Black''''s veterinary dictionary 21st edition - G docx

G Gad-Fly (see FLIES; WARBLES) In Britain, warble flies are on the wing from late May onwards Gadding Excitement, restlessness, uncontrolled rushing around in horses or cattle due to the presence of biting flies; also, in the case of cattle, warble flies Gag A device to facilitate oral examination or treatment by holding the mouth open Gait, Abnormal (see ATAXIA; ‘GOOSE-STEPPING’; LAMENESS) Gall-Bladder The little pouch-like sac in which bile produced by the liver is stored until it is required during the process of digestion It is a hollow, pearshaped organ lying in a depression on the posterior surface of the liver The gall-bladder is not present in the horse and in animals of the horse tribe, but is found in the other domesticated animals Blockages of the bile-duct by liver flukes or by gallstones may result in jaundice as well as severe local inflammation Acute inflammation of the gall-bladder is painful, and there is danger of rupture or gangrene ‘Gall Sickness’ (see ANAPLASMOSIS) Gallstones Gallstones, which are also known as biliary calculi (see under CALCULI), are concretions which are formed in the gall-bladder or in the bile-ducts of the liver As a rule they are hard, brownish in colour, coated with mucus, and of a more or less rounded shape They may be composed of cholesterol; of cholesterol and bile pigments; or of pigment and lime salts One or several may be present, causing pain and jaundice Gallstones are more prevalent in sheep than in cows, dogs, cats, and horses In human medicine, ursodeoxycholic acid has been used to dissolve gallstones Galvanised Bins Galvanised bins, used to store swill, have led to ZINC POISONING in pigs Galvayne’s Groove A vertical groove in the front surface of the horse’s upper corner incisor teeth It first appears at the gum margin at about 10 years old and gradually moves down the surface of the tooth as the horse ages until it grows out at about 30 years old (see DENTITION – Horses) Game Birds, Mortality This may be considered under headings: From farm chemicals Many farm chemicals can cause poisoning in game and other birds Deaths have resulted from the use, as seed dressings, of compounds such as dieldrin, aldrin and heptachlor, now banned in the UK Some of the organophosphorus insecticides; dimethoate; and the ‘nitro-type’ of weedkillers such as DNC, which stains the carcase yellow; are among other chemicals hazardous to birds Pheasant poults have died as a result of being treated for lice with a per cent gamma benzene hexachloride (BHC) dusting powder An organophosphorus insecticide does not necessarily act quickly Death may occur weeks after eating the poisoned food The symptoms shown by poisoned birds include ruffled feathers, saliva around the beak, high-stepping gait or unsteadiness on the legs, distressed breathing, and paralysis However, as their use is now reduced, problems caused by organophosphorus compounds are less frequent Spraying an orchard with either DDD or DDT (now banned) has caused heavy gamebird losses A partridge was found dead in a field where blackcurrants had been sprayed with the insecticide endrin It was reported from the farm that or partridges died within a few hours of eating earthworms which came to the surface of the soil soon after spraying Rat poisons may perhaps be included in the term ‘farm chemicals’ Owls die after eating poisoned rodents From natural causes Impacted gizzard, tuberculosis, aspergillosis, swine erysipelas, fowl-pox, fowl cholera, fowl typhoid, infectious sinusitis Gapes is another cause of death; also in the USA, encephalomyelitis Deaths from fowl pest (Newcastle disease) have been reported in the UK; blackhead in pheasants and partridges ‘Grouse disease’ is the colloquial name for infestation with Trichostrongylus tenuis Mortality Gangrene occurs when food is in short supply as a result of poor growth or overpopulation of birds on a moor In some circumstances, it has been concluded that grouse have died because not enough were shot the previous year Grouse tend to remain in a locality and not move to other moors Louping ill, transmitted by sheep ticks, is generally fatal to red grouse (Lagopus lagopus scoticus), the commonest game bird on British heather moorland, and can reduce stocks to very low densities Inclusion-body hepatitis A 9-day outbreak resulted in an 18 per cent mortality among 1000 intensively reared pheasant poults (19 days old when the outbreak began) Salmonellosis An outbreak killed 50 per cent of 2800 pheasant poults, deaths beginning in 3-day-olds The infection was one of S typhimurium An antibiotic achieved control later Coccidiosis is an important disease of pheasants and other game birds, in chicks to weeks old Milky-white droppings are the most obvious sign (but these are also seen with excess urate excretion due to kidney disease) Yersiniosis is another important disease of pheasants Moniliasis causes lethargy, stunted growth and a heavy mortality in partridges Treatment with formic acid, sprayed on food, has proved successful (See also BOTULISM.) Gametes These are the ova and spermatozoa, and contain half the number (haploid) of chromosomes present in all other body cells (diploid) Gametocide Gametocide for bird control (See TEM.) Gametocyte An oocyte or spermatocyte, the cells which produce