Common Side Effects of Cat Vaccinations: What You Need

1. Key Manifestations of Adverse Reactions in Animals

Local symptoms include inflammatory reactions, nodules, necrosis, and local allergic reactions.

Systemic symptoms may manifest as depression or restlessness, elevated body temperature, decreased appetite, diarrhea, limping, and other signs. Acute reactions are typically allergic responses triggered by vaccinations. The most severe acute reactions can present with a drop in body temperature, pale mucous membranes and skin, difficulty breathing, frothing at the mouth, and can last from a few seconds to no more than an hour. If not promptly treated, animals may quickly go into shock or die.

Induced disease onset occurs when animals in the latent infection phase, showing no or minimal clinical symptoms, experience a coincidental reaction upon receiving the same disease vaccine, leading to acute disease and subsequent manifestation of the disease's symptoms or even death.

Triggered infection can happen when certain weakened live vaccines temporarily suppress the immune system, reducing the body's resistance and making it susceptible to pathogens, potentially causing infection within a few days to a couple of weeks.

2. Factors Contributing to Adverse Reactions

Animalrelated factors: Malnutrition, weakened constitution, low resistance, chronic diseases, late pregnancy, allergic constitution, and animals that are highly stressed. Animals may already be infected with the disease pathogen and in the latent infection phase without showing clinical symptoms before vaccination.

Vaccinerelated factors: Vaccines must stimulate the animal's immune system to produce protective immunity. This process may cause mild local and systemic reactions at the injection site and throughout the body. Weakened vaccines must infect cells and multiply within them, which can lead to visible clinical symptoms. The immune preventive preparations, consisting of vaccine antigens, preservatives, and adjuvants, are foreign or macromolecular substances to the animal's body, which can also induce some adverse reactions.

Quality issues with vaccines: Inactivated vaccines may not be fully inactivated, weakened vaccines may have reactivated virulence, vaccine antigens may be impure, bacterial vaccines may not be fully detoxified, vaccines may be contaminated with exogenous pathogens, there may be too much impurity, or preservatives and adjuvants may be used incorrectly or of poor quality.

Usagerelated factors: Improper vaccine selection, inappropriate use of diluents, improper storage, and unscientific immunization schedules.

3. Measures to Reduce Adverse Reactions

Conduct thorough health checks before vaccination to ensure animals are healthy and free from infectious diseases. Vaccinate only those animals in good health. Animals with diseases or suspected diseases, elevated body temperature, listlessness, decreased appetite, malnutrition, weakness, old age, unhealed wounds, recent births, or young mammals should not be vaccinated or should receive it on a temporary basis. Animals in the later stages of pregnancy should be vaccinated with caution or not at all, especially with vaccines that have a strong reaction.

Treatment of adverse reactions: Use antipyretic and analgesic, blockade, antiinflammatory, cardiotonic, antiallergic, antishock, and symptomatic treatments.

Management of local symptoms:

Minor local reactions generally do not require special treatment and can heal on their own within 2 to 3 days. For severe inflammatory swelling in livestock, use 0.3% procaine for blockade, once daily; apply salicylic zinc oxide ointment or ichthammol ointment twice daily; after inflammation subsides, switch to moist heat therapy to promote the digestion and absorption of inflammatory products. If there is local ulceration, apply gentian violet to prevent infection. Superficial abscesses can heal on their own after being lanced and drained; no antibacterial treatment is generally needed. For deep abscesses, surgical treatment may be necessary. After surgical site disinfection, incise at a low position to drain pus, and then flush with 0.2% potassium permanganate, 3% hydrogen peroxide, or 0.2% rifamycin, followed by the application of iodoform sulfonamide powder.

Management of systemic symptoms:

(1) For mild systemic reactions, such as slight fever, depression, or decreased appetite, no special treatment is usually necessary. Maintain a calm environment, avoid disturbances, and provide palatable feed. Symptoms often resolve or disappear naturally within 1 to 3 days.

(2) For more severe systemic reactions, treatment should be tailored to the condition. For fever, use 30% analgin or compound aminophenazone for antipyretic and analgesic effects, and combine them with longacting broadspectrum antibiotics. For severe vomiting, use antiemetics like metoclopramide. For respiratory failure, use respiratory stimulants like nikethamide. For heart failure and cyanosis, inject 10% sodium benzoate or amyl nitrite, and ensure warmth. For severe dehydration, use intravenous fluids such as 5% glucose生理盐水, VC, composite VB, and compound saline. For ruminal bloating, use a trocar for ruminal decompression. For lameness or torticollis, use salicylate for antipyretic and analgesic effects, along with VB1 for antineuritic effects and calcium (magnesium) for neuromuscular excitability regulation.

(3) For allergic urticaria, use antihistamines for relief or elimination. Subcutaneous injection of epinephrine hydrochloride (20 minutes after the initial injection, repeat the same dose if necessary) at a concentration of 0.1% can be used, or 0.10.5 mL; or intramuscular or intravenous injection of hydroxyzine hydrochloride, 2550 mg; or intramuscular or intravenous injection of dexamethasone sodium phosphate (not for pregnant dogs), 0.251.0 mg.

(4) For chronic allergic reactions, use symptomatic treatment methods. In addition to analgesic and antiinflammatory drugs and digestive aids, intravenous injection of 100g of calcium gluconate, 50150 mL, usually resolves within 3 to 7 days. For symptoms such as eyelid edema, diarrhea, and bronchospasm, use hydrochloride phenyltoloxamine injection, with a muscle injection dose of 550 mg, injected every 12 hours.

(5) For acute allergic reactions, immediately administer 0.1% epinephrine hydrochloride subcutaneously (repeat the same dose after 20 minutes based on the degree of relief), 0.10.5 mL; or intramuscular or intravenous injection of hydroxyzine hydrochloride, 2550 mg; or intramuscular or intravenous injection of dexamethasone sodium phosphate (not for pregnant dogs), 0.251.0 mg.