Protecting your beef herd from Type II Ostertagia
- What is type II Ostertagia?
- What are the signs of type II Ostertagia?
- How do I diagnose type II Ostertagia?
- How do I prevent type II Ostertagia in my beef herd?
Impact of Type II Ostertagia and why farmers need to be aware of it at this time of year!
What is type II Ostertagia?
Ostertagia is one of the worm species that can cause parasitic gastro-enteritis (PGE) in cattle. This disease is commonly seen as poor growth or scour due to a gradual increase in worm burden over the grazing season, known as Type I Ostertagia. However, we can also see problems with Type II Ostertagia if large numbers of worm larvae are ingested by grazing youngstock in late autumn or winter when environmental temperatures are low. Instead of completing their normal life cycle within the animal, the larvae under undergo hypobiosis – a hibernation within the lining of the fourth stomach (the abomasum). In spring, environmental factors, including increasing environmental temperatures and increasing daylength, stimulate larval hatching. If large numbers of larvae are present and hatch out at once they cause severe damage to the lining of the abomasum. This damage prevents the normal production of stomach acid needed to break down food, as well as causing significant loss of body protein into the gut.
What are the signs of type II Ostertagia?
Type II Ostertagia is usually seen in yearlings, usually in late winter or spring after their first grazing season. Often only a proportion of the group is affected, but the disease is often fatal in these animals. Common signs of Type II Ostertagia are:
• Significant weight loss (can be up to 20% in 7-10 days)
• Poor appetite +/- increased thirst
• Diarrhoea (may be intermittent rather than continuous)
• Dull coat
• ‘Bottle jaw’ (fluid swelling under the jaw or brisket) due to the loss of body protein
How do I diagnose type II Ostertagia?
Diagnosis is often based on the animals’ clinical signs and grazing history. In live animals, blood samples may be taken to check levels of a stomach enzyme (pepsinogen) – this enters the bloodstream when the abomasum is damaged. However early treatment of affected animals with an appropriate anthelmintic is vital for any chance of survival so testing may not be done if waiting for results would delay treatment.
If any cattle have already succumbed to the disease, then post-mortem can be a useful tool to identify worm larvae within the abomasum, as well as confirm the abomasal damage. This will allow appropriate treatment of the remainder of the group.
Faecal egg counts are NOT useful in diagnosing Type II Ostertagia as the disease is caused by the immature stages (stage 4 larvae) which are not yet producing any eggs.
How do I prevent type II Ostertagia in my beef herd?
Anthelmintic treatment of youngstock at or around housing can rid them off the larval burden well before the environmental conditions that stimulate Type II Ostertagia. However, it is important to treat cattle only when necessary, to minimise the development of anthelmintic resistance within the herd. Treatment options are covered in ‘Treatment of Type II Ostertagia’ .
Prevention focuses on two aspects: maximising cattle immunity in general and minimising the pasture burden at the end of the grazing season.
Cattle immunity: Good nutrition is an important factor in maximising immunity. It has been shown in sheep that dietary insufficiencies, especially inadequate protein levels, slow down the development of immunity to Ostertagia .1
Pasture burden: It has been shown that infection with high worm burdens or multiple species of worms increases the risk of larvae undergoing hibernation .2 Therefore, control of worms throughout the grazing season is highly important in minimising the risk of damage to the abomasum.
This has been discussed more in ‘Gut worms in beef youngstock – treatment and tips to reduce the development of resistance ’ but includes good grazing management with the aim of providing ‘clean’ pasture for youngstock to go onto in the autumn, and routine FEC monitoring of grazing youngstock throughout the summer in conjunction with checking for any clinical signs of worm burdens.
References:
1. Coop RL, Huntley JF, Smith WD. Effect of dietary protein supplementation on the development of immunity to Ostertagia circumcincta in growing lambs. Res Vet Sci. 1995 Jul;59(1):24-9.
2. Verschave, S.H. & Vercruysse, Jozef & Claerebout, Edwin & Vineer, Hannah & Morgan, Eric & Charlier, Johannes. (2014). The parasitic phase of Ostertagia ostertagi: Quantification of the main life history traits through systematic review and meta-analysis. International journal for parasitology. 44. 10.1016/j.ijpara.2014.08.006.
