AVIAN GOUT DISEASE IN COMMERCIAL POULTRY

Disease A Disease is any depart/deviation

from normal health.

By Dr Wisal Mohammad khan Manager Training Fakieh Poultry Farms KSA Email ; moh_k5pk@yahoo.com

•Infected Birds ( Horizontal )

•Carrier Birds ( vertical )

•Human vectors

•Mechanical vectors

•Contaminated Feed or Water

•Wild Birds and Animals

•Rodents and Insects

•Dead Birds

•Manure

How are diseases spread

Important poultry diseases

There are different types of Poultry diseases mainly divided in to following major groups .

Viral disease ( ND / IB / MD )

Bacterial diseases ( E.coli./ salmonella / F.Cholera ) Metabolic diseases .

Managmantal diseases.

Gout in poultry

Introduction Visceral gout is the deposition of white urates, which are normally excreted as a white cap on well formed faeces, in various tissues. . •In gout, the kidney function is slowed down to a point where uric acid accumulates in blood and body-fluids. Further, it leads accumulation of white uric acid or urate - crystals occurs in soft tissues of various organs in body.

Other names

Nephrosis, Baby Chick Nephropathy

Types of Gout VISCERAL GOUT: A condition in which white uric acid or uratecrystals deposits are seen in soft tissues of various organs in body. ARTICULAR GOUT: Conditions in which urate crystals deposit are seen in joints.

Visceral gout (Visceral urate deposition) Articular gout

Onset: It is usually an acute condition but can be chronic.

It is usually a chronic disease.

Frequency: It is very common. It is rare or sporadic.

Age: 1 day and above. 4-5 months and above. However, immature genetically susceptible chickens may be induced by high protein levels in the diet.

Sex: Both males and females are susceptible. Mostly males.

GROSS LESIONS

Kidney Kidneys are almost always involved and they look grossly abnormal with deposition of white, chalky precipitates.

Kidneys are normal grossly. Kidneys may become abnormal with white urate deposits if the bird gets dehydrated.

Soft Tissues Visceral organs like liver, myocardium, spleen or serosal surfaces like pleura, pericardium, air sacs, mesentery, etc. are commonly involved.

Soft tissues other than synovium are rarely involved, however, comb, wattles, and trachea have been observed to be involved.

Joints Soft tissues around the joints may or may not be involved. Surfaces of muscles, synovial sheaths of tendons and joints are involved in severe cases.

Soft tissues around the joints are always involved, especially feet. Other joints of the legs, wing, spine, and beak are also commonly involved.

Differences between Visceral Gout and Articular Gout in Birds

Microscopic lesions Generally no inflammatory reaction in synovium or visceral surfaces. Kidney has inflammatory reaction around tophus.

Granulomatous inflammation in synovium and other tissues.

Pathogenesis It is generally due to failure of urate excretion (renal failure).

It is probably due to a metabolic defect in the secretion of urates by the kidney tubules.

Causes 1. Dehydration.2. Nephrotoxicity: calcium, mycotoxins, (ochratoxins, oosporein, aflatoxins, etc.), certain antibiotics, heavy metals (lead), ethylene glycol, ethoxyquin etc.3. Infectious agents: nephrotropic IBV and avian nephritis virus (chickens), polyomavirus, PMV-1 (pigeons), Salmonella sp., Yersinia sp., Chlamydia psittaci, Eimeria truncata, microsporidia, cryptosporidia, Aspergillus sp., etc.4. Vitamin A deficiency (please refer to below)

5. Urolithiasis6. Neoplasia (lymphoma, primary renal tumors)7. Immune mediated glomerulonephritis8. Anomalies

9. Others?

a. Genetics.b. High protein in the diet. c. Others?

VG in very early age of about 3 days old chicks

There are white chalky deposits around the heart (in the pericardium) on all major abdominal organs, including liver, gizzard and intestines, and even in the tissues of the thigh. 

Urate deposition in the thing tissues + kidneys

Factors/ Causes of VGThe main causes of gout are many as kidney damage occurs due to multi etiological factors. These causes can be broadly categorized as:

1 ) Infectious causes2 ) Nutritional and metabolic causes3 ) Other causes ( Managemental ) Could be a viral like IB /ANV/ Castro V etc ( possibility for Horizental / vertical transmission )

Could be a bacterail like E.coli strains .

Could be a Management ie at various operations to handle the chiks from hatchery to farm house and due to nutrition ( Feeds) .So due to these casues make it a complex disease .

All poultry species are susceptible.

Today’s bird is genetically engineered for higher productivity. Selection of birds is based on production parameters.

In this process, the health of the vital organs is mostly ignored. This has resulted in increased incidence of metabolic disorders.Main affected body organ Kidney Heart Soft tissues of the body including joints etc KIDENY The kidney is a vital organ of the bird with diverse all metabolic and excretory function FUNCTIONS maintaining the chemical composition of body fluids, removal of metabolic waste and toxic products, regulation of blood pressure and blood volume and conservation of fluids and electrolytes. The Excretion of metabolic waste products is important in poultry and this function is performed by the kidneys.