an ovum or spermatozoon Gamma Globulin Gamma globulin is a protein fraction of the blood serum which contains the antibodies against certain bacteria or viruses (See COLOSTRUM; IMMUNOGLOBULINS.) It can be prepared in a concentrated form and can be used to give protection against infection 293 Gamma Glutamyl Transferase (GGT) An enzyme that tends to increase in liver disease Higher than normal concentrations are found in liver-fluke infection of sheep and cattle Gammexane Gammexane products contain the gamma isomer of benzene hexachloride, a highly effective, persistent insecticide Not now used in treating farm animals (See BENZENE HEXACHLORIDE; also BHC POISONING.) Ganglion Ganglion is a group of nerve cell bodies Ganglioside A glycolipid found in central nervous system (CNS) tissue Gangliosidosis An inherited disease causing poor growth and progressive neuromuscular dysfunction It results from an accumulation of gangliosides in CNS tissue and may be seen in cattle, pigs, dogs and cats Gangrene The presence of dead tissue in a live animal In primary gangrene, bacteria which cause the necrosis also bring about the putrefactive changes In secondary gangrene the putrefaction is caused by organisms which have invaded dead tissue (e.g following a burn) There are varieties of gangrene, dry and moist; dry gangrene is a condition of mummification in which the circulation stops and the part withers up, while in moist gangrene there is inflammation accompanied by putrefactive changes Infection following necrosis may lead to gangrene after burns, scalds, frostbite, crush wounds, puncture wounds, etc Poisoning by ergot results in the same condition in the most distant parts of the body, e.g the feet, tip of tail, ears, and the combs and wattles of poultry Signs There is at first a degree of pain when the affected part is handled, and in a short time it becomes reddened and swollen Later it turns blue or black, the hair falls from it, and there is a distinct line of demarcation between the gangrenous and the healthy surface Around the dividing line there is usually some degree of inflammation, and pus production Moist gangrene is considerably more serious, since it is accompanied by putrefaction and the G 294 Gangrenous Dermatitis absorption of toxins The whole area turns black or greenish, the hair falls out, an offensive smell is evident, and much fluid exudes from the decomposing tissues A high temperature, disturbed heart’s action, and rapid breathing, are shown (See also GAS GANGRENE.) Treatment is mainly surgical, backed up by the use of appropriate antibiotics or sulfonamides In advanced cases, euthanasia becomes necessary (See also FROST-BITE.) Gangrenous Dermatitis A disease of poultry caused by Clostridium sep- G ticum; often associated with infectious bursal disease and inclusion-body hepatitis, it usually affects birds between 25 and 100 days of age Mortality can be very high Ganjam Ulrus The Indian name for a bunyavirus infection transmitted by ticks Gapes Gapes is a disease of young chickens, turkeys, pheasants and other game birds particularly, although all the domesticated and many wild birds may also be affected It is caused by infection with the gapeworm, Syngamus trachea The presence of worms in the bronchial tubes and trachea of the bird causes it to gasp for breath or ‘gape’, from which the name of the disease originated Part of the life-history of the worm is passed in the body of the earthworm, and young chickens eating earthworms may become affected Earthworms can live for 16 years (See also under CAPILLARIASIS.) Nitroxynil, given in the drinking water, is an effective treatment Garden Chemicals Birds, dogs, and cats may be poisoned as a result of the use of pesticides For the poisoning of birds, see preparations listed under GAME BIRDS, MORTALITY Dieldrin is highly toxic for cats, and like DDT, should not be used on them or in their vicinity In fact, all the CHLORINATED HYDROCARBONS are best avoided in places where small domestic animals or their food may become contaminated For the dangers of slug-baits, see METALDEHYDE POISONING (See ORCHARDS for the dangers of fruit-tree sprays For seed dressings, see under SEED CORN See also PARAQUAT; HERBICIDES.) Garden Nightshade Poisoning Garden nightshade poisoning results from animals eating Solanum nigrum, which is found Garden nightshade (Solanum nigrum), also known as black nightshade, has small purple flowers, and large black shiny berries, several of which are attached to a single stalk Height: 1.3 to m (4 to ft) in many parts of the world Its toxicity appears to vary in different localities The berries contain an active alkaloidal glycoside called solanine, which is readily converted into sugar and the poisonous solanidine by the action of the gastric juices in the stomach Signs Staggering, loss of sensation and consciousness, and sometimes convulsions First-aid: strong black tea or coffee Garron A useful type of horse for hill-farm work and carrying deer Garrons not constitute a separate breed, but were a cross between Western Island ponies and the Percheron Nowadays, the Garron is regarded as a larger version of the Highland pony Gas (see AIR; BLOAT; CARBON MONOXIDE; OZONE; ANAESTHETICS; SLURRY; NITROGEN DIOXIDE.) Gas Bubble Disease A condition in which fish swim ‘belly up’ vertically; the cause is