Today the most widespread way of feeding pets is with commercially prepared feed, since it represents an easy and inexpensive way to meet the nutrient needs of dogs and cats at various stages of their life, both in healthy and pathological conditions.

Due to the close relationship that currently exists between owners and their pets, they pay close attention to their health and well-being. The owners perceive the moment of feeding as an opportunity to interact and gratify their pets, thus, the quality of the feed is considered of great importance and many of them prioritize the quality over the cost that the feed may have, which  is possible due to the wide range of feed offered for companion animals.

The most popular pets are cats and dogs and, although they are carnivores, extruded feed contains relatively high levels of cereals and grain by-products that contain starch, which, when going through the extrusion process, gets gelatinized and its digestibility increases. The most commonly used cereals are corn, wheat, rice and barley and, apart from the impact they have on the gastrointestinal tract, especially the changes in the microbiota that they generate, cereals represent a very important source of contamination of pet food since they can be substrate for diverse microorganisms. In this regard, among recent pet food safety concerns, mycotoxin contamination represents a well-known problem, given the cereal content of current foods. In addition, it should be mentioned that the other components of the feed, such as meat, fish, or bone meal, may also be a source of contamination of other toxins.

Characteristics of mycotoxins

Mycotoxins are chemical compounds derived from the metabolism of some genera of fungi such as Aspergillus, Fusarium and Penicillium. A property that makes them a greater risk is their thermostability, since despite the fact that during the extrusion process the feed is subjected to a pressure of 34-37 bars and a temperature of 100-200°C, the toxins are not destroyed. Consequently, extruded feed at high temperatures does not exempt pets from the risk of poisoning.

Today, the most frequently found mycotoxins in feed for dogs, cats, birds, rodents and fish are aflatoxins, ochratoxins, trichothecenes, zearalenone and fumonisins. Among them, aflatoxins represent the most common cause of acute mycotoxicosis outbreaks derived from the ingestion of commercial dog food, and corn is the usual source of the toxin in these cases.

Most important mycotoxins in pets

Aflatoxins (coumarinic group)

After ingestion, aflatoxins are absorbed and go through the circulatory system to the liver. There, they are converted by the liver into toxic substances, capable of causing damage to liver cells. Chronic poisoning cases are characterized by anorexia, lethargy, jaundice and, in subacute or acute cases, they can even cause death. In addition to their hepatotoxic effect, aflatoxins are also carcinogenic.

Ochratoxins (lactinic group)

Ochratoxins are a very potent group of nephrotoxic mycotoxins that widely contaminate cereals such as corn, wheat, and oats in temperate regions.

Initial symptoms of ochratoxin poisoning in all species include anorexia, polydipsia, polyuria, and dehydration, all associated with the kidney damage they cause.

Dogs are especially sensitive to these mycotoxins, the clinical symptoms they present are more extensive, with anorexia, weight loss, vomiting, tenesmus, bloody diarrhea, increased temperature, dehydration, and prostration.

Trichothecenes (sesquiterpene group)

Trichothecenes are mycotoxins produced by fungi of the genus Fusarium, commonly found in corn, wheat, barley, and oats, throughout the world.

These interfere with DNA synthesis, especially affecting rapidly dividing cells. The gastrointestinal and immune systems are particularly damaged. Typical clinical signs of trichothecene poisoning include: loss of appetite, vomiting, diarrhea, gastrointestinal bleeding, ataxia, and immunosuppression. They can also cause irritation and necrosis by contact in the digestive tract.

Zearalenone (lactonic group)

Zearalenone is another mycotoxin produced by Fusarium, which is found in many cereals, but is more common in corn and causes hyperestrogenism.

The most prominent signs of zearalenone poisoning are related to hyperstimulation of estrogen-dependent tissues, resulting in a reduction in the number of corpora lutea in females and arrest of spermatogenesis in males, and, consequently, reproductive issues.

Fumonisins (amino alcohol group)

Once fumonisins enter the circulatory system, they damage numerous organs in all species studied. They cause cell damage, apoptosis, and necrosis. They also affect calcium channels, resulting in heart damage. In cases of acute poisoning, the most sensitive organs to these mycotoxins are the liver and kidneys, while, in chronic poisoning, the immune system is the one that is most affected.