The function of kidneys is affected by a number of specific diseases and disorders.

One of the important disorders associated with kidney damage is GOUT.

In birds uric acid is the end product of Nitrogen metabolism. Uric acid is a Nitrogenous waste from protein breakdown. In mammals, it is converted to less harmful substance with the help of the enzyme uricase.

But in birds this enzyme is absent. Hence, uric acid is the final excretory product.

Uric acid is produced mainly in the liver and is excreted by the kidneys. High blood levels of uric acid favour its precipitation in tissues.

Uric acid is not toxic but precipitated crystals can cause mechanical damage to tissues like kidneys, heart, lungs, intestines and also in the joints. These crystals severely damage body tissues. So Gout is a condition in which kidney function decreases to a point where uric acid accumulates in the blood and body fluids. 

In gout, blood levels of uric acid can be as

high as 44mg/100ml

compared to 5-7mg/100ml in a normal bird.

The kidney damage can arise

with certain strains of Infectious Bronchtiis virus, exposure to some mycotoxins

inadequate water intake (often because the birds have not adapted to a new type of drinker).

Baby Chick Nephropathy can be due to inappropriate egg storage conditions,

excessive water loss during incubation or during chick holding/transport,

inadequate water intake during the first few days of life.  Very low humidity in brooding will also increase the likelihood of this problem.

The timing of mortality is a reasonable guide as to the source of the problem.

NUTRITIONAL AND METABOLIC CAUSES

Excess dietary calcium with low available phosphorus results in precipitation of calcium-sodium-urate crystals.

High levels of vitamin D3 can also increase calcium absorption from the gut which can favour formation and deposition of urate crystals.

Excessive use of sodium bicarbonate when used to combat heat stress to improve egg shell quality in layers. This alkalinity of urine favours kidney stone formation.

Prolonged vitamin A deficiency causes sloughing of tubular epithelium and subsequent blockade resulting in accumulation of urates in the kidney. However, incidence of gout due to vitamin A deficiency is least under field conditions.

Gout due to sodium intoxication is seen in younger birds when the sodium levels exceed 0.4% in water and 0.8% in feed. This generally happens when fish meal is used in the diet (even with normal salt content), since fish meal is rich in salt content. Total content of sodium chloride in feed should not exceed 0.3%.

Feed containing more than 30% of protein causes uric acid production which in turn creates an excretory load on kidneys.At the same time the presence of sulphates decreases calcium resorption causing excessive calcium secretion through urine. This condition favours gout.•Water deprivation leads to concentration of uric acid and other minerals in the blood and later in the kidneys.

Water deprivation especially in the summer is dangerous. This can happen during transportation of birds or due to •blockage of nipples, •Inadequate number of waterers, •extra height of water lines, •overcrowding, •water withholding for long durations during vaccination etc.

Hard water with higher salt content is also a load on the kidneys.

OTHER CAUSESVarious chemicals and toxins are involved in kidney damage as;MYCOTOXINS: Mycotoxins are the most common cause of kidney damage such as citrinin, ochratoxin oosporin important. The combination of ochratoxins with aflatoxin is found to be more dangerous. Because of kidney damage uric acid excretion is reduced resulting in accumulation of uric acid in the body.

ANTIBIOTICS:

Using of Certain antibiotics In Very early ages(1-14 days) when there is facing problem for VG like Gentamycin, sulphonamides and nitrofurosones are known to cause renal damage especially in young chicks. The drugs which get excreted through the kidneys have their own imbalancing effect on pH and renal metabolism

DISINFECTANTS:

Disinfectants like Phenol and Cresol if used erroneously cause residual toxicity.

CHEMICALS: Chemicals like Copper sulphate used in water results in water refusal, dehydration and gout.

SIGNS AND LESIONS ( General)

Gout is characterized by depression,

Dehydration and sometimes with greenish diarrhea.

Affected chicks appear dull with ruffled feathers and moist vent

Mortality among young chicks is high. ( up to 35-50%)

Post-mortem lesions

Chalky white deposits on pericardium, liver, air sacs, peritoneum. Similar deposits may be present in joints and are usually present in the kidney.

DiagnosisLesions.

Treatment

•This is based on correcting any management errors and encouraging water intake.

•Avoid any intentional or unintentional restriction in water intake.

