Hair loss in Angora goatsThursday, 14th March 2019
By Dr Mackie Hobson
The Angora goat has an exceptional ability to convert available food into fibre and it is deservedly considered to be the most efficient fibre-producing animal species. There are a number of factors that effect this fibre production which in effect determine the amount of mohair shorn from a goat. There are however also factors which may result in hair loss which I will discuss in this newsletter.
Over the period 2016-2018 SAMGA investigated over 10 farms that reported excessive hair loss from their Angora goats. These cases investigated excluded cases were parasites (lice) were identified.
Samples from 10 farms where excessive hair loss has been reported were taken and analysed to try determine the cause of the hair loss.
- Skin scrapes and cultures on 7 (70%) of these farms were positive for Dermatophilus congolensis and 3 (30%) tested negative.
Zinc levels (often believed to be an underlying cause) were normal on the farms that were tested.
See below for more information on dermatophilus congolensis.
- 3 of the farms that tested negative on skin scrapes were also investigated further by:
- Skin biopsies
- A mineral analysis on blood samples.
The histopathology reports from the farms that were NEGATIVE for Dermatophilus congolensis.
The skin biopsies reports from the farms were almost identical.
- Hair follicles arrested in either telogen or catagen phase, large amount of hair was missing from multiple follicles – likely poor nutrition or hormonal causes
Flame follicles were abundant which indicates hair cycle arrest which again may reflect poor nutrition.
- Some hair was broken – copper (Cu) deficiency may be the cause of brittle hair.
- There was NO indication of an inflammatory response, NO indication of an infectious cause.
The mineral analysis were also very similar and indicated:
- The Copper levels to be low on 2 of the farms7 and 0.8 and normal 0.91 on the 3rd farm. (0.8-1.2 ug/ml being the normal range)
- The Magnesium (Mg) levels on 3 farms were found to be low82, 1.03 and 0.95 (1.15-1.48 mmol/L being the normal range)
- The Zinc (Zn) Selenium (Se) Calcium (Ca) Phosphorus (P) Iron (Fe) Sodium (Na) Potassium (K), Chloride (Cl) levels were all Normal.
There are no scientific studies to indicate what the impact of Magnesium on Mohair production is? However it is well known that magnesium helps with protein synthesis. Since hair follicles are made almost entirely of protein it may play a role? Better protein synthesis means healthier hair and a predictable hair cycle with normal growing and resting stages which the histopathology reports was not the case on the farms where the biopsy samples were taken.
Low Copper may result in brittle hair which was confirmed on the biopsy results.
Low Cu can cause a goat's hair coat to be rough with a "bleached out" appearance. The formation of a ‘steely ’ fibre (mohair) where the crimp is lost and the hair breaks easily can be seen.
It is interesting to note that high Calcium (Ca) and high Sulpher (S) associated with goats fed lucerne were normal. High levels of Ca and S will suppress Magnesium (Mg) Selenium (Se) levels and decease Zinc (Zn) availability. Mg levels were low on all farms, however Se and Zn levels were normal.
Summary of investigations:
- Of the farms investigated for hair loss: 70% were due to dermatophilus congolensis
- 30% were nutritionally related: Poor nutrition (drought conditions). The low Magnesium (Mg) and low Copper (Cu) may have played a role.
So what are possible causes of hair loss in Angora goats?
- Dermatophilus congolensis
- Nutrition (drought conditions, under nutrition)
- Zinc (Zn) deficiency
- Copper deficiency
- Selenium excess
- Vit A deficiency
- Iodine deficiency
- Role of methionine?
- Stress, fever
- Bacteria and ringworm
- Dermatophilus congolensis
What is Dermatophilus congolensis?
Dermatophilus congolensis is a bacterium that can occur in 2 forms . Hyphal filaments which release pockets of cocci which when exposed to moisture develop long flagellae which penetrate the hair follicle sheath and epidermis results in the inflammatory reaction and hair loss.
Angora goat skin with hair loss and exudate cultured positive for Dermatophilus congolensis
The infection is often seen in carrier goats as crusting lesions on the ear margins of goats. In sheep this bacterium causes ‘klont-wol’.
How is it transmitted?
- Contact between goats especially when wet - such as after dipping.
- Contact with contaminated plants or insects.
