Productive disease PH.D.1.docx

**Productive diseases** **Caged Layer Fatigue:-** Cage layer fatigue is a condition that is unique to hens that are in a high state of egg production, primarily caged layer hens. The cause of the condition is thought to be associated in an imbalance of minerals/electrolytes in the body. Rickets a...

**Productive diseases** **Caged Layer Fatigue:-** Cage layer fatigue is a condition that is unique to hens that are in a high state of egg production, primarily caged layer hens. The cause of the condition is thought to be associated in an imbalance of minerals/electrolytes in the body. Rickets and abnormal bones in adult birds are commonly present. In layers under thirty weeks of age, the cause is usually a temporary calcium deficiency when egg production reaches eighty percent or higher. If intake of calcium does not satisfy the need for egg production, the hen will remove calcium stored in the bones. Ultimately, osteoporosis develops, bones become soft and hens are subject to bone fractures. Crippled and unable to stand, the hen suffers from the caged fatigue symptoms. Many hens show spontaneous recovery if removed from the cages and allowed to walk normally on the floor. This indicates that a lack of exercise may be a partial cause. Cage layer fatigue is more prevalent in single-hen cages than in multiple-hen cages. When two or more hens are caged together, they get more exercise because of competition for feed and water. Supplementation of the diet with phosphate, calcium and vitamin D~3~ is usually helpful. Adding calcium to young birds by top-dressing the feed with twenty pounds of oyster shell or limestone per one thousand hens will often help the condition. In older hens, calcium deficiency is less likely than phosphorus or vitamin D~3~ deficiencies. Recommended treatment in these birds is to remove the hens from cages and top-dress feed with equivalent level of dicalcium phosphate. Adding a vitamin/electrolyte supplement to drinking water is recommended in any age bird suffering from this condition. Flocks that do not respond to the above therapy should be submitted to a poultry disease diagnostic laboratory to determine the cause of the problems. Several diseases can cause symptoms similar to caged layer fatigue. Flock treatment for the condition can be prescribed after diagnosis is completed. **Fatty Liver Hemorrhagic Syndrome:-** Fatty liver syndrome is a condition that affects only hens. The basic cause is thought to be excessive dietary energy intake. Hereditary tendencies vary among various strains of egg production stock, but heredity is not the entire cause for this malady. Laying hens housed in cages are most often affected since they are less able to get sufficient exercise and dispose of the extra dietary energy. Birds within a flock that are most often affected are the high producers. This indicates that physiological energy metabolism and production are closely associated with this condition. Mortality varies considerably among flocks but can become excessive in some cases. Lesions include accumulation of large amount of abdominal fat; enlarged, easily damaged liver and presence of blood clots that indicate that hemorrhages have occurred prior to death. Death usually is caused by a fatal internal hemorrhage originating in a portion of the liver. This hemorrhage is often caused as the hen is straining to lay her egg and the enlarged, friable liver is more vulnerable to injury. When a large blood vessel ruptures, sufficient blood is lost to cause death of the hen. The primary treatment for this condition requires an alteration of the diet or amount of dietary energy consumed. Replacement of some of the corn in the diet with lower energy feedstuffs like wheat bran can provide a lower energy diet. If a complete layer ration is being fed, addition of vitamins can be of benefit. If grains are the primary feedstuff, it is suggested that the birds be switched to a complete layer diet. Control of body fat is the only successful remedy for this condition and is best accomplished by regulation and reduction of total energy intake. **Cannibalism:-** Cannibalism is prevalent among chickens of all ages and can become a serious problem if not corrected early. The problem is most severe when birds are housed in close confinement. In most cases it is a vice that progresses from a minor stimulus and soon becomes a severe problem. Many causes are thought to initiate the problem but it is not understood why it is uncontrollable in some cases but never becomes a problem in other situations. Cannibalism may start as toe picking in baby chicks; feather picking in growing birds; or head, tail and vent picking in older birds. The early symptoms of a cannibalism problem may be difficult to detect. It is necessary that the poultry man be on constant guard to detect any aggressive behavior and