The first 100 days of a lamb’s life are when they are at the highest risk of disease and death. Getting them through this period and preventing disease is critical to having healthy sheep, and good future growth and performance. The trouble is, many of the diseases that affect survival rates can often go unnoticed until it’s too late. To help you spot and understand the diseases that affect your lambs, we’ve summarised the top 6 below and also how to spot them and prevent them. Hopefully, it underlines why it is imperative to have a vaccination program in place, and how it can help maximise lamb survival.
1. Cheesy gland:
- A contagious bacterial disease that impacts sheep of all ages
- Very common, with 95% of flocks shown to be infected
- It causes reduced wool growth as well as financial losses in carcass trim, downgrades and condemnations.
- Prime lamb producers that choose not to vaccinate against cheesy gland are at a much higher risk of losing money through trim and condemnations at abattoirs.
What to look for:
The initial infection usually causes few clinical signs, but fever and loss of appetite may occur. Abscesses are most commonly associated with the lymph nodes of the shoulder, flank and rump. These abscesses may spontaneously rupture, or be cut at shearing, releasing the infective pus. Abscesses involving the internal organs may result in ill thrift. Sheep with lung abscesses may cough up the infective bacteria. Incidence of the disease increases as sheep become older.
(Product solution: Glanvac 3-in-1 and Glanvac 6-in-1 vaccines, NEW GlanEry4in1 and GlanEry7in1, as well as Weanerguard 6-in-1.)
2. Clostridial diseases:
- Caused by a family of bacteria that can survive for very long periods
- The most common ones are tetanus, pulpy kidney, black disease, black leg and malignant oedema
- Death is inevitable with no reliable treatment options
What to look for:
If you suspect lambs are suffering from a clostridial disease, look for any of the following symptoms:
- Tetanus – Stiff-legged gait followed by convulsions that are initially stimulated by sound or touch and that gradually increase in severity. (Glanvac 3 and 6)
- Pulpy kidney – Animals with pulpy kidney have convulsions and sudden death. (Glanvac 3 and 6)
- Blackleg – Severe lameness and swelling on the affected leg. Animals with blackleg are very depressed with a fever and dry cracked skin. Sudden death is common. (Glanvac 6)
- Black disease – Animals with black disease are profoundly depressed and can have abdominal pain. Sudden death is common. (Glanvac 6)
- Malignant oedema – A contaminated wound, often in females that have recently given birth, with local swelling. Animals with malignant oedema are depressed with a fever. Death is common. (Glanvac 6)
(Product solution: Glanvac 3 and 6 where applicable above)
3. Internal parasites:
- Estimated production loss in medium rainfall zones is over $9 per sheep per year.
- Commonly leads to reduced lamb growth rates, reduced wool growth, poor nutrient utilization and deaths.
- Lambs are most susceptible.
What to look for:
Sub-clinical disease (can’t see)
- Reduced appetite
- Reduced wool production
- Reduced meat production
- Decreased reproductive performance
Clinical disease (can see)
- Weight loss
- Bottle Jaw
(Product solution: Drenches, Weanerguard 6-in-1)
4. Erysipelas arthritis:
- Causes severe damage to the joints, lameness, poor growth rates and reduced wool production
- Affects flocks in all sheep zones and impacts all classes of sheep
- The average trim per arthritis-affected carcass is 3kg, costing producers $17.25 per carcass
- Has significant welfare, trading (‘unfit to load’) and financial impacts.
What to look for:
Lambs appear depressed, they may be reluctant to stand and walk, and appear lame or may have a hopping gait. The infected joints are hot and swollen.
(Product solution: Eryvac)
5. Scabby mouth
- A viral disease that’s most common in lambs and weaners, but can occur in sheep of any age
- Causes painful lesions and raised scabs commonly around the lips, muzzle and nostrils
- No specific treatment is available with an outbreak lasting 6–8 weeks
- Sheep stop eating and lose condition
- Secondary infections can occur, including mastitis and flystrike
- Has severe live export implications with scabby mouth putting the entire consignment at risk of being rejected
What to look for:
Although lambs are at greatest risk, all sheep are potential targets. The scabby mouth virus develops and grows on damaged skin caused by contact with thistles, hay, coarse pastures and stubbles. Feedlot environments and the use of pelleted feed are also conducive to virus development by causing abrasions around the mouth and making sheep more vulnerable to infection.
Clinical signs may vary between sheep, however cool areas such as the surface layers of the skin around the face and feet provide ideal environments for disease growth and development. The scabs are most commonly found on the mouth and lips, face, feet, teats and udders as well as the poll of rams. These sores can limit the ability of the sheep to feed and can cause lameness. The disease takes approximately 4 to 5 weeks to resolve.
