disease monitoring and extension system for the …

DISEASE MONITORING AND EXTENSION SYSTEM FOR THE SOUTH AFRICAN DAIRY INDUSTRY

Disease Trend Report: August 2015 A Milk SA Project

Service providers and co-workers

This report was prepared by Dr Danie Odendaal of the Veterinarian Network, in support of the Disease Monitoring and Extension System for the South African dairy industry. All information contained in this report is based on informal disease reporting and the herd veterinarian must be consulted before any specific disease prevention or treatment actions are taken, based on the information contained in this report. This report is provided to dairy farmers in support of better herd health management with the understanding that neither the author/s nor the organisations involved accept any liability whatsoever with regard to any statement, fact or recommendation made in this report.

1. Every single case of disease is important.

2. Occurrence of disease cases, in one veterinary practice area, over the last 12 months.

3. Use of the “Disease Overview” for the benefit of dairy farmers.

4. Disease reporting at farm level.

RuVASA Ruminant Veterinary

Association of South Africa Herkouer Veterinêre

Vereniging van Suid-Afrika

1. Single disease case

The incentive to prevent or manage a

disease condition better the next time,

will only be established

when there is a real

comprehension of the losses due

to the current disease case or

outbreak.

A DISEASE MONITORING AND EXTENSION SYSTEM FOR THE SOUTH AFRICAN DAIRY INDUSTRY

Every single case of clinical disease or outbreak is important, but it should never be regarded or

treated as only an individual, isolated case.

This case must always be linked or associated with the bigger picture in order to establish

importance and priority.

See the bigger picture

Let’s use an Asiatic redwater outbreak

during January 2015 in a dairy production area

in KwaZulu-Natal as an example


The bigger picture

Tick-borne Diseases

Jul

2015

Jun

2015

May

2015

Apr

2015

Mar

2015

Feb

2015

Jan

2015

Dec

2014

Nov

2014

Oct

2014

Sep

2014

Aug

2014

Jul

2014

African redwater

Anaplasmosis

Asiatic redwater

Heartwater

This outbreak occurred in a specific area, in relation to the month of the year (season) and in association with ticks and other tick-borne diseases.

If there is no disease recording and analysis, the importance and priority of this outbreak will be lost, and this disease will be treated as

a single isolated emergency on a never-ending basis.


The bigger picture

Tick-borne diseases

Jul

2015

Jun

2015

May

2015

Apr

2015

Mar

2015

Feb

2015

Jan

2015

Dec

2014

Nov

2014

Oct

2014

Sep

2014

Aug

2014

Jul

2014

African redwater

Anaplasmosis

Asiatic redwater

Heartwater

With this very practical disease-reporting system currently used by veterinarians, a disease overview is generated for each specific geographical area.

Disease occurrence can now be viewed in the context of the bigger picture, which

is needed for cost-effective disease management in the dairy industry.

2. Occurrence of disease cases per area.


The following pages provide a real overview of disease cases, as reported by veterinarians in one veterinary practice area in KwaZulu-Natal over the last 12 months.

This individual practice provides a veterinary service to more than 30 dairy farmers.

This real-time overview was generated with the V-Data electronic disease-monitoring system currently in place to serve the dairy industry and veterinary livestock practices.

Currently this “Disease

Overview” can be generated for the more

than 130 veterinary practices

(areas) that report to

RuVASA on a monthly basis.

Aug

2015

Jul

2015

Jun

2015

May

2015

Apr

2015

Mar

2015

Feb

2015

Jan

2015

Dec

2014

Nov

2014

Oct

2014

Sep

2014

Internal parasites

Brown stomach worm

Conical fluke

Liver fluke

Roundworms in general

Tapeworms

External parasites

Blue ticks

Brown ear ticks

Heartwater (Bont) ticks

Mange mites

Nuisance flies

Resistant blue ticks

Tick-borne diseases

African redwater

Anaplasmosis

Asiatic redwater

Heartwater

Insect-transmitted diseases

Lumpy skin disease

3-day-stiffsickness

Bacterial diseases (other)

Blackquarter

E. coli

Redgut (cattle)

Salmonellosis

Septicaemia

Fungal diseases

Ringworm

Viral diseases (other)