•Sodium bicarbonate at 1g/litre water is mildly diuretic,

TREATMENTIndividual cases of gout may be ignored. •In acute cases of gout mortality following prescription would be beneficial.•Provide plenty of water and adequate drinkers.Avoid a diet higher in protein than the recommended level as per the age and breed. Provide low protein diet for 3-5 days based on need depending on severity of gout.Review IB vaccination programme. In the areas where IB is endemic it is advisable to vaccinate with nephrotropic strain at around 4 days. Day one beak dip vaccination has proved to be beneficial in broilers.Use of urine acidifiers: Any one of the following urine acidifiers may be given in water or feed. Using of methanimine in drinking water for 1 weeks if the problem is severe.(0.5-1gm/ lit.)

Vinegar: 1-2 ml per litre water up to 24 hours.Potassium chloride: 1gram per litre water up to 24 hours.Ammonium chloride: Two and half kg/ton feed for 7 days.•Ammonium sulphate: Two and half kg/ton feed for 7 days.Ensure adequate levels of A, D3, K and B complex vitamins.Excessive use of sodium bicarbonate i.e. more than 2kg/ton should be avoided.Use of electrolytes through water may assist in controlling mortality.Provide broken maize at least for 3 days and jiggery 5g/litre for 3-5 days in case of mortality.Provide 0.6% methionine hydroxyl analogue free acid with 3% calcium in the diet.  

Prevention Careful monitoring of the conditions of hatching egg storage and incubation with a view to achieving a standard egg weight loss profile.Humidification of holding rooms and chick transporters may also be beneficial. Humidifiers/ sprinkling of the water by the small hand pump in chick brooding areas are being used increasingly, especially where whole house hot air brooders are in use. Ample supplies of drinkers should be available and filled with water at house temperature prior to the arrival of the chicks.

PREVENTION

provide Scientifically balanced feed in respect of Calcium-phosphorus ration depending on the type of ration.Vitamin A, D3 and other essential vitamins.Required level of sodium, chloride and other ions.Conventional sources of protein.Analyse the feed for mycotoxin content and if found positive change the feed or use suitable toxin binders.Judicious use of drugs such as antibiotics, sulpha drugs and anticoccidials to avoid kidney damage. Fresh potable water accessible to birds all the time. Copper sulphate should not be used for medication, if used should be used under the directions of a veterinarian or a poultry practitioner. 

Other sources of Prevention and Control or Treatment.

At hatchery level try to minimize Dehydration at all stages including .chick holding and transportation etc. Try to start chick life during day time in cold weather when temperature is ideal.Make sure that the chicks get free and ample access to drinking water. Maintain water temperature to room temperature. Adjust proper height of drinkers. In case of nipple drinking system use Mini bell drinkers for few days or water fonts. Maintain correct temperature at litter level during arrival of chicks and first 10 days at-least. Try to maintain 60 % plus or 70% humidity during first3 days of chick life. Allow chicks to drink water for 1 or 2 hours and then only offer pre-starter feed.Ensure correct level of calcium and phosphorous levels in feed. Use of toxin binders and liver tonics to keep minimum levels of fungal toxins in feed. Avoid excessive protein levels in diet over suggested

Use recommended levels of aluminum-free Sodium bicarbonate (baking soda) in feed during high temperatures. Use of Jaggery 2to5 grams per liter. Of water or electrolyte at recommended doses in water.  Review IB vaccinnation programme in Breeders and broiler farms. Even vaccine spray at hatchery level found to be effective in field condition. Even farms having history Gout problem show this problem to some extent to up coming batch also been reported. However more work needs to be done on this matter. Use of antiviral preparations is found helpful to some extent to farms.Depending upon the history one can use Ammonium-sulphate 5 gram/kg or Ammonium chloride 10 grams/Kg in feed. Use of Potassium Chloride 0.5 gram to 1 gram per liter water also been used. High level of Methionine in feed also found helpful to some extent. Use of diuretic drug preparations like sodium acid citrate also been used. Coconut water is also a good diuretic.

When gout is noticed, reduce the load on kidney by reducing the daily intake of protein either by reducing the quantity of feed or use grinded maize fortified with vitamins and salt at correct level for 24 to 48 hours along with uses of Ammonium sulphate or Ammonium chloride or Potassium chloride at correct levels.  

BIOSECURITY

Procedures that work for bird pathogens also keep out human pathogens

Basic Steps No Visitor Policy – Have Farm Clothes Protect Personnel – Clean Vehicles Clean Equipment – No Contact Other Birds Proper Dead Disposal – No Borrowed Equip No Visits to Problems – No Wild Game Locks & Security Avoid Mixing Animal Species

Shared Equipment and Vehicles•Clean and Disinfect shared equipment between farms

•Establish a wash area away from the poultry buildings

•Log the events

BIOSECURITY

•Biosecurity

•Personal HygieneWash your hands, Wash your hands, Wash your hands

•Separate clothes and boots for the poultry

•Protective gear if creating an aerosol

•Be aware of where you have been

•Get sick birds to a diagnostic lab

•If you have a poultry event schedule in your county let the State Veterinarian Office know.

“Doing the little things now may prevent the need to do major

things later”

BIOSECURITY