Allopurinol for dogs with leishmaniasis. Side effects
Prevalence and distribution of leishmaniasis in Spain
Leishmaniasis is a very serious zoonotic disease with a parasitic aetiology and widespread distribution in several parts of the world. It is caused by a vector-borne diphasic protozoa, specifically Phlebotomus (mosquitoes).
According to the Office of Environmental Welfare and the Epidemiology Office of the Public Health Service of the Community of Madrid in collaboration with the Madrid College of Veterinary Surgeons, leishmaniasis is generally present throughout Europe and is endemic to the Mediterranean basin. It is estimated that 7% of the canine population in Spain has leishmaniasis.
Phlebotomus perniciosus and Phlebotomus ariasi are the main vectors. In addition, a lot wild and domestic animals act as reservoirs for the parasite, making it hard to control the disease.
Clinical signs and treatment
Once the mosquito has bitten the animal, the parasites can migrate from the skin to the blood or lymph, and travel through the vascular system to the lymph nodes and various organs, such as spleen, kidney and liver.
Due to this migration and variable location in the body, and the resulting compromise to the immune system, leishmaniasis has three clinical presentations:
- Visceral: depending on the organ affected, it may cause glomerulonephritis, hepatosplenomegaly, lymphadenopathies, neurological alterations and ophthalmic disorders.
- Cutaneous: based on dermatological signs, such as alopecia, hyperkeratosis, onychogryphosis, ulcerative dermatitis or necrosis at the tip of the ears.
- Mixed.
There isn’t a unique standard protocol for the treatment of leishmaniasis. There is a range of pharmaceutical products available, but allopurinol is the most used.
Side effects of allopurinol
Allopurinol is an active substance that works by reducing the amount of uric acid in plasma and urine. It is an analogue of hypoxanthine, a substance metabolised by the parasite. The drug has a parasitostatic action because it causes alterations in the parasite’s body .
The drug is frequently used by veterinary professionals to treat dogs infected with Leishmania. However, its curative benefit is controversial due to the presentation of side effects in patients given allopurinol.
Torres et al. conducted a study in a group of 320 dogs diagnosed with leishmaniasis and given allopurinol to assess its effects on the urinary system. 13% of subjects developed side effects of a urinary nature, such as xanthinuria, lithiasis and renal mineralisation.
Another study conducted by our Affinity Petcare research department found that the patient’s recovery depends on a combination of pharmacological therapy and a specific diet, reinforcing the immune system, providing dermatological protection and controlling kidney status.
Conclusions
Leishmaniasis is a highly prevalent disease in the canine population and has a nonspecific clinical presentation. Its treatment with allopurinol must be combined with other therapies and diagnostic tests as unwanted side effects have been observed in various studies.