take necessary management changes before the problem progresses into a severe case of cannibalism. Causes that can result in cannibalism include: - High density of birds within a confined area, - Brooding chicks at temperatures that are too warm, - Small or weak chicks, especially those having oddly colored down or feathers, - Exposing birds to light that is too intense or having a color that induces aggression, - Restriction of feed or water intake, - Feeding a diet with a deficiency of salt or sulfur-containing amino acids (protein), - Allowing dead birds to remain exposed to the flock, - Lack of or absence of properly designed nest boxes. Regardless of the cause, some method of preventing this vice must be used. The most common procedure to reduce cannibalism is to debeak the birds. Birds grown in houses with very low light intensity may not require debeaking. Those grown in houses receiving normal daylight should be debeaked at the hatchery or within the first two weeks after hatching. This helps reduce the incidence of feather picking that often develops into a severe case of cannibalism. A special method of hot debeaking has been developed for debeaking broiler chicks at one day of age. Rather than severing or cutting the beak, a hot blade is used to burn an area near the tip of the upper beak (egg tooth). The procedure is designed to leave a thin base to the tip of the upper beak. This makes it easier for the chick to eat without having a sensitive, raw beak. The tip of the upper beak gradually drops off without apparent injury to the chick, thus leaving a shortened upper beak and a normal lower mandible. Reducing the mortality is a primary concern that responds well to adequate floor space. Birds should not be crowded but instead, provide sufficient room so that weaker birds can escape from those that are more aggressive. Reducing the amount of floor space usually results in increased mortality and reduced growth rate. Not only is there a monetary loss involving the cost of the chick, but the value of the feed, labor, and other items necessary to grow a chick until the time of death is a direct loss. There is also the lost profit that could have been earned if the dead birds had lived until market or egg production age. **Reproductive Disorders** +-----------------------------------------------------------------------+ | Reproductive problems hit breeders where it hurts most, right in the | | breeding hen. There is nothing more frustrating than losing a good | | bird when it\'s breeding. The following article describes some of the | | more common problems and some things you can do to help. | | | | - Egg Binding | | | | - Prolapse of the Oviduct and Uterus | | | | - Infections of the Oviduct and Uterus | | | | - Oviduct Impaction | | | | - Oophoritis | | | | - Cloacal Problem | | | | - Ectopic Eggs (Non-Septic Egg Peritonitis) | | | | - Septic Egg Related Peritonitis | | | | - Chronic Egg Laying | | | | - Over Production | | | | - Abnormal Eggs | | | | - Keeping Hens in Good Condition for Breeding | | | |   | | | | EGG BINDING | | | | The failure of an egg to pass through the oviduct at a normal rate. | | | | Causes of egg binding include:- | | | | - oviduct muscle dysfunction due to nutritional deficiencies, | | especially calcium, vitamin E and selenium | | | | - malformed eggs | | | | - excessive egg production which can exhaust the birds reserves of | | calcium, vitamins and energy | | | | - previous reproductive tract damage or infection which may lead to | | scarring and adhesions to other organs | | | | - obesity which is unfortunately a very common problem | | | | - lack of exercise, which leads to poor muscle strength | | | | - Senility. Older birds are more likely to become egg bound | | | | - other stress factors, including severe temperature changes, | | disease or overcrowding | | | | Signs a bird can show include:- | | | | - depression | | | | - reluctance to fly or perch | | | | - persistent tail wagging or straining | | | | - a wide based stance (\"penguin stance\") | | | | - a hard swollen abdomen | | | | - and if severe a leg weakness or paralysis. | | | | Many of the complications of egg binding can lead to the death of the | | bird. | | | | Treatment involves first and foremost stabilizing the patient. Make | | no attempts at delivering the egg until the bird is stable. | | | | If only minimal depression is present then provide supplemental heat | | (28-31°C) with easy access to food and water. Cropping the bird with | | oral calcium, vitamin D and energy supplements can be useful. | | Lubricate the vent (KY jelly or Vaseline are useful). Wait at least | | 20 minutes for the bird to pass her egg on her own before | | intervening. | | | | If the hen stays stable but does not pass the egg then a short | | attempt at gentle manipulation of the egg can be attempted. Don\'t | | press directly