BRSV

EBL

IBR

Poisonings (plant) and fungal diseases

Cardiac glycoside

Seneciosis

Tulip poisoning

Aug

2015

Jul

2015

Jun

2015

May

2015

Apr

2015

Mar

2015

Feb

2015

Jan

2015

Dec

2014

Nov

2014

Oct

2014

Sep

2014

Macro-nutritional problems

Calcium deficiency

Energy deficiency

Protein deficiency

Micro-nutritional problems

Iodine deficiency

Selenium deficiency

Vitamin A deficiency

Multi-factorial Disease Conditions

Abortions

Abscesses

Abscesses in general

Bloat

Blue udder

Diarrhoea

Downer cows

Eye cancer

Eye infections

Joint ill

Lameness

Lung infection

Mastitis in general

Aug

2015

Jul

2015

Jun

2015

May

2015

Apr

2015

Mar

2015

Feb

2015

Jan

2015

Dec

2014

Nov

2014

Oct

2014

Sep

2014

Metabolic diseases

Acidosis

Displaced abomasum

Ketosis

Milk fever

Reproductive diseases

Difficult births

Endometritis

Metritis

Poor conception

Retained afterbirth

Uterus prolapse

Cervical prolapse

Climatical cause

Heat stress

Residues

Drug residues

Non-specific diseases

Sabotage - theft

Trauma

Aug

2015

Jul

2015

Jun

2015

May

2015

Apr

2015

Mar

2015

Feb

2015

Jan

2015

Dec

2014

Nov

2014

Oct

2014

Sep

2014

3. Use of the area-specific “Disease Overview” for the benefit of dairy farmers.


The following pages give an example of how this bigger picture of disease occurrence and distribution can be used, to adapt the approach in order to provide planned herd-health services. In this approach, the full extent of veterinary knowledge, experience and services are used to maintain or improve the production potential of a dairy farm.

A planned herd-health approach focuses on priority diseases as identified with the “Disease Overview”

Internal parasites

Aug

2015

Jul

2015

Jun

2015

May

2015

Apr

2015

Mar

2015

Feb

2015

Jan

2015

Dec

2014

Nov

2014

Oct

2014

Sep

2014

Brown

stomach worm

Conical fluke

Liver fluke

Roundworms

in general

Tapeworms

Brown

stomach worm

Very specific type of worm that also causes outbreaks (diarrhoea and loss of condition or daily gain) under specific environmental conditions. This is due to the unique life cycle and propensity to built up on the pasture (specific stage in the life cycle) and then causes disease problems, especially in younger heifers.

Conical flukes

During the last year, no outbreaks of conical fluke were seen or reported by the veterinarian. But this disease condition was seen during the previous 12 months and therefore it does exist as a possible disease condition in this specific district. There could be cases handled by the farmers themselves that were not recorded. See the next slide for a discussion about this parasite.

Liver fluke

This very common disease problem does occur and still causes clinical cases or even outbreaks but is limited to specific months. This gives the opportunity for a seasonal focus in the prevention or early treatment in order to limit production losses. See next slide for a more in-depth discussion of this problem.

Roundworms

in general

Not a major concern due to good control (farmers are following the given herd-health plan for effective control of these parasites in calves and young heifers) or limited effect in adult dairy cattle.

Tapeworms Good control in calves and young heifers, which keeps this parasite under control to the extent that no signs of this disease problem were recorded or reported.

Specific diseases Conical fluke and liver fluke

Aug

2015

Jul

2015

Jun

2015

May

2015

Apr

2015

Mar

2015

Feb

2015

Jan

2015

Dec

2014

Nov

2014

Oct

2014

Sep

2014

Aug

2014

Jul

2014

Jun

2014

May

2014

Apr

2014

Mar

2014

Feb

2014

Jan

2014

Dec

2013

Nov

2013

Oct

2013

Sep

2013

Conical fluke

Liver fluke

To get a better picture, it is worthwhile to view the occurrence of these disease conditions over the last 2 years or longer (if the records exist) for an even better understanding of the disease prevention or early treatment options.

Conical fluke

Liver fluke

Clinical disease development – more than 10 cases = outbreak

Transmission Clinical disease development – single case of disease

Transmission

Monitoring for the first indication of liver damage (increased liver enzymes) on the specific farms where this problem occurs

on an annual basis, causing severe production losses.

Disease development inside the animal = liver damage

Yearly repetition of clinical disease outbreak

Specific diseases Conical fluke and liver fluke

Aug

2015

Jul

2015

Jun

2015

May

2015

Apr

2015

Mar

2015

Feb

2015

Jan

2015

Dec

2014

Nov

2014

Oct

2014

Sep

2014

Aug

2014

Jul

2014

Jun

2014

May

2014

Apr

2014

Mar

2014

Feb

2014

Jan

2014

Dec

2013

Nov

2013

Oct

2013

Sep

2013

Conical fluke

Liver fluke

Conical fluke

• Review the transmission of this disease with the farmer as well as the first signs of disease - very smelly ,projectile ,watery diarrhoea. (see next 4 slides)

• The objective is that the first case must be identified and reported as soon as it occurs because correct (there are a limited number of parasite control products that are effective against the immature stages of this parasite) and immediate treatment is needed to kill the immature flukes, otherwise it will lead to a number of deaths or severe production losses.