- The zoospores occur mainly in the crusty scabs which when wet are released. The number of viable zoospores decreases as the scabs dry.
- Continuous wetting of the feet, the face and fleece when grazing wet pastures (dew) may play a contributing role.
- Wetting in addition to the activation of the zoospores may also transport the spores to other non-infected sites on the goat.
- Some goats may have crusty lesions remaining on ear margins and these goats may act as carriers.
- Dermatophilosis can survive in contaminated soil for up to 4 months
- Any damage to the skin may predispose it to infection.
- In Angora goats the infection is usually associated with hair loss
- Crusting lesions against the skin can be seen. Flecks of yellowish- white to brownish grease or crusts.
- Reddening (erythema ) of the skin.
The goat is not always itchy. Most affected animals recover within a few weeks of the initial infection. These infections usually have little effect on general health. Animals with severe generalized infections often lose condition
The crusting scaling material on the skin surface cultured positive for Dermatophilus congolensis
How is it diagnosed?
- Clinical appearance
- Smears, skin scraping
- Zinc sulphate 1%-5% dip or spray.
- Preventative treatment by adding Zinc sulphate to dip. (0.5%- 1%)
- Local lesions, crusts can be cleaned with warm water, topical disinfectant (eg. chlorhexidine).
- Antibiotics injection of LA tetracycline or penicillin + streptomycin
- Organisms are susceptible to a wide range of antimicrobials .
Two doses of long-acting oxytetracycline (20 mg/kg) 1 day apart have shown to be curative in 100% of sheep, compared with cure rates of 80% in sheep for a single dose.
- Isolating clinically affected animals,
- controlling ecto-parasites
- Zinc levels should be checked because outbreaks have been associated with Zinc deficiencies.
- Avoiding excessive dipping.
Dermatophilosis can be transmitted to people. Direct contact with an infected animal can lead to infections on the hands and arms. Handwashing with an antibacterial soap is recommended after contact with an infected animal.
- NUTRITIONAL causes
- Nutritional deficiency, drought conditions, pregnancy and lactation
Mohair fibre diameter is directly affected by nutritional status and the fibre diameter of mohair is reduced dramatically during times of nutritional stress.
The tensile strength of a reduced fibre can cause it to become combed out and ‘break’ resulting in hair loss.
Studies in sheep (Rcheulishvili 1980) more than 70% of the lactating ewes suffered from alopecia (loss of wool/hair). He suggested that it was not a metabolic disorder in the hair follicles, but a lack of nutrients when the need of the ewe was at the highest during gestation and Lactation.
Temporary alopecia can occur during pregnancy, lactation, or several weeks after a severe illness or fever. These types of alopecia tend to be non-inflammatory unless a secondary skin infection develops.
See the SAMGA website under the NUTRITION section the Effect on Mohair production, https://www.angoras.co.za/page/the_effect_on_mohair_production#44
- Zinc deficiency
Angora goats need high levels of Zinc because of the role it plays in fibre production. Research articles indicate where this has occurred in goats it was found to be mostly around the head, neck, flanks, perineal areas and lower limbs. The hair thins in most other areas. The skin is often dry and scale and looked dull and shaggy. The hair can be easily pulled from the skin.
What causes a reduction in Zn?
- Excess Calcium in the diet. Lucerne is high in Calcium which suppresses Zn uptake – antagonist
- Periods of drought conditions
- High parasite burdens
- Periods of physiological stress such as pregnancy, kidding
What are the clinical signs of Zn deficiency?
- Hair loss
- The hair can come out in patches and goats may become bald.
- Thinning of coat, dull light fleece that can be easily pulled out at skin.
- Hair becomes brittle and straight
- Hair loss often more around head, neck, flanks, lower abdomen ,legs and perineal areas
- Goats may want to eat, bite at hair of other goats.
- Parakeratosis, where the skin becomes dry, scaly and thick.
- Abnormal hoof growth, stiff joints and lameness.
- Abnormal stance, arched back
- Can get excessive salivation.
- Reduced libido in rams, small testes and low sperm counts.
- Poor appetite
High dietary intakes of Ca and S in lucerne reduces Mn, Mg, and Se absorption and reduces the availability of Zn which forms a high proportion of the Angora goats diet during periods of drought of intensive farming systems raising the goats on Lucerne. Therefore Mn, Mg, Zn and Se supplementation is often advised under these conditions.