down onto the egg. This will push the hard shell | | against the fragile kidneys, adrenal glands and ovary, which can | | cause death or bruising of the kidneys resulting in a leg paralysis. | | | | Pressure can be applied to each side of the egg downwards, towards | | the vent. If there is no immediate success, stop. Put the bird back | | into the heat and wait another 15 to 20 minutes. | | | | This process can be repeated a number of times while the bird is not | | severely depressed. If still no success consider veterinary help, | | either by phone or preferably bring the bird to us before she is too | | unstable. | | | | If the hen shows signs of severe depression then immediate veterinary | | treatment is recommended. We can provide the hen with antibiotics, | | intravenous fluids, hormones (oxytocin) which promote uterine | | contractions, steroids and injectable calcium and energy supplements. | | If necessary we can collapse the egg after draining its contents | | (ovocentesis) or open the uterus under a general anesthetic and | | remove the egg. | | | | Complications - these are the things that can go wrong when you | | finally get the egg out and think you\'re in the clear. Murphy\'s | | Law!! | | | | - More eggs produced. - this can cause repeated egg binding (always | | more serious than the first) | | | | - egg impaction | | | | - peritonitis (infection in the abdominal cavity) | | | | - oviduct and uterine infection | | | | - ruptured oviduct, permanent damage to oviduct | | | | - abdominal hernia which is a rupture of the abdominal muscles | | making egg laying almost impossible - can be surgically repaired | | with varying degrees of success | | | | - prolapses of the oviduct and cloaca | | | | - Hypocalcaemia - drainage of the bird\'s calcium reserves can lead | | to a problem of muscle weakness and inability to fly or even | | stand. Oral calcium supplements over a week to ten days can pull | | many of these birds through | | | | - paralysis and weakness can also be due to kidney damage or | | infection - the sciatic nerve in birds runs through the middle of | | the kidneys and any swelling here can cause weakness or paralysis | | | | - Secondary infection. The stressed bird\'s immune system is | | compromised and secondary bacterial infections or resurgent | | chlamydiosis can occur | | | | - any, some or all of these can lead to DEATH. | | | |   | | | | PROLAPSE OF THE OVIDUCT AND UTERUS:- | | | | An extrusion of the interior cloaca and uterus to the exterior and | | has the appearance of a red inflamed mass of soft tissue at the vent. | | | | It can occur following normal egg laying but is especially common | | after an episode of egg binding. It is more likely to occur in birds | | that are in poor physical condition (eg muscle weakness, obesity or | | malnutrition). More likely with malformed, soft or shell-less eggs. | | | | Treatment:- | | | | - keep exposed tissues moist and clean with copious amounts of | | saline solution or a very dilute iodine (Betadine / PVP-Iodine) | | or chlorhexidine solution (Aviclens or Hibiclens) | | | | - if no egg is present and tissue is not badly damaged then gently | | replace the prolapsed tissue by pushing it back in place with a | | moistened swab or cotton bud | | | | - can and often does recur, however if treated early have a good | | chance at complete repair | | | | - attempt to switch off the birds breeding cycle (see under Chronic | | Egg Laying) | | | | - Veterinary assistance is recommended if; it\'s a valuable bird, | | an egg is caught in prolapsed tissue, keeps on prolapsing or if | | there is significant tissue damage. There are surgeries which can | | assist even the most longstanding prolapses | | | | - Also seek help if the bird shows signs of moderate to severe | | depression. Uterine infections are common following prolapses | | | |   | | | | INFECTIONS OF THE OVIDUCT AND UTERUS | | | | Can be associated with general systemic infections or can occur on | | their own. Infectious agents include bacteria, chlamydia, mycoplasmas | | and fungi. | | | | Factors which make infections more likely include: | | | | - egg impaction in the uterus | | | | - egg related peritonitis | | | | - excess abdominal fat | | | | - more common in older hens | | | | Signs of these infections are very general and non-specific. They | | include; depression, anorexia, weight loss and abdominal enlargement. | | Occasionally a cloaca discharge will see (smelly ooze from the vent). | | | | Birds can produce eggs through an infection but quite commonly these | | eggs will be misshapen with a rough sludgy appearance to the egg | | shell. Normally as the shell forms the egg is rolled smoothly in the | | shell gland. Where there is infection the motion will be jerky and | | the shell rough. | | | | Dead in shell can be as a result of uterine infections in the hen, as | | can