Spiking illness Spiking illness Syndrome in Broiler Syndrome in Broiler Chickens: 2008:in NepalChickens: 2008:in Nepal

Dr.Kedar KarkiDr.Kedar Karki

Background:Background:

A sudden and unexpected increased in A sudden and unexpected increased in mortality in broiler.mortality in broiler.

Age:8-16 days.Age:8-16 days. Location :Chitwon, Kathmandu Valley.Location :Chitwon, Kathmandu Valley. Mortality lasted for 3-5 daysMortality lasted for 3-5 days

Clinical picture:Clinical picture:

Affected birds became recombent.Affected birds became recombent. Depressed.Depressed. Often went to star-gazing spasm.Often went to star-gazing spasm. Hurdling of the birds.Hurdling of the birds. Trembling.Trembling. Blindness.Blindness. Loud chripingLoud chriping

Clinical picture:Clinical picture:

Litter eating.Litter eating. Ataxia.Ataxia. Comatose.Comatose. Birds dead with breast down and Birds dead with breast down and

feet ,legs straight out behindfeet ,legs straight out behind

Postmortem lesions:Postmortem lesions:

Hemorrhage in liver with necrosis of liver Hemorrhage in liver with necrosis of liver cells.cells.

Regressed thymus.Regressed thymus. Regression of bursa of Fabricius.Regression of bursa of Fabricius. Dehydration with accumulation of kidney Dehydration with accumulation of kidney

Urate.Urate.

Postmortem lesions:Postmortem lesions:

Fluid in crop, Fluid in lower gut, watery Fluid in crop, Fluid in lower gut, watery contents in cecacontents in ceca

Yellow elastic shanks.Yellow elastic shanks. Swollen joints.Swollen joints. Molted appearance. Of brainMolted appearance. Of brain

Laboratory investigation:Laboratory investigation:

Mycobiota/Microbiota of postmortem tissueMycobiota/Microbiota of postmortem tissue Lung,liver,Proventriculus,Gizzard,Brain,SpleenLung,liver,Proventriculus,Gizzard,Brain,Spleen Total samples:298Total samples:298 Negative: 24Negative: 24 Mycology; Aspergillus spp, Penicillium spp, in Mycology; Aspergillus spp, Penicillium spp, in

182 samples, Salmonella spp 24182 samples, Salmonella spp 24 Mixed E.coli and Staph 68Mixed E.coli and Staph 68

Review of HistoryReview of History

Spiking mortality syndrome of chickens Spiking mortality syndrome of chickens has been classified as such for has been classified as such for approximately ten years. During the first approximately ten years. During the first experiences with the disease a number experiences with the disease a number of causative agents were implicated, yet of causative agents were implicated, yet the symptoms remained relatively the the symptoms remained relatively the same. same.

Review of HistoryReview of History

1988 to 1990 the syndrome reached critical 1988 to 1990 the syndrome reached critical epidemic proportions particularly in the epidemic proportions particularly in the Delmarva area of the U.S. Delmarva area of the U.S.

Isolated cases were also reported at that time Isolated cases were also reported at that time in Georgia, Alabama and Arkansas. in Georgia, Alabama and Arkansas.

In 1990 the problem became so severe that a In 1990 the problem became so severe that a task force was developed in the Delmarva area task force was developed in the Delmarva area in order to bring some definition to the in order to bring some definition to the syndrome. syndrome.

Review of HistoryReview of History

Approximately around 1992, the Approximately around 1992, the incidence of spiking mortality in chickens incidence of spiking mortality in chickens took a severe jump in Georgia and to a took a severe jump in Georgia and to a lesser extent Alabama. Sporadic cases lesser extent Alabama. Sporadic cases were also still being reported in the were also still being reported in the Delmarva/North Carolina area. Delmarva/North Carolina area.

Review of HistoryReview of History

Several possible causes were implicated, but nothing Several possible causes were implicated, but nothing conclusive was identified. conclusive was identified.

Since that time Dr. James Davis of the Georgia Poultry Since that time Dr. James Davis of the Georgia Poultry Laboratory, in conjunction with several researchers Laboratory, in conjunction with several researchers across the U.S., conducted exhaustive and extensive across the U.S., conducted exhaustive and extensive research and uncovered an emerging virus with other research and uncovered an emerging virus with other interesting revelations. The conclusions of the interesting revelations. The conclusions of the Delmarva task force and the research findings of Dr. Delmarva task force and the research findings of Dr. Davis have helped to reduce the severity of a flock that Davis have helped to reduce the severity of a flock that experiences SMSC. Yet, the syndrome still occurs and experiences SMSC. Yet, the syndrome still occurs and no absolute eradication of the problem is in sight. no absolute eradication of the problem is in sight.

Review of SymptomsReview of Symptoms

The general symptom of spiking mortality The general symptom of spiking mortality in broilers is a sudden and unexpected in broilers is a sudden and unexpected jump in mortality from 8 to 16 days of jump in mortality from 8 to 16 days of age. The mortality lasts for three to five age. The mortality lasts for three to five days, after which, the mortality patterns days, after which, the mortality patterns return to a relatively normal level. return to a relatively normal level.