• This is a disease that can be placed on the “Early Warning Disease List “ – this is a list of diseases for which the veterinarian sends out an early warning to farmers in this specific area if or when the first cases occur.

Liver fluke

• Review the transmission in order to identify when and where this parasite infests the animals. (see next 4 slides) • The objective is to better prevent or carry out specific early tactical treatments to decrease the severe effect of this parasite on the

liver (needed for most metabolic functions of the body) and milk production. • On farms where this specific problem is identified as a priority, targeted monitoring must be done through laboratory tests. • The older test, where liver fluke eggs in the dung were identified and counted, was just used to identify the existence and possible

extent of the problem, or to evaluate the efficacy of treatment, if done before and after treatment. • Blood tests for identifying antibody reaction give a more timely result of infestation, but there is still a lag phase between infestation,

reaction of the immune system and identification through testing. • Newer tests which test for an increase in liver-specific enzymes, give an immediate result for new infestations by immature flukes,

which is the initial case of severe liver damage when there is a very high infestation rate.

As stated in the previous slide, this disease problem does occur in this area, but clinical disease cases are limited.

The plan of action will be to:

As stated in the previous slide, this a disease condition that is experienced on an annual basis, but clinical disease in this case is relatively limited to specific months for this specific geographical area.

The plan of action will be:

Review the diseases that are caused by flukes, the transmission process and the disease development process inside the animals.

Liver fluke A parasite that occurs in the liver of cattle, sheep and

goats, causing damage to this vital organ.

Conical (stomach) fluke The adult flukes are found in the big stomach (rumen),

but the damage is caused by the young flukes in the small intestine of cattle,

sheep and goats.

Conical fluke The lining (wall) of the small intestine is severely damaged by the immature flukes, which cause wounds, causing blood components to seep into the intestine, causing foul-smelling, watery diarrhoea.

Adult stomach

flukes live in the

big stomach

(rumen) and

produce eggs

Immature stomach

flukes live and

feed from the wall

of the small

intestine

Liver fluke The liver is damaged by the immature flukes that tunnel through the liver tissue. The adult flukes in the bile ducts draw a reaction from the body and the ducts become thickened and can be obstructed by the flukes.

Immature liver

flukes tunnel

through the liver

while they feed

and grow.

The general name for this stomach fluke is conical fluke due to the conical shape of the adult flukes.

Adult liver flukes

live in the bile

ducts and suck

blood from the

walls of the ducts.

Life cycle of flukes in the environment

Winter Adult liver and stomach

flukes inside livestock

produce eggs that are

excreted with the

manure. Eggs in the

manure hatch when the

environmental

temperature rises

above 220C.

Spring At this stage of the parasite,

it must be washed out of the

manure by rainwater into

areas with standing water.

Freshwater snails become

infected by this stage of the

flukes. These flukes will now

multiply inside the

freshwater snail.

Summer and Autumn During the period of high rainfall, the flukes that have multiplied inside the freshwater

snails are released into the water again.

At this stage, the flukes can initially swim. The small flukes swim until they reach a

plant that grows in the water. They will attach to the plant and form a protective

capsule around it.

This is the stage that is infective for livestock and in this form, the small flukes can

survive for only a few months if the area becomes dry.

If the area stays wet, these encapsulated flukes can survive for longer periods,

especially in the case of the infective stage of the stomach fluke, that can infect

livestock well into the winter months.

Safer period to graze wetlands Danger period to graze wetlands on infected farms

Liver fluke

Conical (stomach) fluke

Freshwater snails are active during late spring, summer and early autumn

1 → 600

The shell of the

freshwater snail in

which liver flukes

multiply

The shell of the

freshwater snail in

which stomach

flukes multiply

Start of infection The signs of disease will depend

on the number of infective flukes (high, medium or low)

ingested by the animal. The signs that will be seen with a medium to high infection, are

described here.

Week 1-8 Animals show rapid

weight loss, weakness, signs of blood loss and even sudden death if the infection rate is

extremely high.

First signs

of d

isease

Liver fluke – detailed understanding of the disease process that takes place inside the animal

>12 Weeks Affected cattle can lag behind

when herded or develop bottle jaw – a sign of slow blood and protein loss. Continued weight

loss, especially during the period when the grazing is poor.