the weakness and deaths of chicks after hatching. | | | | Treatment of uterine infections is based around antibiotics. | | Identifying the bacteria and the correct antibiotic by cultures is | | worthwhile in valuable birds. | | | | In severe cases uterine flushing can be helpful and to salvage the | | bird, a hysterectomy can be performed. This puts an end to a bird\'s | | breeding career but can save its life. | | | | Complications include:- | | | | - egg binding | | | | - egg impaction | | | | - uterine rupture | | | | - peritonitis | | | | - Septicemia (systemic infection which can be rapidly fatal. In as | | little as 1-2 hours infection can spread to all body organs). | | | | OVIDUCT IMPACTION :- | | | | The binding up in the uterus of successive eggs, egg yolk material | | and where infection occurs also pus material. | | | | This problem usually occurs secondary to egg binding or uterine | | infection. | | | | Signs include; | | | | - a stop in egg production | | | | - progressive loss of condition | | | | - alternations between diarrhea and constipation | | | | - abdominal enlargement | | | | - a reluctance to fly or walk | | | | Treatment is limited to surgery. Attempts can be made to salvage the | | uterus, but most cases have severe scarring and adhesions. The birds | | may be saved by a hysterectomy but have no breeding future. | | | | OOPHORITIS:- | | | | Inflammation or infection of the ovary which is usually secondary to | | systemic disease. | | | | Signs are difficult to distinguish from any other systemic disease | | including:- | | | | - depression | | | | - anorexia | | | | - wasting and death (most cases are diagnosed by post mortem) | | | | Treatment is the same for any severe systemic disease and involves | | supportive care with warmth, fluids and nutrition. Antibiotics are | | useful in cases of bacterial infection. | | | | CLOACAL PROBLEMS | | | | Any problem in the cloaca can cause obstructions to egg laying (eg. | | infections, scarring, fecal stones or chronic prolapses) or to mating | | (e.g. dense vent feathering, abdominal fat, papilloma\'s or warts | | especially those due to vitamin A deficiency). | | | |   | | | | ECTOPIC EGGS (NON-SEPTIC EGG PERITONITIS) | | | | Eggs not taken up by the oviduct and instead are deposited into the | | abdomen. Can also be caused by rupture of the oviduct and is more | | likely to occur if hens are restrained or stressed during ovulation. | | | | Results in yolk material spreading through the air sacs and over the | | abdominal organs which causes a mild inflammatory reaction. If no | | bacteria is present, all yolk material will be reabsorbed. | | | | Signs are:- | | | | - abdominal swelling | | | | - wide based stance | | | | - weight loss | | | | Treatment is mainly supportive, but antibiotics are used in case of | | septic peritonitis. | | | | If the signs are severe then surgery to remove yolk material. | | | | Attempt to switch off laying cycle. Manipulating the amount of light | | the bird gets can be successful. We recommend the hen be removed from | | its cage and sight and sound of its mate, then covered except for | | four hours of light for four days. If this is not successful hormonal | | injections can be used but there is a risk of significant side | | effects including depression, increased urine production, weight | | gain, liver damage, suppression of the immune system and diabetes. | | | |   | | | | SEPTIC EGG RELATED PERITONITIS | | | | Yolk peritonitis that is contaminated with bacteria and causes a | | severe inflammatory reaction throughout the abdomen. It is more | | common than non-septic peritonitis. | | | | Causes congestion, scarring and adhesions of all abdominal organs. | | | | Signs:- | | | | - can simply be sudden death | | | | - see abdominal swelling | | | | - respiratory distress | | | | - depression | | | | - anorexia | | | | - cessation of egg laying | | | | Can be complicated by diabetes, strokes, intestinal obstruction and | | hepatitis. | | | | Treatment initially involves supportive care to stabilize the bird. | | Heat, fluids and antibiotics should be given as well as the provision | | of high protein foods. | | | | Surgery is helpful in valuable birds to remove pus and infected yolk | | material. In pet birds we generally perform a hysterectomy at the | | same time which prevents the disease recurring. | | | | Any episode of this puts the birds breeding future in doubt as there | | is always scarring and adhesions and there can be severe uterine | | damage. | | | |   | | | | CHRONIC EGG LAYING | | | | Laying beyond the normal clutch size or repeated clutches in the | | absence of a mate or breeding season. | | | | Especially common in hand raised hens which have imprinted onto | | humans. | | | | Signs other than the number of eggs are limited to loss of condition. | | | | Eventually malnutrition from