Review of SymptomsReview of Symptoms

Affected birds become recumbent, Affected birds become recumbent, depressed and often go into a star-depressed and often go into a star-gazing spasm. Death often occurs within gazing spasm. Death often occurs within two to six hours after the onset of the two to six hours after the onset of the symptoms. Characteristically, birds that symptoms. Characteristically, birds that exhibit clinical symptoms but survive the exhibit clinical symptoms but survive the acute phase, will continue to be unthrifty acute phase, will continue to be unthrifty and stunted for the rest of the grow-out. and stunted for the rest of the grow-out.

Review of SymptomsReview of Symptoms

surviving birds may weigh as little as one surviving birds may weigh as little as one half of the weight of unaffected flock-half of the weight of unaffected flock-mates by the end of the grow-out cycle. mates by the end of the grow-out cycle.

Review of SymptomsReview of Symptoms

lesions and symptoms into lesions and symptoms into Type AType A and and Type BType B. .

Review of Type AReview of Type A

Type AType A was defined as any house of birds was defined as any house of birds experiencing a daily mortality of >5 birds per 1000 experiencing a daily mortality of >5 birds per 1000 between 8 to 16 days of age.between 8 to 16 days of age.

The symptoms must occur for a duration of not more The symptoms must occur for a duration of not more than three days, with birds exhibiting all or a portion of than three days, with birds exhibiting all or a portion of the physical signs and lesions characteristic of the the physical signs and lesions characteristic of the syndrome. Those signs included, huddling of the birds, syndrome. Those signs included, huddling of the birds, trembling, blindness, loud chirping, litter eating, ataxia, trembling, blindness, loud chirping, litter eating, ataxia, comatose, birds dead with breast down and feet and comatose, birds dead with breast down and feet and legs straight out behind birds. Males are predominantly legs straight out behind birds. Males are predominantly affected and survivors exhibit great variation in sizes. affected and survivors exhibit great variation in sizes.

Type AType A

Lesions described with this syndrome Lesions described with this syndrome include hemorrhages in the liver with include hemorrhages in the liver with necrosis of liver cells, regressed thymus, necrosis of liver cells, regressed thymus, regression of the bursa of Fabricius, regression of the bursa of Fabricius, dehydration with the accumulation of dehydration with the accumulation of kidney urates, fluid in the crop, fluid in the kidney urates, fluid in the crop, fluid in the lower gut and watery contents of the lower gut and watery contents of the ceca. ceca.

Type BType B

Type BType B spiking was defined as any house spiking was defined as any house of birds exhibiting a significant mortality of birds exhibiting a significant mortality during the ages of 8 to 16 days of age. The during the ages of 8 to 16 days of age. The mortality may extend longer than three mortality may extend longer than three days but the rate is less than five deaths days but the rate is less than five deaths per 1000 per day. Also the Type B affected per 1000 per day. Also the Type B affected birds did not exhibit the symptoms and birds did not exhibit the symptoms and lesions of the Type A affected birds. lesions of the Type A affected birds.

"Type""Type"

Regardless of the "Type" of spiking Regardless of the "Type" of spiking mortality, one of the hallmark lesions is mortality, one of the hallmark lesions is hypoglycemia or low blood sugar. Also hypoglycemia or low blood sugar. Also most cases have been refractive to most cases have been refractive to supplemental medication or feed supplemental medication or feed changes. changes.

Causative AgentsCausative Agents

A number of causative agents have been A number of causative agents have been implicated in this devastating syndrome.implicated in this devastating syndrome.

Mycoses :Aspergillus spp; Penicillium Mycoses :Aspergillus spp; Penicillium spp in Nepalspp in Nepal

MycotoxinsMycotoxins Feed ingredientsFeed ingredients ManagementManagement VirusesViruses

MycotoxinsMycotoxins

MycotoxinsMycotoxins or a microtoxin were first or a microtoxin were first implicated. This was based on the implicated. This was based on the evidence of liver lesions and trace-back evidence of liver lesions and trace-back examinations of affected flocks. Through examinations of affected flocks. Through trace-back investigations, several trace-back investigations, several investigators found that affected farms investigators found that affected farms received feed containing feed ingredients received feed containing feed ingredients from specific geographic locations in the from specific geographic locations in the U.S. U.S.

Feed ingredientsFeed ingredients

Feed ingredientsFeed ingredients have also been have also been investigated. Investigations by the investigated. Investigations by the Delmarva Task Force studied the Delmarva Task Force studied the possibility of cocklebur seeds getting into possibility of cocklebur seeds getting into the feed. Nothing was ever substantiated the feed. Nothing was ever substantiated that cocklebur seeds were getting into the that cocklebur seeds were getting into the feed, and laboratory studies proved feed, and laboratory studies proved inconclusive in reproducing the syndrome. inconclusive in reproducing the syndrome.

