Allopurinol is a drug used in human medicine to reduce the level of uric acid in plasma and urine because it inhibits a certain enzyme involved in its formation. In veterinary medicine, in this particular case in dogs, it is a drug that is used in combination with antimonials or miltefosine for the treatment of leishmaniosis.
If you want to know more about this drug, continue reading this article on our site in which we talk about allopurinol for dogs, its uses, recommended dosage and possible side effects.
What is allopurinol and what is it used for?
Allopurinol is an enzyme inhibitor which, more specifically, inhibits the enzyme that metabolizes the conversion of xanthine to uric acid. It is not used alone, but acts as an adjuvant to the main leishmanicidal drug, antimonial or miltefosine, to try to completely eliminate the parasite from all tissues. In this way, the use of allopurinol in dogs is reduced to one: the treatment against leishmania.
This drug is administered orally and its treatment can last from 6 months to a year There are even cases in which it is establishes a longer treatment. In any case, a review and follow-up of the case is required once the treatment has been established, bearing in mind that the frequency of reviews will be established by the veterinarian, since it must be individualized depending on the severity of each case.
Allopurinol therapy should be individualized to the patient. A practical example would be miltefosine daily for approximately 1 month combined with allopurinol daily for approximately 8 months.
Allopurinol for dogs with leishmania
As we said in the previous section, allopurinol is used in the treatment of leishmania. Leishmaniasis is a parasitic disease caused by a protozoan that is transmitted by the bite of a vector: the sandfly mosquito. It is a zoonosis, with a worldwide distribution and is serious, so in addition to the prevention measures used to reduce its prevalence (vaccines, repellent collars and pipettes, immunity modulators) everyone should be treated dogs that present said disease.
Sick dogs are those that show clinical signs and leishmania infection is confirmed by laboratory diagnosis. It is a non-specific disease, that is, it can present with multiple clinical signs, so a good history of the epidemiology of the place where the animal lives is very important. dog and its protection status against it. Some of these signs are: crusty and ulcerative dermatoses, lameness, nasal bleeding, nasal and pad hyperkeratosis, lethargy, etc. The disease can be classified as visceral leishmaniasis or cutaneous leishmaniasis.
It is common that, in addition to leishmania, the dog suffers from another blood parasitic disease, since it is closely linked to the level of antiparasitic protection of our dog. For this reason, leishmaniasis should be treated once the dog is stable, that is, if the disease has caused anemia, kidney failure, dermatitis, etc., these conditions must be supported first.
Miltefosine and antimonials are leishmanicidal drugs (they eliminate the parasite) and their action is faster and more intense, while allopurinol is leishmanistatic (slows down the multiplication of the parasite). For this reason, it is common to use a combination of these drugs. However, more and more veterinarians prefer to search for alternatives to allopurinol due to the adverse effects that this drug presents in patients, and which we will see in the following sections.
Dose of allopurinol in dog
The dose of allopurinol for dogs established for the treatment of leishmaniasis is 10 mg for each kg of weight every 12 hours, that is, twice a day.
The pharmacological presentation that exists is 100 mg and 300 mg tablets of allopurinol, so our veterinarian will tell us how many tablets we should administer according to the weight of our dog. Likewise, let us remember that it must be the specialist who determines the duration of the treatment, which must not be paralyzed without his prior approval.
Allopurinol Side Effects in Dogs
There are two main side effects that allopurinol can cause in dogs that take it:
- Xanthinuria: when purines are degraded by the corresponding enzymes, xanthine is formed and this, in turn, is transformed into acid uric. Allopurinol interferes with the transformation of xanthine into uric acid, which must be eliminated in the urine, leading to a excess of xanthine and its accumulation
- Urolithiasis: Excess xanthine crystals can produce aggregates with organic matter and form uroliths (stones). These uroliths are radiolucent, that is, they are not seen with a simple x-ray and a contrast x-ray or an ultrasound will be required to diagnose them.
The clinical signs that can be observed with these pathologies are:
- dysuria (painful urination)
- hematuria (blood in the urine)
- urinary incontinence
- urinary obstruction
- abdominal pain
Today we can find dog food specifically manufactured for the treatment of leishmaniasis. They are characterized by their low purine content, thus preventing the formation of xanthine crystals. In addition, they present substances that help in the protection of the joints, the skin and immunity. For more details, don't miss our article on Food for dogs with leishmaniasis.
Alternatives to Allopurinol for Dogs
As we have mentioned in previous sections, the side effects of allopurinol have led many veterinarians to choose to look for alternatives to this drug. In this sense, a recent study[1] confirms that impromune, a nutraceutical based on nucleotides, is effective against the progress of leishmania and does not generate unwanted effects.
The new trend in the treatment of leishmania leads us to the use of these new drugs that do not have side effects. The drawback is that it is a more expensive drug compared to allopurinol.