Control of mycotoxicosis in pets

The growth of fungi and the production of mycotoxins depend on several factors throughout the cereal production chain, such as the weather and storage conditions (temperature, humidity), chemical, microbe and insect damage. This situation explains, at least partially, the difficulty of predicting and controlling this problem, as well as the heterogeneity in the levels of contamination that feed shows in different parts of the world.

There are many steps that can be taken to minimize mycotoxin contamination in animal feed. These include the prevention of the growth of mycotoxigenic fungi and, therefore, the production of mycotoxins, and strategies to reduce or eliminate mycotoxins from already contaminated products, which we can be achieved by using some feed additives.

The most effective way to prevent fungal growth is the implementation of control measures during storage. Different grain quality management strategies should be used to reduce any potential increase in temperature, grain moisture content, and the percentage of broken grain (which is directly related to higher amounts of substrates available for microorganisms), since they can trigger mycotoxin production. The application of fungal inhibitors (e.g. cimenol ring), aeration and movement of grains, reduction of internal condensation within the storage structure are among these strategies. Biovet S. A. has studied the properties of the cimenol ring, a component present in different aromatic plants. Thanks to its fungicidal and bactericidal effects, it is an excellent natural preservative for raw materials and feed. It is effective in controlling fungi such as: Penicillium, Aspergillus, Fusarium and Candida, which are important because they are able to to produce mycotoxins (except Candida).

The strategy to control mycotoxins that are present in the feed consists in adding an effective mycotoxin binder (e.g. Silicoglycidol) during feed manufacturing. Silicoglycidol binds mycotoxins in the animal’s digestive tract so that they are excreted from the digestive system without damaging the intestinal wall nor internal organs.

Silicoglycidol is a molecule patented by Biovet S. A. obtained through  thermal and ion exchange processes. Thanks to tjis, it is an effective mycotoxin sequestrant with a unique structure: it has a broad spectrum of action, is effective at low doses and does not adsorb other nutrients (vitamins, amino acids, etc.). Silicoglycidol forms stable bonds with mycotoxins through hydrogen bonds that ensure that the toxin is not released in any of the conditions of the intestinal tract.

After exposure to mycotoxins, pets need help to recover the normal functioning of the affected organs. Usually, the gastrointestinal system and the liver are the most compromised sites. Currently, there are natural solutions on the market based on pronutrients, active organic molecules obtained from plants, that can help in the recovery. There are different types of pronutrients depending on their target cell: intestinal conditioner pronutrients are those that help the regeneration of enterocytes, improving the intestinal structure and nutrient absorption. Another type of pronutrients are liver conditioenrs, which  support the liver, increasing the regeneration of hepatocytes and bile secretion.

Conclusion  

Mycotoxins in companion animals are an underestimated problem, partly because of the clinical picture, as most times is unspecific and subclinical an, because the feed manufacturing companies do not pay much attention to this issue.

Mycotoxin contamination in pet food represents a serious threat to their health, and, considering that the well-being of pets is increasingly important to their owners, the industry must guarantee the safety of these products.

The use of natural preservatives such as the cimenol ring and the inclusion of mycotoxin binders such as Silicoglycidol to the feed are effective tools to prevent this important problem that affects our pets. Thanks the properties described in this article, the combination of the cimenol ring (fungicide against toxigenic fungi) and Silicoglycidol (effective against all mycotoxins, with a high adsorption percentage at any pH) represent a complete prevention strategy.

Silicoglycidol is developed and marketed by BIOVET S. A. under the name Naturbalance Antitox.

Naturbalance comprises a line of natural additives for pets developed and marketed by BIOVET S. A.

Bibliography:

• Requena, E.Saume, Alicia León. 2005. Micotoxinas: Riesgos y prevención (revisión). Disponible en: http://ve.scielo.org/scielo.php?script=sci_arttext&pid=S0798-72692005000400005
• Ficha Aflatoxinas., Fundación Vasca para la seguridad Alimentaria, 2013. Disponible en: http://www.elika.eus/datos/pdfs_agrupados/Documento107/19.Aflatoxinas.pdf.(12). pág. 4
• Borrell, J. (1990). Metabolitos fúngicos en los alimentos. Real Academia de Ciencias Veterinarias de España (RACVE).
• Maxwell C. K. Leung, Gabriel Díaz-Llano, and Trevor K. Smith. Mycotoxins in Pet Food:  A Review on Worldwide Prevalence and Preventative Strategies.