(Product solution: Scabiguard)
6. Prolonged healing from mulesing
Prolonged trauma from mulesing can have an impact on productivity. Lambs that are treated with pain relief will recover faster than ones that aren’t. Treated lambs are much calmer, less stressed, and return to their ewes a lot quicker than untreated lambs. It also helps protect the wound and reduces the risk of infections. This faster mothering-up allows them to continue healthy growth rates, and as a result, can be weaned quicker. Faster recovery also reduces issues around re-opening wounds when handling lambs later on.
(Product solution: Trisolfen)
Risk Periods of Lamb Diseases – Zoetis, 2020
So, what’s the best practice to grow healthy lambs, improve survival rates, and prevent these threats from occurring?
First, look after mum.
At 6-8 weeks out from lambing, (usually around crutching) give your ewes a shot of Glanvac 6 B12 and Eryvac (or NEW GlanEry7in1). This also doubles as her yearly booster and passes protection through the to the lamb. After birth, the ewes maternal antibodies (colostrum) is then consumed by the lamb in the first 48hrs, and these protect the lamb from the corresponding diseases for 6-10 weeks. This practice is essential to protect the lamb from death and illness until their own immune system becomes fully active.
Next, give lambs their first shot of vaccine and Eryvac at marking.
We recommend again using Glanvac 6 B12. This product protects your lambs against cheesy gland and clostridial diseases tetanus, pulpy kidney, as well as black disease, blackleg and malignant oedema. The added B12 prevents against deficiencies and is required for energy production, cell division and replication as well as wool production.
A 1mL dose is easily injected under the skin on the side of the neck just behind and below the base of the ear.
The next product is Eryvac which protects against Erysipelas arthritis, this is also done at marking and can be done in junction with the Glanvac 6 using a dual vaccinator, meaning the lambs can be done in one pass.
NEW: The great minds at Zoetis have thought about it, and now you can save time and money with GlanEry. GlanEry7in1 combines both Glanvac 6 B12 and Eryvac into a convenient, time saving one-shot dose.
Marking is also the right time to apply Scabiguard to prevent against scabby mouth if it’s a concern. Apply using the Scabiguard applicator and scratch on a bare area of skin (side of the brisket or inside of the foreleg) to ensure an effective take. Hold the applicator at 45 degrees to the skin and with both applicator prongs touching the skin, make a single 4 to 5 cm long scratch on the bare skin. The scratch must be sufficient to cause skin damage, but not draw blood.
Next, a follow-up booster shot of vaccine and Eryvac should be done at weaning.
Weaning is also a great time if you’re worried about worms to apply a drench, such as Tri-Guard. Or, you can save time by giving lambs an all-in-one dose of Weanerguard 6-in-1 vaccine which also contains a moxidectin drench. Because of the drench component, Weanerguard’s dosage rate will vary depending on lamb weights.
(Just remember, if you plan on using a dual vaccinator gun to apply vaccine and Eryvac, you’ll need to stick with Glanvac – as both Glanvac and Eryvac are fixed 1ml doses.)
Pro-tip: Don’t try to skimp by using both 3-in-1 vaccines and 6-in-1 vaccines on lambs. It doesn’t work.
If you try to save money by giving lambs one shot of 3-in-1 at marking, then attempting to boost coverage with a 6-in-1 at weaning (or vice versa) – don’t bother. You’ll waste your money.
Well, the first dose of vaccine is what primes and readies the immune system, but only provides a small amount of short-term, if any, protection. It’s not until the animal is given the second dose of vaccine that the immune system is capable of providing protection against the diseases. In simple terms, the first shot ‘teaches’ the immune system what diseases to look for, and the second shot gives protection. If your first shot is a 3-in-1, and the second shot a 6-in-1, the lamb’s immune system will only be capable of protecting against the 3 diseases it ‘learnt’ from the 3-in-1 vaccine. Stick with either all 3-in-1 or all 6-in-1.
The final weapon to have in your armoury is Tri-Solfen.
Tri-Solfen is an anesthetic and antiseptic solution for pain relief used following mulesing and tail docking on lambs. It provides immediate and prolonged pain relief for at least 24 hours post-procedure, reduces bleeding, and abates shock and stress. It also reduces the risk of bacterial wound infection and assists in would healing by sealing and protecting the wound. Due to supply issues, it’s best to pre-order Tri-Solfen in advance, as production runs are small and stock usually sells out before it hits the shelves.
We believe Tri-Solfen is a must when mulesing, read our article on the 5 reasons you should be using it here: www.awvater.com.au/blogs/5-reasons-to-use-trisolfen
Cost to Australian Sheep Producers each year (Zoetis, 2020)
If you want more information on products available to fit your situation, give us a ring today.
This article was originally published in 2020 and has been updated and revamped with fresh, usable information.