Foot and Mouth Disease in Ruminants

foot-and-mouth-disease

Foot and Mouth Disease is a highly contagious viral disease of cloven-hoofed domestic as well as wild animals. This is a serious economic problem in the livestock sector. It is a transboundary animal disease (TAD) that severely affects the production of livestock and disrupts regional and international trade in animals and animal products.

Cause of Foot and Mouth Disease in Ruminants:

FMD in Ruminants is caused by a virus whose name is FMDV ( foot and mouth disease virus). This virus belongs to the genus Apthovirus in the family Picornaviridae. There are 7 serotypes of this virus and these are serotypes A, O, C, ASIA 1, SAT 1, SAT 2, SAT 3. Out of these, the serotype O is the most common. Within these serotypes, there are further 60-70 subtypes. All these serotypes are antigenically distinct from others therefore the antisera raised for one serotype is not effective for the other.

Some Characteristics of FMDV:

It is said that this virus is sensitive to pH less than 6 and more than 9. Therefore this virus persists in the muscles, bones, milk, and milk products and also in the lymph glands. FMDV is killed by some disinfectants like 2% NaOH, 4% Na2CO3, 5.25% sodium hypochlorite, and 0.2% citric acid. But keep in mind that this virus is resistant to phenol, ionophores, and quaternary compounds.

The virus remains viable in the environment for about 3 months but may be longer to 6 months if keep it in shadow place and provide some organic matter.

Virus remains viable
▪ 14 days – dry fecal matter
▪ 39 days – urine
▪ 28 days – soil surface in fall
▪ 3 days – soil surface in summer
▪ 6 months – slurry in winter

Species affected by FMD:

The species that are affected with FMD are cloven-hoofed domestic as well as wild animals. Domestic cloven-hoofed animals include cattle, buffalo, sheep. goats, pigs, camels, etc. Some wildlife cloven-hoofed animals are bison, deer, wildebeest, giraffe, etc.

  • Pigs – amplifying hosts
  • Cattle – indicator hosts
  • Sheep – maintenance hosts

Transmission of Foot and Mouth Disease in Animals:

The foot and mouth disease can be transmitted either by direct or indirect contact with the infected animal. Direct contact includes the transmission of the virus from the infected animal to a healthy animal through body secretions like nasal discharge, urine, ocular discharge or saliva, etc. Indirect contact can occur through the contaminated water and feed, and via fomites. But How? For example, if there is an infected animal and this animal is drinking water from a water tank and as I mentioned earlier the virus sheds in the secretions and excretions, so if the saliva of such animal enters the water the virus in the saliva also go to water and when this water will drink by a healthy animal, this will lead to the onset of disease in healthy animal too. This is how indirect transmission can occur. Transmission can also occur through the semen of the infected bull.

Clinical Sign and Symptoms of FMD:

After being infected with the virus the clinical signs appear after some days and this duration is known as the incubation period. The I.P is highly variable among different species but on average, the incubation period of FMD is 2-12 days. The clinical signs of FMD are:

  • Vesicles on the Oral cavity including the muzzle, lips hard and soft palate, gums, etc
  • Vesicles on teats
  • Blisters on interdigital space of hooves
  • Off feeding due to vesicles in the buccal cavity
  • Drooling saliva
  • Pain
  • Depression
  • Pyrexia
  • Lameness due to blisters on the coronary band
  • General weakness leads to emaciation
  • Decrease in milk production in milk producing cloven hoofed animals due to teat lesions
  • Mastitis can aslo develop due to blisters on teat

Some Pictures of Antemortem and Postmortem FMD infected animals are:

Drooling of saliva in foot and mouth disease
vesicales on tounge and nostrils in FMD
blisters on interdigital sapce in FMD
Teat lesions in foot and mouth disease in cattle
tiger heart in FMD

Diagnosis of Foot and Mouth Disease in Cloven Hoofed Animals:

It is a well-renowned saying that ” forget the treatment, diagnosis is everything. ” Diagnosis of every disease revolves around 3 things

1- History

2- Clinical signs

3- Lab test for isolation of the causative agent

So take some history from the owner of the animal and then look at the obvious clinical signs. It must be mentioned here that clinical signs are somewhat similar in different diseases so the best way of diagnosis is the confirmation by lab test. But there are some signs that are specific in some diseases and those signs can help the veterinarian in the proper diagnosis of a suspected disease.

Differential Diagnosis of FMD with other Disease:

As in FMD, the most obvious signs are vesicles in the oral cavity, teats, and hooves. But there are some other diseases that show similar blisters. So how to differentiate between these? Let’s see

Vesicular Stomatitis: Same vesicles present but the vesicles are dominant on just one site ( either on teats or on the oral cavity whereas in FMD vesicles are on both sites). The equines are also susceptible, unlike FMD. in VS the sheep and goats are resistant but in FMD they are susceptible

PPR: In PPr the vesicles on the teat, coronary band, and oral cavity are present but there is also a sign of a cough, ocular, nasal discharge, and enteritis. PPR is a problem of sheep and goats only.

Bluetongue: The differential sign is the edema and cyanosis of the tongue and it is a problem of sheep.

Malignant Catarrhal Fever: Bilateral corneal opacity and reading of eyelids are the imp diagnostic feature of MCF.

Treatment of Foot and Mouth Disease in Animals:

  • There is no specific treatment of FMD in animals, but symptomatic and supportive treatment can help a lot in alleviating the infection. The best approach of a good veterinarian regarding FMD are
  • For fever, and other inflammation you can use NSAIDs like Flunixin meglumine at the dose rate of 1.1mg/kg for 5 days PO or IV.
  • For lesions in the mouth area, teats, and on hooves, you can apply some CANDID mouth paint or crush clotrimazole tablet mix with glycerine.
  • Wash the lesions with disinfectants like soda ash, household bleach, etc, and then apply betadine.
  • To prevent bacterial secondary infections you can use broad-spectrum antibiotics like enrofloxacin
  • To boost immunity give the vitamins. I can personally suggest you use immunity boosters like VAD3 ICI, Ademax (NAWAN) 15-20 ml IM/SC

Prevention and Control of FMD in Ruminants:

The FMD can be prevented by adopting some precautionary protocols like proper vaccination of healthy animals at the proper times. The culling of the severely infected animal. Isolation of infected animals from the rest of the herd. Properly disinfection of farm with NaOH, Na2CO3, etc.

FAQs about Foot and Mouth Disease in Animals:

Some highly asked questions regarding FMD are:

Is FMD is Zoonotic?

No, foot and mouth disease is not a zoonotic disease and cant spread from animals to humans.

Is there any treatment of FMD in animals?

There is no specific treatment of FMD, the only way is to prevent it by vaccines or adopting preventive protocols.

Can we use same vaccines for different serotypes of FMD virus?

No, the serotypes are antigenically diff, so the vaccines are different for each serotype.

Can we consume the milk and meat of FMD infected animals?

It depends upon the severity of the disease. if the infection is acute then it is recommended by regularity authorities to condemn the products of animals. however, if the signs are not acute and there are no secondary changes then we can consume milk and meat after the preservative management like in case of milk ( boiling) and for meat ( chilling or heat treatment).

Conclusion:

Foot and Mouth Disease is a severe, highly contagious viral disease of livestock that has a significant economic impact. The disease affects cattle, swine, sheep, goats, and other cloven-hoofed ruminants. It can be transmitted either by direct or indirect contact. There is no treatment except vaccines for its prevention.

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