pouring all her resources into egg | | production will result in abnormal eggs or egg binding due to uterine | | muscle dysfunction and general muscle weakness. | | | | Treatment revolves around trying to switch off the laying cycle. | | Involves:- | | | | - light manipulation (see under Ectopic Eggs) | | | | - removing any objects the bird considers as potential mates | | | | - removing nest boxes and nesting materials | | | | - and change of cage | | | | - If the bird is sexually oriented to humans then decreasing the | | amount of time spent with the bird can be helpful | | | | In some particularly determined hens all this will fail and it may be | | necessary to use hormonal injections. (See under Ectopic Eggs for | | side effects that can occur with hormonal injections.) Injections | | will work for a period that can vary from as little as two weeks to | | up to six months. | | | | In some hens the only solution is hysterectomy. | | | |   | | | | OVER PRODUCTION | | | | The maximum safe levels for production have not been determined in | | parrots. In the wild greater than two clutches per year is abnormal | | but this is quite often limited by feed availability. Can breed some | | parrots in captivity (eg. Macaws, Cockatoos, and Eclectus) up to four | | clutches a year with no apparent side effects. | | | | Prolonged laying, hatching and rearing put stresses on a bird. If | | birds are kept in optimal conditions they seem to be able to keep on | | breeding. These birds are however on a knife edge. If anything is | | wrong with management or diet then the birds will not be able to | | cope. Diseases which are usually secondary problems can become major | | concerns, eg. Chlamydia and Mega bacteria (Otherwise known as Bird | | keeper\'s Bogeymen). | | | | While no absolute recommendations can be made, it is best for the | | bird owners not to become greedy and push them for large numbers of | | clutches. Allow the birds a rest period each year. | | | |   | | | | ABNORMAL EGGS | | | | An odd abnormal egg is not a concern and it is quite common for hens | | to throw different shaped eggs with no problems. | | | | However a run of soft-shelled, rough shelled or infertile eggs | | indicates a potential problem. | | | | Causes :- | | | | - dietary insufficiency (esp. vitamins A, D3 & calcium) | | | | - uterine infections - suspect if eggs are rough shelled or sludgy | | in appearance | | | | - organo chlorines (DDT) produce thin-shelled, fragile eggs - this | | is a continuing problem with birds of prey in the wild but be | | careful what you use around your birds | | | | - ovary disease - will produce yolkless, small yolked or infertile | | eggs | | | | - environmental toxins. There are many toxins that can affect the | | hen resulting in lowered egg production, early embryo death or | | weak chicks. Some common examples include: crude oil, exhaust | | fumes, NICOTINE, organochlorines and antibiotics containing | | furazolidone | | | | KEEPING HENS IN GOOD CONDITION FOR BREEDING | | | | 1. ENSURE THE DIET IS ADEQUATE OR EXCELLENT (refer to Dr. Adrian | | Gallagher\'s excellent and award winning notes on avian | | nutrition.) | | | | 2. KEEP BIRDS LEAN. (This doesn\'t mean malnourished !!) Obesity is | | a common predisposing cause to many of these reproductive | | problems. Don\'t feed protein supplements in the off season. | | Allow the birds access to flight cages in off season. | | | | 3. FLUSHING increase protein levels as breeding season commences. | | This simulates flush of feed in wild which is usually tied in to | | breeding season. Can improve fertility of male and female, | | increase sexual activity and ovulation rates. | | | | 4. MINIMAL HANDLING BUT CLOSE ATTENTION for early detection of | | problems. | +-----------------------------------------------------------------------+ +-----------------------------------------------------------------------+ |       | | | |     A **POISON** by any other name is still a poison. To paraphrase | | Paracelsus from 400 years ago, it\'s \'the dose that makes the | | poison\'. Simply stated, almost anything in an overdose or a diet | | restricted to only one ingredient would eventually become toxic to | | your birds. A misplaced decimal point in medication dosage can cause | | toxicity, and I\'ve already written about the toxicity of a group of | | drugs used to treat coccidiosis called sulfonamides. Water mixable | | medications can become toxic if the weather is hot and the birds are | | drinking more water than normal. Even high levels of certain | | vitamins, such as A and D, can be toxic and some doses of medication | | that are perfectly fine for chickens and turkeys can kill your | | waterfowl. (Remember that waterfowl generally consume four times the | | water that chickens do.)\ | | \ | |    Toxins (or poison), fall into several different categories. I | | can\'t list them all here, but I\'ll try to give you an overview for | | general reference.