The use of any medication carries a risk-benefit ratio. The benefit is, logically, the pharmacological effect, while the risk has to do with the appearance of possible secondary effects. Antiparasitic drugs are not exempt from causing these adverse reactions, although their severity and the probability of their appearance can vary considerably depending on the active ingredient and the route of administration.
If you are wondering what happens after deworming a dog, we recommend that you join us in the next article on our site, in which we will talk about the main effects secondary after deworming a dog.
Vomiting and diarrhea
The feces after deworming dogs may be softer or have small white spots, which correspond to the expelled internal parasites. Thus, vomiting and diarrhea are among the most frequent side effects of antiparasitic drugs that are administered orally. These drugs can induce such adverse reactions by producing gastrointestinal mucosal irritation, hypersensitivity or even by cholinergic stimulation
In most cases, vomiting and diarrhea are mild and do not require any treatment. However, when they are very profuse or last a long time, it is important to go to a veterinary centerto establish an adequate therapy and avoid dehydration of the animal. Similarly, in the event that vomiting or diarrhea is accompanied by blood (either fresh or digested), it is important to notify the veterinarian who prescribed the drug.
In this other article we talk about the usual duration of these side effects after deworming a dog: "How long does diarrhea last after deworming a dog?".
Intestinal obstruction
When dogs are heavily infested by gastrointestinal nematodes, antiparasitic treatment can lead to intestinal obstruction by causing the sudden death of all parasites.
The risk of intestinal obstruction is greater when:
- This is small dogs with high parasite loads.
- Antiparasitic drugs are administered, such as pyrantel or praziquantel, which kill the helminths (worms) by generating a rigid paralysisor spastic. Being completely rigid, it is difficult to eliminate with the stool and an intestinal obstruction can occur. For this reason, in case of large parasites, it is recommended to treat with drugs that produce a flaccid paralysis, such as macrocyclic lactones.
Allergic reactions
Both the active ingredients and the accompanying excipients can cause allergic or hypersensitive reactions in dogs, regardless of the route by which they are administered. Signs that may accompany these allergic reactions include:
- Generalized edema
- Pruritus
- Urticaria
- Anaphylaxis
In the case of local allergic reactions, it is usually sufficient to establish symptomatic treatment on an outpatient basis. However, anaphylaxis reactions can have fatal consequences for animals, so in these cases it is essential to act quickly and institute hospital treatment.
It should be noted that these allergic reactions can also occur in handlers when administering these drugs to their dogs. Therefore, people with sensitive skin or known allergies to any medication should handle these products carefully and wear gloves.
Local Reactions
Antiparasitics that are administered parenterally (injectable) or topically (pipettes, collars, etc.), can produce local reactions at the point of inoculation or in the administration area. Some of the most frequent reactions are:
- Erythema (redness of the skin)
- Alopecia
- Pruritus (itch)
- Inoculation site pain
- Granulomatous lesions
In most cases, these are mild reactions that resolve spontaneously or require only symptomatic treatment to relieve associated itching or discomfort.
Neurological signs
Although they are much less frequent, antiparasitic drugs can also produce neurotoxic effects that give rise to the appearance of neurological signs such as:
- Mydriasis: pupil dilation.
- Miosis: pupillary contraction.
- Decreased level of consciousness: such as depression or lethargy.
- Ataxia: incoordination.
- Shaking.
- Seizures.
In the event of the appearance of any of these adverse reactions after deworming a dog, it is essential to go urgently to a veterinary center, where a neurological examination of the animal will be carried out and the appropriate treatment will be established in each case. case.
Effects during pregnancy or lactation
There are antiparasitic drugs capable of crossing the placental barrier and producing embryotoxic, teratogenic or mutagenic effects on embryos or fetusesSimilarly, there are drugs that are eliminated by the lactogenic route (by milk) capable of producing toxicity in lactating puppies
Therefore, during pregnancy and lactation, only antiparasitic drugs whose safety has been proven in pregnant or lactating bitches should be used. In the event that the safety of the drug has not been demonstrated in these stages, it should only be used in accordance with a risk-benefit assessment carried out by a veterinarian.
Other reactions after deworming a dog
Throughout this article we have mentioned the side effects after deworming a dog that tend to appear more frequently. However, these drugs can be toxic for many other devices and systems, and can produce:
- Cardiotoxicity
- Hepatotoxicity
- Nephrotoxicity
- Etc.
Therefore, whenever we administer a drug to our dog, it is essential to monitor the possible appearance of adverse effects. Regardless of whether they are mild or severe, they should be notify the veterinarian who prescribed the drug, who will decide whether or not treatment is necessary.
Finally, in the event of administering an overdose of dewormer in dogs, it is essential to go to the veterinary center as soon as possible. In these cases, the effects that may appear are also those described, but with greater intensity and speed.