Protecting your beef herd from Type II Ostertagia
- What is type II Ostertagia?
- What are the signs of type II Ostertagia?
- How do I diagnose type II Ostertagia?
- How do I prevent type II Ostertagia in my beef herd?
Impact of Type II Ostertagia and why farmers need to be aware of it at this time of year!
What is type II Ostertagia?
Ostertagia is one of the worm species that can cause parasitic gastro-enteritis (PGE) in cattle. This disease is commonly seen as poor growth or scour due to a gradual increase in worm burden over the grazing season, known as Type I Ostertagia. However, we can also see problems with Type II Ostertagia if large numbers of worm larvae are ingested by grazing youngstock in late autumn or winter when environmental temperatures are low. Instead of completing their normal life cycle within the animal, the larvae under undergo hypobiosis – a hibernation within the lining of the fourth stomach (the abomasum). In spring, environmental factors, including increasing environmental temperatures and increasing daylength, stimulate larval hatching. If large numbers of larvae are present and hatch out at once they cause severe damage to the lining of the abomasum. This damage prevents the normal production of stomach acid needed to break down food, as well as causing significant loss of body protein into the gut.
What are the signs of type II Ostertagia?
Type II Ostertagia is usually seen in yearlings, usually in late winter or spring after their first grazing season. Often only a proportion of the group is affected, but the disease is often fatal in these animals. Common signs of Type II Ostertagia are:
• Significant weight loss (can be up to 20% in 7-10 days)
• Poor appetite +/- increased thirst
• Diarrhoea (may be intermittent rather than continuous)
• Dull coat
• ‘Bottle jaw’ (fluid swelling under the jaw or brisket) due to the loss of body protein
How do I diagnose type II Ostertagia?
Diagnosis is often based on the animals’ clinical signs and grazing history. In live animals, blood samples may be taken to check levels of a stomach enzyme (pepsinogen) – this enters the bloodstream when the abomasum is damaged. However early treatment of affected animals with an appropriate anthelmintic is vital for any chance of survival so testing may not be done if waiting for results would delay treatment.
If any cattle have already succumbed to the disease, then post-mortem can be a useful tool to identify worm larvae within the abomasum, as well as confirm the abomasal damage. This will allow appropriate treatment of the remainder of the group.
Faecal egg counts are NOT useful in diagnosing Type II Ostertagia as the disease is caused by the immature stages (stage 4 larvae) which are not yet producing any eggs.
How do I prevent type II Ostertagia in my beef herd?
Anthelmintic treatment of youngstock at or around housing can rid them off the larval burden well before the environmental conditions that stimulate Type II Ostertagia. However, it is important to treat cattle only when necessary, to minimise the development of anthelmintic resistance within the herd. Treatment options are covered in ‘Treatment of Type II Ostertagia’ .
Prevention focuses on two aspects: maximising cattle immunity in general and minimising the pasture burden at the end of the grazing season.
Cattle immunity: Good nutrition is an important factor in maximising immunity. It has been shown in sheep that dietary insufficiencies, especially inadequate protein levels, slow down the development of immunity to Ostertagia .1
Pasture burden: It has been shown that infection with high worm burdens or multiple species of worms increases the risk of larvae undergoing hibernation .2 Therefore, control of worms throughout the grazing season is highly important in minimising the risk of damage to the abomasum.
This has been discussed more in ‘Gut worms in beef youngstock – treatment and tips to reduce the development of resistance ’ but includes good grazing management with the aim of providing ‘clean’ pasture for youngstock to go onto in the autumn, and routine FEC monitoring of grazing youngstock throughout the summer in conjunction with checking for any clinical signs of worm burdens.
References:
1. Coop RL, Huntley JF, Smith WD. Effect of dietary protein supplementation on the development of immunity to Ostertagia circumcincta in growing lambs. Res Vet Sci. 1995 Jul;59(1):24-9.
2. Verschave, S.H. & Vercruysse, Jozef & Claerebout, Edwin & Vineer, Hannah & Morgan, Eric & Charlier, Johannes. (2014). The parasitic phase of Ostertagia ostertagi: Quantification of the main life history traits through systematic review and meta-analysis. International journal for parasitology. 44. 10.1016/j.ijpara.2014.08.006.