\ | | \ | |      Again, the use of **sulfonamides** for the treatment of | | coccidiosis is highly discouraged. Especially with the availability | | of amprolium, which is safe. An effective dose of a sulfonamide is | | toxic to poultry, and can have a negative effect on the immune | | system. Hemorrhagic syndrome and organ damage can occur as a result | | of sulfa poisoning, particularly in the liver and kidneys. I | | discourage the use of sulfonamides for ***all poultry***, including | | ***waterfowl***, unless amprolium is unavailable. In this case, use a | | \'safer\' sulfa such as sulfadimethoxine or sulfamethazine. Avoid | | Sulfaquinoxaline (SQ).\ | | \ | |      Some **antibiotics** can be troublesome if their use is not | | controlled. In ***turkey poults***, the subcutaneous injection of | | **Gentamicin** can cause depression, edema, injection site | | hemorrhage, and kidney damage. **Streptomycin** (and | | dihydrostreptomycin sulfate), injected intramuscularly (IM), can | | cause respiratory distress, paralysis, and mild convulsions. Baytril | | is one of the safest and most effective broad-spectrum antibiotics | | available.\ | | \ | |      Some **antiprotozoals** such as **Nitrazol** and **Emtryl** have | | caused growth depression, drop in egg production, incoordination and | | tremors, convulsions, and death in ***geese***, ***ducks***, | | ***pigeons***, and ***turkeys***. Doses safe for other poultry may be | | poisonous to ***waterfowl***. **Quinacrine HCI** (Atabrine), is fatal | | at a dose of 50mg/kg of body weight in ***pigeons***, but is safe for | | other poultry at that dose.\ | | \ | |      **Parasitic** and **worming treatments** should also be used | | with caution. When you worm your birds, you\'re giving them poison to | | kill the worms. With that in mind, you should never worm a sick bird | | as a shotgun approach to treatment. Rule everything else out first. | | Benzimidazoles (cambendazole, mebendazole, and fenbendazole), and | | phenothiazine are all pretty well tolerated by most birds. Ivermectin | | is probably the safest though.\ | | \ | |      **Levamisole** (and **tetramisole**, which is no longer | | available in most countries), should be used with caution. (Because | | of it\'s chemical makeup, an effective dose of levamisole is half | | that of tetramisole.) It has a wide range of toxicity from as little | | as 66 mg/kg of body weight in ***wild birds***, on up to 300 mg/kg in | | ***geese***. Levamisole can be toxic to ***ducks*** at 40-80mg/kg of | | body weight.\ | | \ | |      Under the group of **minerals** and **metals**, three stand out | | as the most problematic: **sodium chloride** or **sodium bicarbonate | | (salt)**, **lead**, and **calcium** (as in the over-use of oyster | | shell).\ | | \ | |      Most sodium problems arise as a result of ***young chicks*** and | | ***turkey poults*** consuming too much saline water. Avoid using | | softened tap water to supply water to your birds while brooding. Some | | ***waterfowl*** have nasal salt glands that allow them to excrete | | excess, but play it safe with them too since they consume more water | | than chickens and turkeys. Sodium poisoning can cause kidney damage | | (more so in young birds than adults because their kidneys may not be | | fully developed when first hatched), and heart failure.\ | | \ | |      **Lead** poisoning remains a serious problem in this country - | | primarily with ***wild birds*** and ***waterfowl***, but can be a | | hazard for the free-range backyard flock or birds confined to an old | | coop with lead paint. Three primary sources of lead are lead shot or | | bullets used in hunting or target practice, lead weights from fishing | | lines, and lead paint chips. ***Chickens*** are more tolerant, but | | can die from lead poisoning as well. Lead that is consumed typically | | remains in the gizzard and gets ground and released into the system | | slowly, so many lead poisoning cases are of a chronic nature. | | Lameness, paralysis, weakness, wasting, and watery green diarrhea can | | be symptoms. However, sometimes ducks and geese can die from lead | | poisoning while still in good flesh, which results in an inaccurate | | diagnosis. Many state labs can test tissues from dead birds to | | confirm metal or chemical compound toxicity.\ | | \ | |      **Calcium** overdose is a common occurrence when people over-use | | calcium supplements such as oyster shell. Oyster shell offered to any | | female before first egg can cause kidney damage. Never mix oyster | | shell into feed where young females or males of any age can | | free-feed. Oyster shell should be provided to laying females. | | However, if you see \'calcium bumps\' on your eggshells, they\'re | | getting too much. A good vitamin and mineral supplement added to | | drinking water can sometimes provide enough calcium.