Treating haemorrhagic diseases

Dear Prof McCrindle,

Could you please advise me how to treat haemorrhagic diseases in animals? Kind regards,

Robert

A haemorrhagic disease is one where the blood does not clot and the patient can bleed to death. The condition can be hereditary, an autoimmune syndrome, or caused by an infectious agent.

Rat poison stops blood clotting; however, if accidentally swallowed by a pet, there is an antidote available (vitamin K) that can be injected by the veterinarian.

Heritable causes are more common in human beings and can be recognised in babies at the time of birth. Autoimmune diseases that result in destruction of the endothelial cells in blood vessels are another cause in human beings. The most notorious infectious haemorrhagic diseases in humans are Crimean-Congo haemorrhagic fever, Ebola, and hantavirus pulmonary syndrome. All three are very dangerous as treatment seldom succeeds. In South Africa, the main infectious haemorrhagic diseases in animals are African horse sickness (AHS) and bluetongue (BT).

Epizootic haemorrhagic disease (EHD), which is an orbivirus, was isolated in cattle at Potchefstroom in 2014. Its structure is very similar to that of BT and AHS, which are also transmitted by Culicoides midges. It’s probable that EHD is fairly widespread in South Africa, but is not being diagnosed because it is relatively unknown here.

Accurate blood tests based on the DNA of these viruses are now available. Vaccination is the best method of prevention for EHD, BT and AHS, as treatment is not always effective.

In my experience, mild BT can be treated with anti-inflammatory drugs such as Finadyne and cortisone intravenously. I also tend to use two Disprin tablets dissolved in about 100ml of water dosed orally.

This is not only an anti-inflammatory medication that brings down fever and reduces inflammation, but new research has indicated that it may be anti-viral.

The haemorrhage is mainly caused by viral infections that damage the endothelial cells lining micro-capillaries. I also give five Disprin tablets dissolved in water orally to horses with AHS. In addition, I inject antiinflammatory medications and cortisone intravenously to reduce the high fever. Many AHS cases also have babesiosis at the same time, so I do a blood smear and check for anaemia and parasites. If positive, I will also inject antiparasitic medications and tetracyclines.

In dogs, Babesia and Ehrlichia are blood parasites that cause sudden, severe anaemia. These could possibly be characterised as haemorrhagic diseases. Positive dogs will be treated with anti-parasitic medication, and supportive treatment will include cortisone (to diminish auto-immune reactions) as well as vitamin B12 to regenerate red blood cells. Kind regards,

Prof Cheryl McCrindle

ȊȲSource: Jiménez-Cabello L, Utrilla-Trigo S, Lorenzo G et al. ‘Epizootic Hemorrhagic Disease Virus: Current Knowledge and Emerging Perspectives’. Microorganisms. 2023 May 19;11(5):1339. Visit mdpi. com/2076-2607/11/5/1339.

Cheryl McCrindle is an emeritus full professor in the Faculty of Veterinary Science at the University of Pretoria, and has extensive experience in animal health. Email her at farmersweekly@caxton.co.za. Subject line: Ask our vet.