Coccidiosis in Angora Goat Kids
By Dr Mackie Hobson

Coccidiosis in Angora goat kids

Coccidiosis is one of the most important diseases affecting Angora goat kids, and outbreaks can lead to severe losses. Apart from the mortality caused by coccidiosis, affected kids who do not die suffer a serious setback. The chronic form of coccidiosis usually results in stunted growth, lowered resistance to other diseases, and secondary problems such as Lymphocytic Plasmacytic Enteritis.

At what age is coccidiosis first seen?

Nursing kids appear more at risk of acute severe coccidiosis. Occasionally, kids as young as 2 weeks may be affected (usually 4weeks to 5months). Older animals can also be affected if not previously exposed as kids.

Kids post-weaning to up to a year old are commonly affected by chronic coccidiosis resulting in poor growth, lowered blood protein levels and a more deficient immune system.

In the above photo, diarrhoea is seen caused by coccidiosis. However, remember, in cases of chronic coccidiosis, diarrhoea is seldom seen. In the picture below of a formed faecal pellet, the weaned goat kid who died of chronic coccidiosis had an oocyte count of 384 000 per gram of faeces.

How do kids get infected?

The infection occurs by ingesting the sporulated oocyst through the pasture, water or faecal contaminated feed troughs. Oocysts can be transferred by wind and flies. Kids sucking ewes contaminated teats can potentially pick up the infection. After infection, oocysts will be passed through the faeces to the environment in about 2 to 3 weeks. However, they must undergo a period of sporulation in order to be contagious to another host. This sporulation period occurs when there is adequate moisture and warm temperatures. The incidence of the disease is significantly reduced under cold conditions, such as when frost occurs.

How is the damage done?

What makes a Coccidia species more pathogenic is if it infects both the small and large intestine. There are many stages in the development of the coccidia, and at each stage, intestinal cells are invaded and then destroyed – causing repeated damage to the intestine. The intestinal damage can release blood and cause inflammation of the gut lining. The animal loses blood, water and protein and cannot absorb nutrients as efficiently.

Kids suffering from chronic coccidiosis are often found for these reasons to have low Albumin (blood protein) levels of below 20g/dl, which would typically be in the region of 30-37g/dl. The low albumin levels often result in the ascites (fluid collection in the abdomen), as pointed out by the arrow in the photo below on the left.

The Chronic stimulation of the coccidiosis damage and inflammation of the intestine results in the massive lymph nodes draining the intestine, as seen in the photo on the left (usually the thickness of a pencil).

For this reason, I believe chronic coccidiosis is one reason we see so many cases of LPE (Lymphocytic Plasmacytic Enteritis) and roundworm stimulation.

For more info on LPE, see our website https://www.angoras.co.za/article/lymphocytic-plasmacytic-enteritis-lpe-in-angora-goats

One of the problems of chronic coccidiosis is lowered blood protein. Immunoglobulins, also known as antibodies, are glycoprotein molecules. They act as a critical part of the immune response by specifically recognising and binding to particular antigens, such as bacteria or viruses, and aiding in their destruction.

This is why the kids may die from other conditions such as pneumonia when suffering from chronic coccidiosis.

Clinical signs

The intensity of clinical signs of the disease depends on how many intestinal cells are damaged by invading organisms, the susceptibility of the animal, and the body condition.

Acute severe coccidiosis

 Signs may appear fairly suddenly, and a kid may be only mildly ill the day before and may be very sick the next day.

• Diarrhoea is an important feature and may be watery and brown or may have blood in the stool (black and tarry and/or red streaks of fresh appearing blood).
• The kids may be dehydrated
• Pale mucous membranes (anaemic).
• They will invariably be depressed, but fever is not always present.
• Weakness
• Some animals may strain from the inflammation of the lower large intestine and pass only watery blood.
• They sometimes grind their teeth in discomfort
• They may appear to have stiff hindquarters 

Chronic coccidiosis

• The kids will be in poor condition and will be growing slowly.
• The kids are thin, pot-bellied and small – although their heads may continue to grow, giving them a runty appearance.
• The hind end may be dirty due to the soft stools and intermittent diarrhoea, but often, they have normal formed pellets.

Kids with chronic coccidiosis may never fully recover from the effects of the disease. Coccidiosis may lead to Lymphocytic Plasmacytic Enteritis (PLE), as discussed earlier.

SEE https://www.angoras.co.za/article/the-impact-of-brown-stomach-worm-and-coccidiosis-on-angora-kids

Post Mortem Findings

The inner layer of the intestine may reveal haemorrhaging or ulcerations in the intestinal wall.

The mesenteric lymph nodes (lymph nodes draining the intestinal tract) are enlarged. In chronic cases, weight loss, dehydration, diarrhoea and signs of maldigestion and hypo-proteineamia (oedema resulting in fluid in abdominal cavity ‘swelpens’ or subcutaneous tissue ‘swelsiekte’.

In acute cases, blood in faeces may occur.

Diagnosis

The best way to diagnose coccidiosis is based on the clinical signs shown in the group of animals and evidence of infection based on post mortem if any animals have died. Taking a faecal sample and having a quantitative count of the number of oocysts (faecal oocyst count or FOC) in the ‘mismonster’ can also be helpful.

Remember that shedding of the coccidia eggs – oocysts – is not evidence of disease but only evidence of infection.

A low FOC does not rule out coccidiosis in the acute disease form. As mentioned before, the acute disease may be present before the pre-patent period is reached – so the FOC may be very low.

Why does one flock have a problem with coccidiosis and another does not?

Why are some years or times of the year worse than others?

It is important to realise that different factors all play a role.