\ | | \ | |      **Vitamins A, D3** (cholecalciferol), and **B6** (pyridoxine), | | can be toxic when overdosed. Excess Vitamin A can reduce egg | | production and growth rate, and cause osteoporosis. A simple | | top-dressing of Vitamin D3 on feed consumed by ***chicks*** has | | caused kidney damage in field studies. Also be careful when using | | rodenticides that contain **25-hydroxycholecalcoferol** (from the | | same family of D3), as ***poultry***, ***pigeons***, and ***wild | | birds*** can also be poisoned. Vitamin B6 is toxic to ***pigeons*** | | at 200mg/kg of body weight by injection.\ | | \ | |      **Disinfectants** and **fungicidal fumigants** such as | | **phenolics**, **quats**, **chlorine bleach**, **formaldehyde**, | | **organic mercurials**, **thiram**, and **captan** cause toxicity | | when ingested or inhaled. The overexposure rates are too numerous to | | list here, so use them all with caution. Oxine is a relatively safe | | disinfectant and fungicide, and can also be used as a medical | | treatment for upper respiratory fungal infections when fogged. It\'s | | 200 times more effective than chlorine bleach, colorless and | | odorless, and relatively safe to use for just about anything.\ | | \ | |      Almost all **insecticides** are toxic and most attack the | | nervous systems of ***all birds***. One group that\'s relatively safe | | and effective to use is pyrethrum and synthetic pyrethroids. Most | | poultry dust and flea and tick sprays used for the control of feather | | mite contain a form of pyrethrum. These products are relatively safe | | to use. It\'s been difficult for me to find documentation that | | anything else is as safe. Most **rodenticides** (rodent control), are | | deadly to ***all birds***, so poultry keepers should avoid all of | | them to be on the safe side.\ | | \ | |      Two common **toxic gases** that affect ***all birds*** are | | **ammonia** and c**arbon monoxide**. Corneal ulceration and blindness | | can be caused by ammonia fumes from overspent litter. Heart rate and | | breathing may be affected with bronchial hemorrhage, and egg | | production can drop when ammonia levels rise. Growth rate of | | youngsters will be affected and they won\'t thrive in an environment | | where there are strong ammonia levels. Clean, dry litter will avoid | | this problem. If you can smell ammonia in your coop, your levels are | | too high. Carbon monoxide poisoning can occur when birds are exposed | | to faulty ventilating systems, engine exhaust, and when open-flame | | brooders and furnaces are used without proper ventilation.\ | | \ | |      **Household** and **commercial products** such as **alcohol**, | | **antifreeze (ethylene glycol)**, old solvent cleaners that contain | | carbon **tetrachloride**, **fertilizers**, and **mothballs | | (naphthalene)**, are highly toxic and most cause liver and/or kidney | | damage in ***all birds***.\ | | \ | |      Botulism is caused by a **biotoxin** and is a common problem | | among ***waterfowl*** breeders with a pond, but can also be a problem | | when dead ***poultry*** are left in litter to be picked at by the | | live birds. Very small amounts of this toxin are deadly.\ | | \ | |      Another biotoxin is **algae** and there are several species of | | blue-green algae that when concentrated by rapid growth (bloom), may | | poison ***all birds*** when consumed. Poisoning can cause paralysis, | | a dilated, distended heart, and liver damage. Anyone who keeps a pond | | should research the proper care and maintenance of ponds. It\'s a | | fragile ecosystem that can help, or sometimes harm, your waterfowl.\ | | \ | |      My last group of toxins is **phytotoxins (plants)**. Since the | | group is complex and ranges from deadly to chronic, I\'ll just list | | some of them here. If ***any bird*** free-ranges and has access to | | nice grass or pasture, it will probably avoid these. If they\'re the | | only things to eat though, the birds may consume them and die. Simply | | use this list for awareness: **avocado, black locust, bladder pod, | | cacao, cassava, castor bean, coffee senna, sickle pod, corn cockle, | | cotton seed meal, coyotillo, crotalaria, daubentonia, death camas, | | eucalyptus cladocalyx, hemlock, jimsonweed, leucaena leucocephala, | | lily of the valley, milkweed, nightshade, oak, oleander, parsley, | | pokeberry, potato, ragwort, rapeseed meal, canola, sweet pea, tobacco | | (includes nicotiana), velvetweed, vetch, yellow jessamine,** and | | **yew**. You should be able to locate these names somewhere on a seed | | packet if the seed is sold under a more common name. I would carry | | this list when shopping for plants and seeds for your garden.\ | | \ | |                | +-----------------------------------------------------------------------+