supersaturation of gases in the water in very intensive farming It can be prevented by proper maintenance of pumps and normal (not pressurised) aeration of the water Gelatin Sponge Gas Gangrene Gas gangrene is an acute bacterial disease due to the inoculation of wounds with organisms belonging to the ‘gas gangrene’ group Gas gangrene may attack any of the domestic animals and man The horse is least resistant and the cow least susceptible Causes Gas gangrene is produced by Clostridium oedematiens, Cl welchii, Cl septicum and Cl chauvei gaining access to the tissues of an animal through a small wound; after castration or docking, or parturition, etc Signs A few hours after the organisms gain entrance, the area of invasion is found swollen, hot, painful on pressure, and may crackle when handled This latter effect is due to gas formation below the skin The skin and underlying tissues rapidly become discoloured In a series of cases in horses, the signs were fever, depression, painful muscular swellings, and toxaemia All were dehydrated Colic had been evident in of the horses; laminitis in Infection had followed intra-muscular injections in of the horses, and a puncture wound in The Clostridia isolated were: chauvei (1); septicum (6); and perfringens (6) Prevention Vaccination is effective (See also BRAXY; BLACKQUARTER; GANGRENE.) Gastralgia Pain in the stomach Gastrectasis Dilatation of the stomach Gastrectomy Gastrectomy is an operation for the removal of the whole or part of the stomach Gastric Gastric means anything connected with the stomach, e.g gastric ulcer, gastric juice Gastric Ulcers These are seen in pigs in some cases (but not all) of SWINE FEVER They have also been found in piglets under a fortnight old, due to Rhizopus microsporus, isolated from both stomachs and bedding (See MUCORMYCOSIS.) Associated with this infection may be another fungal one – MONILIASIS – caused by the yeast-like organism Candida albicans Gastric ulcers may also be produced by the toxin of Aspergillus flavus (see AFLATOXIN), and by COPPER POISONING 295 In mini-pigs, gastric ulcers are quite common when the diet lacks roughage For gastric ulcers in cattle, see under STOMACH, DISEASES OF In the USA, gastric ulcers have been an important cause of foal mortality Gastritis Inflammation of the stomach Gastrocnemius Gastrocnemius is the large muscle which lies behind the stifle-joint and the tibia and fibula, and ends in the Achilles tendon or ‘hamstring’ which is attached to the ‘point of the hock’ Gastrodiscus Amphistome flukes, e.g G aegyptiacus, are common parasites of horses and pigs in the tropics and subtropics A heavy infestation has caused collapse in the horse Gastroenteritis Inflammation of the stomach and intestines, causing vomiting and diarrhoea It is an acute condition commonest in young animals It may be specific or due to irritant organic or inorganic poisons (See also HAEMORRHAGIC, PARASITIC, and TRANSMISSIBLE GASTROENTERITIS; also DIARRHOEA.) Gastropexy A surgical operation in which the stomach is fixed, usually, to the abdominal wall to prevent a recurrence of torsion In dogs it has been carried out after spot coagulation of the surface of the fundus by diathermy The stomach is fixed in its normal position against the diaphragm by to 10 rows of silk sutures (7 or 10 to a row) The incision into the abdominal wall is closed by absorbable synthetic sutures This operation is also known as fundupexy Gastrotomy An operation to open the stomach, usually to remove a foreign body Gavage Feeding an animal by means of a stomach tube Gel Gel is a colloid substance which is firm in consistency, although containing much water, e.g ordinary gelatin Gelatin Sponge Gelatin sponge is prepared as a haemostatic, and can be left in a wound; complete absorption G 296 Gelatin, Succinylated taking place in to weeks The sponge may be sterilised in dry heat, and applied either dry or moistened with normal saline, an antibiotic solution, or a solution of thrombin Absorbable gelatin sponge complies with the requirements of the British Pharmacopoeia Gelatin, Succinylated A modified, fluid, gelatin used as a plasma substitute to restore body fluid volume in cases of hypovolemic shock Gelbviehs This German yellow breed of cattle, as it is also G known, was evolved by crossing Swiss breeds with German breeds, and is dual-purpose, averaging nearly 3640 litres (800 gallons) of milk at per cent butterfat Fattening stock give a daily liveweight gain of 1.1 kg (2.5 lb) and are ready for the butcher at 405 days in Germany Gelding A castrated horse Occasionally a horse which has had both testicles completely removed shows stallion-like behaviour, when it is known as a ‘false rig’ Such an animal may mount mares and achieve both erection and intromission The chasing, or rounding up, of mares, and nipping them, may also occur This behaviour is not hormonally induced or hormone dependent; it has been suggested that it is part of the normal social interaction between horses ‘False rigs’ and cryptorchids may show similar behaviour Blood samples from 104 horses with either sexual and/or aggressive male behaviour, but which had no palpable or visible testes, were assayed for testosterone levels 30 to 100 minutes after an intravenous injection of human chorionic gonadotrophin All but horses were classified as either geldings (