeds, e.g. LAGOTTO ROMAGNOLO. (See EPILEPSY.)