In recent decades there has been a growth in the interaction of people with dogs and cats, mainly because of the proximity of the human relationship with pets. This relationship involves walking, bathing and grooming, visits to the veterinarian and even a special diet, as pets are treated as an integral part of the family. Recent data from IBGE (Brazilian Institute of Geography and Statistics) show that Brazil has 53 million dogs and 22 million cats, placing the country in fourth place in the ranking of the population of pets and third with higher revenues in the sector; nutrition, which includes feed formulations, biscuits and snacks in general, accounts for almost 70% of this total.
As an integral part of the feed composition of these animals are corn, soybean, rice, wheat, and poultry, beef and fish meat. Many of these raw materials, especially those of plant origin, are susceptible to fungal contamination that can lead to mycotoxins production. Mycotoxins are a group of secondary metabolites produced by various filamentous fungi that can cause damage if ingested.
The main mycotoxin-producing fungi involved in the production and storage of grains belong to three main genera: Aspergillus, Penicillium and Fusarium. The effects of these mycotoxins are variable and often difficult to diagnose. Clinical signs include immunosuppression and estrogenic and neurotoxic effects, which may lead to death.
The factors that determine the sensitivity of the species also vary according to the mycotoxin (type, and rate and period of ingestion), the subject (gender, age, race, immunity and nutritional status) and the environment (management, hygiene and temperature). The evolutionary process has made dogs and cats highly susceptible to mycotoxins, since they are carnivorous animals and no significant amount of mycotoxins is found in meats. The most common mycotoxicoses in these two species are those caused by aflatoxins, deoxynivalenol and zearalenone.
Aflatoxins are highly toxic and carcinogenic metabolites produced mainly by Aspergillus flavus and A. parasiticus, which grow in various grain crops, especially in corn. Dogs are extremely vulnerable to the effects of these toxins. Several studies conclude that diets with aflatoxin B1 concentrations above 60 μg/kg already cause clinical signs of aflatoxicosis. However, sensitivity depends on individual susceptibility, which, in turn, depends on factors such as age and hormonal (gestational) and nutritional status. Pregnant and young animals are more sensitive to the toxicity of aflatoxin B1 than the adults or non-pregnant ones. Clinical signs are often difficult to detect and the animal may suddenly die.
Deoxynivalenol, or vomitoxin, is a member of trichothecenes, a group of mycotoxins produced by fungi of the genus Fusarium spp, generally found in corn and wheat. Studies with dogs disclose that doses above 4,500 μg/kg cause refusal of food. This effect may also occur in cats and be accompanied by vomiting at concentrations above 8,000 μg/kg.
Zearalenone is a fungal metabolite of species of the genus Fusarium, mainly produced by F. graminearum. It is a mycotoxin that causes estrogenic activity, which is often the cause of vulvovaginitis and other estrogen responses in swine matrices. The effects observed in dogs are reduced fertility, increased embryo absorption, decreased number of litters, changes in serum progesterone and estradiol levels, and changes in adrenal, thyroid and pituitary weight. Studies suggest that concentrations above 1000 μg/kg already cause negative changes in the fertility of these animals.
Fumonisins are mycotoxins produced by Fusarium verticillioides and appear to have a somewhat milder effect in dogs and cats. Nevertheless, their monitoring is important, since they are mycotoxins of high prevalence in corn, which is often the basic ingredient of diets for pets.
Thus, the quality of raw materials that are part of the composition of pets’ diet is of paramount importance. To assist in monitoring these ingredients, one can now rely on the Near Infrared Technology (NIR), which is a highly accurate tool that emits electromagnetic radiation. Energy absorption is the result of the organic compounds present in the sample and can be used to obtain a direct or indirect estimate of the concentration of a given substance. This method has the advantages of providing fast results, easy sample preparation, non-use of chemicals and simple operation. It is a clean technology that brings benefits for it facilitates decision-making and enables the management of the major mycotoxins.
Given the value pets have, their tutors are concerned about providing quality food, thus increasing their longevity, health and well-being. Therefore, the demand for quality food, traceability of the ingredients and control of toxic substances is essential for the feed industry. The use of NIR has become frequent in the Quality Control sector of the pet food industry by employing an easy methodology that provides rapid diagnosis to support decision-making. With NIR, mycotoxins diagnosis can be made when every load of raw materials is being delivered, as well as in the internal process of the factory, throughout feed production, allowing continuous management of the mycotoxins risk.