Stress is the predisposing factor in kids during the post-weaning period. It is easier to consider the factors in three categories:

1. The Parasite

• What species of coccidia are present, and how pathogenic are they?

• How many oocysts are present in the environment, and where are the oocysts?
•  Are they contaminating places that allow for easier transmission to the kids?

2. The kid

• How immune is the kid? Younger animals are more susceptible. Are the kids ill with another disease that could weaken their immune systems (e.g. brown stomach worm, wireworm or orf?) See the article on the poor immunity of the young Angora goat https://www.angoras.co.za/article/immunity-in-angora-goats

• Have they been stressed by changes in the diet or a poor diet?
• Have the kids been moved?
• Have groups been mixed (e.g. younger moved in with older)? Has there been competition at the feeders?
• Have they recently been weaned? Although coccidiosis can occur year-round, a higher incidence occurs post-weaning.

3. The environment

• Are the conditions crowded? High stocking densities and build-up over the kidding period increase the load of oocysts in the environment and thus increase the risk of disease developing.

•  Bad weather or sudden changes in the weather? (cold, heat, high humidity)
• Time to sporulation depends on moisture, oxygen (e.g. exposed to the air rather than buried in the bedding pack) and temperature.
•  Exposure to sunlight will assist in killing the oocysts

How to reduce the predisposing factors?

• As far as possible, avoid any conditions that will put kids under stress.
• Ensure adequate intake of roughage.
• Supply energy supplements from weaning until up to a year old but minimally at least two months after weaning.
• Ensure the kids do not defecate into the feed troughs
• Supplement vitamin E and selenium and other mineral deficiencies
• Vaccinate against clostridial disease and Pasteurella to ensure the kids’ immunity against other diseases.
• Monitor internal parasites closely.
• There have been major coccidial parasite problems before the ewes may be given coccidiostats in their feed to reduce the peri-parturient rise in oocyte numbers.
• Coccidiostats can be included in the feed where conditions are favourable for coccidiosis (cultivated pastures, kraal systems).

Preventative Treatment

1. Reduce the predisposing factors (see above).
2. Drugs to control the level of coccidiosis

The goal of using medications is to control the level of infection to prevent the disease but to still allow enough infection so that the young animal develops immunity.

Coccidiosis commonly occurs just after weaning.  As a preventative measure a coccidiostat can be included in a balanced ration for a period of two weeks before weaning to four weeks after weaning.  It can be followed by the regular inclusion of the coccidiostats approximately every three weeks for a period of three to five days each time.

Drugs are an expense, and there should be a benefit higher than their cost to decide to use them.  Even the best drug cannot protect stressed goat kids or those in a heavily contaminated environment.

• Decoquinate  (Deccox)

The therapeutic dose is 0.5 mg/kg BW daily for sheep and goats, although there is strong evidence that 1 mg/kg body weight is much more effective in goats. It is not toxic but is much more expensive than lasalocid or monensin. Decoquinate works very early in the life cycle, killing only the sporozoites as they first infect the kid or lamb, so it is ineffective in animals with a disease. Decoquinate is non-toxic. It is less dangerous to make an error on the high side to ensure they receive enough.

• Lasalocid - Ionophore

It kills the “free-living”(sporozoites) stages of the coccidia as they move from cell to cell in the intestine and may help control disease after the animal is infected.  To be effective, kids need to eat 1 mg lasalocid /kg body weight per day, and Tauratec dosage advice is 0.1-0.4 per animal per day. Too high of a dose may be toxic to goats, but fortunately, lasalocid is the least toxic of the ionophores.

• Monensin - Ionophore

Monensin is more toxic than lasalocid. 11-22g per ton feed. 11.9 mg/kg BW/day (only slightly more than 10 times the therapeutic dose will kill 50% of the kids). Kids must be introduced to a ration slowly over 2-3 weeks to acclimatise the rumen organisms.

Treating kids

• Totrazuril (Baycox )

Very safe and has high tissue levels for longer periods than Diclazuril (Vecoxan). Do not use in pregnant goats. However, in field studies with Angora kids, there is no additive advantage, and the duration is

Dose 0.4ml/kg. There is some evidence in the literature that goats may require a higher dose of 0.6ml/kg. Totrazuril kills coccidia in the intracellular stages. All the rest of the coccidiostat drugs only kill the “free-living” stages as they swim to the next cell to infect. This means that they effectively wipe out any infection in the animal when they are treated. It is more suited for pasture-based systems when creep feeding is not used. But several factors must be considered before deciding that this is the method to control coccidiosis.

• Diclazuril  (Vecoxan)

Like toltrazuril (Baycox), diclazuril works against the intracellular forms of coccidia.  Commonly used at about 6-8 weeks of age, or two administrations beginning at 3 to 4 weeks of age and the second about 3 weeks later. Like toltrazuril, you need to give it early in the disease to prevent damage. Unlike toltrazuri (baycox), the efficacy is shorter; however, in field studies in Angora goat kids, the duration with both drugs was

See the article on field studies on the efficacy of Baycox and Vecoxan in Angora goat kids on our website. https://www.angoras.co.za/article/drugs-for-treating-coccidiosis-in-angora-kids#359

• Sulfonamides

Treatment must be continued for at least 4 days to be effective.

Many producers have used products off label, such as using Deccox as a paste or liquid for treatment.

Chlorine Dioxide has also been shown in field studies to effectively treat Coccidia.

SEE THE USE OF OFF LABEL TREATMENTS

https://www.angoras.co.za/article/off-label-coccidiosis-treatments-angora-goat-kids

Dr Mackie Hobson