Examination of dead animals

When a veterinarian cuts open the dead animal, he will look

for signs of liver damage (thickened bile ducts) and

flukes in the bile ducts.

Development of liver fluke inside cattle When animals graze in wet areas they ingest the immature flukes , which are attached to plants.

Inside the animal, these immature worms move through the wall of the small intestine, migrate to and penetrate the liver. The immature flukes will then start to eat liver tissue, forming small tunnels in the process.

Immature growing worms feed on the liver for the next 6-8 weeks while causing

severe damage to the liver.

Liver damage depends on the number of immature flukes feeding on the liver tissue.

By 8 weeks, they become adult flukes that enter the small bile ducts (tubes) and migrate to the larger bile ducts.

These adult flukes attach to the walls of the bile ducts and feed by drinking blood. After a month, each adult starts to produce eggs (20 000 per day), which go with the bile into the intestine and out with manure.

The thin walls of the bile ducts now become thickened and white and the whole liver can become hard (fibrotic) due to the body’s reaction against this infestation.

Diagnosis of infestation in live animals

To confirm infestation in the live animal, manure must be collected and sent to the veterinarian for tests to determine if there is a liver fluke infestation. The latest blood antibody tests can identify the infestation relatively early (from 4 weeks after infestation), which will be at the time when the first signs of disease are observed in the case of a very severe infestation. More intensive blood tests (liver-specific enzymes) can identify liver damage as soon as it occurs.

Start of infestation No signs of disease can be

observed and the animal will look healthy and will eat and

produce normally.

When the animals graze in wet areas they ingest the immature flukes attached to plants.

Inside the animal, these immature flukes go to the small intestine where they lose the protective capsule that was protecting them in the environment.

They now attach to the wall of the small intestine with very strong suckers in order to drink blood.

The immature flukes suck a piece of the lining of the intestinal wall into their body opening, which causes damage to and holes in the lining of the intestine. This causes blood components to leak into the intestine.

The damage depends on the number of immature flukes, which will become adults after 6-8 weeks.

Conical (stomach) fluke – detailed understanding of the disease process that takes place inside the animal

> 12 Weeks The adult stomach flukes cause no harm to the animal and no signs of disease are apparent.

This adult worms migrate to the big stomach (rumen), where they will attach without causing damage to the animal.

After 4 weeks they will start to produce eggs that will pass out with the manure onto the grazing.

Under the right conditions, these eggs will hatch to infect the freshwater snails again.

Examination of the dead animal

When a veterinarian cuts the dead animal open he will look for the presence of immature

flukes in the small intestine and signs of damage in the small

intestine.

Development of stomach flukes inside cattle, sheep and goats

Week 1- 8 The first signs of disease are that the animals stop eating,

develop severe, foul-smelling, watery diarrhoea and lose condition rapidly. Many

animals can die when there is a severe infection.

Diagnosis of infestation in live animals

It is difficult to confirm the infestation in live animals by only inspecting the watery dung. In most cases the diagnosis will be based on the background information of where the animals were grazing during the last few weeks, the specific signs of disease and the reaction to treatment, which is very fast if the correct treatment is used.

Use of the area-specific “Disease Overview” as basis for the development and provision of a holistic herd-health service by the herd veterinarian.


The description in the previous few pages is just an example of the approach that can be followed for better management of internal parasites in the veterinary practice area under discussion. The critical factor is that disease patterns and priorities differ totally from one area to the next, and therefore such a “Disease Overview” is of use only in the specific area where the recording was done.

It must be accepted that this planned health approach

will only develop if the dairy industry needs and supports

such services.

Total dedication and availability of resources will

determine further development of planned

herd-health services.

4. Disease-reporting at farm level


Every single case of clinical disease or outbreak at farm level is very important because of the large differences in disease patterns between different farms.

The case must always be linked or associated with the bigger picture in order to establish

importance and priority.

See the bigger picture

No single case of disease can ever be viewed as a

independent, isolated case.


The bigger picture

Tick-borne diseases

Jul

2015

Jun

2015

May

2015

Apr

2015

Mar

2015

Feb

2015

Jan

2015

Dec

2014

Nov

2014

Oct

2014

Sep

2014

Aug

2014

Jul

2014

African redwater

Anaplasmosis

Asiatic redwater

Heartwater

More than 50% of disease cases are treated by the dairy farmer himself and the herd veterinarian will not be able to see the bigger picture if this is not recorded and reported.