Many other vitamin or mineral deficiencies can also cause hair loss or impact on hair quality.
- Vitamin A deficiency can create a rough, dry coat with a shaggy appearance and dandruff.
- Copper deficiency can cause a goat's hair coat to be rough with a "bleached out" appearance. The first signs of deficiencies in animals with pigmented hair are the loss of colour and formation of a ‘steely ’ fibre (wool/mohair) where the crimp is lost and the hair breaks easily.
For more info on Cu deficiency see https://www.angoras.co.za/article/copper-deficiency-in-angora-goats#307
- Iodine deficiency can cause hair loss.
- Selenium excess can also contribute to hair loss. For more info on Selenium see the SAMGA website https://www.angoras.co.za/article/selenium-supplementation#232
- Vit B12 and Cobalt deficiency. Younger goats, especially weaned kids can be more susceptible to deficiencies. This can cause redduced appetite (poorer growth) and reduced mohair growth
See article on SAMGA website for more info https://www.angoras.co.za/article/cobalt-vit-b12#306
The importance of specific nutrients affecting mohair production has not been established in Angora goats, apart from one study showing that mohair growth responded to parenteral supplementation with methionine.
Methionine (Met) is an amino acid that is used in the biosynthesis of proteins. The main function of methionine is to provide cysteine for mohair protein synthesis.
- Stress, fever
A sick or stressed goat that has a reduced intake for a period of time will have part of the fibre having a reduced fibre diameter. The tensile strength of a reduced fibre can cause it to become combed out and ‘break’ resulting in hair loss. The mohair fibres are thinned and eventually breaks, causing parts of the fleece to come away. This could be secondary effects caused by malnutrition or diseases.
- Red and Blue Lice
In trial by Brown, van der Linde, Fourie and Horak lice adversely affected both the quantity and quality of mohair produced. During the 6 months after treatment the goats in the treated group produced an average of 271 g more mohair per animal than those in the untreated group.
When the mohair clips of the 2 groups were classed it was found that the treated goats produced better quality cuts with less damage to the hair than the untreated animals It is suggested that changes quality are indirect and result from the irritation caused by lice, which elicit host responses such as rubbing, scratching and biting. However, lice also cause the skin to thicken, and a decrease in production due to alterations in the skin structure.
- ‘Brandsiekte’ Sheep Scab, psoroptic mange
DOES NOT affect Angora goats. Angora goats must however be considered to be potential mechanical vector in the same way clothing, vehicles and shears may introduce the mite to a farm and hence the importance of bio-security. Trials (Meinties, Fourie, Horak) demonstrated that Angora and Boer goats do not develop lesions from sheep scab mites and did not harbour the mites
- Psoroptes cuniculi (Ear Mange) does occur in Angora goats but it is NOT ‘brandsiekte’. This mite usually affects the ears but can spread to the head, neck, and body and cause severe irritation. This occurs particularly in Angora goats, in which the mohair is considerably damaged.
- Demodectic Mange
This has been reported in goats (D caprae), in which it causes non-pruritic papules and nodules in goats, especially over the face, neck, shoulders, and sides. The nodules contain a thick, waxy, grayish material that can be easily expressed.
- Chorioptic Mange
Chorioptes caprae can occur in goats. Papules and crusts are seen on the feet and legs.
- Bacterial and fungal infections
- Caprine Staphylococcal Dermatitis
Staphlococcus is a bacteria normally found on the skin. Under certain conditions when this skin’s defence barrier becomes compromised the bacteria may invade the skin leading to dermatitis and pustule formation. A crusty exudate may result on the skin surface and lead to hair loss. The areas involved are often on the udder or around the anal area but in bad cases the hair loss may occur along the flank, back and neck.
- Ringworm in Goats ‘omlope’
Ringworm is a fungal infection. Affected goats generally lose hair in circular patches on the neck, ears and face. Ringworm is usually itchy. It is very easily transmitted by contact and mechanical vectors.
The causes of potential hair loss in Angora goats can be multiple but the farms investigated to date suggest that Dermatophilus congolensis, Nutrition, Cu and Mg deficiencies are the likely the main causes.