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- Cryptosporidiosis is an intestinal infection caused by the Cryptosporidium pervum parasite.
- The disease affects young calves and lambs yet mature animals are seldomly affected.
- The disease has an incubation period of two to five days.
- Dr Hobson says biosecurity on a farm is critical in preventing an outbreak of cryptosporidiosis.
- When an outbreak occurs, there are a few options for treating cryptosporidiosis.
Cryptosporidiosis is of considerable importance when it comes to newborn ruminants, and has for some years been a major problem in especially young calves and lambs reared under intensive conditions in South Africa. The disease, commonly known as crypto, is an intestinal infection caused by the single-celled parasite Cryptosporidium parvum which causes severe scours in young and immunocompromised animals.
Graaff-Reinet based veterinarian, Dr Mackie Hobson, says young animals become infected when they ingest the parasite, which over its life cycle produces large numbers of oocysts (encysted eggs) that are shed in the faeces of animals. They can spread via subclinical carriers (cattle, sheep, goats), waterways, fomites, wildlife, flies, mechanical vectors and humans.
He says the fact that mature animals are seldom affected by cryptosporidiosis suggests immunity plays a major role in reducing the impact of the disease. Both acquired immunity and host age therefore determine the animal’s susceptibility to and the severity of the infection.
The disease has an incubation period of two to seven days, but it can be as long as ten days. Dr Hobson says clinical signs usually last two weeks in kids and lambs, and animals can relapse a week or two after recovery (recovery typically takes up to 30 days).
Goat kids are mostly affected in the first two weeks of life, but can show clinical signs up until the age of three months. Older young animals are often asymptomatic. Symptoms in young animals can last seven to 15 days, with infection that is either not detected or that causes mild diarrhoea, except when occurring in very young animals. Typically, the disease occurs in calves younger than six weeks old and in lambs, the same as goat kids, at one to four weeks old.
Clinical signs in calves, lambs and goat kids include:
- Rectal temperature is usually around 40°C.
- Reduced appetite and lethargy are present at the start, followed by yellow, white or grey diarrhoea with mucous.
- Loss of bodyweight and anorexia.
- Abdominal pain and straining while trying to defecate.
- Stiffness, hyperpnoea (rapid breathing), slow gait and depression.
Biosecurity as prevention measure
Dr Hobson says biosecurity on a farm is critical in preventing an outbreak of cryptosporidiosis. Producers must ensure they have an owner’s declaration signed by the owner’s veterinarian or agent that cryptosporidiosis has not been diagnosed on the farm when purchasing cattle, sheep and goats.
“The protocol on your farm must not only be for new animals being introduced, but must include vehicles and people entering your farm,” he adds. It boils down to good hygiene and farm management that can reduce the chances of the infection spreading.
How to treat the disease
No successful vaccine has been developed yet, but some treatments have shown to be beneficial in treating the disease incalves, lambs and goat kids.
When an outbreak occurs, there are a few options for treating cryptosporidiosis. Parofor® Crypto (Huvepharma) is now licensed in South Africa and is a treatment that reduces oocyte counts and the severity of diarrhoea (it is also licenced to treat enteric colibacillosis in calves). Halocur (halofuginone) treats free, and not intracellular, stages while reducing oocyte counts and allowing immunity to develop. “It requires a special order application by your veterinarian for off-label use,” says Dr Hobson. Another option is chlorine dioxide off-label use such as AQUAVi2000-500 (ready to use) calf and lamb preparation.
- Treat ewes by adding Deccox (decoquinate) to feed from four weeks before kidding or lambing. It can also be given to lactating ewes and added to creep feed for young animals. This reduces the impact of cryptosporidiosis and is also effective in controlling coccidiosis. Make sure ewes have been vaccinated and provide a mineral and vitamin supplement four to six weeks before kidding or lambing.
- Electrolytes must be administered prior to the Halocur treatment, but it is also important to ensure that sick young animals are rehydrated.
- Mineral and vitamin supplements containing vitamin E and selenium, among others, also provide optimum support.
- Pain and inflammation can be treated by injecting Meloxicam under the skin.
- Probiotics can be added to water for young animals or be applied as a probiotic feed additive, which improves the microflora in the gut.
- Antibiotics are advised for animals with clinical signs, to control secondary infections if indicated. – Christal-Lize Muller, Stockfarm
For more information, contact your local veterinarian or Dr Mackie Hobson on 082 860 0406 or email@example.com, or visit www.angoras.co.za.