If there is no bigger picture, the importance and priority of a single disease case or outbreak will be lost and this disease will be treated as

a single isolated emergency on a never-ending basis.

All dairy farmers are invited to participate in the system through which you can report disease cases directly to your herd veterinarian. Your “Disease Overview” report is only viewed and used by your own herd veterinarian that provides a service to you. The best way to get started is to send an e-mail to Frikkie Beukes (administrator at V-Data) and he will ensure that you are connected to the system under the name of your herd veterinarian – [email protected]


Call for participation

The next two pages are the paper-based disease -eporting system that can be used by the farmer to report monthly disease occurrence to the herd veterinarian if you can’t use the electronic system. This form can be printed and used on the farm, by the farmer to record disease conditions and add comments. This is a very practical form, easy to use and it can then be shared with the veterinarian when he/she visits the farm. The form also gives an overview of the reporting categories.

mailto:[email protected]

Internal parasites

1,2,3

External parasites

1,2,3

Tick-borne

diseases

1,2,3

Insect trans-

mitted diseases

1,2,3

Venereal

diseases

1,2,3

Intestinal roundworms Blue ticks Biting lice African redwater Lumpy skin disease Vibriosis

Resistant roundworms Resistant blue ticks Sucking lice Asiatic redwater Three-day-stiffsickness Trichomoniasis

Tapeworms Heartwater tick Biting flies Anaplasmosis Rift Valley fever

Liver fluke worms Brown ear tick Nuisance flies Heartwater

Conical fluke worms Bont-legged tick Midges Sweating sickness

Other bacterial, fungal, protozoal or

viral diseases

1,2,3

Poisoning

1,2,3

Macro-nutritional

problems

1,2,3

Micro-nutritional

problems

1,2,3

Environmental

conditions

1,2,3

Blackleg/Quarter evil Bovine malignant catarrh Tulip poisoning Low condition Copper Available grazing

Redgut Rabies Prussic acid poisoning Acidosis Zink Heat stress

Botulism Enzootic Bovine

Leucosis

Urea poisoning Selenium

Ringworm Warts Vitamin A

Multi-factorial

disease

conditions

1,2,3

Metabolic

disease

conditions

1,2,3

Reproductive

disease

conditions

1,2,3

Dairy-specific

disease

conditions

1,2,3

Calf diseases

1,2,3

Name other

diseases not on

the list.

1,2,3

Lung infection Ketosis Abortion Mastitis - infectious Lung infection

Diarrhoea Milk fever Poor conception Mastitis - environmental Diarrhoea

Eye problems Dystocia Lameness Eye problems

Abscesses Metritis Nave ill

Retained afterbirths Joint ill

Disease Monitoring and Extension System for the South African Dairy Industry – A Milk SA Project Month and year / /20 Name of owner

Farm Name of manager

District/Town Contact number

Herd Veterinarian E-mail

Contact number Veterinarian-Network contact number 0829095996 / 0824540532 1. Go down the list of disease conditions or disease-causing factors.

2. Please select and mark the ones that caused clinical cases, production losses or problems during the month.

Mark as 1, 2 or 3 according to degree and priority of the problem. See scale in the column to the right.

3. If it was not a problem, leave the block next to the specific disease-causing factor open.

4. If any other disease/problem occurred and it is not mentioned in that segment, please add it in the space provided.

5. If any specific diseases or conditions were marked and more information needs to be supplied, it can be done at the

end/reverse side of the form where the 5 most important diseases or tendencies for the month can be described.

6. Please share this information with your herd veterinarian during a herd visit or send it to

the practice at the end of the month

Further description of the 5 most important diseases or problems that occurred during

the month. The diseases have been marked already, please supply more information

about the conditions and the severity of the disease in order to get the full picture. Disease or

problem

Age or

production

group

affected

Number of

animals

affected

Describe the conditions and the severity of the disease or

problem to give the herd veterinarian better insight into the

problem. 1

2

3

4

5

Monthly general disease reports and disease distribution maps as reported by the Ruminant Veterinary Association of South Africa. This represents the countrywide occurrence of diseases as informally reported by veterinarians for all livestock species.

See the full report on the website of Milk SA by opening the following link (www.milksa.co.za/content/project-

reports), which gives an overview of all the general disease trends for July 2015, as reported by the veterinarians.

There are also maps that give an indication of the

distribution of the different diseases as reported during July 2015.


http://www.milksa.co.za/content/project-reports



You are invited to look at the short video on the webpage of Milk SA that gives an overview of the need, and working, of the disease monitoring and extension system.

disease monitoring and extension system for the …

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