ManagementManagement factorsfactors

ManagementManagement factors were suspected during factors were suspected during the early outbreaks of SMSC by many live the early outbreaks of SMSC by many live production managers. Several ideas were put production managers. Several ideas were put forth such as cold half house brooding, forth such as cold half house brooding, starvation of the birds and starting chicks on starvation of the birds and starting chicks on old feed. Substantiation of these old feed. Substantiation of these mismanagement situations are difficult to mismanagement situations are difficult to address. However, it is interesting that as some address. However, it is interesting that as some attention has been given to improving attention has been given to improving management practices, the incidence of SMSC management practices, the incidence of SMSC has declined. has declined.

VirusesViruses

VirusesViruses were suspected during the initial were suspected during the initial outbreaks of SMSC. The Delmarva Task outbreaks of SMSC. The Delmarva Task Force reported on the isolation of an Force reported on the isolation of an adenovirus from flocks experiencing the adenovirus from flocks experiencing the syndrome. Additional studies on the effect syndrome. Additional studies on the effect of an adenovirus have been conducted at of an adenovirus have been conducted at the University of Georgia. These the University of Georgia. These experiments have also not been experiments have also not been conclusive. conclusive.

An arenavirusAn arenavirus

from the feces of chicks exhibiting SMSC. from the feces of chicks exhibiting SMSC. Dr. Davis' work has shown that higher Dr. Davis' work has shown that higher numbers of arenavirus particles are found numbers of arenavirus particles are found in the feces of broilers, broiler breeders in the feces of broilers, broiler breeders and commercial layers experiencing and commercial layers experiencing enteritis. However, the feces of chickens enteritis. However, the feces of chickens experiencing spiking mortality, have experiencing spiking mortality, have particularly high numbers of virus particles. particularly high numbers of virus particles.

An arenavirusAn arenavirus

Arenaviruses are known to infect mice, Arenaviruses are known to infect mice, other rodents, birds and men. The virus other rodents, birds and men. The virus infects areas of the brain that regulate infects areas of the brain that regulate hormone levels in the body, particularly hormone levels in the body, particularly growth hormone. Mice infected with the growth hormone. Mice infected with the arenavirus have been found deficient in arenavirus have been found deficient in growth hormone which results in growth hormone which results in hypoglycemia and growth depression. hypoglycemia and growth depression.

Syndrome SolutionsSyndrome Solutions

As there have been a number of different causative As there have been a number of different causative agents suggested, there have been a number of agents suggested, there have been a number of suggested treatments and preventative measures. suggested treatments and preventative measures.

The only successful treatment of SMSC in the face of The only successful treatment of SMSC in the face of an outbreak has been the therapeutic use of quinolone an outbreak has been the therapeutic use of quinolone antibiotic in the water. Other remedies tried have antibiotic in the water. Other remedies tried have included, changing feed, vitamin supplementation in included, changing feed, vitamin supplementation in the water, and adding sugar to the drinking water. No the water, and adding sugar to the drinking water. No consistent success have been achieved with these consistent success have been achieved with these treatments. treatments.

Syndrome SolutionsSyndrome Solutions

A number of management techniques A number of management techniques have been employed to reduce the have been employed to reduce the chance of SMSC. Some common-sense chance of SMSC. Some common-sense measures such as adequate warming of measures such as adequate warming of the post-brood chambers, rodent control the post-brood chambers, rodent control and darkling beetle control appear to and darkling beetle control appear to have offered some help. have offered some help.

Syndrome SolutionsSyndrome Solutions

One technique that has offered the best help in One technique that has offered the best help in reducing the incidence of the syndrome is a reducing the incidence of the syndrome is a lighting program, which restricts the amount of lighting program, which restricts the amount of light the broilers are exposed to. The theory of light the broilers are exposed to. The theory of the lighting program is to increase the amount the lighting program is to increase the amount of darkness the broiler is exposed to as the of darkness the broiler is exposed to as the bird matures. The effect of this is to increase bird matures. The effect of this is to increase the level of melatonin (a natural hormone the level of melatonin (a natural hormone released from areas of the brain). released from areas of the brain).

Syndrome SolutionsSyndrome Solutions

Higher levels of melatonin may help to elevate Higher levels of melatonin may help to elevate the level of growth hormone and reduce the the level of growth hormone and reduce the opportunity for hypoglycemia. Thus far, it opportunity for hypoglycemia. Thus far, it appears that the lighting program has been appears that the lighting program has been successful both experimentally and in practical successful both experimentally and in practical usage. However, the lighting program has not usage. However, the lighting program has not proven to be a cure-all. Sporadic outbreaks of proven to be a cure-all. Sporadic outbreaks of SMSC still occur regardless of what SMSC still occur regardless of what management practices have been employed. management practices have been employed.

Syndrome SolutionsSyndrome Solutions

Liquid toxin binder.Liquid toxin binder. Immunomodulaters.Immunomodulaters. Multivitamins.Multivitamins. Liquid microminirals.in water has given Liquid microminirals.in water has given

promising result in Kathmandu valley promising result in Kathmandu valley area out breakarea out break