Cooperia, commonly referred to as ‘small intestinal worms’, are coiled worms found in the small intestine of both sheep and cattle but predominately causes disease in cattle. While the Cooperia worms are 5 to 9 mm in length, they are incredibly difficult to see with the naked eye. Diagnosing Cooperia infections is done by faecal egg count and larval culture, the same process as for many gastrointestinal worms.
There are 3 common species of Cooperia that are found in different climatic regions of Australia:
- C. punctata (Warm, summer rainfall regions)
- C. pectinata (Warm, summer rainfall regions)
- C. oncophora (Temperate, wet winter regions)
Life Cycle
Cooperia follow the common lifecycle of a roundworm.
- Worm eggs are excreted in cattle faeces
- Worm eggs hatch in cattle dung pats within 7 days when climatic conditions suit, or as long as 5 weeks in tougher conditions.
- Larvae mature to an infective larval stage (L1 to L3) in dung pats. The time frame for this ranges from 11 to 22 days, depending on the subspecies of Cooperia.
- Infective larvae (L3) migrate onto the pasture and are ingested by grazing cattle.
- Consumed larvae develop into adult worms* in the small intestine, where they stay to reproduce.
*If larval intake is high, up to 50% of the larvae will ‘inhibit’ before reaching the adult stage and can remain dormant for up to 6 months.
Note: in favourable conditions (e.g., autumn break), the life cycle of Cooperia can be as short as 14 days (from egg to adult). Therefore, pastures grazed by weaner/yearling cattle can become heavily soiled with Cooperia very quickly, leading to very high rates of reinfestation that may require further drenching.
Ideal conditions for Cooperia larvae development include temperatures of 10°C to 30°C and 65% humidity at ground level. Larval numbers found on pastures typically peak during summer and autumn. If left untreated in autumn, the worst of the disease effects will manifest in cattle in late winter to early spring. Hence, stressing the importance of staying on top of ‘autumn break’ worming treatments to help control them earlier in its life cycle. Cooperia infections often ‘piggyback’ on infections of other worms (e.g., Ostertagia), which is particularly detrimental to young calves and weaners. Adult cattle (15+ months old) develop a strong natural immunity to Cooperia.
Signs of Cooperia Infection
Cooperia reduces the animal’s nutrient absorption by damaging the lining of the small intestine. This increases fluid loss and intestinal mucous secretion. Lack of nutrient absorption then causes slow growth and appetite reduction.
Signs of Cooperia are typical of most gastrointestinal worms, including:
- Diarrhoea
- Loss of appetite
- Lethargy
- Reduced weight gain to rapid weight loss
- Death (especially in young calves)
While the Cooperia worms are 5 to 9 mm in length, they are incredibly difficult to see with the naked eye. Diagnosing Cooperia infections is done by faecal egg count and larval culture.
Treatment & Prevention
Cooperiosis is essentially a disease of young cattle. As cattle grow into their own immunity, the focus of treatment is on preventing Cooperia-related production losses and maintaining animal welfare standards for the most susceptible stock – calves and weaners.
Look after calves and weaners by:
- Giving your cows a pre-calving drench to reduce their output of worm eggs onto pastures that calves will start to graze.
- Pasture management and rotation techniques to minimise the amount of time that calves and weaners spend grazing grass that is less than 15cm tall, as this is the zone where most worm larvae sit.
- At weaning, treat with an effective drench and put weaners onto low worm risk pastures (e.g., ex. Hay/silage paddocks or spelled pastures).
Effective chemical treatments for Cooperia include macrocyclic lactones (ML/Mectins), benzimidazoles (BZ/White), and levamisole (Clear) drenches.
The efficacy of each drench group can be different for each property. In Australia, there are strains of Cooperia that are resistant to the “mectin” drenches. Combat resistance by always using Vetmec LEV Pour-On (levamisole) in conjunction with any ‘mectin-based drench product to deliver a broad-spectrum, double-active drench. Levamisole remains a very powerful drench against Cooperia.
At Chemvet Australia, we stock a large range of products that treat or prevent Cooperia infection, including:
- Vetmec LEV Pour On
- Vetmec Antiparasitic Cattle Injection
- Vetmec F Broad Spectrum Injection
- Vetmec LA Long Acting Injection for Cattle (21 days protection)
- Vetmec Doraguard Antiparasitic Injection (COMING SOON)
- Vetmec Pour On
References
Summer Worm Problems in Cattle, Goats & Sheep | Paraboss
Small Intestinal Worms of Cattle | Wormboss
Pasture Management to Control Cattle Worms | Wormboss